Eccentric strength training of the plantar flexors in patients with Achilles tendinosis results in remodeling of the muscle architecture in the medial gastrocnemius not seen in the lateral gastrocnemius, according to a study from Columbus, OH.
Researchers at the Orthopedic Foot & Ankle Center used ultrasound to assess the morphology of the medial and lateral gastroc muscles in 10 patients with Achilles tendinosis, before and after eight weeks of eccentric strengthening. All patients, who had pain 2 to 4 cm proximal to the calcaneus and were unable to do five heel raises without pain, underwent supervised physical therapy twice a week for four to five weeks, followed by home-based exercises.
In the medial gastroc, fascicle length increased by 1.4 cm at eight weeks. No significant changes in fascicle length were seen in the lateral gastroc, however; the authors suggested a longer training period might have more pronounced effects. Pennation angle and muscle thickness did not change in either muscle. The findings were presented in March at the annual ACFAS meeting.