Poznan University of Physical Education, Department of Neuromuscular Physiotherapy, Poznan, Poland.
Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Department of Motor Control, Sofia, Bulgaria.
Acta Neurobiol Exp (Wars). 2024 Jun 27;84(2):191-202. doi: 10.55782/ane-2024-2584.
Some evidence indicates that lower back muscles located at the non‑dominant side of the body are more fatigue resistant than their opposite counterparts presumably due to preferential use of the dominant hand. The aim of the study was to determine if any distinction exists in the surface electromyographic activity of corresponding contralateral non‑fatigued lumbar multifidus (LM) muscles as a function of hand dominance. The relative to maximum root mean square, the median frequency (MdF) and spike shape parameters were computed from the surface myoelectric signals of ipsilateral and contralateral lumbar multifidus muscle of 46 adult healthy subjects (27 right‑handed, 19 left‑handed) during voluntary contractions evoked by the single arm lifts in prone position. Activation of LM as a contralateral muscle to lifted arm was greater than as ipsilateral muscle, independently of handedness. Regardless if LM performed ipsi‑ or contralateral action to the lifted arm, the mean spike amplitude, slope, number of peaks per spike and spike duration were greater and mean spike frequency as well as MdF were smaller in the muscle of dominant than non‑dominant side. Combined changes of spike shape measures indicate increased recruitment, lower firing rates and higher synchronization of motor units in the LM of dominant side as compared to its counterpart.
一些证据表明，身体非优势侧的下背部肌肉比其对侧肌肉更能抵抗疲劳，这可能是由于惯用手的优先使用。本研究的目的是确定在惯用手的影响下，非疲劳状态下相应对侧腰椎多裂肌（LM）的表面肌电活动是否存在差异。从 46 名成年健康受试者（27 名右利手，19 名左利手）的同侧和对侧腰椎多裂肌的表面肌电信号中计算出相对最大均方根、中值频率（MdF）和尖峰形状参数，在俯卧位单臂抬起时进行自主收缩。作为对侧肌肉，LM 的激活大于同侧肌肉，与惯用手无关。无论 LM 是作为对侧肌肉还是同侧肌肉参与手臂抬起，优势侧肌肉的平均尖峰幅度、斜率、每个尖峰的峰值数和尖峰持续时间较大，而尖峰频率和 MdF 较小。尖峰形状测量的综合变化表明，与对侧相比，优势侧 LM 中的运动单位募集增加、放电频率降低、同步性提高。
