Figure 1. (A) Position for passive knee extension test using an isokinetic dynamometer. Left - Start position with the knee and hip both in approximately 110° of flexion. Right - The knee is extended passively until the subject experiences the onset of pain (maximum knee extension). (B) Typical torque-angle curves showing pre-stretching and 15-min post-stretching data. Stiffness was determined using a regression line between 50% and 100% of the pre-stretching range of motion (ROM)-passive torque (PT) relationship. PT at the onset of pain and ROM were determined using the PT and knee extension angle at the onset of pain.