Terminology used in the analysis of joint function

Abstract

Joint function is described by biomechanical parameters like range of motion (ROM), stiffness, laxity and stability. However, these terms are frequently used ambiguously. Due to the lack in standardisation, it is difficult to compare results of examinations. A literature survey is performed and an inventory is made about the definitions used for the terms. The final definition for ROM is the range of translation and rotation through which a joint may be actively or passively moved in a certain direction. Joint stiffness describes the resistance of the joint to imposed relative movement between two joint surfaces. Laxity is the normal amount of motion that results from passive forces or moments and stability is the ability to control positions or movements of joints.