A Joint Coordinate System for the Clinical Description of Three-Dimensional Motions: Application to the Knee

Abstract

The experimental study of joint kinematics in three dimensions requires the description and measurement of six motion components. An important aspect of any method of description is the ease with which it is communicated to those who use the data. This paper presents a joint coordinate system that provides a simple geometric description of the three-dimensional rotational and translational motion between two rigid bodies. The coordinate system is applied to the knee and related to the commonly used clinical terms for knee joint motion. A convenient characteristic of the coordinate system shared by spatial linkages is that large joint displacements are independent of the order in which the component translations and rotations occur.

Compliant positioning of total hip components for optimal range of motion

“…A non-orthogonal joint coordinate system similar to that defined for the knee [9] was used to describe hip joint motion. Simulated motions started from the neutral joint position.…”

Concrete use of the joint coordinate system for the quantification of articular rotations in the digital joints of the horse

“…Different mathematical models associated with kinematic measurements have been proposed for the quantitative evaluation of human locomotion [3,41,52]. Because the subject is of high interest and necessitates standardisation, the International Society of Biomechanics recommends the use of the Joint Coordinate System (JCS) [55] described by Chao [14] and Grood and Suntay [30]. It provides a precise mathematical description of clinical terminology for joint rotational motions [29].…”

“…Kinematics provide a way to express R p and R d in R 0 , and thus R d can be defined relative to R p . This relative orientation of one body segment with respect to the other can also be expressed in terms of three successive rotations [19,28] using the JCS [30]. This involves a specific sequence of cardanic angles in which the proximal segment was considered as the reference and the distal one moved relative to it.…”

“…This sequence defines a specific system of axes presented in Figure 2. In this configuration, the distal local coordinate system is first assumed to be coincident with the proximal coordinate system [30]. Then, the distal segment rotates successively around three axes to its final orientation: -the first movement is a rotation of an angle θ 1 around the common Y axis (Y d = Y p ); it corresponds to the flexion/extension of the joint; -then the distal segment rotates with an angle θ 2 around the rotated X', called the floating axis [30], which is at each time orthogonal with the two extreme axes; it simulates the collateromotion of the joint; -the final rotation is of an angle θ 3 around the twice-rotated axis Z'' (corresponding to Z d in its final position); it corresponds to the axial rotation of the joint.…”

“…First, translations are difficult to define precisely by the kinematics [11], as they are generally very small and prone to be hidden by experimental artefacts and errors [28]. Second, rotations are independent of the choice of the base point, but the magnitude of the translation vector, and hence its components, depends upon where the reference points are located in each bone [30]. This implies that the external coordinate systems cannot be directly used to compute the translations but should be re-located at a specific point of the bones.…”