ROLE OF JOINT AFFERENTS IN KNEE MEDIO-LATERAL STABILITY

我们建议研究关节传入在促进人膝关节内外侧稳定性中的作用。保持关节稳定性对于预防软骨损伤和骨性关节炎是必要的。关节稳定性归因于五个因素：骨和软骨接触力，韧带和关节囊刚度，固有刚度，固有刚度和主动肌肉，以及反射性调节肌肉刚度。反过来，反射作用可能由肌肉拉伸感受器或关节周围组织传入(韧带和关节囊)来调节。后一类反射在关节内翻/外翻负荷异常的情况下，通过肌肉激活来潜在地保护关节。我们假设，对人类膝关节施加机械内翻/外翻刺激可以引起针对性肌肉收缩，这些反应显著增加了关节在内翻/外翻平面上的僵硬程度。将在35名受试者中确定个人膝关节肌肉活动的量化测量。我们将使用肌肉内电极来选择性地刺激横跨膝盖的肌肉，一个6自由度的称重单元将测量产生的运动。对于相同的受试者群体，将通过伺服马达在受试者膝部施加快速内翻/外翻位置扰动。在机械扰动期间，将记录所有受试者的肌肉活动和膝关节主要肌肉的反射反应。根据飞行员的数据，我们认为，导致关节韧带拉伸的机械扰动将在横跨膝关节的肌肉中产生反射反应，这些反射可以被组织成选择性地补偿内翻或外翻的负荷，这些反射的组织可以选择性地补偿内翻和外翻的负荷。为了改善反射调节肌肉收缩带来的僵硬程度，在神经阻断前后，对所有35名受试者的膝关节进行伪随机内翻/外翻扰动。关节刚度和阻尼系数将使用线性模型进行估计。由关节周围传入神经传递的反射刚度将被计算为在有和没有神经阻断的情况下计算的关节刚度的差异。我们认为膝关节关节周围组织中的拉伸感受器在促进关节中外侧稳定性方面发挥着重要作用，我们进一步预计，有关神经和机械部件之间相互作用的信息将对训练如何提高关节整体稳定性产生重大影响。通过物理疗法对关节的神经成分进行重新编程，可能有助于弥补关节松弛导致的韧带功能丧失，从而限制OA的进展速度。

We propose to study the role of joint afferents in promoting medio- lateral stability of the human knee joint Preservation of joint stability is necessary to prevent cartilage damage and osteoarthritis. Joint stability has been attributed to five factors: bone and cartilage contact forces, ligament and capsule stiffness, intrinsic stiffness, intrinsic stiffness and active muscles, and reflexively mediated muscle stiffness.. Reflex action may, in turn, be mediated either by muscle stretch receptors or by periarticular tissue afferents (ligaments and capsule). The latter class of reflexes potentially protects the joint through muscle activation in situations of abnormal varus/valgus loading of the joint. We hypothesize that targeted muscle contractions can be elicited by the application of a mechanical varus/valgus stimulus to the human knee, and that these responses significantly increase the joint's stiffness in the varus/valgus plane. Quantitative measures of individual knee muscle action will be determined in 35 subjects. We will use intramuscular electrodes to selectivity stimulate muscles traversing the knee, and a 6-degree of freedom load cell will measure the movements produced. For the same subject population, a rapid varus/valgus positional perturbation will be applied at the subject knee via a servomotor. During the mechanical perturbation, muscle activity will be recorded and the reflex responses in major knee muscles recorded in all subjects. Based on pilot data, we believe that mechanical perturbations resulting in the stretching of joint ligaments will produce a reflex response in muscle traversing the knee joint, and that these reflexes may be organized so as to compensate selectively for varus or valgus loading, and that these reflexes may be organized so as to compensate selectively for varus and valgus loading. To quality the stiffness contributed by reflexively mediated muscle contractions, a pseudo-random varus/valgus perturbation will be applied to the knees of all 35 subjects before and after nerve blockade. Joint stiffness and damping coefficients will be estimated using linear models. The reflex stiffness mediated by periarticular afferents will be calculated to be the difference in the computed joint stiffness with and without the neural blockade. We believe that stretch receptors in periarticular tissues of the knee joint play a major role in promoting joint media-lateral stability, and we further expect that information about the interaction between neurological and mechanical components will have a major impact on how training may improve overall joint stability. Reprogramming the neural component of the joint by physiotherapy may help substitute the loss of function of ligaments induced by joint laxity and thus limit the rate of OA progression.