A 62-year-old woman had knee osteoarthritis. There is a 5 degree restriction of extension in the right knee. Unilateral restriction is most easily detected when the extremities are relaxed and the examiner holds under the heels, keeping the patellas on the same level. The toes remain lower on the side of the affected knee. The restriction of flexion is easily measured as the distance of the heel from the buttock.
Assessing range of motion of the knee