Some patients have suffered microtrauma to structures which may lead to an acquired instability. This is determined by specific testing with the patient at rest, and is compared to the uninvolved side. The muscle spindle and golgi tendon organs maintain normal muscular tone and tension. This may be more difficult to determine objectively, however, a kinesthetic evaluation may be an indicator of the neuromuscular coordination during active movement. B. Hypomobility .
Some patients are inherently more stable than others.
However, selective hypomobility of the capsule may occur, which will limit specific motions. Normal patella tracking includes a slight medial translation during mid-range. If the patella does not track medially during this passive test, it may indicate a hypomobility of the static patella stabilizers. If the test is repeated actively from 90-0 and the patella does not track medially, weakness of the VMO may be present. Connective tissue surrounding the knee may also cause restricted motion.