Medial gastrocnemius muscle fascicle function during heel-rise after non-operative repair of Achilles tendon rupture

Background To better understand muscle remodelling in dynamic conditions after an Achilles tendon rupture, this study examined the length of medial gastrocnemius muscle fascicles during a heel-rise at 6- and 12-months after non-operative ATR treatment. Methods Participants (15 M, 3F) were diagnosed with acute Achilles tendon rupture. Medial gastrocnemius subtendon length, fascicle length and pennation angle were assessed in resting conditions, and fascicle shortening during bi- and unilateral heel-rises. Findings Fascicle shortening was smaller on the injured side (mean difference [95% CI]: −9. 7 mm [−14.7 to −4.7 mm]; −11.1 mm [−16.5 to −5.8 mm]) and increased from 6- to 12 months (4.5 mm …