Abstract

Electrical Muscle Stimulation (EMS) and voluntary muscle contraction (VMC) are both acceptable rehabilitative modalities to preserve muscle strength loss. The study aimed to compare respiratory, metabolic, and cardiac parameters during quadriceps muscle contraction (QMC) using either EMS or VMC with comparable generated low intensity muscle force. Thirty healthy non-smoker males, age 20–58 years with normal BMI and low to moderate physical activity, underwent two 20-min sessions of comparable QMC using EMS vs VMC at the same day. The BIODEX III isokinetic dynamometer was used to assess maximum isometric force and the comparable force generated during each condition (EMS vs VMC), while the METAMAX 3B portable metabolic system was used to measure continuously the physiological parameters. Tolerable EMS was used (mean: 33 ± 1.5 mA, at 75 Hz). Each contraction lasted 10 sec followed by 20 sec rest. Paired t-tests were used for comparisons between sessions. A relatively low proportion of maximum isometric force (EMS: 8.5% vs VMC: 8.6%) and torque (EMS: 16 ± 1.3 vs VMC: 16 ± 1.1 Nm) were generated during each session. Mean minute ventilation (EMS: 10.8 L vs VMC: 9.8 L), tidal volume (EMS: 0.6 L vs VMC: 0.5 L), O₂ uptake (EMS: 0.31 L/min vs VMC: 0.26 L/min) and O₂ pulse (EMS: 3.9 ml/beat vs VMC: 3.6 ml/beat) were different between sessions (p ≤ .05); while heart rate (EMS: 72 beats/min vs VMC: 71 beats/min) was equal. Quadriceps muscle EMS induces higher respiratory and metabolic responses compared to equal magnitude VMC in healthy males.

摘要

肌肉电刺激 (EMS) 和随意肌肉收缩 (VMC) 都是可以接受的康复方式，以保持肌肉力量损失。该研究旨在比较股四头肌收缩 (QMC) 期间的呼吸、代谢和心脏参数，使用 EMS 或 VMC 与产生的低强度肌肉力量相当。30 名年龄 20-58 岁、BMI 正常且体力活动低到中等的健康非吸烟男性，在同一天使用 EMS 与 VMC 进行了两次 20 分钟的类似 QMC 会议。BIODEX III 等速测力计用于评估最大等长力和每种条件下产生的可比力（EMS 与 VMC），而 METAMAX 3B 便携式代谢系统用于连续测量生理参数。使用了可容忍的 EMS（平均值：33 ± 1.5 mA，75 Hz）。每次收缩持续 10 秒，然后休息 20 秒。配对 t 检验用于会话之间的比较。每次会话期间产生的最大等长力（EMS：8.5% 与 VMC：8.6%）和扭矩（EMS：16 ± 1.3 与 VMC：16 ± 1.1 Nm）的比例相对较低。平均每分钟通气量（EMS：10.8 L 对 VMC：9.8 L）、潮气量（EMS：0.6 L 对 VMC：0.5 L）、O₂吸收（EMS：0.31 L/min vs VMC：0.26 L/min）和 O ₂脉冲（EMS：3.9 ml/beat vs VMC：3.6 ml/beat）在会话之间不同（p  ≤ .05）；而心率（EMS：72 次/分钟 vs VMC：71 次/分钟）是相等的。与健康男性的同等幅度 VMC 相比，股四头肌 EMS 诱导更高的呼吸和代谢反应。