Three dimensional surface representation of knee and hip joint torque capability

The need to develop objective functional muscle torque capability models has been a major concern for exercise scientists, rehabilitation therapists, as well as biomechanists and ergonomists, for many decades. This study provides a surface response normative database of 3-D dynamic torque capability profiles for the lower extremity knee and hip joints for twenty normal males and females. The results of the regression analyses were presented for each subject per direction of exertion for each joint depicting a wide range of adjusted R² values for each of the two joints (knee flexion: .26-.91, knee extension: .23-.80; hip flexion: .33-81, hip extension: .31-.80). Furthermore, the results showed that joint torque capability was significantly influenced by dynamic parameters such as the angular velocity, and that the interaction between angular position and velocity was highly significant. Such 3-D representation may be used as a "performance capacity envelope" to comprehensively characterize an individual's dynamic joint torque capability. Potential applications cover a broad spectrum ranging from rehabilitation to ergonomic and biomechanical applications and have significant implications in terms of guiding job assignment, return to work, as well as prognosis during the rehabilitation processes.