Abstract
The purpose of this study was to assess the intratester reliability of torque variables of the hip and knee extensor musculature during an isokinetic, concentric contraction in a closed kinematic chain. Nineteen healthy subjects (10 females, 9 males, mean age 24 ± 4) were tested on the Kin-Com on two occasions, exactly 1 wk apart. The subjects were stabilized in the supine position with their dominant foot fixed to a foot plate, in approximately 115 deg of hip and knee flexion, and asked to extend to full hip and knee extension. Testing was performed at 30, 120, and 210 deg/sec. Reliability was determined on the female group (n = 10), the male group (n = 9), and the combined group (n = 19). Torque measurements of the hip and knee extensors in a closed kinematic chain using this protocol were reliable except for the male group at 30 deg/sec. The intraclass correlation coefficients (lCCs) for combined group torque values were comparable to those of previous studies performed on the knee extensors in an open kinematic chain. These results indicate that isokinetic concentric testing of the hip and knee extensors in a closed kinematic chain can be reliable when this protocol is used.