**3. Systematic literature review**

#### **3.1. Objectives**

The purpose of this study is to systematically review the existing literature that addresses the conservative treatment of muscle injuries in adult (skeletally mature) athletes.

#### **3.2. Methods**

Electronic databases searched for the purpose of this systematic review included: Medline and PubMed.

The research question (PICO) was defined with the following criteria:

P: Adult (skeletally mature) athletes; I: conservative treatment; C: other treatment or no treatment; O: recovery of pre-injury muscle parameters and functional activities.


The following search method was used:

("Athletic injuries"(Mesh) OR "Muscle, Skeletal/injuries"(Mesh) OR "Sprains and strains"(Mesh) OR Muscle injur\*(Tw)) AND ("Rehabilitation"(Mesh) OR "Rehabilitation programs"(TW) OR Treatment(Tw) OR "Physical therapy modalities"(Mesh) OR "Therapeu‐ tics"(Mesh)) AND ("Treatment outcome"(Mesh) OR "Muscle strength"(Mesh) OR "Recovery of function"(Mesh) OR "Evidence based medicine"(Mesh))

Filters: Randomized Controlled Trial; Systematic Reviews; Guideline; published in the last 10 years

For more details on the search strategy see Appendix 1.

### **3.3. Results**

**2. Context**

172 Muscle Injuries in Sport Medicine

injuries.

athlete.

**3.1. Objectives**

**3.2. Methods**

**P I C O** 

The following search method was used:

PubMed.

**3. Systematic literature review**

Preparing this work we wanted to identify a context characterized by muscle injury in an adult person, skeletally mature, involved in sport activities. The target population was identified in high level professional athletes, but it is obvious that the fallout application in clinical practice involves above all amateur athletes, including different sports from soccer. It seems that the sports involving sprinting, acceleration, deceleration, rapid change of direction and jumping (e.g. soccer, American football, rugby, etc.) may exposed athletes to an increased risk of muscle

The choice of a conservative treatment program for muscle injuries should be based on its effectiveness, its cost-effectiveness analysis, as well as on the expectations and aims of the

The purpose of this study is to systematically review the existing literature that addresses the

Electronic databases searched for the purpose of this systematic review included: Medline and

P: Adult (skeletally mature) athletes; I: conservative treatment; C: other treatment or no

**I**ntervention Conservative treatment

("Athletic injuries"(Mesh) OR "Muscle, Skeletal/injuries"(Mesh) OR "Sprains and strains"(Mesh) OR Muscle injur\*(Tw)) AND ("Rehabilitation"(Mesh) OR "Rehabilitation

**P**opulations/**P**atient Adult (skeletally mature) athletes

**C**omparison intervention Other treatment or no treatment

**<sup>O</sup>**utcome Recovery of pre-injury muscle

parameters and functional activities

treatment; O: recovery of pre-injury muscle parameters and functional activities.

conservative treatment of muscle injuries in adult (skeletally mature) athletes.

The research question (PICO) was defined with the following criteria:

Initially, 488 papers were identified for potential inclusion. After an analysis about the internal requirements of the studies, only five reports met the inclusion searching criteria. "The Physiotherapy Evidence Database (PEDro) Scale was used by two independent reviewers to assess the methodological quality of each included full text article" (Centre for Evidence-Based Physiotherapy. Physiotherapy Evidence Database (PEDro) Scale. Available at: http:// www.pedro.fhs.usyd.edu.au/scale\_item.html.)

To view the studies included and excluded from this review of the literature see appendix 2.

From the analysis of the few items found arises that there is no research on therapeutic interventions of muscle injuries. There are only a few studies on hamstring muscle injuries, which may not provide strong scientific evidence.

A recent Cochrane review (Mason et al., 2012) highlights the lack of studies about the thera‐ peutic interventions of muscle injuries, especially that there are not right drawings studies, precisely Randomized Controlled Trials. The authors contend that at the moment there is limited evidence to suggest an increased frequency of daily stretching to reduce recovery time and the percentage of recurrence.

Some preliminary scientific evidence available, suggests exercises to improve movement dysfunction. Another recent systematic review (Reurink et al., 2012) demonstrates that the therapeutic interventions for acute hamstring injuries such as stretching, agility and trunk stabilization exercises have limited evidence.

Sherry and Best (2004) performed a prospective randomized study to compare two rehabili‐ tation programs for the treatment of acute hamstring muscle injury. The study concludes that a rehabilitation program which consisted of exercises of agility and trunk stabilization was more effective than a program emphasizing isolated stretching and selective strengthening exercises of the hamstring muscles.

#### **3.4. Discussion**

Following a comprehensive appraisal of the available literature five studies were included in this systematic review. Our findings suggest a lack of research studies that addresses the conservative management of muscle injuries. All five studies included in this review concern the hamstring muscle injuries. As a consequence this limits the possibility to effectively generalize these findings to the clinical settings. The limited number of relevant articles as well as their focus only on the hamstring muscle injuries, highlights the need for future welldesigned randomized controlled trials to conclusively evaluate the effectiveness of conserva‐ tive treatment in the management of muscle injuries, particularly for muscles other than the hamstrings.

Despite the inconclusive results of our review, we will try to provide the reader with the tools to build a reasoned approach to manage the muscle injuries, having as a benchmark the basic

Conservative Treatment of Muscle Injuries: From Scientific Evidence to Clinical Practice

http://dx.doi.org/10.5772/56550

175

**4. Conservative treatment: from scientific evidence to clinical practice**

�Describe the stages of tissue healing and the importance of application of this knowledge in

�Identify characteristics of the different grades of strains and application of this to rehabilitation.

�Design appropriate interventions for describe the conservative treatment from scientific evidence to

Although a variety of conservative treatment strategies exist for the management of muscle injuries, and the "RICE (Rest, Ice, Compression, Elevation) approach" is widely accepted, there is still no consensus regarding the best conservative treatment to offer to patients with muscle

Knowledge of basic principles of skeletal muscles regeneration and repair mechanisms may help to define a rational rehabilitation program. Many authors highlighted that the healing process of an injured skeletal muscle is characterized by three phases. The first phase or *destruction phase*, is characterized by disruption and subsequent necrosis of muscle myofibrils, by the formation of a hematoma between the stumps muscle and by the inflammatory reaction. The second phase or *repair phase* consists in the phagocytosis of necrotized tissue with the regeneration of myofibers and the concomitant production of connective tissue scar and revascularization into the injured area.The third phase or *remodeling phase*, characterized by the maturation of the regenerated myofibers, contraction and reorganization of the scar tissue and recovery of the functional capacity of the muscle. Relying on the basic knowledge on connective tissue healing, an ideal treatment and rehabilitation program of an acute soft-tissue

Firstly, immediately after the injury, the ideal treatment should follow RICE (rest, ice, com‐ pression, elevation) principles; allowing to minimized pain, swelling, inflammation, and

hemorrhage, to offering the best possible condition for the healing process.

sciences and the few available evidences from clinical studies.

**Keys points** 

rehabilitation.

clinical practice.

injuries.

**4.1. End points of therapy**

�State aspects of the clinical evaluation.

injury has been formulated to fulfill some requirements.

### **IMPLICATION FOR RESEARCH**

In order to standardize the therapeutic approach and intervention strategies for muscular injuries should produce scientific literature characterized by an appropriate design of studies (RCT) as well as a high methodological quality.

In addition, researchers should also produce studies on alternatives muscle groups and not only hamstring muscles.

#### **3.5. Author's conclusions**

There is no consensus regarding treatment for muscle injuries. Most proposed conservative rehabilitation treatment of muscle injuries have not been assessed using randomized control‐ led trials. Even when randomized controlled trials have been conducted, most have low total numbers of injured athletes, which potentially explains the variability among study results. Most other studies do not provide a level of evidence greater than expert opinion. Although the initial treatment of rest, ice, compression, and elevation is accepted for muscle injuries, no consensus exists for their rehabilitation. Until further evidence is available, current practice and widely published rehabilitation protocols cannot either be supported or refuted. As medical science does not help us we have to turn our attention to the basic sciences to have an approach based on biomedical fundamentals. Thus, factors that impact skeletal muscle structure, function and regeneration are of great importance and interest not only scientifically but also clinically.

#### **TAKE HOME MESSAGE**

There is no consensus regarding the rehabilitation treatment for muscle injuries. There is a very low production of research studies about therapeutic interventions. The basic sciences are a benchmark for developing a rehabilitation program to manage the muscle injuries.

Despite the inconclusive results of our review, we will try to provide the reader with the tools to build a reasoned approach to manage the muscle injuries, having as a benchmark the basic sciences and the few available evidences from clinical studies.
