Body position influences arterial occlusion pressure: implications for the standardization of pressure during blood flow restricted exercise.

ABSTRACT

PURPOSE: Arterial occlusion pressure (AOP) measured in a supine position is often used to set cuff pressures for blood flow restricted exercise (BFRE). However, supine AOP may not reflect seated or standing AOP, thus potentially influencing the degree of occlusion. The primary aim of the study was to investigate the effect of body position on AOP. A secondary aim was to investigate predictors of AOP using wide and narrow cuffs. METHODS: Twenty-four subjects underwent measurements of thigh circumference, skinfold and blood pressure, followed by assessments of thigh AOP in supine and seated positions with a wide and a narrow cuff, respectively, using Doppler ultrasound. RESULTS: In the supine position, AOP was 148 ± 19 and 348 ± 94 mmHg with the wide and narrow cuff, respectively. This increased to 177 ± 20 and 409 ± 101 mmHg in the seated position, with correlations between supine and seated AOP of R 2 = 0.81 and R 2 = 0.50 for the wide and narrow cuff, respectively. For both cuff widths, thigh circumference constituted the strongest predictor of AOP, with diastolic blood pressure explaining additional variance with the wide cuff. The predictive strength of these variables did not differ between body positions. CONCLUSION: Our results indicate that body position strongly influences lower limb AOP, especially with narrow cuffs, yielding very high AOP (≥ 500-600 mmHg) in some subjects. This should be taken into account in the standardization of cuff pressures used during BFRE to better control the physiological effects of BFRE.