The authors have requested that this preprint be removed from Research Square

Abstract

Background Asymptomatic spinal biomechanical alterations may generate impaired central nervous system proprioceptive input, and motor control, and central processing deficits, which could impair sports performance. Several of the demonstrated neurophysiological effects of spinal manipulative therapy (SMT) could theoretically influence sports performance. Further, some studies have demonstrated that SMT' may improve aspects of sports performance. These include improved full-swing in golfers, judoka grip strength, taekwondo muscle strength, and ball kicking speed in soccer. The purpose of this study was to assess the effect on the performance of elite athletes of one session of SMT to correct asymptomatic, biomechanical dysfunction, using professional soccer players and sprint and change of direction (COD) tests. Also, the proposed placebo intervention was tested for efficacy in achieving blinding. MethodsA parallel-randomized, controlled, clinical trial was performed with 20 elite soccer players who were randomly assigned to one of two groups by a coin flip: one receiving SMT (n=10) and the other a placebo intervention (n=10). All players were from the same team, and were injury free and naive to SMT. Data were collected at the team training facility. Measured outcome tests (30-meter sprint run with a 10-meter split and COD test) were performed at the same time by all subjects immediately prior to and after interventions. Photocell devices were used for data acquisition. Participants and those assessing outcomes were blinded to group assignment. Care givers were not able to be blinded.Results20 participants were analyzed, 10 in each group. There were no changes to the sprint (10m and 30m) and COD test results immediately following either of the interventions. All subjects (SMT and placebo) answered YES to a question after the intervention asking if they were treated by SMT. No adverse events were reported.ConclusionSpinal manipulative therapy to correct asymptomatic, biomechanical dysfunction in the spine and pelvis did not have any immediate effect on the performance of elite soccer players as measured by 10- and 30-meters sprint times and COD sprint times. Additionally, the proposed placebo strategy was successful in blinding these athletes. Trial registration ISRCTN29691307. Retrospectively registered in 07/02/2018. http://www.isrctn.com/ISRCTN29691307.