Stance controlled knee flexion improves stimulation driven walking after spinal cord injury
Stance controlled knee flexion improves stimulation driven walking after spinal cord injury
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DOI：
10.1186/1743-0003-10-68
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发表时间：
2013-07-04
影响因子：
5.1
通讯作者：
Triolo, Ronald J.
中科院分区：
文献类型：
--
作者：
Bulea, Thomas C.;Kobetic, Rudi;Triolo, Ronald J.
背景资料：功能性神经肌肉刺激（FNS）通过以协调的方式电激活肌肉来恢复脊髓损伤瘫痪后的行走功能。将FNS与可控矫形器组合以创建混合神经假体（HNP），通过在站立期间机械锁定膝关节以允许膝伸肌在刺激关闭的情况下休息，具有延长步行距离和时间的潜力。最近的努力集中在创建先进的HNP，其耦合关节运动（例如，关节运动）。例如，在一个实施例中，髋关节和膝关节或膝关节和踝关节），以改善关节协调在摆动阶段，而保持僵硬的腿在stance phase.Methods：本研究的目的是调查纳入stance控制膝关节屈曲在负载响应和摆动前阶段恢复步态的影响。HNP中的膝关节控制通过专门设计的可变阻抗膝关节机构（VIKM）实现。入组了1例T7节段脊髓损伤的受试者，并将其作为自己的对照，检查两种技术以恢复水平地面行走：仅FNS（在站立期间保持膝关节僵硬）和VIKM-HNP（在站立期间允许控制膝关节运动）。两种技术的刺激模式驱动的步行运动保持不变，唯一的区别是，膝伸肌刺激是恒定的，在立场与FNS只有和调制与VIKM一起控制膝盖运动在立场与VIKM-HNP.Results：立场相膝关节角度更自然在VIKM-HNP步态，而膝盖过伸坚持在僵硬的腿FNS只有步行。在负载响应阶段，垂直地面反作用力较少脉冲和瞬时步态速度增加与VIKM-HNP，这表明，膝关节屈曲有助于重量转移到领先的肢体。增强膝关节屈曲在前摆动阶段也有助于屈曲在摆动过程中，特别是当对刺激的反应compromised.Conclusions：这些结果显示了潜在的优势，将立场控制膝关节屈曲到一个混合神经假体行走。将这种控制添加到FNS驱动行走还可以实现非水平行走任务，例如不平坦地形、斜坡导航和楼梯下降，其中在负重期间受控的膝关节屈曲是至关重要的。
Background: Functional neuromuscular stimulation (FNS) restores walking function after paralysis from spinal cord injury via electrical activation of muscles in a coordinated fashion. Combining FNS with a controllable orthosis to create a hybrid neuroprosthesis (HNP) has the potential to extend walking distance and time by mechanically locking the knee joint during stance to allow knee extensor muscle to rest with stimulation turned off. Recent efforts have focused on creating advanced HNPs which couple joint motion (e. g., hip and knee or knee and ankle) to improve joint coordination during swing phase while maintaining a stiff-leg during stance phase.Methods: The goal of this study was to investigate the effects of incorporating stance controlled knee flexion during loading response and pre-swing phases on restored gait. Knee control in the HNP was achieved by a specially designed variable impedance knee mechanism (VIKM). One subject with a T7 level spinal cord injury was enrolled and served as his own control in examining two techniques to restore level over-ground walking: FNS-only (which retained a stiff knee during stance) and VIKM-HNP (which allowed controlled knee motion during stance). The stimulation pattern driving the walking motion remained the same for both techniques; the only difference was that knee extensor stimulation was constant during stance with FNS-only and modulated together with the VIKM to control knee motion during stance with VIKM-HNP.Results: Stance phase knee angle was more natural during VIKM-HNP gait while knee hyperextension persisted during stiff-legged FNS-only walking. During loading response phase, vertical ground reaction force was less impulsive and instantaneous gait speed was increased with VIKM-HNP, suggesting that knee flexion assisted in weight transfer to the leading limb. Enhanced knee flexion during pre-swing phase also aided flexion during swing, especially when response to stimulation was compromised.Conclusions: These results show the potential advantages of incorporating stance controlled knee flexion into a hybrid neuroprosthesis for walking. The addition of such control to FNS driven walking could also enable non-level walking tasks such as uneven terrain, slope navigation and stair descent where controlled knee flexion during weight bearing is critical.