How is joint stiffness primarily characterized?

Joint stiffness is primarily characterized by the condition of the joint capsule and ligaments. The joint capsule is a fibrous structure that encloses the joint, and it contains synovial fluid, which lubricates the joint and contributes to its movement. The ligaments are strong bands of tissue that connect bones within the joint and provide stability. When the joint capsule and ligaments are healthy and flexible, the joint can move freely; however, if these structures become tight, inflexible, or damaged, it can lead to increased stiffness and restrict the range of motion.

While muscle tightness, the elasticity of connective tissues, and age-related changes in muscle composition can all influence joint movement and overall flexibility, they are not the primary contributors to joint stiffness itself. Joint stiffness is more directly related to the integrity and condition of the structures that encapsulate and stabilize the joint.