Medial Gastrocnemius Strain

Updated: May 22, 2023
  • Author: Anthony J Saglimbeni, MD; Chief Editor: Sherwin SW Ho, MD  more...
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Practice Essentials

A medial calf injury is a musculotendinous disruption of varying degrees in the medial head of the gastrocnemius muscle that results from an acute, forceful push-off with the foot. [1, 2, 3, 4, 5, 6]  This injury occurs commonly in sports activities (eg, hill running, jumping, tennis), but it can occur in any activity. A medial calf injury is often seen in the intermittently active athlete, often referred to as the "weekend warrior.

This condition has been termed "tennis leg" because of its prevalence in this particular sport, but medial calf injury can happen in a variety of sports or other activities. One mechanism that occurs is on the back leg during a lunging shot, in which the knee is extended while the foot is dorsiflexed. This action puts maximal tension on the gastrocnemius muscle as the lengthened muscle is contracted at the "push off," resulting in a medial calf injury. (See also the Medscape Reference article Calf Augmentation.)

An unusual presentation of a medial gastrocnemius injury during namaz praying was reported by Yilmaz et al, who performed a retrospective study of the sonographic and magnetic resonance image (MRI) findings of patients referred over 7 years with leg pain and swelling. [7]  Of 543 patients, 14 had a final diagnosis of medial gastrocnemius rupture that occurred during namaz praying. Nine of 14 (64.2%) patients had incomplete tears at the musculotendinous junction, and 5 of 14 (35.8%) patients had partial tears.

The diagnosis in 4 of 14 (28.6%) patients was misattributed to deep vein thrombosis due to clinical findings and presentation, associated fluid collection between the gastrocnemius and soleus muscles was found in 11 of 14 (78.5%) patients, and isolated fluid collection between the gastrocnemius and soleus muscles was seen in 1 patient. [7]  The investigators suggested ultrasonography and MRI can be used to correctly diagnose patients with medial gastrocnemius injuries.



International statistics

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.


Functional Anatomy

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]


Sport-Specific Biomechanics

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.


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.