Effect of Drop-Piece High-Velocity, Low-Amplitude Manipulation to the Midfoot of Asymptomatic Adult Sprinters on Performance During a Unilateral Horizontal Drop-Jump Test: A Feasibility Investigation

Bell S, Howarth SJ CanadianMemorialChiropracticCollege

Abstract

Objective

The purpose of this study was to investigate the feasibility of measuring the immediate effects of drop-piece highvelocity, low-amplitude (DP-HVLA) manipulation to the midfoot region on jump distance in competitive adult sprinters during a standardized unilateral horizontal dropjump (U-HDJ) test.

Methods

Seven asymptomatic competitive adult sprinters (4 women) were recruited for this study. Testing was conducted on the dominant leg. Participants completed a 10-minute self-selected warm-up, followed by a 6-jump familiarization period with the U-HDJ test. All participants completed 3 U-HDJ trials before and after receiving DP-HVLA chiropractic manipulation to the joints of the midfoot assessed as being hypomobile by a licensed sports chiropractor. The primary outcome of the U-HDJ test was horizontal displacement, measured using an optoelectronic motion-capture system. Mean, SD, and 95% confidence intervals were determined for the posttreatment change in jump distance. A single-sample t test withα = 0.05 assessed the posttreatment change in jumping distance.

Results

We were able to measure immediate effects. The preliminary findings showed an increase in jump distance after DP-HVLA manipulation to the midfoot region (mean = 0.06 m, SD = 0.05 m; P = .014; 95% confidence interval, 0.02-0.11; effect size = 1.30).

Conclusion

This study demonstrates that it was feasible to measure immediate improvement in performance after DP-HVLA chiropractic manipulation in a clinical assessment with correlation to sprinting performance in a population of elite sprinters. As this was a feasibility study, the small sample size, overlapping confidence intervals, and specific niche population limit the extrapolation of these findings.

RepublishedwithpermissionfromElsevier

Access online:doi.org/10.1016/j.jmpt.2021.12.006

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