An electrical muscle stimulation suit for increasing blood pressure.

Background: Electrical muscle stimulation (EMS) is used to strengthen muscles in rehabilitation of patients and for training of athletes. Voluntary muscle straining and an inflated anti-G suit increase the arterial blood pressure (BP) and give a pilot G protection during increased +G z . This study's aim was to measure whether BP also increases with EMS of lower body muscles. Methods: A suit with new cloth electrodes sewn into the garment was developed. There were 12 subjects who were tested in sitting position during 3 conditions with 10 consecutive periods of EMS, inflated anti-G suit (GS), or lower body muscle anti-G straining maneuvers (AGSM). BP was continuously measured noninvasively. Results: The means of the baseline systolic BP, before each of the test conditions, were 127 ± 16, 128 ± 11, and 145 ± 14 mmHg for GS, AGSM, and EMS, respectively. During inflation of the GS, execution of the AGSM, and EMS, mean systolic BP during the first 10 s was 143 ± 15, 146 ± 13, and 150 ± 13 mmHg, respectively, with no statistical difference between the conditions. The corresponding mean resting heart rate before each test was 57-63 bpm for all conditions. During the test periods with GS, AGSM, and EMS, heart rate was 59 ± 11, 79 ± 16, and 61 ± 15 bpm, respectively, with statistical differences (P < 0.001) between AGSM and the other two conditions. Conclusion: EMS created similar BP as GS and AGSM at 1 G and also had higher pre- and post-control values. Further studies are required to evaluate if this principle may be used for G protection of pilots.