Gerrits, KH and Maganaris, CN and Reeves, Neil D and Sargeant, AJ and Jones, DA and de Haan, A (2005) Influence of knee joint angle on muscle properties of paralyzed and nonparalyzed human knee extensors. Muscle and Nerve, 32 (1). pp. 73-80. ISSN 0148-639X
Full text not available from this repository.Abstract
Muscles of individuals with a spinal cord injury (SCI) exhibit an unexpected leftward shift in the force (torque)–frequency relationship. We investigated whether differences in torque–angle relationships between SCI and able-bodied control muscles could explain this shift. Electrically stimulated knee-extensor contractions were obtained at knee flexion angles of between 30° and 90°. Torque–frequency relationships were obtained at 30°, 90°, and optimum angle. Optimum angle was not different between groups but SCI-normalized torques were lower at the extreme angles. At all angles, SCI muscles produced higher relative torques at low stimulation frequencies. Thus, there was no evidence of a consistent change in the length of paralyzed SCI muscles, and the anomalous leftward shift in the torque–frequency relationship was not the result of testing the muscle at a relatively long length. The results provide valuable information about muscle changes occurring in various neurological disorders. Muscle Nerve, 2005