Biomechanical Analysis of Joint Movement

1. 一种利用磁源和传感器的个人计算机系统已被开发用于测量关节运动的三维平移和旋转。八通道肌电图与该系统相结合，以检查关节运动与运动中涉及的肌肉活动之间的关系。联合系统对上肢运动的分析表明：(1)随着上肢额面外展和矢状面抬高，前、中、后三角肌的活动逐渐增加；(2)随着上肢从最大屈曲位置水平伸展，中、后三角肌、肱二头肌分支和冈上肌的活动增加。在关节运动学领域，临床术语如内-外旋转或内-外侧旋转通常用于表示身体部分围绕其自身长轴的旋转。然而，这些术语并不是严格的机械意义上的定义。为了避免轴向旋转的模糊性，提出了轴向旋转的新的数学定义，并给出了由实测欧拉角计算轴向旋转的方法。该定义是基于角速度矢量的分量的积分投影到身体部分的长轴上。著名的柯德曼悖论可以用这个定义来解决。这个定义已被推广到给出当两个体段在三维空间中运动时，一个体段相对于另一个体段的相对轴向旋转。瞬时旋转中心（ICR）是描述刚体平面运动的基本量，可用于分析解剖关节运动。传统的ICR计算方法对位置测量误差很敏感，因此可靠的ICR数据很少报道。通过采用光敏半导体传感器和平滑技术以及改进实验条件，我们将ICR的总体误差降低到<正负>.3 mm。颞下颌关节运动的ICR测量较少

1. A personal computer system using magnetic sources and sensors has been developed to measure three-dimensional translations and rotations of joint movement. Eight-channel electromyograph has been combined with the system to examine relationships between joint movement and the muscle activities involved in the movement. Analysis of the motion of the upper limb by the combined system has shown that (1) activities in the anterior, middle and posterior deltoids gradually increase as the upper limb is elevated in abduction in the frontal plane and in elevation in the sagittal plane and that (2) activities in the middle and posterior deltoid, the biceps brach and the supraspinatus increase as the upper limb is extended from the maximally flexed position in horizontal extension.2. In the field of joint kinematics, clinical terms such as internal-external, or medial-lateral, rotations are commonly used to express the rotation of a body segment about its own long axis. However, these terms ar … More e not defined in a strict mechanical sense. A new mathematical definition of axial rotation has been proposed to avoid vagueness, and methods to calculate it from the measured Euler angles have been given. The definition is based on the integration of the component of the angular velocity vector projected onto the long axis of the body segment. The well-known Codman's paradox can be solved using the definition. This definition has been generalized to give the relative axial rotation of one body segment with respect to another body segment when the two segments are moving in the 3-dimensional space.3. The instantaneous center of rotation (ICR) is a basic quantity for describing planar motion of rigid bodies and useful for analysis of anatomical joint motion. The conventional methods for calculating ICR have been sensitive to measurement error in position so that few reliable ICR data have been reported. We have reduced the overall error in ICR to <plus-minus> 3 mm by employing photo-sensitive semiconductor sensors and smoothing technique and improving experimental conditions. ICR of temporomandibular joint motion has been measure Less