Haffajee, D., U. Moritz, and G. Svantesson. “Isometric Knee Extension Strength As a Function of Joint Angle, Muscle Length and Motor Unit Activity”. Acta Orthopaedica 43, no. 2 (January 1, 1972): 138–147. Accessed May 23, 2026. https://actaorthop.org/actao/article/view/29798.