Bochkezanian Vanesa, Newton Robert U, Trajano Gabriel S, Vieira Amilton, Pulverenti Timothy S, Blazevich Anthony J
Department of Exercise and Health Sciences, School of Health, Medical and Applied Sciences, Central Queensland University, Building 34.1.02, Bruce Highway, North Rockhampton, Qld, 4702, Australia.
Exercise Medicine Research Clinic, Edith Cowan University, Perth, Australia.
BMC Neurol. 2018 Feb 13;18(1):17. doi: 10.1186/s12883-018-1020-9.
Neuromuscular electrical stimulation (NMES) is commonly used in skeletal muscles in people with spinal cord injury (SCI) with the aim of increasing muscle recruitment and thus muscle force production. NMES has been conventionally used in clinical practice as functional electrical stimulation (FES), using low levels of evoked force that cannot optimally stimulate muscular strength and mass improvements, and thus trigger musculoskeletal changes in paralysed muscles. The use of high intensity intermittent NMES training using wide-pulse width and moderate-intensity as a strength training tool could be a promising method to increase muscle force production in people with SCI. However, this type of protocol has not been clinically adopted because it may generate rapid muscle fatigue and thus prevent the performance of repeated high-intensity muscular contractions in paralysed muscles. Moreover, superimposing patellar tendon vibration onto the wide-pulse width NMES has been shown to elicit further increases in impulse or, at least, reduce the rate of fatigue in repeated contractions in able-bodied populations, but there is a lack of evidence to support this argument in people with SCI.
Nine people with SCI received two NMES protocols with and without superimposing patellar tendon vibration on different days (i.e. STIM and STIM+vib), which consisted of repeated 30 Hz trains of 58 wide-pulse width (1000 μs) symmetric biphasic pulses (0.033-s inter-pulse interval; 2 s stimulation train; 2-s inter-train interval) being delivered to the dominant quadriceps femoris. Starting torque was 20% of maximal doublet-twitch torque and stimulations continued until torque declined to 50% of the starting torque. Total knee extensor impulse was calculated as the primary outcome variable.
Total knee extensor impulse increased in four subjects when patellar tendon vibration was imposed (59.2 ± 15.8%) but decreased in five subjects (- 31.3 ± 25.7%). However, there were no statistically significant differences between these sub-groups or between conditions when the data were pooled.
Based on the present results there is insufficient evidence to conclude that patellar tendon vibration provides a clear benefit to muscle force production or delays muscle fatigue during wide-pulse width, moderate-intensity NMES in people with SCI.
ACTRN12618000022268 . Date: 11/01/2018. Retrospectively registered.
神经肌肉电刺激（NMES）常用于脊髓损伤（SCI）患者的骨骼肌，目的是增加肌肉募集，从而提高肌肉力量产生。NMES传统上在临床实践中作为功能性电刺激（FES）使用，采用低水平的诱发力，无法最佳地刺激肌肉力量和质量的改善，因此无法引发瘫痪肌肉的肌肉骨骼变化。使用宽脉冲宽度和中等强度的高强度间歇性NMES训练作为一种力量训练工具，可能是增加SCI患者肌肉力量产生的一种有前景的方法。然而，这种方案尚未在临床上采用，因为它可能会导致快速的肌肉疲劳，从而阻碍瘫痪肌肉中重复高强度肌肉收缩的进行。此外，在健全人群中，将髌腱振动叠加到宽脉冲宽度的NMES上已被证明能进一步增加冲动，或者至少降低重复收缩中的疲劳率，但在SCI患者中缺乏支持这一观点的证据。
9名SCI患者在不同日期接受了两种NMES方案，一种是叠加髌腱振动（即STIM+vib），另一种不叠加（即STIM），两种方案均包括向优势股四头肌重复施加30Hz的58个宽脉冲宽度（1000μs）对称双相脉冲序列（脉冲间期0.033秒；刺激序列2秒；序列间期2秒）。起始扭矩为最大双波抽搐扭矩的20%，刺激持续到扭矩下降至起始扭矩的50%。计算总膝伸肌冲动作为主要结局变量。
叠加髌腱振动时，4名受试者的总膝伸肌冲动增加（59.2±15.8%），而5名受试者的总膝伸肌冲动减少（-31.3±25.7%）。然而，将这些亚组之间或合并数据后的不同条件之间进行比较，均未发现统计学上的显著差异。
基于目前的结果，没有足够的证据得出结论，即对于SCI患者，在宽脉冲宽度、中等强度的NMES过程中，髌腱振动能为肌肉力量产生带来明显益处或延迟肌肉疲劳。
ACTRN12618000022268。日期：2018年1月11日。回顾性注册。
