Exercise Science and Applied Biomechanics, Department of Computer Science - Therapy Sciences, Trier University of Applied Sciences, Trier, Germany; University Outpatient Clinic, Sports Medicine & Sports Orthopaedics, University of Potsdam, Potsdam, Germany.
School of Sport, Exercise and Rehabilitation Sciences, Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom; Centro de Investigacion en Fisiologia del Ejercicio (CIFE), Universidad Mayor, Santiago, Chile.
J Biomech. 2020 Mar 26;102:109646. doi: 10.1016/j.jbiomech.2020.109646. Epub 2020 Jan 16.
Persons with low back pain (LBP) exhibit delayed trunk muscle onset and increased co-contractions as a response to quasi-static and dynamic sudden trunk loading in comparison to back-healthy controls. Although LBP is more prevalent in females, sex-specific responses have not been well documented. Therefore, the purpose was to explore sex-specific neuromuscular differences, to gait perturbation, in LBP patients. Twenty-nine LBP patients (12m/17f;31 ± 10yrs; 174 ± 12 cm; 71 ± 16 kg) walked on a split-belt treadmill at 1 m/s, while 15 right-sided random perturbations (treadmill-belt decelerating, 40 m/s, 50 ms duration; 200 ms after heel contact) were applied. Muscle activity was assessed using a 12-lead surface EMG (6 back/6 abdominal muscles; 4000 Hz). EMG-RMS [%] (0-200 ms after perturbation) was calculated and normalized to RMS of unperturbed gait for each muscle. Furthermore, muscle onsets (ms) were determined. Two-way ANOVA (factors: sex/muscle) was applied to account for sex differences in main outcomes. EMG-RMS (amplitudes; mean) ranged from 356% to 901% in males and 349% to 694% in females representing a significant interaction effect (sex * muscle: p = 0.017). Post-hoc analysis revealed significant differences for EMG-RMS analysis of rectus abdominis left (p = 0.043; f > m) as well as obliques externus right/left (p = 0.018/p = 0.005; f < m). In the time domain, females showed overall, shorter (mean: 90 ± 16 ms) response times compared to males (mean: 98 ± 22 ms, sex effect: p < 0.0001). In this LBP population, abdominal muscle activation discriminated females from males. Specifically, females had higher activity of the rectus abdominis muscles and lower activation of the externus oblique muscles. These different activation strategies might be relevant to the development of sex-specific intervention strategies.
腰痛（LBP）患者在应对准静态和动态突然躯干负荷时，与背部健康对照组相比，躯干肌肉起始延迟，并出现协同收缩增加。尽管 LBP 在女性中更为普遍，但尚未很好地记录性别特异性反应。因此，目的是探索 LBP 患者的性别特异性神经肌肉差异，以了解步态干扰。29 名 LBP 患者（12 名男性/17 名女性；31±10 岁；174±12cm；71±16kg）在 1m/s 的分带跑步机上行走，同时施加 15 个右侧随机扰动（跑步机带减速，40m/s，50ms 持续时间；在跟骨接触后 200ms）。使用 12 导联表面肌电图（6 个背部/6 个腹部肌肉；4000Hz）评估肌肉活动。计算肌电图 RMS[％]（在扰动后 0-200ms），并将其归一化为每个肌肉未受扰步态的 RMS。此外，确定肌肉起始（ms）。应用双因素方差分析（因素：性别/肌肉）来解释主要结果中的性别差异。男性的肌电图 RMS（幅度；平均值）范围为 356%至 901%，女性为 349%至 694%，这表明存在显著的交互效应（性别*肌肉：p=0.017）。事后分析显示，左侧腹直肌（p=0.043；f>m）和右侧/左侧外斜肌（p=0.018/p=0.005；f<m）的肌电图 RMS 分析存在显著差异。在时域中，女性的反应时间总体上比男性短（平均值：90±16ms）（性别效应：p<0.0001）。在这个 LBP 人群中，腹部肌肉激活可将女性与男性区分开来。具体来说，女性的腹直肌活动较高，外斜肌活动较低。这些不同的激活策略可能与性别特异性干预策略的发展有关。
