Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis

We prospectively studied the effect of heavy-load ec-centric calf muscle training in 15 recreational athletes (12 men and 3 women; mean age, 44.3! 7.0 years) who had the diagnosis of chronic Achilles tendinosis (degenerative changes) with a long duration of symp-toms despite conventional nonsurgical treatment. Calf muscle strength and the amount of pain during activity (recorded on a visual analog scale) were measured before onset of training and after 12 weeks of eccentric training. At week 0, all patients had Achilles tendon pain not allowing running activity, and there was sig-nificantly lower eccentric and concentric calf muscle strength on the injured compared with the noninjured side. After the 12-week training period, all 15 patient