Li Xin, Lo Wai Leung Ambrose, Lu Song-Wei, Liu Howe, Lin Ke-Yu, Lai Jian-Yang, Li Le, Wang Chu-Huai
Department of Rehabilitation Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510080, China.
Department of Physical Therapy, University of North Texas Health Science Center, Fort Worth, TX, 76101, USA.
BMC Musculoskelet Disord. 2020 Aug 22;21(1):569. doi: 10.1186/s12891-020-03565-y.
Pressure biofeedback unit (PBU) is a widely used non-invasive device to assist core muscle training by providing pressure feedback. The aim this study was to compare the muscle activities of transverse abdominis (TA) and multifidus (MF) at different target pressures (50, 60 and 70 mmHg) of PBU between individuals with and without cLBP.
Twenty-two patients with chronic LBP (cLBP) and 24 age matched healthy individuals were recruited. Electromyography (EMG) signals were recorded from the TA and MF muscles while the TA and MF were contracted to achieve PBU pressure value of 50, 60 and 70 mmHg in random order. The average EMG amplitude (AEMG) of 3 replicate trials was used in the analysis after normalization to %MVIC. %MVIC is defined as the mean of the three AEMG divided by the AEMG of MVIC. Two-way ANOVA was performed to assess the effects of groups (healthy and cLBP) and the three different target pressures of PBU. Independent sample t-test was conducted to compare between the two groups. Spearman's correlation analysis was performed in the cLBP group to determine potential correlations between EMG activity, NPRS and ODI.
The %MVIC of the TA and MF in the cLBP group were higher than the control group at each pressure value (P<0.05). During maximal voluntary isometric contraction (MVIC) of TA and MF, compared with healthy groups, cLBP subjects showed a decrease (TA mean = 47.61 μV; MF mean = 42.40 μV) in EMG amplitudes (P ≤ 0.001). The MVIC of MF was negatively correlated with Numerical Pain Rating Scale (r = - 0.48, P = 0.024) and Oswestry Disability Index (r = - 0.59, P = 0.004).
We measured the trunk muscles activities at different PBU pressure values, which allows the individual to estimate trunk muscle contraction via PBU. Clinicians may be able to confer the data obtained through EMG recordings to adjust the exercise intensity of PBU training accordingly.
压力生物反馈装置（PBU）是一种广泛使用的非侵入性设备，通过提供压力反馈来辅助核心肌肉训练。本研究的目的是比较有和没有慢性下腰痛（cLBP）的个体在PBU不同目标压力（50、60和70 mmHg）下腹横肌（TA）和多裂肌（MF）的肌肉活动。
招募了22名慢性下腰痛患者（cLBP）和24名年龄匹配的健康个体。在TA和MF收缩以随机顺序达到50、60和70 mmHg的PBU压力值时，记录TA和MF肌肉的肌电图（EMG）信号。在归一化为%MVIC后，分析3次重复试验的平均EMG振幅（AEMG）。%MVIC定义为三个AEMG的平均值除以MVIC的AEMG。进行双向方差分析以评估组（健康和cLBP）和PBU的三种不同目标压力的影响。进行独立样本t检验以比较两组之间的差异。在cLBP组中进行Spearman相关性分析，以确定EMG活动、数字疼痛评分量表（NPRS）和Oswestry功能障碍指数（ODI）之间的潜在相关性。
在每个压力值下，cLBP组中TA和MF的%MVIC均高于对照组（P<0.05）。在TA和MF的最大自主等长收缩（MVIC）期间，与健康组相比，cLBP受试者的EMG振幅降低（TA平均值=47.61μV；MF平均值=42.40μV）（P≤0.001）。MF的MVIC与数字疼痛评分量表（r=-0.48，P=0.024）和Oswestry功能障碍指数（r=-0.59，P=0.004）呈负相关。
我们测量了不同PBU压力值下的躯干肌肉活动，这使个体能够通过PBU估计躯干肌肉收缩。临床医生或许能够利用通过EMG记录获得的数据来相应地调整PBU训练的运动强度。
