Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany.
Eur J Appl Physiol. 2012 Nov;112(11):3829-38. doi: 10.1007/s00421-012-2364-2. Epub 2012 Mar 6.
Peripheral neuropathy is the most common long-term complication in diabetes and is involved in changes in diabetic gait and posture. The regression of nerve function leads to various deficits in the sensory and motor systems, impairing afferent and efferent pathways in the lower extremities. This study aimed to examine how reduced plantar-afferent feedback impacts the gait pattern. Cutaneous sensation in the soles of both feet was experimentally reduced by means of intradermal injections of an anaesthetic solution, without affecting foot proprioception or muscles. Ten subjects performed level walking at a controlled velocity before and after plantar anaesthesia. Muscle activity of five leg-muscles, co-contraction ratios for the knee and ankle joint, ground reaction forces (GRF), spatiotemporal characteristics, joint angles and moments of the hip, knee and ankle were analysed. The intervention significantly lowered plantar sensation, reducing it to the level of sensory neuropathy. Spatiotemporal gait characteristics remained unchanged. The ankle joint was more dorsiflexed which coincided with increased tibialis anterior and decreased gastrocnemius medialis muscle activity during foot flat to mid-stance. In addition, the knee joint was more flexed accompanied by increased biceps femoris activity and higher internal knee-extension moment. With regard to gait dynamics, a delay of the first peak of the vertical GRF was observed. Increased soleus and tibialis anterior muscle activity were found during the end of stance. Short-term loss of plantar sensation affects lower-limb kinematics and gait dynamics, particularly during the first half of stance, and contributes to modified muscle-activation patterns during locomotion.
周围神经病变是糖尿病最常见的长期并发症，与糖尿病步态和姿势的变化有关。神经功能的衰退导致感觉和运动系统的各种缺陷，损害下肢的传入和传出通路。本研究旨在探讨足底传入反馈减少如何影响步态模式。通过在脚底皮内注射麻醉溶液来实验性地降低足底感觉，而不影响足部本体感觉或肌肉。十位受试者在足底麻醉前后以控制速度进行水平行走。分析了五个腿部肌肉的肌肉活动、膝关节和踝关节的共同收缩比、地面反作用力 (GRF)、时空特征、髋关节、膝关节和踝关节的关节角度和力矩。干预措施显著降低了足底感觉，使其降低到感觉神经病变的水平。步态的时空特征保持不变。踝关节背屈增加，与足平到中足时胫骨前肌和腓肠肌内侧活动减少相吻合。此外，膝关节更弯曲，伴随着股二头肌活动增加和更高的内侧膝伸力矩。就步态动力学而言，观察到垂直 GRF 的第一个峰值延迟。在站立末期发现比目鱼肌和胫骨前肌的活动增加。足底感觉的短期丧失会影响下肢运动学和步态动力学，特别是在站立的前半部分，并导致运动时肌肉激活模式的改变。
