Medial Gastrocnemius Strain

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Medial calf injuries occur more commonly in men than in women, and these injuries usually afflict athletes and others in the fourth to sixth decade of life. Medial calf injuries are most commonly seen acutely, but up to 20% of affected patients report a prodrome of calf tightness several days before the injury, thus suggesting a potential chronic predisposition.

The medial head of the gastrocnemius muscle originates from the posterior aspect of the medial femoral condyle, and as it courses distally, the medial head merges with the lateral head of the gastrocnemius. Further distally, the joined heads of the gastrocnemius merge with the soleus muscle-tendon complex to form the Achilles tendon. The main function of the gastrocnemius muscle is to plantar flex the ankle, but it also provides some knee flexion, as well as contributes to the posterior stability of the knee and partially to the motion of the menisci with flexion/extension of the knee. Throughout the belly of the muscle, the medial gastrocnemius has several origins of tendinous formation. Most strains occur at this musculotendinous junction.

Using shear wave elastography, Yoshida et al found that the elastic moduli of the medial gastrocnemius vary significantly at different points on the aponeurosis, specifically, the point at the center of the musculotendinous junction and those 10 mm proximal and 10 mm distal to it, with the highest modulus found at the distal point (4.83 m/s) and the lowest at the proximal (2.82 m/s). Moreover, the distal modulus, as well as the elastic modulus at a point on the muscle belly, was found to be significantly higher in males than in females, while the muscle-belly modulus was higher in younger persons than in those in middle age.[8]

The medial calf injury usually occurs when an eccentric force is applied to the gastrocnemius muscle, which usually happens when the knee is extended, the ankle is dorsiflexed, and the gastrocnemius attempts to contract in the already lengthened state.[1, 2, 3, 4, 5, 6] This is the common position of the back leg in a tennis stroke, and it results in the greatest force to the muscle unit; but medial calf injuries can also occur during a typical contraction of ankle plantar flexion, especially if the athlete is pushing or lifting a large weight or force.

Age/activity status

As indicated in the Practice Essentials section, medial calf injuries occur more commonly in the middle-aged recreational athlete. This population typically continues to be physically active at a moderate to high intensity but not on a regular basis, and these individuals are also likely to have maintained a moderate degree of the muscle mass from their more active days. Yet weekend warriors seem to have started to lose some of the flexibility they had when they were younger, resulting in a relatively large gastrocnemius muscle that is less flexible than it had been, and on occasion, the muscle is challenged with a ballistic or explosive force, leading to a partial or complete rupture.

Deconditioned/unstretched muscles

The cold and unstretched muscles that recreational athletes often use to compete with are very likely to rupture when challenged compared with conditioned and stretched muscles. However, because medial calf injuries also occur in the physically fit, the role of stretching in prevention is not completely understood. This phenomenon may mean that force versus elasticity is the key formula, and if the force overcomes the elasticity, even in a conditioned athlete, then a rupture or injury can occur.

Previous injury

The athlete with recurrent calf strains is likely to have healed with fibrotic scar tissue, which absorbs forces differently and is thus more likely to result in rupture when the muscle is challenged.

If the above treatments are followed (see Treatment, Acute Phase, Recovery Phase, and Maintenance Phase), the prognosis for recovery and return to sports after a medial calf injury is excellent.

Complications

The most common complication of a medial calf injury is scar-tissue formation, which results in chronic pain or dysfunction that is caused by a functional shortening of the muscle-tendon unit. This scar tissue can then predispose to frequent reinjury. Another complication is the formation of a DVT as a result of patient inactivity and trauma.

An audible pop when the injury to the medial calf occurred is usually reported, and the patient complains of feeling like a stick struck his/her calf.

The patient complains of pain in the area of the calf, which also radiates to the knee or the ankle. In addition, the patient complains of pain with range of motion (ROM) of the ankle.

The patient complains of a swollen leg that extends down to the foot or ankle, as well as the associated color changes of bruising. (See also the Medscape Reference article Contusions.)

Inspection

Asymmetric calf swelling and discoloration, potentially spreading to the ankle and foot, is noted on physical examination.

If the stage of swelling has resolved, a visible defect in the medial gastrocnemius muscle may be evident.

Palpation

Tenderness is noted upon palpation in the entire medial gastrocnemius muscle, but this tenderness is observed to be exquisitely more painful at the medial musculotendinous junction.

Depending on the degree of swelling, a palpable defect may be evident at the medial musculotendinous junction; however, with extreme swelling, this finding may not be appreciable.

Palpation of the Achilles tendon should demonstrate an intact tendon.

The peripheral pulses should be present and symmetric.

Provocative maneuvers

Moderate to severe pain is demonstrated with passive ankle dorsiflexion (due to stretching of the torn muscle fibers), as well as with active resistance to ankle plantar flexion (due to the firing of the torn muscle fibers).

The ruptured medial gastrocnemius can usually be diagnosed clinically. Although laboratory and imaging studies can also be used to evaluate some of the other diagnostic possibilities (see Differentials and Other Problems to Be Considered), they are not necessary.

Laboratory studies are usually not necessary in the workup of gastrocnemius strains. They may, however, aid in the evaluation of a potential DVT, if clinical suspicion is present.

Complete blood cell (CBC) count: If a DVT is present, the platelet count may be abnormal, but in gastrocnemius strains, the CBC count is normal.

Coagulopathy panel: Before initiating treatment for DVT, prothrombin time (PTT), activated partial thromboplastin time (aPTT), protein C, protein S, and D-dimer levels should be measured. Of course, these results all are within the normal reference range in a medial gastrocnemius strain.

Radiographs

In the face of a classic history and presentation for a medial gastrocnemius strain, radiographs are usually normal and do not offer additional information for treatment.

X-ray films may be ordered to rule out an avulsion fracture, especially when the patient describes an audible pop or any history of impact or trauma to the calf region. (See also the Medscape Reference article Tibial Tubercle Avulsion.)

Plain films of the leg and tibia/fibula are usually normal, except for the finding of soft-tissue swelling.

MRI

Studies have shown that magnetic resonance imaging (MRI) and ultrasound studies can be useful in the diagnosis and/or follow-up of injuries to the lower leg. MRI is the most sensitive and specific imaging method, and this technique is able to show the area of disrupted soft tissue better than other imaging modalities (eg, computed tomography [CT] scanning, ultrasonography).[10, 11]

Koulouris et al retrospectively reviewed 59 MRIs from patients who had sustained calf muscle injuries.[12] The authors reported that of the 39 isolated strains, gastrocnemius injuries were the most common (48.7%), in which the majority of these (94.7%) involved the medial head, followed by soleus muscle injuries (46.2%), including 2 cases of distal avulsions of the plantaris. In cases in which there were dual injuries, the most common finding (60%) was a combined gastrocnemius and soleus muscle injury. Koulouris et al concluded that dual injuries to the calf region may be more common than has been reported and such injuries may have a prognostic significance. The authors also noted that in the literature, soleus muscle injury is a rarely reported finding with ultrasonography.

In a retrospective review by Dai et al of 58 patients who had a clinical diagnosis of tennis leg, MRI showed that 90.2% of the patients had edema or disruption of the gastrocnemius, 36.1% had edema or disruption of the soleus, and 11.5% had plantaris tendon disruption. Reparative tissue at the distal myotendinous junction of the medial head of the gastrocnemius was noted on follow-up MRI in four patients.[13]

Ultrasonography

In areas where ultrasound experience is good, this modality may also demonstrate the medial gastrocnemius injury and usually costs less than MRI. However, limited MRI protocols, in which a few images of the suspected region of pathology are performed, can have competitive pricing and demonstrate superior images than ultrasonography. However, in emergency department settings, rapid diagnostic ultrasonography can be used to evaluate the structure of the medial gastrocnemius and to rule out some of the diagnostic possibilities, such as DVT (see Differentials and Other Problems to Be Considered).[14]

In a Korean study, 22 patients with clinically suspected ruptures of the medial head of the gastrocnemius under went ultrasound examination of both the affected and unaffected limbs.[15] The authors reported that 7 of the 22 patients were diagnosed with a partial rupture, and the remaining 15 patients were diagnosed with complete ruptures of the head of the gastrocnemius. In addition, the authors noted fluid collection between the head of the gastrocnemius and the soleus muscle in 20 patients, and they reported the thickness of the fluid collection was significantly greater in those patients with complete gastrocnemius medial head ruptures (mean: 9.7 mm) compared with those of the individuals with partial tears (6.8 mm). The authors concluded that ultrasound is a useful imaging modality for the diagnosis and follow-up of patients with ruptures of the medial head of the gastrocnemius.

Other tests are not necessary for the diagnosis of an uncomplicated medial gastrocnemius strain. If the suspicion of DVT persists, then further evaluation with Doppler ultrasonography is indicated.

Rehabilitation Program

Physical Therapy

Initial treatment of a medial calf injury includes relative rest, ice, compression, elevation (RICE), and early weight bearing, as tolerated. The initial treatment should continue for 24-72 hours. Ice therapy is best instituted over a damp elastic wrap, which also provides compression. Preventing the limb from hanging dependently prevents further swelling. The use of crutches with a feathering gait and bilateral heel lifts is indicated if normal gait is compromised. Active foot and ankle ROM can be carried out if there is pain-free ROM.

Medical Issues/Complications

Pain management should include analgesics as indicated. Caution should be used with nonsteroidal anti-inflammatory drugs (NSAIDs) during the acute injury phase, as these agents can predispose the patient to increased bleeding and hematoma formation in the initial days after an injury. Theoretically, cyclooxygenase-2 (COX-2) inhibitors may provide pain control without the risk of bleeding in acute injuries, which is a concern with traditional NSAIDs.

Other Treatment

Ankle/foot bracing should be used to keep the ankle in a position of maximal tolerable dorsiflexion. Studies have shown an increased rate of healing with this intervention.

As with any large muscle strain, hematoma formation can be complicated by heterotopic ossification resulting in myositis ossificans. Studies do support the use of nonsteroidal anti-inflammatory medication, which may help prevent this.

Rehabilitation Program

Physical Therapy

Ice therapy and active resistance dorsiflexion exercises can be undertaken until the athlete is pain free. Then, light plantar flexion exercises against resistance are initiated. Progression of therapy includes reduction in heel-lift height and gradual introduction of stationary cycling, leg presses, and heel raises. At this stage, ultrasonography, used with or without phonophoresis, and muscle stimulation are also applicable. Massage techniques can help with the removal of interstitial fluid. Apply compression dressing from the metatarsal heads to the gastrocnemius for the first 2 weeks. Partial weight-bearing ambulation should begin as soon as tolerable to maximize the contact of the sole of the foot to the ground, then progress to increased cyclic loading, advanced proprioception and balance training, and eventual full weight-bearing ambulation, with dynamic change of speed and direction as tolerable.

Rehabilitation Program

Physical Therapy

Once the athlete is pain free with full and symmetric ROM and full strength is regained, sports-specific activities can be resumed. Strengthening and stretching of the injured area should continue for several months to overcome the increased risk for reinjury due to the deposition of scar tissue that is involved in the healing process.

A 2014 randomized trial reported that the use of shock-absorbing insoles during 3 weeks of training on artificial turf resulted in a significant increase in the pain threshold for the medial head of the gastrocnemius muscle.[16]

When an athlete will be able to return to play is predicated on the patient being pain free and recovering full ROM. This period can last 1-12 weeks, depending on the degree of tissue damage that was sustained. Strength testing should reveal that more than 90% of the uninjured side accounts for the patient's dominance preference.

A medial calf injury may not be preventable, but regular physical activity with maintenance of flexibility in the gastrocnemius muscle may help to reduce one's chances of sustaining such an injury.

Instructions for appropriate stretching and warm-up techniques should be provided to the patient for the implementation of maximal prevention of reinjury.

Medications are directed at maintaining patient comfort in what can be a very painful injury of the medial head of the gastrocnemius. Clinicians must carefully consider pain therapy in the first 48 hours, as decreased platelet activity may result in increased bleeding and larger hematoma formation—with resultant effects on healing.

The simplest, yet least powerful of the recommended analgesics is acetaminophen. Typical doses of 1000-1300 mg, 3-4 times daily can be used as needed. This agent does not affect platelet function but may not greatly control pain.

To gain better pain control, more potent analgesics can be used, such as NSAIDs or an acetaminophen/narcotic combination. As referred to above (see Medical Issues/Complications in the Treatment, Acute Phase section), NSAIDs may enhance bleeding shortly after the injury has occurred. These agents are also likely to cause symptoms of gastrointestinal (GI) discomfort, and they can result in mucosal injury and even bleeding ulcers. On the other hand, opioid analgesic agents may cause GI side effects but not result in bleeding issues; these medications are generally better at pain control, but opioid analgesics have the possible complication of addiction or abuse.

Opioid medications come in various forms and various dosages. An alternative to the above medications is to use a newer NSAID from the COX-2 inhibitor class. The newer COX-2 inhibitor drugs affect inflammation in a more specific manner by not affecting the prostaglandins that can cause the above side effects; these agents have also been shown to provide equianalgesia to the traditional NSAIDs.

Class Summary

Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet (ie, decrease pulmonary secretions, open the airways), and have sedating properties, which are beneficial for patients who have sustained trauma or injuries.

Acetaminophen (Tylenol, Feverall)

DOC for pain in patients with documented hypersensitivity to aspirin or NSAIDs, with upper GI disease, or who are taking oral anticoagulants. No benefit as an anti-inflammatory agent. No effect on platelet function.

Acetaminophen with codeine 300/30 (Tylenol #3)

First-line agent for moderate to severe pain. Has no anti-inflammatory benefit. With the combination of a narcotic and acetaminophen, pain control is much better than acetaminophen alone.

Class Summary

COX-2 inhibitors promote control of moderate pain and anti-inflammatory effects, especially in patients who have sensitivity to the traditional NSAIDs. Although increased cost can be a negative factor, the incidence of costly and potentially fatal GI bleeding is clearly less with COX-2 inhibitors than with the traditional NSAIDs. Ongoing analysis of the cost avoidance of GI bleeding will further define the populations that will benefit from the use of COX-2 inhibitors.

Celecoxib (Celebrex)

Inhibits primarily COX-2. COX-2 is considered an inducible isoenzyme during pain and with inflammatory stimuli. Inhibition of COX-1 may contribute to NSAID GI toxicity. At therapeutic concentrations, COX-1 isoenzyme is not inhibited, thus GI toxicity may be decreased. Seek the lowest dose of celecoxib for each patient.

Class Summary

Nonsteroidal anti-inflammatory agents (NSAIDs) inhibit prostaglandin synthesis resulting in decreased inflammation and pain.

Naproxen (Aleve, Anaprox, Naprosyn)

Naproxen is used for relief of mild to moderate pain; it inhibits inflammatory reactions and pain by decreasing activity of cyclo-oxygenase, which results in a decrease of prostaglandin synthesis.

Indomethacin (Indocin)

Indomethacin inhibits the synthesis of prostaglandins in body tissues by inhibiting at least 2 cyclooxygenase isoenzymes, cyclooxygenase-1 (COX-1) and -2 (COX-2). It may inhibit chemotaxis, may alter lymphocyte activity, may decrease proinflammatory cytokine activity, and may inhibit neutrophil aggregation. These effects may contribute to its anti-inflammatory activity.