Joint-afferent-mediated muscle activations yield a near-maximum torque response of the quadriceps.
Joint-afferent-mediated muscle activations yield a near-maximum torque response of the quadriceps.
复制标题
关节传入介导的肌肉激活产生股四头肌接近最大的扭矩响应。
DOI：
10.1016/j.jneumeth.2003.09.014
复制
发表时间：
2004
影响因子：
3
通讯作者：
Dhaher,YasinY
中科院分区：
文献类型：
--
作者：
Dhaher,YasinY
我们实验室以前的工作表明，反射活动是由人类膝关节的大（>5°）（非生理性）外展角扰动系统地诱发在许多主要膝关节肌肉中。这种反射作用被证明是源于关节周围组织传入。此外，它被证明，特定的肌肉激活模式存在于膝关节肌肉与优先激活内侧肌肉响应于外侧扰动。本研究探讨的假设，在响应机械刺激，这些传入的结果，提供最大的阻力矩由膝关节肌肉的激活模式介导的感觉信息。进一步假设，仅通过选择性激活内侧肌肉不能实现这种接近最大阻力。为了研究这一点，以前报道的机械诱导反射EMG激活模式，随机3D肌肉骨骼髌股关节模型，并从选择性电刺激实验的新数据被使用。使用该模型，膝关节内收-外展力矩响应于在膝关节处施加的外展载荷，计算每个可能的随机股四头肌活动集。然后将这些内收力矩与使用机械诱导的肌肉激活模式时由模型计算的内收力矩进行比较。这里提供的数据表明，选择性激活内侧肌肉单独将导致外展力矩，无论膝关节屈曲角度。此外，这项研究的结果显示，记录的肌肉活动组合提供了股四头肌抵抗外部施加的外展刺激的接近最大的能力。得出的结论是，在外展方向的稳定只能通过一个控制策略，涉及在膝关节内侧和外侧肌肉的激活。它还得出结论，这种控制策略是接近最佳的联合传入介导时。
Previous work from our laboratory has shown that reflex activity is systematically evoked in a number of major knee muscles by large (>5°) (non-physiological) abduction angular perturbations of the human knee. This reflex action was shown to originate from periarticular tissue afferents. Furthermore, it was demonstrated that specific muscle activation patterns exist in knee muscles with preferential activation in medial muscles in response to the lateral perturbations. This study examines the hypothesis that in response to the mechanical stimulus, the sensory information mediated by these afferents results in activation patterns that provide the largest resisting moment by the knee muscles. It is further hypothesized that this near maximum resistance cannot be achieved by the selective activation of medial muscles alone. To examine this, the previously reported mechanically induced reflex EMG activation patterns, a stochastic 3D musculoskeletal patello-femoral joint model, and new data from selective electrical stimulation experiments were used. Using the model, the knee adduction–abduction moment in response to an applied abduction load at the knee joint for every possible random set of quadriceps activity was computed. These adduction moments were then compared to the adduction moment computed by the model when the mechanically induced muscle activation patterns were used. The data presented here illustrated that selective activation of a medial muscle alone would result in an abduction moment, regardless of the knee flexion angle. Furthermore, the findings of this study revealed that the recorded combinations of muscle activity provide a near maximum capability of the quadriceps muscles to resist externally applied abducting stimuli. It was concluded that stabilization in the abduction direction could only be achieved by a control strategy that involves activation of both medial and lateral muscles at the knee. It was also concluded that this control strategy was near optimal when mediated by joint afferents.