Summary

The study on healthy recreational athletes divided into interventional and placebo, and control groups determined that the inflated blood flow restriction band on the arm impairs the sense of wrist joint position.

Abstract

The literature confirms that compared with low-load training, low-load blood flow restriction (BFR) training is more effective and tolerable; therefore, the potential usage of BFR in sports medicine has been recently highlighted. With a sensation of joint motion, the joint position sense (JPS) constitutes proprioception, being crucial in joint stability, coordination, and protection against injurious movements. To date, the safety issues of using BFR haven’t been raised; therefore, the study determined the effect of a worn arm BFR band on the wrist JPS. The prospective randomized, double-blind placebo-control study was conducted in a medical university laboratory. Sixty healthy right-handed young recreational athletes (30 females, 30 males) were randomly assigned to three groups, equal in size and gender rate: Group I, the interventional group; Group II, the placebo group; and Group III, the controls. The participants, examiner, and statistician were blinded. In all groups, the active wrist joint position reproduction was measured using the isokinetic dynamometer (Biodex System 4 Pro) on two separate occasions at a 90-minute-long interval. The examination was performed bilaterally, and the participants in each group were randomly assigned to start with the right (RL) or left (LL) limb. During measurements, the participants were wearing masks covering their eyes. The starting position was 0°, and the target position was 30° of wrist flexion. During the first session, the measurements were performed with no bands. During the second session, the wireless BFR cuff (AirBands, Vald Performance) was worn in Group I and Group II on a standardized level of the arm of the examined limb. In Group I, a standardized pressure was applied, while in Group II, the bands stayed uninflated. The collected parameter was the absolute difference between the target and actively replicated position, defined as an absolute angular error, AAE (degrees). The studied group arithmetic mean (x) and the standard deviation (±) were calculated for AAE for each limb during the two sessions. The variables were normally distributed. The results obtained during the first session were compared to those in the second session separately in each group using a parametric t-test for dependent samples. The same test was used for the between-limbs comparative analysis. A minimal sample was calculated before the study. In Group I, the AAE was statistically significantly higher (p=0.002-0.004) in the second session (RL, x=12.81±8.23°; LL, x=13.17±6.99°) compared to the first session (RL, x=8.29±7.38°; LL, x=7.40±5.22°). Contrarily, the mean AAE obtained in the two other groups during the second session was smaller than during the first session, and the differences were not statistically significant. The analysis of the results obtained in both sessions didn’t detect any differences between the right and left limbs in any of the groups. It can be concluded that even in healthy athletes, wearing an arm BFR band adversely affects the JPS of the wrist; therefore, special care should be taken during BFR training.