Meyer Peter F, Oddsson Lars I E, De Luca Carlo J
Injury Analysis and Prevention Laboratory, Neuromuscular Research Center, Boston University, 19 Deerfield Street, Boston, MA 02215, USA.
Exp Brain Res. 2004 Aug;157(4):526-36. doi: 10.1007/s00221-004-1868-3. Epub 2004 Mar 17.
There is considerable evidence that lower-limb somatosensation contributes to the control of upright balance. In this study, we investigated the specific role of foot sole cutaneous afferents in the generation of balance corrections following lateral accelerations of the support surface. Participants were subjected to balance perturbations before and after targeted anesthesia of the cutaneous soles induced by intradermal injections of local anesthetic. Subject responses were quantified in terms of net joint torques at the ankles, hips and trunk. Contrary to the conclusions drawn in earlier studies, response torque impulses at the ankles and hips were clearly scaled with the perturbation impulse under both control and anesthetized conditions. Reduced plantar sensitivity produced a relative shift in compensatory torque production from the ankles and trunk to the hips. These findings demonstrate that plantar cutaneous afferents play an important role in the shaping of dynamic postural responses. Furthermore, the results suggest that loss of plantar sensation may be an important contributor to the dynamic balance deficits and increased risk of falls associated with peripheral neuropathies.
有大量证据表明下肢躯体感觉有助于维持直立平衡的控制。在本研究中，我们调查了足底皮肤传入神经在支撑面横向加速后平衡校正产生过程中的具体作用。在皮内注射局部麻醉剂诱导足底皮肤产生针对性麻醉之前和之后，让参与者接受平衡扰动。根据脚踝、髋部和躯干处的净关节扭矩对受试者的反应进行量化。与早期研究得出的结论相反，在对照和麻醉条件下，脚踝和髋部的反应扭矩冲动均明显与扰动冲动成比例。足底敏感性降低导致补偿性扭矩产生从脚踝和躯干相对转移至髋部。这些发现表明足底皮肤传入神经在动态姿势反应的形成中发挥重要作用。此外，结果表明足底感觉丧失可能是导致动态平衡缺陷以及与周围神经病变相关的跌倒风险增加的重要因素。
