MUSCLE FUNCTION IN DEFORMED AND SURGICALLY ALTERED LIMBS

描述(改编自申请人的摘要)：长期目标 本工作旨在为临床治疗蹲姿提供科学依据。 痉挛双瘫患者中最常见的运动异常。 蹲姿的特点是膝关节持续屈曲，这是 通常伴随着关节过度屈曲、内收和内旋 臀部。这是一种效率极低的移动方式；如果不是 矫正后往往会导致关节退变。尽管外科手术，如： (I)延长腿筋；。(Ii)股骨转位；及。(Iii) 经常进行股直肌移位术，以尝试 改善肌肉骨骼功能，这些手术的结果是 不可预测，往往令人不满意，给患者留下了严重的， 终生的身体缺陷。这项工作的目的是开发 生物力学模型解释蹲下步态的原因并预测 常用手术治疗的功能后果。 目的#1将检查膝关节过度屈曲的原因。基于 初步数据显示，据推测，许多具有蹲姿的人 具有正常行走所需的足够长度的腿筋。这一假设 将通过估计正常和正常情况下腿筋的长度进行测试 使用详细的肌肉骨骼模型结合 测量了关节的三维运动学。这一分析可以使 需要制定更合理的基础来决定谁应该和不应该， 把腿筋拉长。目标2将检查原因和纠正 髋关节过度内旋的症状。旋转力矩臂 横跨臀部的肌肉将根据量化确定 解剖研究和构建的三维计算机模型 磁共振图像。计算机模型将被用来分析 股骨畸形和去旋截骨术对股骨近端骨折的影响 肌肉的旋转功能。这一分析旨在揭示 恢复正常肢体旋转的最佳方法。目标#3将比较 股直肌移位后受试者的测量结果 手术的计算机模拟。这项研究还将确定 受试者将股直肌移转后作为屈膝肌 在膝盖后面。申请人建议，虽然多关节 运动异常，如蹲下的步态异常复杂， 对正常人肌肉功能定量描述的发展， 这里提出的畸形和外科手术改变的四肢是一个重要的 也是设计更有效的治疗方法的必要的第一步。

DESCRIPTION (Adapted from the Applicant's Abstract): The long-term goal of this work is to provide a scientific basis for treating crouch gait, the most common movement abnormality among persons with spastic diplegia. Crouch gait is characterized by persistent flexion of the knee, which is usually accompanied by excessive flexion, adduction and internal rotation of the hip. It is an extremely inefficient means of locomotion; if not corrected it often leads to joint degeneration. Although surgeries such as: (i) lengthening of the hamstrings; (ii) derotation of the femur; and (iii) transfer of the rectus femoris are frequently performed in an attempt to improve musculoskeletal function, the outcomes of these surgeries are unpredictable and often unsatisfactory, leaving patients with serious, life-long physical limitations. The purpose of this work is to develop biomechanical models that explain the causes of crouch gait and predict the functional consequences of commonly used surgical treatments. Aim #1 will examine the causes of excessive knee flexion. Based on preliminary data, it is hypothesized that many persons with crouch gait have hamstrings that are of adequate length for normal walking. This hypothesis will be tested by estimating the lengths of the hamstrings during normal and crouch gait using detailed musculoskeletal models in conjunction with measured three-dimensional joint kinematics. This analysis may enable a more rational basis to be developed for deciding who should, and should not, have hamstring lengthening. Aim #2 will examine the causes and corrections of excessive internal rotation of the hip. The rotational moment arms of the muscles crossing the hip will be determined based on quantitative anatomical studies and three dimensional computer models constructed from magnetic resonance images. The computer models will be used to analyze the effects of femoral deformities and derotational osteotomies on the rotational function of the muscles. This analysis is intended to reveal the best means to restore normal limb rotation. Aim #3 will compare measurements taken from subjects after transfer of the rectus femoris to a computer simulation of the surgery. This study will also determine if subjects use the rectus femoris as a knee flexor after it is transferred behind the knee. It is suggested by the applicant that although multijoint movement abnormalities such as crouch gait are exceptionally complex, the development of quantitative descriptions of muscle function in normal, deformed, and surgically altered limbs, as proposed here, is an important and necessary first step toward designing more effective treatments.