Effect of Eccentric Strengthening on Pain, Muscle Strength, Endurance, and Functional Fitness Factors in Male Patients with Achilles Tendinopathy

OBJECTIVE: The aim of this study was to investigate the effect of eccentric strengthening on pain, muscle strength, endurance, and functional fitness factors in Achilles tendinopathy patients. DESIGN: Thirty-two male patients with Achilles tendinopathy were assigned to either the experimental group that performed eccentric strengthening or the control group that performed concentric strengthening (n = 16, both groups) for 8 wks (50 mins per day, three times per week). A visual analog scale, an isokinetic muscle testing equipment, the side-step test, and the Sargent jump test were used to assess pain, muscle strength, endurance, and functional fitness factors before and after the intervention. RESULTS: In comparison with the control group, the experimental group showed significant improvement in pain, ankle dorsiflexion endurance, total balance index, and agility after the intervention (P < 0.05). However, there was no significant difference in dexterity between the two groups. CONCLUSIONS: Eccentric strengthening was more effective than concentric strengthening in reducing pain and improving function in patients with Achilles tendinopathy; therefore, regular eccentric strengthening is important for patients in a clinical setting.