Dataset: Biomechanics of Copenhagen adduction exercise and eccentric hip adductor exercises on a novel isokinetic dynamometer with test–retest reliability

This study biomechanically evaluated short and long lever Copenhagen adduction exercise (CAE) and compare them with unilateral and bilateral eccentric hip adductor exercises performed on a novel isokinetic dynamometer (DEHA). Fifteen participants completed two CAE variations and five exercises on DEHA. Three-dimensional kinematics and force data were collected to compute hip joint torque, range of motion (ROM), and angle at peak torque during the CAE, while the same output variables were derived from the DEHA. The effects of exercise type and lever length on biomechanical outcomes, as well as relative and absolute test–retest reliabilities, were evaluated. The CAE produced significantly lower peak eccentric torques than all DEHA variants, regardless of lever length or unilateral/bilateral performance. Long lever CAE elicited greater peak and average torques than the short lever CAE, but through a reduced ROM. DEHA exercises generated significantly greater peak torques during bilateral performance, demonstrating the presence of bilateral facilitation (27.9 ± 16.5 %). Angles at peak torque were similar across all exercises (31–39°). With the exception of angle at peak torque during the CAE, all measurements showed good to excellent relative and moderate to good absolute reliability. Increasing lever length during CAE effectively raises hip adductor loading but limits ROM. In contrast, all DEHA variations enable greater loading across the full ROM and exhibit pronounced bilateral facilitation. Future intervention studies should determine whether such biomechanical advantages translate into superior clinical outcomes.