Proximal and Distal Impairments in Runners With Achilles Tendinopathy Compared With Matched Controls.

Abstract: Rathod, V, Oh, C, Ling, W, and Rao, S. Proximal and distal impairments in runners with Achilles tendinopathy compared with matched controls. J Strength Cond Res 39(10): e1202-e1211, 2025-This study investigated drop countermovement jump (DCMJ) performance in runners with midportion Achilles tendinopathy (AT). Recreational runners with midportion AT ( n = 23) were compared with age- and sex-matched control (CON) runners ( n = 23). Subjects performed a minimum of 3 trials of single leg DCMJ that involved jumping off a 20 cm box. Pain during and after jump performance was assessed using a Numeric Pain Rating Scale. Victorian Institute of Sport Assessment- AT and Tampa scale of Kinesiophobia were recorded. Three-dimensional motion analysis was used to assess jump height and lower extremity joint kinematics. Paired t-tests ( p < 0.05) and regression analyses were conducted to examine between-group differences and the role of group membership (AT/CON) age, body mass index, and weekly running mileage on dependent variables. Runners with AT demonstrated impaired single-leg DCMJ performance, particularly in ankle kinematics during the propulsion phase. Jump height and ankle plantarflexion during the propulsion phase were significant predictors of group membership (AT/CON). In addition, clinically relevant subgroups with reduced hip extension torque were identified. Drop countermovement jump proved to be a robust assessment tool for evaluating AT in high-impact sports subjects. Notably, all subjects were highly functioning recreational runners with no ankle strength deficits or symptoms during the jump; however, moderate-to-large performance deficits were found in the AT group. Clinicians may incorporate DCMJ assessments to monitor progress and guide rehabilitation in individuals with AT.