Chronic Achilles Tendinitis and Calf Muscle Strength

Abstract

We evaluated 10 men and 3 women (mean age, 44 ± 8.5 years) with chronic Achilles tendinitis who under went surgical treatment. Surgery was followed by im mobilization in a weightbearing below-the-knee plaster cast for 6 weeks and a stepwise increasing strength training program. We prospectively studied calf muscle strength on the injured and noninjured sides preoper atively and at 16, 26, and 52 weeks postoperatively. Preoperatively, concentric peak torque in dorsiflexion at 90 deg/sec and plantar flexion at 225 deg/sec was significantly lower on the injured side. Postoperatively, concentric plantar flexion peak torque on the injured side increased significantly between Weeks 16 and 26 at 90 deg/sec but was significantly lower than the noninjured side from Weeks 16 to 52 at 90 and 225 deg/sec. Dorsiflexion peak torque at 90 and 225 deg/ sec increased between Weeks 0 and 26 and was significantly higher on the injured side at Week 26. Eccentric plantar flexion peak torque was significantly lower on the injured side at Week 26 but not at 1 year. This prospective study demonstrates that 6 months of postoperative rehabilitation for chronic Achilles tendi nitis is not enough to recover concentric and eccentric plantar flexion muscle strength compared with the non injured side.