What is the most stable position of a joint or joint complex called?

The most stable position of a joint or joint complex is referred to as the close packed position. In this position, the articular surfaces of the bones within the joint fit snugly together, providing maximum surface contact and stability. This occurs because the ligaments and joint capsules surrounding the joint are under tension, which further enhances stability.

In this state, the joint is less mobile but significantly more secure, making it less prone to injury. Close packed positions vary from one joint to another; for example, the knee is in a close packed position when it is fully extended. Understanding close packed positions is crucial in clinical biomechanics, as it influences how rehabilitation and treatment strategies are designed following injuries or surgeries.

While terms like open chain and closed chain refer to different types of movements and functional patterns, they do not specifically indicate joint stability in the way that close packed does. Open packed positions are characterized by decreased stability, as the joint surfaces are not fully congruent.