David Rhodri Scourfield Evans1, Katherine J Williams2, Paul H Strutton3, Alun H Davies4. 1. Cardiff University School of Medicine, Cardiff, United Kingdom. 2. Academic Section of Surgery, Imperial College London, London, United Kingdom. 3. Department of Surgery and Cancer, Imperial College London, London, United Kingdom. 4. Academic Section of Surgery, Imperial College London, London, United Kingdom. Electronic address: a.h.davies@ic.ac.uk.
Abstract
BACKGROUND: Circulation in the limbs can be augmented using transcutaneous electrical stimulation devices. The optimum muscle stimulation sites for enhancement of vascular hemodynamic parameters have not been identified. METHODS: Seven suitable anatomic sites were identified within the right leg. Twelve healthy participants were recruited (mean age, 23.1 ± 3 years; body mass index, 23.1 ± 3 kg/m(2)). Muscles were stimulated by transcutaneous bipolar electrodes at a current twice their motor threshold, at 1 Hz, for 5 minutes. Hemodynamic ultrasound measurements were taken from the right femoral vein. Laser Doppler measurements from the feet of the stimulated and nonstimulated sides were obtained. Baseline measurements were compared with readings after 5 minutes of stimulation, with device active. Discomfort experienced for stimulation of each muscle was rated out of 100. RESULTS: Hemodynamic changes displayed large intersubject variation, with no muscle statistically superior to the others. All muscles increased peak velocity; contraction of medial gastrocnemius increased time-averaged maximum velocity and volume flow. All muscles increased foot fluximetry (P < .05). Discomfort correlated weakly with current applied. Tibialis anterior and vastus lateralis were most tenable. CONCLUSIONS: Transcutaneous stimulation increases hemodynamic parameters significantly, locally and systemically. No optimum stimulation site has been identified, and it is limited by comfort and variability in the subject's response. Gastrocnemius, tibialis anterior, and vastus lateralis all provoke large changes in hemodynamic parameters, but clinical efficacy in disease prevention and management has not been explored.
BACKGROUND: Circulation in the limbs can be augmented using transcutaneous electrical stimulation devices. The optimum muscle stimulation sites for enhancement of vascular hemodynamic parameters have not been identified. METHODS: Seven suitable anatomic sites were identified within the right leg. Twelve healthy participants were recruited (mean age, 23.1 ± 3 years; body mass index, 23.1 ± 3 kg/m(2)). Muscles were stimulated by transcutaneous bipolar electrodes at a current twice their motor threshold, at 1 Hz, for 5 minutes. Hemodynamic ultrasound measurements were taken from the right femoral vein. Laser Doppler measurements from the feet of the stimulated and nonstimulated sides were obtained. Baseline measurements were compared with readings after 5 minutes of stimulation, with device active. Discomfort experienced for stimulation of each muscle was rated out of 100. RESULTS: Hemodynamic changes displayed large intersubject variation, with no muscle statistically superior to the others. All muscles increased peak velocity; contraction of medial gastrocnemius increased time-averaged maximum velocity and volume flow. All muscles increased foot fluximetry (P < .05). Discomfort correlated weakly with current applied. Tibialis anterior and vastus lateralis were most tenable. CONCLUSIONS: Transcutaneous stimulation increases hemodynamic parameters significantly, locally and systemically. No optimum stimulation site has been identified, and it is limited by comfort and variability in the subject's response. Gastrocnemius, tibialis anterior, and vastus lateralis all provoke large changes in hemodynamic parameters, but clinical efficacy in disease prevention and management has not been explored.