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

#### **Keys points**

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

In order to standardize the therapeutic approach and intervention strategies for muscular injuries should produce scientific literature characterized by an appropriate design of

In addition, researchers should also produce studies on alternatives muscle groups and

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

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

hamstrings.

174 Muscle Injuries in Sport Medicine

**IMPLICATION FOR RESEARCH** 

not only hamstring muscles.

**3.5. Author's conclusions**

but also clinically.

**TAKE HOME MESSAGE** 

the muscle injuries.

studies (RCT) as well as a high methodological quality.

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

�Identify characteristics of the different grades of strains and application of this to rehabilitation. �State aspects of the clinical evaluation.

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

#### **4.1. End points of therapy**

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 injuries.

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 injury has been formulated to fulfill some requirements.

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.

The second requirement is protection and immobilization of the damaged muscle area. To prevent additional bleeding to injury site, muscle secondary strains, and early lengthening of injured structures. A short period of immobilization following muscle injury is beneficial for the healing process. However, it was suggested that restricting the length of immobilization to a period of less than a week, the adverse effects of immobility per se can be minimized.

precisely. It has been shown that appropriate management decisions, return to training and competitions, and prediction of injury recurrence may all be enhanced with appropriate imaging examination (Verrall et al., 2003; Gibbs et al., 2004; Cross et al., 2004; Hasselman et al., 1995). Usually, US is the imaging modality of choice in visualizing sport-related muscle injuries, since it is widely available, safe, and inexpensive tool and allows dynamic evaluation which often can be helpful in distinguishing between a partial or complete tear of injured muscle. It has the disadvantage of being examiner-dependent. In athletes in whom an US examination does not provide an adequate assessment of a suspected muscle injury, MRI should be the next imaging modality to be used. MR imaging is more sensitivity in depicting

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The initial assessment is often carried out within 12h to 2 days post-injury (Askling et al., 2007).

Possible signs of swelling and ecchymosis may arise a few days later the injury and conse‐ quently may not be noticed at the initial examination (Wood et al., 2008; Askling et al., 2006).

A rapid phase change of muscle contraction from eccentric to concentric has been suggested as the underlying mechanism for hamstring injuries. During running, especially fast running, the bi-articular arrangement of the hamstring muscles across the hip and knee allow the hamstrings to work eccentrically during late swing phase to decelerate the lower leg and control knee extension. A concentric contraction follows to initiate hip extension prior to heel strike. So that hamstrings are maximally loaded and lengthened during this rapid change from

edema and extent of injury, as well as in evaluating muscle-tendon injuries.

**Figure 1.** The cadaver anatomy hamstring

Thirdly, 2-3 weeks after injury, during the maturation and remodeling phase, scar tissue forms initially in a random pattern. However, perform gentle and controlled movements along the main axis of injured muscle that does not produce or increase pain at the injury site leads to a better healing process allowing to the scar tissue to align parallel to muscle fascicles ("mobile scar"). Gentle and controlled movements along the main axis of injured muscle that do not produce or increases pain at the injury site stimulates the healing process allowing to the scar tissue to assume a structural architecture with an alignment parallel to the muscle fascicles.

Finally, 6-8 weeks after injury, there are no reasons to continue to protect the affected area.

And so the rehabilitation is directed towards quick and complete return to exercise and sport activities.

From these principles we must try to build our treatment plan; will develop methods of approach to the pathological condition and therapeutic intervention strategies to be used.

It's important to understanding tissue-healing phases before discussing pathology and ultimately deciding appropriate treatment, because knowledge of tissue-healing phases will help guide the decision-making process during patient rehabilitation treatment.

Most muscle injuries will respond to rehabilitation treatment without complications. However, in cases of excessive fibroblast proliferation or of abnormal response of myoblasts to bone morphogenetic protein, exuberant scar tissue or myositis ossificans can form, respectively.

#### **4.2. Purposes of therapy**

As with other athletic injuries, the primary objective of a rehabilitation treatment for muscle injuries management is to return the athlete to sporting activities at the pre-injury level of performance with a minimal risk of injury recurrence. There are some factors that can increase the recurrence in a muscle injury such as the formation of non-functional scar tissue that is associated with an alteration in muscle tissue lengthening mechanics, reduced flexibility, muscle weakness, alteration in lower limb biomechanics (Malliaropoulos et al., 2010). It should keep in mind these factors when a rehabilitation program is prepared.

#### **4.3. Clinical and diagnostic evaluation**

As previously suggested (Askling et al. 2006), the diagnosis of muscle injuries is mainly clinical, based on detailed history of trauma and physical examination with inspection, palpation, ROM tests, manual muscle testing, and special tests.

Although clinical evaluation remain very important, imaging examinations such as ultrasound (US) and magnetic resonance (MR) provide useful information for defining the injury more precisely. It has been shown that appropriate management decisions, return to training and competitions, and prediction of injury recurrence may all be enhanced with appropriate imaging examination (Verrall et al., 2003; Gibbs et al., 2004; Cross et al., 2004; Hasselman et al., 1995). Usually, US is the imaging modality of choice in visualizing sport-related muscle injuries, since it is widely available, safe, and inexpensive tool and allows dynamic evaluation which often can be helpful in distinguishing between a partial or complete tear of injured muscle. It has the disadvantage of being examiner-dependent. In athletes in whom an US examination does not provide an adequate assessment of a suspected muscle injury, MRI should be the next imaging modality to be used. MR imaging is more sensitivity in depicting edema and extent of injury, as well as in evaluating muscle-tendon injuries.

The initial assessment is often carried out within 12h to 2 days post-injury (Askling et al., 2007).

Possible signs of swelling and ecchymosis may arise a few days later the injury and conse‐ quently may not be noticed at the initial examination (Wood et al., 2008; Askling et al., 2006).

The second requirement is protection and immobilization of the damaged muscle area. To prevent additional bleeding to injury site, muscle secondary strains, and early lengthening of injured structures. A short period of immobilization following muscle injury is beneficial for the healing process. However, it was suggested that restricting the length of immobilization to a period of less than a week, the adverse effects of immobility per se can be minimized.

Thirdly, 2-3 weeks after injury, during the maturation and remodeling phase, scar tissue forms initially in a random pattern. However, perform gentle and controlled movements along the main axis of injured muscle that does not produce or increase pain at the injury site leads to a better healing process allowing to the scar tissue to align parallel to muscle fascicles ("mobile scar"). Gentle and controlled movements along the main axis of injured muscle that do not produce or increases pain at the injury site stimulates the healing process allowing to the scar tissue to assume a structural architecture with an alignment parallel to the muscle fascicles.

Finally, 6-8 weeks after injury, there are no reasons to continue to protect the affected area.

activities.

176 Muscle Injuries in Sport Medicine

**4.2. Purposes of therapy**

**4.3. Clinical and diagnostic evaluation**

tests, manual muscle testing, and special tests.

And so the rehabilitation is directed towards quick and complete return to exercise and sport

From these principles we must try to build our treatment plan; will develop methods of approach to the pathological condition and therapeutic intervention strategies to be used.

It's important to understanding tissue-healing phases before discussing pathology and ultimately deciding appropriate treatment, because knowledge of tissue-healing phases will

Most muscle injuries will respond to rehabilitation treatment without complications. However, in cases of excessive fibroblast proliferation or of abnormal response of myoblasts to bone morphogenetic protein, exuberant scar tissue or myositis ossificans can form, respectively.

As with other athletic injuries, the primary objective of a rehabilitation treatment for muscle injuries management is to return the athlete to sporting activities at the pre-injury level of performance with a minimal risk of injury recurrence. There are some factors that can increase the recurrence in a muscle injury such as the formation of non-functional scar tissue that is associated with an alteration in muscle tissue lengthening mechanics, reduced flexibility, muscle weakness, alteration in lower limb biomechanics (Malliaropoulos et al., 2010). It should

As previously suggested (Askling et al. 2006), the diagnosis of muscle injuries is mainly clinical, based on detailed history of trauma and physical examination with inspection, palpation, ROM

Although clinical evaluation remain very important, imaging examinations such as ultrasound (US) and magnetic resonance (MR) provide useful information for defining the injury more

help guide the decision-making process during patient rehabilitation treatment.

keep in mind these factors when a rehabilitation program is prepared.

A rapid phase change of muscle contraction from eccentric to concentric has been suggested as the underlying mechanism for hamstring injuries. During running, especially fast running, the bi-articular arrangement of the hamstring muscles across the hip and knee allow the hamstrings to work eccentrically during late swing phase to decelerate the lower leg and control knee extension. A concentric contraction follows to initiate hip extension prior to heel strike. So that hamstrings are maximally loaded and lengthened during this rapid change from eccentric to concentric contraction (Proske et al., 2004). In case of an acute hamstring injury, the hip and knee ROM of the injured leg is significantly decreased compared to the uninjured leg. However, the flexibility of the hip in the acute situation is often influenced by pain as a consequence of which the test may be poor accurate.

Although is important evaluate also the eccentric component of strength, this should not be evaluated after an acute muscle injury due to the high load that eccentric contraction causes

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Differential diagnosis of posterior thigh pain should include sciatic pain caused by nerve roots compression by herniated disc at L4-L5 or L5-S1 levels, sacro-iliac joint referred pain, gluteal trigger point referred pain, as well as other neural syndromes such as piriformis syndrome

Keeping in mind that "back related" hamstring injuries are characterized by a gradual buildup of pain, if these conditions are suspected, the active slump test can be used to confirm whether a patient has a neural component to their hamstring pain (Orchard et al., 2004). To completing

Although imaging evaluation may not be necessary in all cases of muscle injuries, its use not only confirms the diagnosis of muscle injury but also supplies information that helps to determine the degree and location of a muscle injury, and to predict the time to sport resump‐

Several groups (Koulouris and Connell, 2006; De Smet and Best 2000) compared the perform‐ ance of US and MRI. Among them, a prospective study (Connell et al., 2004) found US to be as useful as MRI in detecting the presence of an acute muscle (hamstrings, in this case) injury. However, the same authors affirm that more detailed analysis of the injury profile was

Gibbs et al. (2004) and Verrall et al. (2003) found that MRI negative hamstring strains had a significantly faster rehabilitation interval (6.6 and 16 days, respectively) compared with MRI positive strains (20.2 and 27 days, respectively) in their studies of elite Australian footballers. However, it should be keeping in mind that repeat MR imaging of athletes who have been cleared to return to sport, often show persistent high signal changes and muscle edema

In the only study to relate radiological parameters of hamstring injury to injury recurrence on return to competition Verrall et al. (2006) showed that a larger size of hamstring injury was indicative of higher risk for recurrent injury but only after the subsequent playing season was

Determining the appropriate grade of strain will help guide the clinician through the rehabil‐ itation process. A grade 1 strain may leave the athlete with slight discomfort and minimal swelling but full ROM and little functional deficit. A grade 2 strain is characterized by a small to moderate palpable area of involvement along with increased pain and swelling. A grade 2 muscle strain will often demonstrate restricted ROM and impaired gait. A grade 3 muscle strain is typified by a moderate to severe palpable area of involvement and sometimes a defect at the site of injury. The patient demonstrates significant deficits in ROM, and functional

patient evaluation also an MRI could be used to rule out these conditions.

on the muscle structures.

and hamstring syndrome.

tion in professional and recreational athletes.

achieved using MRI during the healing phase.

(Slavotinek et al., 2002; Connellet al., 2004).

considered along with the same playing season.

mobility will be severely impaired (Järvinen et al., 1978).

**4.4. Treatment strategies: How—to—treat**

Active ROM is decreased in the acute phase of the injury and it is advised to be measured at the end of the second day. Knee active ROM deficit 48 h after a unilateral posterior thigh muscle injury is an objective and accurate measurement.

No difference was found between active and passive ROM tests. Knee flexion and extension ROM can be estimated with a goniometer.

Strength of the hamstring muscles can be tested with the patient lying in a prone position by applying a manual resistance at the heel. The prone-resisted knee flexion should be done with different angles of knee flexion (e.g. 90°, 30°, and 15°), and with internal or external tibial rotation to target the medial (semimembranosus and semitendinosus) and lateral (biceps femoris) hamstring muscles, respectively. Due to their biarticular nature, the hamstring muscles also extend the hip, so it is recommend that hip extension strength is assessed with the knee positioned at 90° and 0° of flexion while resistance is applied to the distal posterior thigh and heel, respectively.

**Figure 2.** Test ROM knee with goniometer

Although is important evaluate also the eccentric component of strength, this should not be evaluated after an acute muscle injury due to the high load that eccentric contraction causes on the muscle structures.

Differential diagnosis of posterior thigh pain should include sciatic pain caused by nerve roots compression by herniated disc at L4-L5 or L5-S1 levels, sacro-iliac joint referred pain, gluteal trigger point referred pain, as well as other neural syndromes such as piriformis syndrome and hamstring syndrome.

Keeping in mind that "back related" hamstring injuries are characterized by a gradual buildup of pain, if these conditions are suspected, the active slump test can be used to confirm whether a patient has a neural component to their hamstring pain (Orchard et al., 2004). To completing patient evaluation also an MRI could be used to rule out these conditions.

Although imaging evaluation may not be necessary in all cases of muscle injuries, its use not only confirms the diagnosis of muscle injury but also supplies information that helps to determine the degree and location of a muscle injury, and to predict the time to sport resump‐ tion in professional and recreational athletes.

Several groups (Koulouris and Connell, 2006; De Smet and Best 2000) compared the perform‐ ance of US and MRI. Among them, a prospective study (Connell et al., 2004) found US to be as useful as MRI in detecting the presence of an acute muscle (hamstrings, in this case) injury. However, the same authors affirm that more detailed analysis of the injury profile was achieved using MRI during the healing phase.

Gibbs et al. (2004) and Verrall et al. (2003) found that MRI negative hamstring strains had a significantly faster rehabilitation interval (6.6 and 16 days, respectively) compared with MRI positive strains (20.2 and 27 days, respectively) in their studies of elite Australian footballers. However, it should be keeping in mind that repeat MR imaging of athletes who have been cleared to return to sport, often show persistent high signal changes and muscle edema (Slavotinek et al., 2002; Connellet al., 2004).

In the only study to relate radiological parameters of hamstring injury to injury recurrence on return to competition Verrall et al. (2006) showed that a larger size of hamstring injury was indicative of higher risk for recurrent injury but only after the subsequent playing season was considered along with the same playing season.

#### **4.4. Treatment strategies: How—to—treat**

eccentric to concentric contraction (Proske et al., 2004). In case of an acute hamstring injury, the hip and knee ROM of the injured leg is significantly decreased compared to the uninjured leg. However, the flexibility of the hip in the acute situation is often influenced by pain as a

Active ROM is decreased in the acute phase of the injury and it is advised to be measured at the end of the second day. Knee active ROM deficit 48 h after a unilateral posterior thigh muscle

No difference was found between active and passive ROM tests. Knee flexion and extension

Strength of the hamstring muscles can be tested with the patient lying in a prone position by applying a manual resistance at the heel. The prone-resisted knee flexion should be done with different angles of knee flexion (e.g. 90°, 30°, and 15°), and with internal or external tibial rotation to target the medial (semimembranosus and semitendinosus) and lateral (biceps femoris) hamstring muscles, respectively. Due to their biarticular nature, the hamstring muscles also extend the hip, so it is recommend that hip extension strength is assessed with the knee positioned at 90° and 0° of flexion while resistance is applied to the distal posterior

consequence of which the test may be poor accurate.

injury is an objective and accurate measurement.

ROM can be estimated with a goniometer.

thigh and heel, respectively.

178 Muscle Injuries in Sport Medicine

**Figure 2.** Test ROM knee with goniometer

Determining the appropriate grade of strain will help guide the clinician through the rehabil‐ itation process. A grade 1 strain may leave the athlete with slight discomfort and minimal swelling but full ROM and little functional deficit. A grade 2 strain is characterized by a small to moderate palpable area of involvement along with increased pain and swelling. A grade 2 muscle strain will often demonstrate restricted ROM and impaired gait. A grade 3 muscle strain is typified by a moderate to severe palpable area of involvement and sometimes a defect at the site of injury. The patient demonstrates significant deficits in ROM, and functional mobility will be severely impaired (Järvinen et al., 1978).

Today, we have a considerable amount of scientific, mostly experimental, evidence to support the early mobilization treatment approach of muscle injuries. It has been shown that early mobilization induces more rapid and intensive capillary ingrowth into the injured area, better regeneration of muscle fibers and more parallel orientation of the regenerating myofibers in comparison to immobilization, the previously preferred treatment for injured muscle (Järvi‐ nen, 1976; Järvinen and Sorvari, 1975; Järvinen, 1975; Järvinen, 1978 ).

Finally, concerning the last component of the RICE principle, elevation, the rationale for its use is based on the basic principles of physiology which suggests as the elevation of an injured extremity above the level of the heart results in a decrease in hydrostatic pressure and,

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181

The patient to move very carefully for the first 3 to 7 days after the injury to prevent the injured

After this period of relative rest, more active use of the injured muscle can be started gradually

The use, in this phase, of some neuromuscular control exercises of the lumbo-pelvic region are essential for optimal functional recovery. Furthermore, the normal gait should be implemented

Both passive and active exercises that apply a longitudinal strain to the injured structure will

The treatment practiced in most of the muscle injury is the "deep transverse friction" massage. This procedure is widely used, and based on a biological hypothesis feasible with regard to the proposed mechanism of action, but the scientific evidence regarding the clinical effective‐

The request for sports massage among competitive athletes is high, but the scientific support

In the DOMS, massage administered 2 hours after muscle insult did not improve the function of the hamstring, but reduced the intensity of pain 48 hours after the muscle insult (Hilbert et

Pain-free stretching and strengthening exercises are essential to regain flexibility and strength and prevent further injury and should be initiated quickly at the end of inflammatory response

Stretching exercises should be included to determine the stress lines along which collagen will be oriented. The type, duration, and frequency of stretches are three factors, which may

Strengthening exercises program is a composite of different variables that include: muscle actions used, resistance used, volume (total number of sets and repetitions), exercises selected and workout structure (e.g., the number of muscle groups trained), the sequence of exercise performance, rest intervals between sets, repetition velocity, and training frequency. Manip‐ ulation of the program variables should be performed to be beneficial to recovery progression. Progression may be maximized by the incorporation of progressive overload, specificity, and

During a rehabilitation program, strengthening exercises should begin with isometric type, and progress with isotonic type, initially without and then with the application of an external

resistance such as elastic devices, dumbbells, barbells, weight-machines, etc.

subsequently, reduces the accumulation of interstitial fluid.

muscle from stretching.(Järvinen and Lehto, 1993).

help the tissue accommodate to the new stress.

ness of "deep transverse friction" has been negative.

for the effect of sport massage is very limited.

influence or even determine its effectiveness.

training variation in the program.

within the limits of pain.

as soon as the pain allows.

al., 2003).

phase.

The positive effects of early mobilization on the regeneration of the injured skeletal muscle are not only limited to morphostructural changes, since it has been shown that the biomechanical strength of the injured muscle achieved the level of uninjured muscle more rapidly using active mobilization rather than immobilization after a muscle injury. (Järvinen, 1976)

A short period of rest relative after muscle injury is beneficial, but it should be limited only to the first few days after the injury. This rest period allows the scar tissue connecting the injured muscle stumps to gain the required strength to withstand the contraction-induced forces applied on it without a re-injury, but being restricted to the first few days only, the adverse effects of immobility can be limited to a minimum. The experimental data showing that beginning active mobilization after the short period of immobilization enhances the penetra‐ tion of muscle fibers through the connective tissue scar, limits the size of the permanent scar, facilitates the proper alignment of the regenerating muscle fibers, and helps in regaining the tensile strength of the injured muscle.

The immediate treatment of the injured skeletal muscle is known as RICE principle - Rest, Ice, Compression and Elevation. The overall justification for the use of the RICE principle is very practical, as all 5 means aim to minimize bleeding into the injury site. It needs to be stressed that there is not a single, randomized clinical trial to prove the effectiveness of the RICE principle in the treatment of soft tissue injury. However, there is scientific proof for the appropriateness of the distinct components of the concept, the evidence being derived from experimental studies. The most persuasive proof for the use of rest has been obtained from studies on the effects of immobilization on muscle healing. By placing the injured extremity to rest immediately after the trauma, one can prevent further retraction of the ruptured muscle stumps (the formation of a large gap within the muscle) as well as reduce the size of the hematoma and, subsequently, the size of the connective tissue scar. Regarding the use of ice, it has been shown that the early use of cryotherapy is associated with a significantly smaller hematoma between the ruptured myofiber stumps, less inflammation, and somewhat accel‐ erated early regeneration (Deal et al., 2002; Hurme et al., 1993).

Although compression reduces the intramuscular blood flow to the injured area, (Kalimo et al., 1997) it is debatable whether compression applied immediately after the injury actually accelerates the healing of the injured skeletal muscle (Thorsson et al., 1997).

However, according to the prevailing belief, it is recommended that the combination of ice (cryotherapy) and compression be applied in shifts of 15 to 20 minutes in duration, repeated at intervals of 30 to 60 minutes, as this kind of protocol has been shown to result in a 3° to 7° C decrease in the intramuscular temperature and a 50% reduction in the intramuscular blood flow (Thorsson et al., 1987; Thorsson et al., 1985).

Finally, concerning the last component of the RICE principle, elevation, the rationale for its use is based on the basic principles of physiology which suggests as the elevation of an injured extremity above the level of the heart results in a decrease in hydrostatic pressure and, subsequently, reduces the accumulation of interstitial fluid.

Today, we have a considerable amount of scientific, mostly experimental, evidence to support the early mobilization treatment approach of muscle injuries. It has been shown that early mobilization induces more rapid and intensive capillary ingrowth into the injured area, better regeneration of muscle fibers and more parallel orientation of the regenerating myofibers in comparison to immobilization, the previously preferred treatment for injured muscle (Järvi‐

The positive effects of early mobilization on the regeneration of the injured skeletal muscle are not only limited to morphostructural changes, since it has been shown that the biomechanical strength of the injured muscle achieved the level of uninjured muscle more rapidly using active

A short period of rest relative after muscle injury is beneficial, but it should be limited only to the first few days after the injury. This rest period allows the scar tissue connecting the injured muscle stumps to gain the required strength to withstand the contraction-induced forces applied on it without a re-injury, but being restricted to the first few days only, the adverse effects of immobility can be limited to a minimum. The experimental data showing that beginning active mobilization after the short period of immobilization enhances the penetra‐ tion of muscle fibers through the connective tissue scar, limits the size of the permanent scar, facilitates the proper alignment of the regenerating muscle fibers, and helps in regaining the

The immediate treatment of the injured skeletal muscle is known as RICE principle - Rest, Ice, Compression and Elevation. The overall justification for the use of the RICE principle is very practical, as all 5 means aim to minimize bleeding into the injury site. It needs to be stressed that there is not a single, randomized clinical trial to prove the effectiveness of the RICE principle in the treatment of soft tissue injury. However, there is scientific proof for the appropriateness of the distinct components of the concept, the evidence being derived from experimental studies. The most persuasive proof for the use of rest has been obtained from studies on the effects of immobilization on muscle healing. By placing the injured extremity to rest immediately after the trauma, one can prevent further retraction of the ruptured muscle stumps (the formation of a large gap within the muscle) as well as reduce the size of the hematoma and, subsequently, the size of the connective tissue scar. Regarding the use of ice, it has been shown that the early use of cryotherapy is associated with a significantly smaller hematoma between the ruptured myofiber stumps, less inflammation, and somewhat accel‐

Although compression reduces the intramuscular blood flow to the injured area, (Kalimo et al., 1997) it is debatable whether compression applied immediately after the injury actually

However, according to the prevailing belief, it is recommended that the combination of ice (cryotherapy) and compression be applied in shifts of 15 to 20 minutes in duration, repeated at intervals of 30 to 60 minutes, as this kind of protocol has been shown to result in a 3° to 7° C decrease in the intramuscular temperature and a 50% reduction in the intramuscular blood

nen, 1976; Järvinen and Sorvari, 1975; Järvinen, 1975; Järvinen, 1978 ).

erated early regeneration (Deal et al., 2002; Hurme et al., 1993).

flow (Thorsson et al., 1987; Thorsson et al., 1985).

accelerates the healing of the injured skeletal muscle (Thorsson et al., 1997).

tensile strength of the injured muscle.

180 Muscle Injuries in Sport Medicine

mobilization rather than immobilization after a muscle injury. (Järvinen, 1976)

The patient to move very carefully for the first 3 to 7 days after the injury to prevent the injured muscle from stretching.(Järvinen and Lehto, 1993).

After this period of relative rest, more active use of the injured muscle can be started gradually within the limits of pain.

The use, in this phase, of some neuromuscular control exercises of the lumbo-pelvic region are essential for optimal functional recovery. Furthermore, the normal gait should be implemented as soon as the pain allows.

Both passive and active exercises that apply a longitudinal strain to the injured structure will help the tissue accommodate to the new stress.

The treatment practiced in most of the muscle injury is the "deep transverse friction" massage. This procedure is widely used, and based on a biological hypothesis feasible with regard to the proposed mechanism of action, but the scientific evidence regarding the clinical effective‐ ness of "deep transverse friction" has been negative.

The request for sports massage among competitive athletes is high, but the scientific support for the effect of sport massage is very limited.

In the DOMS, massage administered 2 hours after muscle insult did not improve the function of the hamstring, but reduced the intensity of pain 48 hours after the muscle insult (Hilbert et al., 2003).

Pain-free stretching and strengthening exercises are essential to regain flexibility and strength and prevent further injury and should be initiated quickly at the end of inflammatory response phase.

Stretching exercises should be included to determine the stress lines along which collagen will be oriented. The type, duration, and frequency of stretches are three factors, which may influence or even determine its effectiveness.

Strengthening exercises program is a composite of different variables that include: muscle actions used, resistance used, volume (total number of sets and repetitions), exercises selected and workout structure (e.g., the number of muscle groups trained), the sequence of exercise performance, rest intervals between sets, repetition velocity, and training frequency. Manip‐ ulation of the program variables should be performed to be beneficial to recovery progression. Progression may be maximized by the incorporation of progressive overload, specificity, and training variation in the program.

During a rehabilitation program, strengthening exercises should begin with isometric type, and progress with isotonic type, initially without and then with the application of an external resistance such as elastic devices, dumbbells, barbells, weight-machines, etc.

In the isometric training (ie, muscle contractions in which the length of the muscle remains constant and the tension improves) all the contractions must be done without pain. Isometric training can begin with short-duration and progress to long-duration muscle contractions. Strength training with isometric contractions produces large but highly angle-specific adap‐ tations, thus it is important to exert the muscle at different joint angles as well as in sport specific positions.

Isotonic training (i.e., the muscle length changes and the tension remains constant during muscle contraction) can be started when long-duration muscle contraction of isometric training can be performed pain free. Isotonic exercises should be firstly performed without an external resistance, which should then be introduced and progressively increased. The strength training includes single-joint exercises, multiple-joint exercises, but above all functional exercises that mimic the actual sport actions. Weakness after painful musculoskeletal injury is typically mediated by both muscular and neural adaptations. After a knee injury with anterior cruciate ligament rupture, maximal voluntary activation of the quadriceps is reduced despite restora‐ tion of knee stability over the years. In the muscle injuries little attention has been paid to the possibility that prolonged deficits in muscular activation due to a reduction of the nervous system constitutes a strategy to unload damaged tissues. The athlete often expressed fear in carrying out the action that caused the injury. The execution of this action must be re-pro‐ grammed, performed, and correct if necessary. The training in specific position may prepare in an optimal manner the structure to stress that then can expect during sport activities. The progression of exercises should consider also the ROM andThe training in specific position may prepare in an optimal manner the structure to stress that then can expect during sport in to injuryangular velocity of joint. The eccentric exercises are also important. It consists in a "negative" muscular activity (muscle-tendon system absorbs energy) in which there is an overall lengthening of the muscle while under tension, in response to an external load (such as a weight) that is greater than the force generated by the muscle.

**Figure 3.** The patient is lying on the ground: submaximal to maximal isometric contractions at different knee angles. 5

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**Figure 4.** The patient should rotate the trunk as for kicking with the aim to train the core muscolature.

sec of contraction 5 sec of rest for 6 times. 4 – 5 times / day.

Scar tissue increasing passive stiffness of the muscle-tendon unit and making it more suscep‐ tible to injury during large eccentric contractions. Optimum tension-length curve of healthy or injured muscle can be optimized (such that peak tension is generated at longer muscle lengths) by eccentric training. Given the length-dependent nature of muscle damage in hamstring strains near end range, this structural adaptation optimizes the angle of peak torque to reduce the risk for potential injury. Despite the inherent limitations and lack of supporting evidence, Croisier et al. (2002) recommended that eccentric exercise should be included in the rehabilitation of hamstring injuries to help prevent recurrent injuries.

It has been suggested that all rehabilitation treatments should always start with an adequate warm-up of the injured muscle (Magnusson et al., 1995; Safran et al., 1988; Safran et al., 1989).

When warm-up is combined with stretching, the flexibility of muscle is improved. Painless elongation of the scar tissue can be achieved by stretching the duration of which should be gradually increased from 15 seconds to 1 minute.

In the isometric training (ie, muscle contractions in which the length of the muscle remains constant and the tension improves) all the contractions must be done without pain. Isometric training can begin with short-duration and progress to long-duration muscle contractions. Strength training with isometric contractions produces large but highly angle-specific adap‐ tations, thus it is important to exert the muscle at different joint angles as well as in sport specific

Isotonic training (i.e., the muscle length changes and the tension remains constant during muscle contraction) can be started when long-duration muscle contraction of isometric training can be performed pain free. Isotonic exercises should be firstly performed without an external resistance, which should then be introduced and progressively increased. The strength training includes single-joint exercises, multiple-joint exercises, but above all functional exercises that mimic the actual sport actions. Weakness after painful musculoskeletal injury is typically mediated by both muscular and neural adaptations. After a knee injury with anterior cruciate ligament rupture, maximal voluntary activation of the quadriceps is reduced despite restora‐ tion of knee stability over the years. In the muscle injuries little attention has been paid to the possibility that prolonged deficits in muscular activation due to a reduction of the nervous system constitutes a strategy to unload damaged tissues. The athlete often expressed fear in carrying out the action that caused the injury. The execution of this action must be re-pro‐ grammed, performed, and correct if necessary. The training in specific position may prepare in an optimal manner the structure to stress that then can expect during sport activities. The progression of exercises should consider also the ROM andThe training in specific position may prepare in an optimal manner the structure to stress that then can expect during sport in to injuryangular velocity of joint. The eccentric exercises are also important. It consists in a "negative" muscular activity (muscle-tendon system absorbs energy) in which there is an overall lengthening of the muscle while under tension, in response to an external load (such

Scar tissue increasing passive stiffness of the muscle-tendon unit and making it more suscep‐ tible to injury during large eccentric contractions. Optimum tension-length curve of healthy or injured muscle can be optimized (such that peak tension is generated at longer muscle lengths) by eccentric training. Given the length-dependent nature of muscle damage in hamstring strains near end range, this structural adaptation optimizes the angle of peak torque to reduce the risk for potential injury. Despite the inherent limitations and lack of supporting evidence, Croisier et al. (2002) recommended that eccentric exercise should be included in the

It has been suggested that all rehabilitation treatments should always start with an adequate warm-up of the injured muscle (Magnusson et al., 1995; Safran et al., 1988; Safran et al., 1989).

When warm-up is combined with stretching, the flexibility of muscle is improved. Painless elongation of the scar tissue can be achieved by stretching the duration of which should be

as a weight) that is greater than the force generated by the muscle.

rehabilitation of hamstring injuries to help prevent recurrent injuries.

gradually increased from 15 seconds to 1 minute.

positions.

182 Muscle Injuries in Sport Medicine

**Figure 3.** The patient is lying on the ground: submaximal to maximal isometric contractions at different knee angles. 5 sec of contraction 5 sec of rest for 6 times. 4 – 5 times / day.

**Figure 4.** The patient should rotate the trunk as for kicking with the aim to train the core muscolature.

**Figure 5.** Walking hamstring stretch: the patient is in standing position. The injured limb is extended. Trunk flexion to stretch the hamstring muscles.

**Figure 6.** Hamstring stretch: swing phase position with slow side to side rotation and flexion extension of the knee.

**Figure 7.** Lunges in all planes of motion. The patient is in standing position: must make small steps in all directions as

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to a change of direction.

**Figure 5.** Walking hamstring stretch: the patient is in standing position. The injured limb is extended. Trunk flexion to

**Figure 6.** Hamstring stretch: swing phase position with slow side to side rotation and flexion extension of the knee.

stretch the hamstring muscles.

184 Muscle Injuries in Sport Medicine

**Figure 7.** Lunges in all planes of motion. The patient is in standing position: must make small steps in all directions as to a change of direction.

**Figure 8.** Foot catch exercise. The athlete stands parallel to a wall, and simulates the swing phase of walking at the first phase and after of the running. During the swing phase, the athlete performs a quick quadriceps contraction and then attempts to catch or stop the lower leg before reaching full knee extension by a hamstring contraction. In first phase with a little hip and knee extension. In a second phase increase hip and knee extension and the velocity.

**Figure 9.** The patient is in an upright position on a single leg. Flexion of the trunk in all directions.

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Conservative Treatment of Muscle Injuries: From Scientific Evidence to Clinical Practice http://dx.doi.org/10.5772/56550 187

**Figure 9.** The patient is in an upright position on a single leg. Flexion of the trunk in all directions.

**Figure 8.** Foot catch exercise. The athlete stands parallel to a wall, and simulates the swing phase of walking at the first phase and after of the running. During the swing phase, the athlete performs a quick quadriceps contraction and then attempts to catch or stop the lower leg before reaching full knee extension by a hamstring contraction. In first phase with a little hip and knee extension. In a second phase increase hip and knee extension and the velocity.

186 Muscle Injuries in Sport Medicine

**4.5. How to monitor treatment and clinical outcomes**

defining the location, extent and severity of muscle injury.

choice for follow-up imaging evaluations.

on availability, cost, and operators expertise.

an adequate rehabilitation treatment program.

for higher grade injuries appear to be beneficial.

6 weeks.

**5. Conclusions**

recreational athletes.

Although many athletes will return to activity before the MR imaging findings are resolved, follow-up imaging is useful in the case of complications and in order to provide additional information of clinical progress through a rehabilitation program and consequently to support the decision-making for return to sports.US and MRI are both useful imaging modalities in

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These modalities can assess healing or scar formation, detect associated complications, predict prognosis and monitor treatment response in muscle injuries. Greater availability, low cost, short imaging time, no contraindications (e.g., pacemakers), and dynamic capability of US favors its use in the initial assessment and subsequent follow-up of the majority of muscle injuries. However, overall its limitations, including user dependence and lower sensitivity, tend to outweigh its advantages as far as accurate pathology delineation in elite athletes is concerned. Moreover, MRI due to its higher contrast resolution appears to be the technique of

The optimum time to carry out assessments of imaging follow-up is different for each case, and so it is difficult to generalize. However, it should to keep in mind that abnormalities appear to resolve sooner on US than on MRI, and US detected fewer abnormalities than MRI at 2 and

The choice of imaging modality selected for the evaluation of muscle injuries will also depend

Since the re-injury rate can be as high as 34% after 1 year, it's very important monitor rehabil‐

While efforts have been made to minimize their effect, several limitations are present in this review and it is possible that some relevant articles may have been overlooked. However, we can conclude that due to a real lack of published scientific studies until now there is no

A consensus classification system for muscle injuries currently does not exist, but classify muscle injuries according to their severity it may be useful for a prognosis and for establish

Diagnosis of a muscle injury is mainly clinical, but enhanced by imaging findings which allow to determine its degree and location, and to predict return to sport in professional and

Although commonly recommended, there is little evidence to support the RICE principles. Early mobilization for lower grade injuries and brief (1-3 days) immobilization of the extremity

itation treatment progress by imaging evaluations. (Orchard and Best, 2002)

consensus about the rehabilitation treatment of muscle injuries.

**Figure 10.** The patient is in an upright position on a single leg: flexion of the trunk with arms that push forward to increase the difficulty.

**Figure 11.** Lunges in all planes with return to start position. Increasing the length of the step and / or the execution speed of each sitting to vary the training stimulus.

#### **4.5. How to monitor treatment and clinical outcomes**

Although many athletes will return to activity before the MR imaging findings are resolved, follow-up imaging is useful in the case of complications and in order to provide additional information of clinical progress through a rehabilitation program and consequently to support the decision-making for return to sports.US and MRI are both useful imaging modalities in defining the location, extent and severity of muscle injury.

These modalities can assess healing or scar formation, detect associated complications, predict prognosis and monitor treatment response in muscle injuries. Greater availability, low cost, short imaging time, no contraindications (e.g., pacemakers), and dynamic capability of US favors its use in the initial assessment and subsequent follow-up of the majority of muscle injuries. However, overall its limitations, including user dependence and lower sensitivity, tend to outweigh its advantages as far as accurate pathology delineation in elite athletes is concerned. Moreover, MRI due to its higher contrast resolution appears to be the technique of choice for follow-up imaging evaluations.

The optimum time to carry out assessments of imaging follow-up is different for each case, and so it is difficult to generalize. However, it should to keep in mind that abnormalities appear to resolve sooner on US than on MRI, and US detected fewer abnormalities than MRI at 2 and 6 weeks.

The choice of imaging modality selected for the evaluation of muscle injuries will also depend on availability, cost, and operators expertise.

Since the re-injury rate can be as high as 34% after 1 year, it's very important monitor rehabil‐ itation treatment progress by imaging evaluations. (Orchard and Best, 2002)

## **5. Conclusions**

**Figure 10.** The patient is in an upright position on a single leg: flexion of the trunk with arms that push forward to

**Figure 11.** Lunges in all planes with return to start position. Increasing the length of the step and / or the execution

increase the difficulty.

188 Muscle Injuries in Sport Medicine

speed of each sitting to vary the training stimulus.

While efforts have been made to minimize their effect, several limitations are present in this review and it is possible that some relevant articles may have been overlooked. However, we can conclude that due to a real lack of published scientific studies until now there is no consensus about the rehabilitation treatment of muscle injuries.

A consensus classification system for muscle injuries currently does not exist, but classify muscle injuries according to their severity it may be useful for a prognosis and for establish an adequate rehabilitation treatment program.

Diagnosis of a muscle injury is mainly clinical, but enhanced by imaging findings which allow to determine its degree and location, and to predict return to sport in professional and recreational athletes.

Although commonly recommended, there is little evidence to support the RICE principles. Early mobilization for lower grade injuries and brief (1-3 days) immobilization of the extremity for higher grade injuries appear to be beneficial.

Most muscle injuries will respond to rehabilitation treatment without complications. Grade I strains have a low risk of tear extension and heal within 2 weeks with conservative manage‐ ment. Grade II strains require at least 4 weeks of conservative management, with a significant risk of tear extension if the patient returns to full exercise too early. It has been shown that if more than 50% of the cross-sectional area of the hamstring is torn, this correlates well with a convalescence period of greater than six weeks. Increasing length of a strain has also been correlated with an increased period of convalescence.

**Appendix**

**Standing** 

**Therapeutic exercise**

**PHASE 1 Goals: Correct gait Start Isometric training Gentle stretch pain free**

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**1. 5' of low stationary biking with no resistance or 5' walking if it possibile** 

**ԲNeuromuscolar exercise for the lumbopelvic region. 20 – 30 repetitions (foto 6 – 7)** 

**1.** Progression from phase 1 to phase 2 is allowed when the athlete showed a normal gait pattern, and can perform a pain-free isometric contraction against submaximal (60%-80%)

> **PHASE 2 Goals: Start isotonic training Stretching training Cardiovascular training**

**ԲStanding hip flexion with knee extension stretch with slow side to side rotation.** 

**ԲSubmaximal isometric hamstrings sets 5 sec x 6 times 4 – 5 times/days** 

resistance during prone knee flexion (90°) manual strength test.

�**10' of low stationary biking with little resistance or 10' walking** 

**Բhamstring stretch sport position. 3 x 30 sec** 

**ԲLight lunges in all planes ( foto 10) 5 x 15 sec** 

**ԲProne or standing position knee flexion . 3 – 4 x 12 – 15** 

**2. Supine hip flexion with knee exstension stretch 3 x 30 sec** 

**ԲIce in long sitting position for 20min.**

Prevention strategies, although promising, have not yet proven their effectiveness. Currently, there are very few scientific evidences that a determined preventative protocol has been effective, leading to a statistically significant decrease in muscular injuries. Therefore further research is needed to define its role.

Due to the lack of experimental studies on treatment of muscle injuries, basic sciences are fundamentals to build up a rationale rehabilitation treatment program.

#### **From scientific evidence to clinical practice**


#Ultrasonography is equally useful at identifying hamstring muscle injuries and may be preferable because of lower costs.


Among different therapeutic interventions, exercise plays a very important role in the prevention and treatment of muscle injuries.
