Relationship between calf muscle size and strength after achilles rupture repair.

The object was to study the relationships between calf muscle size and strength in 85 patients an average of 3.1 years after repair of achilles tendon rupture. The isokinetic calf muscle strength results were excellent or good for 73% of the patients, whereas calf muscle size was normal in only 30%. The average plantar flexion peak torque per unit muscle cross-sectional area was higher on the injured side than on the uninjured side. The average calf muscle cross-sectional area deficit was 15+/-9% (p<0.001) of that on the unaffected side, while the average plantar flexion peak torque deficit was speed-dependent, being 9+/-18%, 10+/-18 and 2+/-13% of that on the unaffected side at 30, 90, and 240 degrees/sec (p<0.001). The correlation between cross-sectional area and peak torque varied in the range 0.52-0.61 at 30, 90 and 240 degrees/sec (p<0.001).