Shoulder Tumors and Dyskinesis

## Shoulder Surgery for Bone Tumors

*Stephanie D. Zarate and Ana C. Belzarena*

#### **Abstract**

The proximal humerus is a common location for bone tumors. Those can affect patients of different ages and can be of benign or malignant nature. For bone sarcomas is the 3rd most common location and is a frequent site of spread in non-axial metastatic disease. In pediatric patients is frequent to encounter benign bone tumors in this location but also osteosarcomas and Ewing's sarcomas. Careful assessment of the patients by a surgeon with the appropriate training is paramount. Shoulder reconstruction for patients with bone tumors encompasses a diverse group of patients, diagnoses and surgical options. While most patients with primary bone tumors may be of a younger age and more involved in sport activities, those with metastatic disease oftentimes are associated with an older age, worse preoperative function and worse prognosis due to the primary disease. The surgeon must weigh in all factors that need to be taken into consideration in the treatment decision-making plan. Currently, with new advances in oncology treatments patients may benefit from longer survivals times than in the past, thus restoring the patient's function and quality of life is essential.

**Keywords:** shoulder surgery, bone tumors, sarcoma, metastatic disease, shoulder reconstruction

#### **1. Introduction**

The proximal humerus is a common location for bone tumors, benign and malignant, in all age ranges [1–3]. For bone sarcomas is the 3rd most common location and is a frequent site of spread in non-axial metastatic disease [2]. The most common primary tumors to cause bone secondary lesions are breast, prostate and lung usually through a mechanism of hematogenous spread [4]. In the pediatric population benign tumors outnumber the malignant ones, with osteochondromas and enchondromas being the most frequent [5]. Primary malignant bone tumors are more common at a younger age, with osteosarcoma being the most common followed by Ewing's sarcoma [6]. While most benign primary bone tumors tend to be asymptomatic and usually diagnosed as an incidental finding, malignant tumors are more likely to cause symptoms. Pain constitutes the main complaint followed by tenderness locally and swelling of the soft tissues. The pain located over the affected bone can be nocturnal, present at rest or constant, of progressive intensity and more or less resistant to overthe-counter pain medication [7]. Malignant and aggressive tumors that remain long periods undiagnosed or without treatment may progress to a pathological fracture, event occurring in up to 10% of osteosarcomas [8]. In the case of metastatic disease, it is an ominous sign and carries a poor prognosis and increased mortality [9].

#### **Figure 1.**

*Antero-posterior radiograph of a 17-year-old patient with a destructive lesion of the proximal right humerus with a mixed patter, of lytic lesions and osteoid production, and periosteal reaction.*

When patients present initially without a diagnosis the first step is obtaining a thorough history and performing a detailed physical examination, with emphasis on the shoulder function. Following imaging studies need to be obtained. The first imaging exam is a radiograph of the shoulder as well as the humerus (**Figure 1**). The orthopedic surgeon should assess for the type of lesion; if it is blastic, lytic or mixed; its limits, the presence of periosteal reaction, associated soft tissue masses or a pathological fracture (**Figure 2**). Computed tomography can also be obtained to assess the cortical integrity of the bone and for surgical planning as well (**Figure 3**). Additionally computed tomography can show calcifications, healing response in case of pathological fractures and are useful for biopsy guidance as well. The biopsy tract when performed by a physician other than the surgeon should be discussed with the surgeon performing the definitive treatment [10].

In cases where a primary bone sarcoma is suspected a magnetic resonance should be obtained with and without contrast (**Figure 4**). The entirety of the bone must be imaged due to the occasional presence of skip lesions [11]. In the case where metastatic disease is suspected or for staging purposes of a primary sarcoma, a bone scan should be obtained to assess for additional bone lesions (**Figure 5**).

*Shoulder Surgery for Bone Tumors DOI: http://dx.doi.org/10.5772/intechopen.102746*

#### **Figure 2.**

*Radiographic images, anterior–posterior and lateral of proximal right humerus lytic lesion and pathological fracture in a lung cancer patient.*

#### **Figure 3.**

*Coronal and axial view of a proximal humerus computed tomography without contrast depicting an aggressiveappearing destructive lesion that has eroded through the cortex.*

Once a diagnosis has been made the treatment plan needs to be formulated. The goal of surgery will depend on the diagnosis, benign versus malignant, primary versus secondary lesion. In the case of benign lesions surgical treatment is usually reserved for symptomatic patients, for example in the case of an osteochondroma impinging at the extremes of range of motion. For metastatic lesions the goal is to render a pain free and functional patient, taking into consideration the overall prognosis of the disease. For primary bone sarcomas, the mainstay of treatment is surgical resection with adequate margins and a functional reconstruction, preferably performed by a surgeon with experience on sarcoma care [12].

*Magnetic resonance of the humerus with and without gadolinium enhancement. Coronal and axial T1-fatsuppresed with contrast sequence depicting a proximal humerus bone sarcoma with associated surrounding soft tissue component.*

#### **Figure 5.**

*Bone scintigraphy study with Tecnecium-99 depicting a lesion in the proximal left humerus and sternum.*

#### **2. Internal fixation for metastatic disease of the proximal Humerus**

After assessing the lesion characteristics and the patient's overall prognosis, a decision has to be made regarding the surgical planning. For widely metastatic disease and

**Figure 6.** *Radiograph depicting disease progression of a metastatic lesion in the proximal humerus and bony destruction.*

a pathological fracture of the proximal metadiaphyseal region internal fixation can be indicated. Intramedullary nailing or a proximal plate and screws are valid options. Both procedures are performed according to the traditional technique and approach. Depending on the location and extent of the lesion, curettage and cement augmentation may be incorporated into the procedure as a means of enhancing disease local control and implant survival. A novel device composed of a liquid photodynamic monomer is an additional alternative providing strength and stability under rotational forces [13]. The advantage of long intramedullary devices in patients with metastatic disease is the protection of the entire bone in the event of further disease progression. Radiotherapy is often indicated postoperatively to increase local disease control [14]. In the event of disease progression, the fixation implant may fail requiring a second, potentially more morbid, surgical procedure for revision (**Figure 6**).

#### **3. Proximal Humerus resection and reconstruction**

Primary bone malignancy as well as extensive secondary disease with poor bone stock may require a bone resection followed by reconstruction. In the decisionmaking process is important to take into account the diagnosis, the patient's prognosis as well as the structures involved by the tumor which may need to be resected along the bone such as the rotator cuff or the axillary nerve. For proximal humerus tumors the approach is usually the delto-pectoral approach including the biopsy tract, slightly lateral to the delto-pectoral line, with the resection specimen in the case of primary tumors. The surrounding structures involved and included in the resection will determine the postoperative function of the patient and will dictate the type of reconstruction indicated. When both the rotator cuff and an innervated deltoid muscle can be preserved allograph-prostheses composite can be used. If only a functional deltoid is maintained but the rotator cuff is involved in the resection, a reverse total shoulder can be used for the reconstruction. For tumors extending outside of the humerus where the deltoid and rotator cuff have to be resected, a proximal humerus endoprosthesis can be used as a spacer (**Figure 7**).

#### **Figure 7.**

*Clinical images and radiographs of a proximal humerus resection. A: Resection piece and trial implant. B: Surrounding soft tissues remaining tagged. C: Implant in place, tagged from the surrounding soft tissues are later attached to the implant. D: Final radiograph showing the implant in place, a long stem was chosen given the presence of metastatic lesions distally.*

For proximal humerus tumor resection and reconstruction the complication rate ranges from 20 to 45% [15]. Dislocation of the implant along infection are the most common encountered problems (**Figure 8**). Besides any hardware or surgically related complications, local recurrences can be another problematic event for these patients. Occurring in 12% of patients, tumor recurrences are a common cause for a subsequent amputation [16]. For surgical constructs where an allograft is added or used as a reconstruction option, the most common complications are fracture, infection and collapse of the subchondral surface [17, 18]. Comparing the diverse options for tumor resection, endoprosthetic replacement is the one associated with lowest complication rates whereas allograft-implant composites would have a better functional outcome [19]. Some authors advocate for the use of a vascular synthetic mesh around the implant for proximal humerus endoprosthetic reconstructions to reduce the rate of dislocations [20, 21]. The mesh creates a surface for adherence of the remaining surrounding soft tissue attachments (**Figure 9**). For a small percentage of patients, resection and reconstruction may not be an option and an amputation will have to be indicated, fortunately due to advances in surgical implants as well as adjuvant treatments such as radiotherapy and chemotherapy, most patients can benefit from a limb

#### **Figure 8.**

*Radiographic image depicting a dislocated humeral endoprostheses, one of the most common complications.*

#### **Figure 9.**

*Clinical image of a proximal humerus endoprosthetic replacement with surrounding vascular synthetic mesh and surrounding soft tissues tagged for later reattachment to the mesh.*

salvage procedure [22]. In cases where the tumor extends into the glenohumeral joint or even into the scapula a Tikhoff-Linberg amputation may be indicated. This procedure consists of an extra-articular resection of all the areas involved by the tumor plus a surrounding adequate surgical margin [23]. This procedure has been associated with high rate of complications and mortality [24, 25].

Prior studies have shown that the implant survivorship for proximal humerus replacement due to primary bone sarcomas is 77% for the first year and 74% at 5 years from the index procedure [26]. Most common reasons for implant failure are infections and local tumor recurrences [26]. The functional outcomes for these patients are going to be determined by the reconstruction type but also by the extent of the resection and the structures involved. The activity level has been shown to decrease significantly in the first year from the initial operation with some improvement after 3 years, yet to lower levels than preoperatively [27]. Moreover, even though most patients remain active and are able to get back and be involved in sport activities, most patients have to switch to a lower extremity activity such as soccer, bicycling or running. Those who prior to surgery practiced sports with overhead activities, unfortunately are usually not able to return to that sport [27]. A slightly improved level of sport performance can be expected in patients where the resection can spare an active deltoid muscle [28]. Some authors also advocate for the use of the synthetic vascular mesh as a means of increasing shoulder function as well [21].

#### **4. Curettage and grafting of benign and aggressive lesions**

The proximal humerus is a common location for benign bone tumors such as osteochondromas, enchondromas and unicameral bone cysts. Additionally, it is also a frequent location for more aggressive lesions such as or chondroblastomas. As with other bone tumors the assessment starts with a thorough history taking and physical examination followed by the appropriate imaging studies. In questionable cases or where imaging findings are non-specific a biopsy is indicated, performed ideally by a physician with the appropriate training on bone tumors. For most benign lesions patients are asymptomatic and diagnosis is made incidentally. Non-aggressive lesions such as non-ossifying fibromas, asymptomatic osteochondromas or enchondromas, observation may be all the necessary treatment. Curettage is indicated in the case of aggressive bone tumors that tend to continue to grow causing bone destruction or even a pathological fracture. Others such as atypical cartilaginous tumors may later on dedifferentiate into a higher-grade tumor [29]. The surgery usually involved a small incision over the most direct pathway to the lesion. Once the bone is reached a small window is created with the help of a burr or an osteotome. The lesion is thoroughly and carefully curetted avoiding any spilling of the surrounding tissues. Fluoroscopic visualization may help confirm all the extent of the lesion has been reached (**Figure 10**). In the case of unicameral bone cysts, intramedullary decompression with the help of a curette or a Kirschner wire of the canal is indicated [30]. In the case of aggressive lesions, the use of adjuvants such as nitrogen, phenol or high-speed burr can help decrease the local recurrence, a common outcome for these type of tumors [31]. Once the lesion has been curetted there are several options for filling such as autologous bone graft, allografts and synthetic bone substitutes (**Figure 10**).

#### **Figure 10.**

*Radiographic images depicting a recurrent unicameral bone cyst of the proximal humerus in a pediatric patient and its treatment. A: Unicameral bone cyst of the proximal left humerus. B: Decompression of the canal during the surgical procedure. C: Curettage of the lesion. D: Filling of the cavity with biosynthetic material composed of calcium sulfate with calcium phosphate.*

#### **5. Conclusions**

Shoulder reconstruction for patients with bone tumors encompasses a diverse group of patients, diagnoses and surgical options. While most patients with primary bone tumors may be younger and more active, those with metastatic disease oftentimes are associated with an older age, worse preoperative function and worse prognosis; all factors that need to be taken into consideration in the treatment decision-making. Currently, with new advances in oncology treatments patients may benefit from longer survivals times than in the past, thus restoring the patient's function and quality of life is paramount. Ideally, an oncology orthopedic specialist ought to be included in the multidisciplinary treating team from the moment of diagnosis of bone disease.

### **Conflict of interest**

The authors state no conflict of interest related to the writing of this chapter.

### **Author details**

Stephanie D. Zarate and Ana C. Belzarena\* Oncology Orthopedic Service, Miami Cancer Institute, Baptist Health South Florida, Miami, Florida, United States

\*Address all correspondence to: ceciliabel@baptisthealth.net

© 2022 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### **References**

[1] Damron TA, Ward WG, Stewart A. Osteosarcoma, chondrosarcoma, Ewing's sarcoma: National Cancer Date Base Report. Clinical Orthopaedics and Related Research. 2007;**459**(3):40-47. DOI: 10.1097/BLO.0b013e318059b8c9

[2] Frassica FJ, Frassica DA. Evaluation and treatment of metastases to the Humerus. Clinical Orthopaedics and Related Research. 2003;**415**:S212-S218. DOI: 10.1097/01.blo.0000093052.96273.a7

[3] Trăilescu MD, Pavel AI, Pop MA, Zurbău-Anghel N, Stoica GA, Fruntelată RF, et al. Pathological fractures of humerus in children. Therapeutic and pathological considerations. Romanian Journal of Morphology and Embryology = Revue roumaine de morphologie et embryologie. 2019;**60**(3):831-840

[4] Kakhki VR, Anvari K, Sadeghi R, Mahmoudian AS, Torabian-Kakhki M. Pattern and distribution of bone metastases in common malignant tumors. Nuclear Medicine Review. 2013;**16**(2):66-69. DOI: 10.5603/ NMR.2013.0037

[5] Aboulafia AJ, Kennon RE, Jelinek JS. Benign bone tumors of childhood. The Journal of the American Academy of Orthopaedic Surgeons. 1999;**7**:377-388

[6] Özkan EA, Göret CC, Özdemir ZT, Yanık S, Doğan M, Gönültaş A, et al. Pattern of primary tumors and tumor-like lesions of bone in children: Retrospective survey of biopsy results. International Journal of Clinical and Experimental Pathology. 2015;**8**(9):11543-11548

[7] Ruiz-Alva SK, Cortes-Cerda R, Mora-Ríos FG, Benítez-Romero A, Isunza-Ramírez A, Mejía-Rohenes LC. Tumores que producen metástasis óseas [Tumors that cause bone metastases]. Acta Ortopedica Mexicana. 2021;**35**(2):201-205

[8] Lozano Calderón SA, Garbutt C, Kim J, et al. Clinical and molecular analysis of pathologic fracture-associated osteosarcoma: MicroRNA profile is different and correlates with prognosis. Clinical Orthopaedics and Related Research. 2019;**477**(9):2114-2126. DOI: 10.1097/CORR.0000000000000867

[9] Freeman AK, Sumathi VP, Jeys L. Metastatic tumours of bone. Orthopaedics I: General Principles Surgery. 2015;**33**(1):34-39. DOI: 10.1016/ j.mpsur.2014.10.005

[10] Mintz DN, Hwang S. Bone tumor imaging, then and now: Review article. HSS Journal: The Musculoskeletal Journal of Hospital for Special Surgery. 2014;**10**(3):230-239. DOI: 10.1007/ s11420-014-9403-y

[11] Barnett JR, Gikas P, Gerrand C, Briggs TW, Saifuddin A. The sensitivity, specificity, and diagnostic accuracy of whole-bone MRI for identifying skip metastases in appendicular osteosarcoma and Ewing sarcoma. Skeletal Radiology. 2020;**49**(6):913-919. DOI: 10.1007/ s00256-019-03364-0

[12] Gomez-Brouchet A, Mascard E, Siegfried A, de Pinieux G, Gaspar N, Bouvier C, et al. Assessment of resection margins in bone sarcoma treated by neoadjuvant chemotherapy: Literature review and guidelines of the bone group (GROUPOS) of the French sarcoma group and bone tumor study group (GSF-GETO/RESOS). Orthopaedics & Traumatology, Surgery

& Research: OTSR. 2019;**105**(4):773-780. DOI: 10.1016/j.otsr.2018.12.015

[13] Zoccali C, Attala D, Pugliese M, di Uccio AS, Baldi J. The IlluminOss® photodynamic bone stabilization system for pathological osteolyses and fractures of the humerus: Indications, advantages and limits in a series of 12 patients at 24 months of minimum follow-up. BMC Musculoskeletal Disorders. 2021;**22**(1):63. DOI: 10.1186/ s12891-020-03927-6

[14] Drost L, Ganesh V, Wan BA, Raman S, Chan S, Christakis M, et al. Efficacy of postoperative radiation treatment for bone metastases in the extremities. Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology. 2017;**124**(1):45-48. DOI: 10.1016/j. radonc.2017.05.010

[15] Sirveaux F. Reconstruction techniques after proximal humerus tumour resection. Orthopaedics & Traumatology, Surgery & Research: OTSR. 2019;**105**(1S):S153-S164. DOI: 10.1016/j.otsr.2018.04.024

[16] Liu T, Zhang Q, Guo X, Zhang X, Li Z, Li X. Treatment and outcome of malignant bone tumors of the proximal humerus: Biological versus endoprosthetic reconstruction. BMC Musculoskeletal Disorders. 2014;**15**:69. DOI: 10.1186/1471-2474-15-69

[17] Aponte-Tinao LA, Ayerza MA, Muscolo DL, Farfalli GL. Allograft reconstruction for the treatment of musculoskeletal tumors of the upper extremity. Sarcoma. 2013;**2013**:925413

[18] Abdeen A, Hoang BH, Athanasian EA, Morris CD, Boland PJ, Healey JH. Allograft-prosthesis composite reconstruction of the proximal part of the humerus: Functional outcome

and survivorship. The Journal of Bone and Joint Surgery. American Volume. 2009;**91**(10):2406-2415. DOI: 10.2106/ JBJS.H.00815

[19] van de Sande MA, Dijkstra PD, Taminiau AH. Proximal humerus reconstruction after tumour resection: Biological versus endoprosthetic reconstruction. International Orthopaedics. 2011;**35**(9):1375-1380. DOI: 10.1007/s00264-010-1152-z

[20] Marulanda GA, Henderson E, Cheong D, Letson GD. Proximal and total humerus reconstruction with the use of an aortograft mesh. Clinical Orthopaedics and Related Research. 2010;**468**(11):2896-2903. DOI: 10.1007/ s11999-010-1418-1

[21] Tang X, Guo W, Yang R, Tang S, Ji T. Synthetic mesh improves shoulder function after intraarticular resection and prosthetic replacement of proximal humerus. Clinical Orthopaedics and Related Research. 2015;**473**(4):1464- 1471. DOI: 10.1007/s11999-015-4139-7

[22] Prantl L, Roll C, Feser D, Schreml S, Nerlich M, Mayr E, et al. Senkung der Amputationsrate bei Knochen- und Weichgewebssarkomen durch interdisziplinäres Vorgehen [Reduction of the amputation rate in bone and soft tissue sarcoma by interdisciplinary cooperation]. Handchirurgie, Mikrochirurgie, plastische Chirurgie: Organ der Deutschsprachigen Arbeitsgemeinschaft fur Handchirurgie: Organ der Deutschsprachigen Arbeitsgemeinschaft fur Mikrochirurgie der Peripheren Nerven und Gefasse: Organ der V…. 2006;**38**(3):178-184. DOI: 10.1055/s-2006-924244

[23] Voggenreiter G, Assenmacher S, Schmit-Neuerburg KP. Tikhoff-Linberg procedure for bone and soft tissue tumors of the shoulder girdle. Archives

*Shoulder Surgery for Bone Tumors DOI: http://dx.doi.org/10.5772/intechopen.102746*

of Surgery (Chicago, Ill: 1960). 1999;**134**(3):252-257. DOI: 10.1001/ archsurg.134.3.252

[24] Tagliero AJ, Bukowski BR, Rose PS, Morrey ME, Elhassan BT, Barlow JD, et al. High incidence of complications associated with shoulder girdle reconstruction utilizing a Stryker proximal humerus cap endoprosthesis following Tikhoff-Linberg resections. International Orthopaedics. 2020;**44**(11): 2449-2455. DOI: 10.1007/s00264- 020-04576-z

[25] Weisstein J. E.U. Conrad 3rd tumors and related conditions. In: Rockwood C, Matsen F, Wirth M, Lippitt S, editors. The Shoulder. 4th ed. Vol. 2. Philadelphia: Saunders Elsevier; 2009. pp. 1509-1556

[26] Schneider KN, Bröking JN, Gosheger G, Lübben T, Hardes J, Schorn D, et al. What is the implant survivorship and functional outcome after Total humeral replacement in patients with primary bone Tumors? Clinical Orthopaedics and Related Research. 2021;**479**(8):1754-1764. DOI: 10.1097/CORR.0000000000001677

[27] Lang NW, Kasparek MF, Synak L, Waldstein W, Funovics PT, Windhager R, et al. What sports activity levels are achieved in long-term survivors with modular endoprosthetic humerus reconstruction following primary bone sarcoma resection? Wiener Klinische Wochenschrift. 2021;**133**(1-2):14-20. DOI: 10.1007/s00508-020-01779-7

[28] Böhler C, Brönimann S, Kaider A, Puchner SE, Sigmund IK, Windhager R, et al. Surgical and functional outcome after Endoprosthetic reconstruction in patients with osteosarcoma of the Humerus. Scientific Reports. 2018;**8**(1):16148. DOI: 10.1038/ s41598-018-34397-5

[29] Weber KL, Raymond AK. Lowgrade/dedifferentiated/high-grade chondrosarcoma: A case of histological and biological progression. The Iowa Orthopaedic Journal. 2002;**22**:75-80

[30] Mik G, Arkader A, Manteghi A, Dormans JP. Results of a minimally invasive technique for treatment of unicameral bone cysts. Clinical Orthopaedics and Related Research. 2009;**467**(11):2949-2954. DOI: 10.1007/ s11999-009-1008-2

[31] Deventer N, Deventer N, Gosheger G, de Vaal M, Budny T, Laufer A, et al. Chondroblastoma: Is intralesional curettage with the use of adjuvants a sufficient way of therapy? Journal of Bone Oncology. 2020;**26**:100342. DOI: 10.1016/j.jbo.2020.100342

## **Chapter 7** Scapular Dyskinesis

*Mohammed Hegazy*

#### **Abstract**

In order for correct shoulder function to occur, the scapula plays a number of responsibilities. These functions include synchronous scapular rotation during humeral motion, providing a stable basis for rotator cuff activation, and acting as a kinetic chain link. Scapular dyskinesis is defined as a change in the resting or dynamic position of the scapula. Scapular dyskinesis is a nonspecific response to a painful shoulder ailment rather than a specific response to glenohumeral pathology. Visual assessment of the scapular position at rest and during dynamic humeral motions, as well as objective posture measurements and scapular corrective techniques, is used to diagnose scapular dyskinesis. Treatment for scapular dyskinesis focuses on improving dynamic scapular stability by improving the motor control and strength of scapular stabilizers, as well as the flexibility of tight muscles and other connective tissues.

**Keywords:** kinetic chain, dynamic stability, scapular dyskinesis

#### **1. Introduction**

Scapular dyskinesis is a disorder characterized by altered scapular mechanics and motion, with "dys" denoting alteration and "kinesis" denoting motion [1]. Scapular dyskinesis is not always a medical word. In fact, it has been seen in both asymptomatic and symptomatic patients with shoulder girdle discomfort [2–5]. It was thought to be caused by abnormalities in scapular stabilizing muscle activation [6], injury to the long thoracic, dorsal scapular, or spinal accessory nerves, or potentially decreased pectoralis minor muscle length [7].

SICK (scapular malposition, inferior medial border prominence, coracoid pain and malposition, and dyskynesis of scapular motion) was coined by Burkhart et al. [8], who recognized the importance of scapular dyskinesis in overhead athletes complaining of shoulder pain. As a result, this term should only be used when scapular dyskinesis is clearly present.

#### **2. Clinical features of scapular dyskinesis**

The anterior and/or posterosuperior aspects of the shoulder, as well as the upper region of the lateral arm below the acromion, may be painful in the symptomatic patient with scapular dyskinesis. Pain may radiate into the lateral part of the neck along the UT or follow a radicular pattern along the upper extremity. Pain in the coracoid region due to constriction of the pectoralis minor as a result of downward tilt and lateral displacement of the coracoid is the most common presenting symptom, followed by posterosuperior scapular pain [8].

Three dyskinetic patterns were found by Kibler et al. [9]: The inferomedial border of the scapula is prominent due to an excessive posterior tilt along a horizontal axis

**Figure 1.** *Type I dyskinesis (adopted from [10]).*

**Figure 2.** *Type II dyskinesis (adopted from [10]).*

**Figure 3.** *Type III dyskinesis (adopted from [10]).*

#### *Scapular Dyskinesis DOI: http://dx.doi.org/10.5772/intechopen.104852*

in the plane of the scapula; when this type is isolated, the scapula may be lower than the opposite side (**Figure 1**). Due to excessive external rotation around a vertical axis via the plane of the scapula, Type II is characterized by the prominence of its entire medial border (**Figure 2**). These types are frequently linked to superior labrum injuries. Type III is characterized by upward rotation of the scapula's superomedial border around a horizontal axis perpendicular to the plane of the scapula, resulting in abnormal superior migration of the scapula (**Figure 3**); this pattern is linked to a reduction in the acromiohumeral space and the possibility of rotator cuff injuries. The pattern of Type IV is symmetric.

#### **3. Role of scapula**

The scapula has three key functions in producing smooth, coordinated movement throughout the shoulder girdle. To sustain the glenohumeral connection and provide a stable foundation for muscle function, these tasks are intertwined. The scapula's primary function is to maintain dynamic stability and regulated motion at the glenohumeral joint. The scapula must move in sync with the moving humerus in order to keep the humeral head restricted within the glenoid during the whole range of shoulder motion [11].

Maintaining appropriate glenoid fossa alignment not only provides for ideal bony restraint, but it also aids muscular constraint by maintaining proper length tension relationships for efficient rotator cuff muscle contraction, squeezing the humeral head into the fossa [11, 12]. The scapular musculature must maintain dynamic stability while also providing regulated movement. The scapula must be protracted in a smooth fashion laterally and then anteriorly around the thoracic wall during throwing motions to allow the scapula to retain a normal positional relationship with the humerus. This motion is controlled by eccentric contraction of the medial-stabilizing musculature (mostly the rhomboids and middle trapezius), which allows part of the deceleration forces experienced during the follow-through phase to be dissipated [11].

With overhead exercises, the scapula must also rotate upward to free the acromion from the rotator cuff [13]. The scapula travels laterally in normal abduction for the first 30°–50° of abduction. As the shoulder reaches maximal elevation, the scapula rotates around a fixed axis across an arc of roughly 65° [14]. With overhead activity, the 2:1 ratio between glenohumeral abduction and scapulothoracic rotation is explained by this motion. To tilt the acromion upward and reduce the possibility of impingement and coracohumeral arch compression, upward rotation and elevation are necessary (**Figure 4**) [16].

The scapula's second function is to serve as a basis for muscular attachment. The muscles that control the position of the scapula attach to the medial border of the scapula, stabilizing it. Scapular motion is primarily controlled by this musculature through synergistic cocontractions and force couples, which are paired muscles that regulate the movement or position of a joint or a body part [17–20]. Muscles that attach along the lateral edge of the scapula perform gross motor tasks of the glenohumeral joint in addition to acting as scapular stabilizers. The rotator cuff muscles adhere to the whole surface of the scapula and are positioned so that their most efficient stabilizing activity occurs when the arm is abducted between 70° and 100° [21]. The humeral head is compressed into the socket by these muscles, which are referred to as a "compressor cuff" [20].

The scapula's third function is best described as the link in the proximal-to-distal energy transfer that enables for the ideal shoulder placement for optimal performance [16, 22–24].

**Figure 4.** *Scapulohumeral rhythm (adopted from [15]).*

The scapula plays a critical role in transporting enormous forces and high energy from the principal sources of force and energy, the legs and trunk, to the actual delivery mechanism of the energy and force, the arms and hands [23–25]. Forces generated in the proximal segments must be efficiently and effectively transferred via the shoulder and into the hand. The scapula provides a secure and regulated platform for these activities, allowing the entire arm to rotate as a unit around the sturdy base given by the scapulothoracic joint and the glenohumeral joints [20].

#### **4. Scapular kinetics during arm elevation**

The musculature connected to the scapula, humerus, thoracic cage, and spinal column controls the scapulothoracic articulation. During the first phase of glenohumeral elevation, the UT and lower SA operate as a force couple to cause scapular upward rotation. The LT contributes more in the intermediate phase of glenohumeral elevation, while the LT, UT, and lower SA are roughly equally active in the final phase of glenohumeral elevation. The scapular muscle is responsible for stabilizing the scapula and supporting the glenohumeral joint's base. A loss in the surrounding musculature's ability to stabilize the scapula may result in a shift in scapular position or motion. The length-tension relationship can be adjusted by changing the scapular position.

A malfunctioning rotator cuff can theoretically be caused by changes in scapular posture and scapular muscular strength [26]. The force couples' primary roles are to provide maximum congruency between the glenoid fossa and the humeral head in order to provide dynamic glenohumeral stability and maintain an ideal length-tension relationship [12, 25]. The UT and LT muscles, along with the rhomboid muscles and the SA muscle, are the appropriate force partners for scapular stabilization. The LT and SA muscles, in combination with the UT and rhomboid muscles, are the suitable force partners for acromial elevation (**Figure 5**) [20, 28].

#### **5. Scapular kinematics during arm elevation**

Normal shoulder function depends on scapular location on the thorax and control during motion. The scapula should upwardly rotate and posteriorly tilt on the

**Figure 5.** *Force couples of scapular stabilization (adopted from [27]).*

thorax when raising the arm overhead (**Figure 6** and **Table 1**) [30]. The most common scapulothoracic motion is upward rotation. The scapula's motion in response to changes in scapular internal rotation angle is more variable between participants, investigations, elevation planes, and elevation range of motion points [30, 31]. Early in the range of arm elevation in scapular plane abduction and flexion, slight increases in scapular internal rotation may be normal. Although there is minimal data, it is generally acknowledged that end range elevation in healthy patients requires some scapulothoracic external rotation [30].

The sternoclavicular (SC) and acromioclavicular (AC) joints move together in scapulothoracic kinematics. In healthy people, substantial 3-D motions occur

**Figure 6.**

*Scapular motions from (a) posterior (upward/downward rotation), (b) superior (internal/external rotation), and (c) lateral (anterior/posterior tilting) views. Axes of rotation are indicated as black dots (adopted from [29]).*


**Table 1.**

*Summary of scapular kinematics during arm elevation in healthy and pathologic state [29].*

at both the SC and AC joints during arm elevation [30, 32, 33]. As arm elevation progresses upward, the clavicle exhibits a pattern of mild elevation and progressive retraction [30, 32]. At the AC joint, the scapula rotates upwardly, internally, and posteriorly relative to the clavicle at the same time [33]. Elevation/depression and abduction/adduction scapulothoracic "translations" have also been described in the past [33, 34]. These movements are caused by clavicular motions at the SC joint. SC elevation causes scapulothoracic elevation, and SC protraction/retraction causes abduction/adduction [33].

#### **6. Potential biomechanical mechanisms contributing to alterations in scapular kinematics**

Pain, soft tissue tightness, muscle activation or strength imbalances, muscle exhaustion, and thoracic malposture are all potential contributors to aberrant scapular kinematics (**Table 2**) [26].

#### **6.1 Effect of muscle activity alteration on scapular kinematics**

Muscle activation is the most commonly studied feature in patient populations; however, these changes in muscle activity are rarely connected to scapular kinematic changes. Significantly less SA muscle activation and greater UT activation were found in subjects with impingement or shoulder dysfunction who had less scapular upward rotation and posterior tilt as well as greater scapular elevation [35, 36].

When these findings are combined with knowledge of these muscles' ability to induce or govern scapular rotations, the lesser serratus activations may play a key role in the observed lower posterior tilt and upward rotation. Increased UT activation is likely related to greater scapula elevation by increasing clavicular elevation [37]. Scapulothoracic muscle activation timing has also been studied. In competitive freestyle swimmers with shoulder impingement, the temporal recruitment pattern of the UT, LT, and SA showed much more variability than in a control group of competitive swimmers [38].

In comparison to a control group, overhead athletes with shoulder impingement showed significantly delayed activation of the middle trapezius (MT) and


**Table 2.**

*Potential biomechanical mechanisms contributing to scapular kinematic alterations [29].*

long trapezius (LT) in response to an unexpected drop of the arm from an abducted posture [39]. The experimental production of muscular fatigue is a model for relating muscle activation patterns to changes in scapular kinematics. However, none of the studies on shoulder fatigue that have been found so far have tried to tire isolated scapulothoracic muscles, and the inability to fatigue a particular muscle or muscle group hampers interpretation of the results. One study found that after a resisted humeral external rotation fatigue treatment, scapular upward rotation, posterior tilt, and external rotation all decreased significantly. However, another study that used resisted humeral external rotation to induce shoulder fatigue reported significant increases in scapular upward rotation rather than decreases. The findings for reduced posterior tilt after fatigue were identical in direction in both studies [40, 41].

#### **6.2 Effect of pain on scapular kinematics**

The impact of pain on muscle activation patterns is likewise a mystery. Interestingly, during repetitive bilateral flexion in otherwise healthy subjects, experimentally induced pain caused by injection of hypertonic saline directly into the upper, middle, and lower divisions of the trapezius resulted in decreased UT and increased LT activation on the painful side and increased trapezius activation on the contralateral side [42].

#### **6.3 Effect of soft tissue tightness on scapular kinematics**

Another possible cause for the development of the scapulothoracic changes found in patients is soft tissue stiffness of muscles or tissues that can inhibit normal scapular motions during arm raising. Pectoralis minor and posterior shoulder stiffness have both been studied [7, 43].

#### *6.3.1 Effect of pectoralis minor tightness on scapular kinematics*

The pectoralis minor can provide scapular internal rotation, downward rotation, and anterior tilt thanks to its attachments from the coracoid process to the third to fifth ribs. Excessive active or passive tension in this muscle may prevent normal scapular upward rotation, posterior tilt, and maybe scapular external rotation from occurring during arm raising. Those with a short pectoralis minor resting length, indicative of muscular tightness, had considerably less scapular posterior tilt and

more scapular internal rotation during arm elevation than those with a long pectoralis minor resting length [7].

A rounded shoulder and forward head position is a frequent postural presentation in both sedentary people and overhead sportsmen. The subacromial space shrank as the shoulder progressed from a retracted to a protracted posture, according to dynamic magnetic resonance imaging [44]. Previously, this scapula posture was linked to diminished pectoralis minor flexibility or adaptive shortening. This decreased flexibility might impact scapula posture as well as create axillary artery compression, resulting in neurovascular complaints. Because of the prolonged elongation, this postural presentation might lead to stretch weakness of the posterior scapular musculature, especially the rhomboid muscles and lower trapezius [45, 46].

#### *6.3.2 Effect of tightness of posterior capsule on scapular kinematics*

Tightness in the glenohumeral joint's posterior capsule, or posterior shoulder, has also been proposed as a mechanism for changing scapular kinematics by passively "pushing" the scapula laterally over the thorax, especially during humeral internal rotation in raised arm positions [20]. Subjects with no shoulder complaints but a glenohumeral internal rotation range-of-motion deficit on their dominant arm (indicative of posterior shoulder tightness) were compared with a control group with no such deficit in a subsequent study. The humerus was elevated 90° into both flexion and abduction postures, and scapular positioning was evaluated at end range humeral internal rotation. At end range humeral internal rotation locations, the group with less glenohumeral joint internal rotation range of motion had considerably more scapular anterior tilt [7, 43].

#### **6.4 Effect of thoracic mal posture on scapular kinematics**

Changes in scapular location have also been linked to thoracic posture. When healthy volunteers were requested to sit in a "slouched" position and raise their arm, scapular upward rotation and posterior tilt were dramatically reduced, whereas scapular internal rotation and scapular elevation were significantly increased [47]. With the arm relaxed at the side, increased scapular anterior tilt and scapular internal rotation have also been reported in women with increasing thoracic kyphosis, as well as increased scapular anterior tilt with age [48].

#### **7. Assessment of scapular dyskinesis**

The reliable and correct identification of the presence or absence of scapular position or motion abnormalities is one of the problems of the clinical diagnostic procedure in people who have shoulder pain. In one study, moderate kappa values for inter-tester and intra-tester reliability were obtained employing blinded evaluators who assessed recorded patients [9]. Another study found lower inter-rater reliability when patients were recorded and examined by therapists who were unaware of the individuals' symptom status. These dependability levels are below what is ideal for routine clinical use. Improved reliability could be achieved through direct evaluation (as opposed to film), improved training, or revision of movement category definitions [49].

The examination begins with the patient's arm at a rest. Only one, two, or all three dyskinesis patterns can be found. The stability of the SC and AC joints should be tested

#### *Scapular Dyskinesis DOI: http://dx.doi.org/10.5772/intechopen.104852*

in the resting position, and the clavicle should be inspected for any shortening, angulation, malrotation, or hypermobility. The coracoid should be palpated to establish its position in relation to the opposite side, as well as any soreness along its medial border, where the pectoralis minor is implanted. After that, the subject is asked to raise and then drop his or her arm in the sagittal and/or scapular planes. The third stage involves watching the scapular action while lifting and lowering the arm with a 3–5 pound weight [50].

A study was conducted in asymptomatic persons and patients with shoulder discomfort to examine the reliability of the clinical assessment [2]. The patients' medial and superior scapular borders were measured as they conducted three to five arm elevation trials in the sagittal and scapular planes. The scapular motion was classified by two assessors using either the Kibler et al. [7] approach or a two-type method (yes/no). Yes, if one or more dyskinetic patterns are present, and no, if normal motion is present. To identify the presence of dyskinesis and to establish criteria validity of the two approaches, a 3-D kinematic analysis utilizing an electromagnetic tracking device was also done.

The yes/no method had a greater inter-rater agreement (79%) than the method used by Kibler et al. [51] (61%). The former strategy demonstrated a higher sensitivity (76%) and positive predictive value (100%) than the latter (74%). Multiple-plane asymmetries were detected in a substantially higher percentage of symptomatic participants (54%) than in asymptomatic subjects (14%). The researchers concluded that the yes/no technique is a good screening tool for scapular dyskinesis [10].

In contrast to these findings, Ellenbecker et al. [52] discovered that the Kibler et al. [7] technique of evaluation had a low reliability in baseball players who were videotaped performing five repetitions of scapular plane elevation while gripping a 2-pound weight. McClure et al. [50], Tate et al. [53] described a new approach for identifying scapular dyskinesis and determining its severity than Kibler et al. [7], which they called the scapular dyskinesis test. Overhead athletes were asked to do five repetitions of bilateral weighted shoulder flexion and abduction.

Dysrhythmia (premature or excessive scapular elevation or protraction, nonsmooth or stuttering motion on elevation or lowering, or fast downward rotation during lowering) and/or winging are symptoms of scapular dyskinesis (medial border or inferior scapular angle posteriorly displaced from the thorax). Normal motion,

**Figure 7.** *Scapular assistance test (adopted from [55]).*

slight abnormalities, or evident abnormalities were assigned to each scapulothoracic deviation. The raters' agreement in identifying normal or dyskinetic patients ranged from 75 to 80%. The presence of dyskinesis, on the other hand, was not linked to shoulder discomfort.

#### **7.1 Clinical tests of scapular dyskinesis**

Two corrective maneuvers can be used to confirm the kinematic changes and see if correcting them normalizes the arm motion and relieves the patient's symptoms [5, 6, 54].

#### *7.1.1 Scapular assistance test*

During humeral elevation, the examiner passively supports the scapula into upward rotation and posterior tilt with the scapular assistance test (SAT) (**Figure 7**). While the patient elevates the arm, the test is performed by pushing upward and laterally on the inferior angle of the scapula and drawing the superior aspect of the scapula posteriorly. If symptoms are relieved and motion is increased, the test is positive. The SAT helps detect the scapular contribution to impingement and rotator cuff dysfunction by increasing acromiohumeral space [56].

#### *7.1.2 Scapular retraction/repositioning test*

Tate et al. [57] described the scapular retraction/repositioning test (SRT). If a positive impingement test is found, the procedure can be redone with the scapula adjusted manually using the SRT (**Figure 8**). If symptoms are relieved and motion is increased, the test is positive. The SRT is performed by grasping the scapula with the fingers anteriorly contacting the acromioclavicular joint and the palm and thenar eminence posteriorly contacting the scapula's spine, with the forearm obliquely angled toward the inferior angle of the scapula for additional support on the medial border. The examiner's hand and forearm apply a mild push on the scapula in this manner to stimulate scapular retraction (scapular retraction test) or posterior tilting and external rotation (posterior tilting and external rotation test) (scapular repositioning test).

**Figure 8.** *Scapular retraction or repositioning test (adopted from [55]).*

#### **8. Rehabilitation of scapular dyskinesis**

#### **8.1 Stretching of pectoralis minor and posterior capsule**

The pectoralis minor, posterior shoulder, and glenohumeral joint capsule are prospective candidates for stretching in individuals with scapular kinematic changes based on biomechanical variables [7, 43]. Stretching techniques for both of these tissues have been recommended. Despite the paucity of research, there have been comparisons made across procedures in terms of gains in range of motion or the potential to appropriately extend the targeted tissue [7, 58].

For posterior capsule tightness, McClure et al. [58] compared the effectiveness of a sleeper stretch, which is thought to better support the scapula, to a more standard cross-body stretch. After a 4-week stretching regimen, the passive internal rotation range of motion of asymptomatic participants was measured. Both stretching groups were also compared with a nonstretching control group. When compared with their nonstretched side, both stretching groups exhibited significant within-subject gains in range of motion. Surprisingly, only the cross-body stretch group improved much more than the control group.

In healthy subjects, the mean length change with three recommended stretches for the pectoralis minor was also compared. A unilateral self-stretch or corner stretch, as well as sitting and supine manual stretches, was among the stretches. Standing with the humerus abducted 90° and the elbow flexed 90°, the unilateral corner stretch requires placing the hand of the shoulder to stretch on the wall with the humerus abducted 90° and the elbow flexed 90°. The patient next twists their body away from the shoulder being stretched until they feel a slight strain in their pectoral muscles. The most length change was seen in the corner stretch, followed by the supine manual stretch. This shows that a corner stretch would be more successful in lengthening the pectoralis minor; however, the patients were not tracked over time in a randomized controlled trial [59].

#### **8.2 Scapular muscle control and balance**

The rehabilitation's goal is to reestablish scapular muscle control and balance [60]. The goal is to equalize the ratio between the three sections of the trapezius, that is, UT/LT and UT/MT, and activate SA, because scapular dyskinesis suggests a larger activation of the UT and a lower control of the LT, MT, and SA [10]. The push-up plus, wall slide exercises, and shoulder elevation in the scapular plane have all been demonstrated to promote SA activation, with the push-up plus causing minimal UT activation [61, 62].

In the treatment of patients with shoulder discomfort and scapular motion abnormalities, strengthening or retraining the SA muscle warrants special consideration. The SA is the only scapulothoracic muscle capable of producing all of the desired 3-D scapular rotations of upward rotation, AC joint posterior tilting, and AC joint external rotation [37, 63]; hence, this recommendation is based on its biomechanical capabilities.

The serratus anterior's position as an external rotator of the scapula may appear counterintuitive at first, given the serratus anterior's lateral line of pull around the thorax, which has led to the serratus anterior being described as causing shoulder protraction. The clavicle protracts on the thorax at the SC joint, causing this protraction. Before this secondary joint rotation can take place, the SA's line of action will

pull the scapula's vertebral border and inferior angle toward the chest wall, causing external rotation of the scapula at the AC joint and stabilizing the scapula on the thorax while the clavicle protrudes [63].

A number of activities to activate the SA muscle have been recommended based on electromyographic examinations, typically in healthy participants. Push-up plus and push-up progression exercises, the dynamic embrace, supine punch, and wall sliding workouts have all been used. Supine punch and push-up plus may be advantageous for people with SIS because they increase SA muscle activation while decreasing UT muscle activation. Patients with scapular control issues may benefit from starting with supine punch exercises that stabilize the scapula against the table [48, 57, 64, 65].

The LT is another muscle that can help to support the scapula and allow for upward rotation. Shoulder flexion in the side-lying position up to 135°, prone horizontal abduction with external rotation, and shoulder external rotation in side laying have been demonstrated to elicit a beneficial ratio of lowering UT activity and raising LT activity [66].

After a brief time of teaching, Mottram et al. [67] demonstrated that normal participants can learn and repeat movements to shift the scapula into posterior tilt and upward rotation without the assistance of a physiotherapist. They discovered that all regions of the trapezius were active using a motion analysis system and surface electromyography. In two of the four exercises described by Cools et al. [66], De Mey et al. [68] discovered that conscious patient control of the scapula orientation greatly improves the activation of the three components of the trapezius without affecting the UT/MT and UT/LT ratios.

Manual scapula adjustment has been demonstrated to improve supraspinatus strength and enhance subacromial space in individuals with subacromial impingement [5, 69]. Manual scapular assistance is utilized in clinical practice to provide tactile cueing for scapula positioning in order to identify patients for whom subacromial space is a contributing factor. Shirts intended to provide tactile stimulation for good scapular placement can also be used to provide postural cueing for scapular positioning. These shirts can be worn during a rehabilitation program as well as during everyday activities (ADLs) [70].

#### **8.3 Correction of thoracic mal posture**

Thoracic posture should also be addressed in the rehabilitation of patients with shoulder impingement or rotator cuff tendinopathy, given the evidence for changed scapular kinematics with thoracic kyphosis or flexed thoracic postures [29, 47]. This includes paying attention to maintaining erect postures while performing daily activities that require arm elevation, as well as when performing shoulder workouts. Where suitable to the patient's presentation, exercises aimed at enhancing thoracic extension range of motion, strength, and endurance should be considered, keeping in mind that typical thoracic extension during arm elevation is only 10° or less [71].

Given the rhomboid's capabilities as a downward rotator of the scapula, it was suggested that excessive reliance on shoulder retraction exercises for rhomboid training as part of a postural exercise program be avoided. Another therapy option to explore is joint mobilization in the thoracic spine. In a randomized clinical trial for shoulder impingement, adding manual treatment to a supervised exercise regimen resulted in much better results than supervised exercise alone [72]. In a sample of 14 patients with primary SIS, Conroy and Hayes [73] investigated the effect of joint mobilization as part of a comprehensive therapy plan. They found that mobilization reduced pain over the course of a day as well as pain during a subacromial compression test.

#### **8.4 Therapeutic taping**

The use of therapeutic taping in the treatment of shoulder discomfort has also been studied recently. Significant changes in posture and increases in arm elevation pain-free range of motion were observed with thoracic and scapular taping designed to change posture in both participants with shoulder impingement and healthy subjects. In the impingement group, there was no significant reduction in pain during arm elevation. However, for scapular plane abduction and flexion, the point in the range of motion when increased pain was first reported was much higher (average of 15° and 16° increase in pain-free range of motion, respectively). Another study found that using taping reduced upper trapezius electromyographic activation while increasing lower trapezius electromyographic activation in participants with shoulder impingement during arm motion [74, 75].

#### **8.5 Rhythmic stabilization exercises**

Wilk and Arrigo [76] devised specific exercises to regulate the scapulothoracic joint's muscle force coupling while also stimulating proprioceptive and kinesthetic awareness to improve the scapulothoracic joint's neuromuscular control. Because of a prevalent weakness, the scapular retractors, protractors, and depressors are commonly emphasized with isolation strengthening exercises. The exercise routine for the scapula can include neuromuscular control and PNF drills. Proprioceptive awareness can be harmed as a result of macro or microtrauma; consequently, early in the rehabilitation program, the clinician should undertake drills to restore the neurosensory qualities of the joint capsule to heighten the sensory awareness of the afferent mechanoreceptors [77, 78].

#### *8.5.1 Types of rhythmic stabilization exercises*

#### *8.5.1.1 Open kinetic chain rhythmic stabilization exercises*

Manual rhythmic stabilization exercises are performed with the arm in the scapular plane at 30° of shoulder abduction, starting with the internal and external rotators. A cocontraction of the internal and external rotators is enabled by varying manual input, which necessitates the patient's isometric stability. These stability drills can also be done with the arm at around 100° of elevation and 10° of horizontal abduction. Because of the combined centralized resultant force vectors of both the rotator cuff and deltoid musculature that induce humeral head compression, this "balanced position" is a favorable beginning point [14, 79].

#### *8.5.1.2 Closed kinetic chain rhythmic stabilization exercises*

Proprioceptive drills are used to advance closed kinetic chain workouts. Advanced weight-shifting drills include a table push-up on a ball or on an unstable surface. Completing a push-up exercise on an unstable or modified surface has been demonstrated to create higher upper trapezius, middle trapezius, and serratus anterior activation in overhead throwing athletes with impingement than performing a regular push-up exercise. While the patient's hand is on a little ball and the physician performs perturbation drills on the patient's arm, wall stabilizations are conducted [15].

#### **9. Conclusions**

Scapular dyskinesis is a multifactorial disorder characterized by changes in scapular kinematics during position and motion. Scapular dyskinesis should be assessed on both static and dynamic levels, with treatment focusing on scapula motor control and increasing the force couple around the scapula to improve shoulder dynamic stability.

### **Acknowledgements**

I thank ALLAH for all things in my life. My thanks to my parents, my wife, and my dear sons.

#### **Notes/thanks/other declarations**

Thanks to ALLAH for helping me to finish this work.

#### **Acronyms and abbreviations**


#### **Author details**

Mohammed Hegazy1,2

1 Faculty of Physical Therapy, Cairo University, Giza, Egypt

2 Faculty of Allied of Medical Sciences, Isra University, Amman, Jordan

\*Address all correspondence to: mohamed.mostafa@pt.cu.edu.eg; mohammed.hegazy@iu.edu.jo

© 2022 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### **References**

[1] Kibler WB, Sciascia A. Current concepts: Scapular dyskinesis. British Journal of Sports Medicine. 2010;**44**(5):330-335

[2] Uhl TL, Kibler WB, Gecewich B, Tripp BL. Evaluation of clinical assessment methods for scapular dyskinesis. Arthroscopy. 2009;**25**(11):1240-1248

[3] Silva RT, Hartmann LG, de Souza Laurino CF. Clinical and ultrasonographic correlation between scapular dyskinesia and subacromial space measurement among junior elite tennis players. British Journal of Sports Medicine. 2010;**44**(6):407-410

[4] Juul-Kristensen B, Hilt K, Enoch F, Remvig L, Sjøgaard G. Scapular dyskinesis in trapezius myalgia and intraexaminer reproducibility of clinical tests. Physiotherapy Theory and Practice. 2011;**27**(7):492-502

[5] Seitz AL, McClure PW, Lynch SS, Ketchum JM, Michener LA. Effects of scapular dyskinesis and scapular assistance test on subacromial space during static arm elevation. Journal of Shoulder and Elbow Surgery. 2012;**21**(5):631-640

[6] Kibler WB, McMullen J. Scapular dyskinesis and its relation to shoulder pain. The Journal of the American Academy of Orthopaedic Surgeons. 2003;**11**(2):142-151

[7] Borstad JD, Ludewig PM. The effect of long versus short pectoralis minor resting length on scapular kinematics in healthy individuals. The Journal of Orthopaedic and Sports Physical Therapy. 2005;**35**(4):227-238

[8] Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: Spectrum of pathology part III: The SICK scapula, scapular dyskinesis, the kinetic chain, and rehabilitation. Arthroscopy. 2003;**19**(6):641-661

[9] Kibler WB, Uhl TL, Maddux JW, Brooks P, Zeller B, McMullen J. Quantitative clinical evaluation of scapular dysfunction: A reliability study. Journal of Shoulder and Elbow Surgery. 2002;**11**:11550-11556

[10] Postacchini R, Carbone S. Scapular dyskinesis: Diagnosis and treatment. OA Musculoskeletal Medicine. 2013;**1**(2):20

[11] Pink M, Perry J. Biomechanics. In: Jobe FW, editor. Operative Techniques in Upper Extremity Sports Injuries. St Louis, MO: Mosby; 1996. pp. 109-123

[12] Kamkar A, Irrgang JJ, Whitney SL. Nonoperative management of secondary shoulder impingement syndrome. The Journal of Orthopaedic and Sports Physical Therapy. 1993;**17**:212-224

[13] Kibler WB. Evaluation of sports demands as a diagnostic tool in shoulder disorders. In: Matsen FA, Fu F, Hawkins RJ, editors. The Shoulder: A Balance of Mobility and Stability. Rosemont, IL: American Academy of Orthopaedic Surgeons; 1993. pp. 379-395

[14] Poppen NK, Walker PS. Normal and abnormal motion of the shoulder. Journal of Bone and Joint Surgery. 1976;**58**:195-201

[15] Levangie, P. K., & Norkin, C. C. (2011). *Joint structure and function: a comprehensive analysis*. FA Davis

[16] Kennedy K. Rehabilitation of the unstable shoulder. Operative Techniques in Sports Medicine. 1993;**1**:311-324

[17] Bagg SD, Forrest WJ. Electromyographic study of the scapular rotators during arm abduction in the scapular plane. American Journal of Physical Medicine. 1986;**65**:111-124

[18] DiGiovine NM, Jobe FW, Pink M, Perry J. An electromyographic analysis of the upper extremity in pitching. Journal of Shoulder and Elbow Surgery. 1992;**1**:15-25

[19] Moseley JB Jr, Jobe FW, Pink M, Perry J, Tibone JE. EMG analysis of the scapular muscles during a shoulder rehabilitation program. The American Journal of Sports Medicine. 1992;**20**:128-134

[20] Kibler WB. The role of the scapula in athletic shoulder function. American Journal of Sports Medicine. 1998;**26**:325-337

[21] Bak K, Faunl P. Clinical findings in competitive swimmers with shoulder pain. The American Journal of Sports Medicine. 1997;**25**:254-260

[22] Fleisig GS, Dillman CJ, Andrews JR. Biomechanics of the shoulder during throwing. In: Andrews JR, Wilk KE, editors. The Athlete's Shoulder. New York, NY: Churchill Livingstone; 1994. pp. 355-368

[23] Elliott BC, Marshall R, Noffal G. Contributions of upper limb segmentrotations during the power serve in tennis. Journal of Applied Biomechanics. 1995;**11**:433-442

[24] Kibler WB. Biomechanical analysis of the shoulder during tennis activities. Clinical Journal of Sport Medicine. 1995;**14**:79-85

[25] Kibler WB. Role of the scapula in the overhead throwing motion. Contemporary Orthopaedics. 1991;**22**:525-532

[26] Michener LA, McClure PW, Karduna AR. Anatomical and

biomechanical mechanisms of subacromial impingement syndrome. Clinical Biomechanics. 2003;**18**(5):369-379

[27] Hamill, J., & Knutzen, K. Foundations of human movement & functional anatomy. In *Biomechanical Basis of Human Movement*. Wolters Kluwer Health/Lippincott Williams & Wilkins. 2009. pp. 3-25

[28] Peat M. Functional anatomy of the shoulder complex. Physical Therapy. 1986;**66**:1855-1865

[29] Van der Helm FC, Pronk GM. Threedimensional recording and description of motions of the shoulder mechanism. Journal of Biomechanical Engineering. 1995;**117**:27-40

[30] McClure PW, Michener LA, Sennett BJ, Karduna AR. Direct 3-dimensional measurement of scapular kinematics during dynamic movements in vivo. Journal of Shoulder and Elbow Surgery. 2001:269-277

[31] Borstad JD, Ludewig PM. Comparison of scapular kinematics between elevation and lowering of the arm in the scapular plane. Clinical Biomechanics (Bristol, Avon). 2002;**17**:650-665

[32] Ludewig PM, Behrens SA, Meyer SM, Spoden SM, Wilson LA. Three-dimensional clavicular motion during arm elevation: Reliability and descriptive data. The Journal of Orthopaedic and Sports Physical Therapy. 2004:140-149

[33] Teece RM, Lunden JB, Lloyd AS, Kaiser AP, Cieminski CJ, Ludewig PM. Three-dimensional acromioclavicular joint motions during elevation of the arm. Journal of Orthopaedic & Sports Physical Therapy. 2008;**38**:181-190

[34] Lukaseiwicz AC, McClure P, Michener L, Pratt N, Sennett B.

#### *Scapular Dyskinesis DOI: http://dx.doi.org/10.5772/intechopen.104852*

Comparison of 3 dimensional scapular position and orientation between subjects with and without shoulder impingement. Journal of Orthopaedic and Sports Physical Therapy. 1999;**29**(10):574-583

[35] Ludewig PM, Cook TM. Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement. Physical Therapy. 2000;**80**(3):276-291

[36] Lin JJ, Hanten WP, Olson SL. Functional activity characteristics of individuals with shoulder dysfunctions. Journal of Electromyography and Kinesiology. 2005;**15**:576-586

[37] Fey AJ, Dorn CS, Busch BP, Laux LA, Hassett DR, Ludewig PM. Potential torque capabilities of the trapezius [abstract]. The Journal of Orthopaedic and Sports Physical Therapy. 2007;**37**:A44-A45

[38] Wadsworth DJ, Bullock-Saxton JE. Recruitment patterns of the scapular rotator muscles in freestyle swimmers with subacromial impingement. International Journal of Sports Medicine. 1997;**18**:618-624

[39] Cools AM, Witvrouw EE, Declercq GA, Danneels LA, Cambier DC. Scapular muscle recruitment patterns: Trapezius muscle latency with and without impingement symptoms. The American Journal of Sports Medicine. 2003;**31**(4):542-549

[40] Tsai NT, McClure PW, Karduna AR. Effects of muscle fatigue on 3-dimensional scapular kinematics. Archives of Physical Medicine and Rehabilitation. 2003;**84**:1000-1005

[41] Ebaugh DD, McClure PW, Karduna AR. Scapulothoracic and glenohumeral kinematics following an external rotation fatigue protocol. The Journal of Orthopaedic and Sports Physical Therapy. 2006;**36**:557-571

[42] Falla D, Farina D, Graven-Nielsen T. Experimental muscle pain results in reorganization of coordination among trapezius muscle subdivisions during repetitive shoulder flexion. Experimental Brain Research. 2007;**178**:385-393

[43] Borich MR, Bright JM, Lorello DJ, Cieminski CJ, Buisman T, Ludewig PM. Scapular angular positioning at end range internal rotation in cases of glenohumeral internal rotation deficit. The Journal of Orthopaedic and Sports Physical Therapy. 2006:926-934

[44] Solem-Bertoft E, Thuomas KA, Westerberg CE. The influence of scapular retraction and protraction on the width of the subacromial space. An MRI study. Clinical Orthopaedics and Related Research. 1993;**296**:99-103

[45] Rohrer MJ, Cardullo PA, Pappas AM, Phillips DA, Wheeler HB. Axillary artery compression and thrombosis throwing athletes. Journal of Vascular Surgery. 1990;**11**(6):761-768

[46] Sotta RP. Vascular problems in the proximal upper extremity. Clinics in Sports Medicine. 1990;**9**(2):379-388

[47] Kebaetse M, McClure P, Pratt NA. Thoracic position effect on shoulder range of motion, strength, and threedimensional scapular kinematics. Archives of Physical Medicine and Rehabilitation. 1999;**80**:945-950

[48] Decker MJ, Hintermeister RA, Faber KJ, Hawkins RJ. Serratus anterior muscle activity during selected rehabilitation exercises. The American Journal of Sports Medicine. 1999;**27**:784-791

[49] Hickey BW, Milosavljevic S, Bell ML, Milburn PD. Accuracy and reliability of observational motion analysis in identifying shoulder symptoms. Manual Therapy. 2007:263-270

[50] McClure PW, Tate AR, Kareha S, Irwin D, Zlupko E. A clinical method for identifying scapular dyskinesis, part 1: Reliability. Journal of Athletic Training. 2009;**44**(2):160-164

[51] Kibler, W. B., Uhl, T. L., Maddux, J. W., Brooks, P. V., Zeller, B., & McMullen, J. Qualitative clinical evaluation of scapular dysfunction: a reliability study. *Journal of shoulder and elbow surgery*. 2002;**11**(6):550-556

[52] Ellenbecker TS, Kibler WB, Bailie DS, Caplinger R, Davis GJ, Riemann BL. Reliability of scapular classification in examination of professional baseball players. Clinical Orthopaedics and Related Research. 2012;**470**(6):1540-1544

[53] Tate AR, McClure P, Kareha S, Irwin D, Barbe MF. A clinical method for identifying scapular dyskinesis, part 2: Validity. Journal of Athletic Training. 2009;**44**(2):165-173

[54] Jobe FW, Moynes DR. Delineation of diagnostic criteria and a rehabilitation program for rotator cuff injuries. The American Journal of Sports Medicine. 1982;**10**(6):336-339

[55] Struyf, F., Nijs, J., Mottram, S., Roussel, N. A., Cools, A. M., & Meeusen, R. Clinical assessment of the scapula: a review of the literature. *British journal of sports medicine*. 2014;**48**(11):883-890

[56] Tate AR, McClure PW, Kareha S, Irwin D. Effect of the scapula reposition test on shoulderimpingement symptoms and elevation strength in overhead athletes. The Journal of Orthopaedic and Sports Physical Therapy. 2008;**38**:4-11

[57] Rubin BD, Kibler WB. Fundamental principles of shoulder rehabilitation: Conservative to postoperative management. Arthroscopy. 2002;**18** (9 Suppl. 2):29-39

[58] Borstad JD, Ludewig PM. Comparison of three stretches for the pectoralis minormuscle. Journal of Shoulder and Elbow Surgery. 2006;**15**:324-330

[59] Culham E, Peat M. Functional anatomy of the shoulder complex. The Journal of Orthopaedic and Sports Physical Therapy. 1993;**18**:342-350

[60] Hardwick DH, Beebe JA, McDonnell MK, Lang CE. A comparison of serratus anterior muscle activation during a wall slide exercise and other traditional exercises. The Journal of Orthopaedic and Sports Physical Therapy. 2006;**36**(12):903-910

[61] Cricchio M, Frazer C. Scapulothoracic and scapulohumeral exercises: A narrative review of electromyographic studies. Journal of Hand Therapy. 2011;**24**(4):322-333

[62] Van der Helm FC. Analysis of the kinematic and dynamic behavior of the shoulder mechanism. Journal of Biomechanics. 1994;**27**:527-550

[63] Lear LJ, Gross MT. An electromyographical analysis of the scapular stabilizing synergists during a push-up progression. The Journal of Orthopaedic and Sports Physical Therapy. 1998;**28**:146-157

[64] Ludewig PM, Hoff MS, Osowski EE, Meschke SA, Rundquist PJ. Relative balance of serratus anterior and upper trapezius muscle activity during push-up exercises. The American Journal of Sports Medicine. 2004b;**32**:484-493

[65] Cools AM, Dewitte V, Lanszweert F, Notebaert D, Roets A, Soetens B. Rehabilitation of scapular muscle balance: Which exercises to prescribe? The American Journal of Sports Medicine. 2007;**35**(10):1744-1751

#### *Scapular Dyskinesis DOI: http://dx.doi.org/10.5772/intechopen.104852*

[66] Mottram SL, Woledge RC, Morrissey D. Motion analysis study of a scapular orientation exercise and subjects' ability to learn the exercise. Manual Therapy. 2009;**14**(1):13-18

[67] De Mey K, Danneels LA, Cagnie B, Huyghe L, Seyns E, Cools AM. Conscious correction of scapular orientation in overhead athletes performing selected shoulder rehabilitation exercises: The effect on trapezius muscle activation measured by surface electromyography. The Journal of Orthopaedic and Sports Physical Therapy. 2013;**43**(1):3-10

[68] Kibler WB, Sciascia A, Dome D. Evaluation of apparent and absolute supraspinatus strength in patients with shoulder injury using the scapular retraction test. American Journal of Sports Medicine. 2006;**34**:1643-1647

[69] Escamilla RF, Hooks TR, Wilk KE. Optimal management of shoulder impingement syndrome. Open Access Journal of Sports Medicine. 2014;**5**:13

[70] McClure PW, Balaicuis J, Heiland D, Broersma ME, Thorndike CK, Wood A. A randomized controlled comparison of stretching procedures for posterior shoulder tightness. Journal of Orthopaedic & Sports Physical Therapy. 2007;**37**(3):108-114

[71] Ludewig PM, Reynolds JR. The association of scapular kinematics and glenohumeral joint pathologies. Journal of Orthopaedic and Sports Physical Therapy. 2009;**39**(2):90-104

[72] Conory DE, Hayes KW. The effect of joint mobilization as a component of comprehensive treatment for primary shoulder impingement syndrome. Journal of Orthopaedic & Sports Physical Therapy. 1998;**28**:3-14

[73] Lewis JS, Wright C, Green A. Subacromial impingement syndrome: The effect of changing posture on shoulder range of movement. The Journal of Orthopaedic and Sports Physical Therapy. 2005:72-87

[74] Selkowitz DM, Chaney C, Stuckey SJ, Vlad G. The effects of scapular taping on the surface electromyographic signal amplitude of shoulder girdle muscles during upper extremity elevation in individuals with suspected shoulder impingement syndrome. The Journal of Orthopaedic and Sports Physical Therapy. 2007;**37**:694-702

[75] Wilk KE, Arrigo CA. An integrated approach to upper extremity exercises. Orthopaedic Physical Therapy Clinics of North America. 1992;**1**:337-360

[76] Lephart SM, Warner JJ, Borsa PA, Fu FH. Proprioception of the shoulder joint in healthy, unstable, and surgically repaired shoulders. Journal of Shoulder and Elbow Surgery. 1994;**3**(6):371-380

[77] Lephart SM, Pincivero DM, Giraldo JL, Fu FH. The role of proprioception in the management and rehabilitation of athletic injuries. The American Journal of Sports Medicine. 1997;**25**(1):130-137

[78] Walker PS, Poppen NK. Biomechanics of the shoulder joint during abduction in the plane of the scapula [proceedings]. Bulletin of the Hospital for Joint Diseases. 1977;**38**(2):107-111

[79] Tucker WS, Armstrong CW, Gribble PA, Timmons MK, Yeasting RA. Scapular muscle activity in overhead athletes with symptoms of secondary shoulder impingement during closed chain exercises. Archives of Physical Medicine and Rehabilitation. 2010;**91**(4):550-556

## *Edited by Dimitrios D. Nikolopoulos and George K. Safos*

Orthopedic surgeons manage a wide array of shoulder injuries, including impingement syndrome, rotator cuff (RC) ruptures, shoulder fractures, scapular dyskinesis, and more. This book describes the pathology, evaluation, and management of shoulder and RC pathologies and highlights the role of an interprofessional team in the care of patients with these conditions. Chapters address such topics as shoulder biomechanics and pathology, arthroscopic evaluation and management of shoulder RC pathology, mini-open and arthroscopic balloon techniques for arthroplasty in severe arthritis, and difficult pathologies such as shoulder bone tumors and scapular dyskinesia.

Published in London, UK © 2022 IntechOpen © Osipets / iStock

Shoulder Surgery for RC Pathology, Arthropathy and Tumors

Shoulder Surgery for RC

Pathology, Arthropathy

and Tumors

*Edited by Dimitrios D. Nikolopoulos* 

*and George K. Safos*