Comparison of blood flow restriction devices and their effect on quadriceps muscle activation.

OBJECTIVES: Blood flow restriction training (BFRT) provides an alternative approach to traditional strength training. The purpose of this study was to determine differences in quadriceps muscle activation, subject reported pain, and perceived exertion between three exercise conditions: low-load resistance BFRT with (1) regulated and (2) standardized devices, and (3) high-load resistance exercise without BFRT. DESIGN: Randomized cross over study. SETTING: XX University Biomechanics laboratory. PARTICIPANTS: Thirty-four healthy subjects (18 male/16 female) each completed three randomized sessions of knee extensions using Delfi's Personalized Tourniquet System (R) at 30% of 1 repetition maximum (1RM), the B-Strong™ device (S) at 30% 1RM, and high-load resistance exercise (HL) at 80% 1RM. MAIN OUTCOME MEASURES: Quadriceps EMG activity, numeric pain rating scale (NPRS), and perceived exertion (OMNI-RES) were recorded. RESULTS: Average and peak EMG were greater in HL sessions than both S and R (p < .001). NPRS was greater in the R sessions compared to both S (p < .001) and HL (p < .001). OMNI-RES was greater in the R sessions compared to S (p < .02) and HL (p < .001). No differences (p > .05) in average or peak EMG activation were found between S and R sessions. CONCLUSIONS: Quadriceps EMG amplitude was greater during high-load resistance exercise versus low-load BFR exercise and there were no differences in EMG findings between BFRT devices.

BTrackS Balance Test for Concussion Management is Resistant to Practice Effects.

OBJECTIVE: Recent guidelines advocate for ongoing balance testing in the assessment of management of concussion injuries. This study sought to determine whether the Balance Tracking System (BTrackS) provides stable balance results over repeated administration and, thus, is a reliable tool for concussion management. DESIGN: Repeated measures and test-retest reliability. SETTING: University Biomechanics Laboratory. PARTICIPANTS: Random sample of 20 healthy young adults. INTERVENTIONS: Force plate balance testing using BTrackS on days 1, 3, 8, and 15. MAIN OUTCOME MEASURES: Practice-induced changes in the average center of pressure excursion over 4 repeated administrations of the BTrackS Balance Test (BBT). Test-retest reliability of center of pressure excursion from day 1 to day 15. RESULTS: No significant practice-induced balance differences were found across testing days (P > 0.4), and test-retest reliability of the BBT was excellent from day 1 to day 15 (R 0.92). CONCLUSIONS: These findings indicate that the BBT does not elicit a practice effect over repeat administrations. BTrackS provides excellent reliability and objectivity, which can increase clinician accuracy when monitoring sport-related concussions.

Combination of BTrackS and Geri-Fit as a targeted approach for assessing and reducing the postural sway of older adults with high fall risk.

Atypically high postural sway measured by a force plate is a known risk factor for falls in older adults. Further, it has been shown that small, but significant, reductions in postural sway are possible with various balance exercise interventions. In the present study, a new low-cost force-plate technology called the Balance Tracking System (BTrackS) was utilized to assess postural sway of older adults before and after 90 days of a well-established exercise program called Geri-Fit. Results showed an overall reduction in postural sway across all participants from pre- to post-intervention. However, the magnitude of effects was significantly influenced by the amount of postural sway demonstrated by individuals prior to Geri-Fit training. Specifically, more participants with atypically high postural sway pre-intervention experienced an overall postural sway reduction. These reductions experienced were typically greater than the minimum detectable change statistic for the BTrackS Balance Test. Taken together, these findings suggest that BTrackS is an effective means of identifying older adults with elevated postural sway, who are likely to benefit from Geri-Fit training to mitigate fall risk.