Residual Eccentric Strength Deficits and Deep Scar Tissue Thickness in Patients With Tennis Leg

ConditionsTennis Leg Muscle Contusion

Trial statusRecruiting

Trial phaseNot listed

Trial typeObservational

Biological sexAll

Age18-40

SponsorAl Hayah University In Cairo

About this trial

This study investigates the relationship between the thickness of deep scar tissue and residual weakness in the calf muscles of patients who have recovered from a condition known as "tennis leg." Tennis leg is a common calf muscle injury caused by a partial tear of the inner part of the gastrocnemius (calf) muscle at the point where muscle meets tendon. While patients often return to daily activities after healing, many continue to experience hidden weakness in their calf muscles, particularly during activities that require the muscle to lengthen under load (eccentric contractions), such as walking downhill, running, or landing from a jump.

This study uses diagnostic ultrasound imaging to measure the thickness of scar tissue that forms inside the muscle after injury. It also uses an isokinetic dynamometer to objectively measure the eccentric (lengthening) strength of the calf muscles. By comparing the injured leg to the uninjured leg in the same person, the study determines whether patients with thicker scar tissue have greater residual strength deficits.

The study enrolls adults aged 18 to 40 years who have had a confirmed unilateral calf muscle tear at least 3 months ago and have returned to normal daily activities. No treatment or intervention is provided. All assessments are performed at a single time point. Understanding how scar tissue relates to persistent muscle weakness could help clinicians better predict long-term outcomes, design more effective rehabilitation programs, and make more informed decisions about when patients are ready to return to sport and physical activity.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Age between 18 and 40 years

History of unilateral plantar flexor muscle tear (tennis leg) involving the medial gastrocnemius, confirmed by diagnostic ultrasound

Ultrasound diagnostic criteria: hypoechoic or anechoic fluid collection between the medial gastrocnemius and soleus muscles, with partial or complete disruption of the normal muscle fiber architecture at the myotendinous junction

Grade I (mild strain, <10% fiber involvement) or Grade II (moderate partial tear, 10-90% fiber involvement) injury

Disqualifiers

Bilateral calf injuries

Grade III (severe/complete) gastrocnemius muscle rupture

Previous Achilles tendon rupture or surgery

Previous injuries or surgeries to the lower extremity (other than the index tennis leg injury)

Trial population

Patients referred from orthopedic clinics to physiotherapy clinics and/or sports rehabilitation centers in Cairo, Egypt, who have a history of unilateral medial gastrocnemius muscle tear (tennis leg) confirmed by diagnostic ultrasound, have completed acute healing (≥3 months post-injury), and have returned to daily activities.

Trial design

Design model

Other

Time perspective

Cross-sectional

Treatments tested in this trial

B-mode Diagnostic Ultrasound - Scar Tissue Assessment
Diagnostic test
B-mode diagnostic ultrasound is used to measure deep scar tissue thickness (in millimeters) at the musculotendinous junction of the medial gastrocnemius muscle. Measurements are obtained in both longitudinal and transverse planes at the site of maximal scar thickness. The contralateral uninjured limb is measured for comparison. Assessments are performed by a blinded experienced sonographer using a standardized probe position. This is a diagnostic exposure measurement, not a therapeutic intervention.
Isokinetic Dynamometry - Eccentric Plantar Flexor Strength Assessment
Diagnostic test
Eccentric plantar flexor strength is assessed using an isokinetic dynamometer at angular velocities of 30°/s and 60°/s. Peak torque (Nm) is recorded for both the injured and uninjured limbs. Testing follows a standardized warm-up protocol with randomized testing order and adequate rest between trials. The percentage deficit between limbs is calculated. This is a diagnostic measurement, not a therapeutic intervention.

Treatment groups

40 Participants

are divided into 1 treatment group

Group A: Tennis Leg Patients - Post-Healing2 interventions

Trial outcomes

Primary outcomes

Eccentric Plantar Flexor Strength Deficit (Percentage)

The percentage difference in eccentric peak torque (Nm) of the plantar flexor muscles between the injured and uninjured limbs, measured using isokinetic dynamometry at 30°/s and 60°/s. Deficit is calculated as: \[(Uninjured - Injured) / Uninjured\] × 100. A higher percentage indicates greater residual weakness.

Time frame