Oba M
Department of Orthopedic Surgery, Akita University School of Medicine, Japan.
Nihon Seikeigeka Gakkai Zasshi. 1995 Sep;69(9):708-20.
In order to use functional electrical stimulation effectively in paralyzed muscle treatment, changes in the maximal muscle force, muscle fatigue, and histological changes were evaluated in electrically stimulated muscles. Study 1. Tissue damage by percutaneous intramuscular electrodes implanted into the quadriceps muscle was examined in rat. Stimulation was conducted at various output voltages, and for various durations of time, in order to assess the histological changes in the muscle around the electrodes. Study 2. Electrodes were implanted into the bilateral quadriceps and gastrocnemius muscles of adult cat, and the unilateral muscles were then stimulated from 3 weeks following the transection of the spinal cord at the T9 level. Stimulus parameters were divided into two groups; as "A" stimulation: at -8V for 15min twice/week, and as "B" stimulation: at -16V for 30 min 4 times/week. The histological changes were examined using the myofibrillar ATPase method to determine the diameters and occupation ratios for each muscle fiber type. RESULTS. Study 1. Significant tissue damage began to occur when the voltage output created the maximum muscle contraction force. Until that critical voltage point was reached, tissue damage was not significant, regardless of the duration of the stimulation. Study 2. The maximum muscle force decreased until 4 weeks after the transection, then increased regardless of the presence of electrical stimulation. The muscle fatigability of the non-stimulated muscle was greater than that of the stimulated muscle. High voltage, long duration, and frequent stimulation was effective in controlling fatigue. The ratio of type I fibers was higher in the stimulated muscle. There was no evidence, however, of suppressing muscle fiber atrophy after electrical stimulation. These results suggested that electrically stimulating paralyzed muscles was effective for suppressing muscle fatigue, and for reducing the ratio of type I fibers. In clinical use, the output voltage should be kept below the voltage that induces the maximum muscle contraction to prevent tissue damage.
为了在瘫痪肌肉治疗中有效使用功能性电刺激，对电刺激肌肉的最大肌肉力量变化、肌肉疲劳和组织学变化进行了评估。研究1. 在大鼠中检查经皮肌内电极植入股四头肌造成的组织损伤。在不同输出电压和不同持续时间下进行刺激，以评估电极周围肌肉的组织学变化。研究2. 将电极植入成年猫的双侧股四头肌和腓肠肌，然后在T9水平脊髓横断后3周开始对单侧肌肉进行刺激。刺激参数分为两组；“A”刺激：-8V，15分钟，每周两次；“B”刺激：-16V，30分钟，每周4次。使用肌原纤维ATP酶法检查组织学变化，以确定每种肌纤维类型的直径和占有率。结果。研究1. 当电压输出产生最大肌肉收缩力时，开始出现明显的组织损伤。在达到该临界电压点之前，无论刺激持续时间如何，组织损伤都不明显。研究2. 最大肌肉力量在横断后4周内下降，然后无论是否存在电刺激均增加。未刺激肌肉的肌肉疲劳性大于刺激肌肉。高电压、长时间和频繁刺激在控制疲劳方面有效。刺激肌肉中I型纤维的比例较高。然而，没有证据表明电刺激后可抑制肌纤维萎缩。这些结果表明，电刺激瘫痪肌肉对抑制肌肉疲劳和降低I型纤维比例有效。在临床应用中，输出电压应保持在诱导最大肌肉收缩的电压以下，以防止组织损伤。
