Effect of sub-concussive impacts sustained throughout a contact-sport season on quiet stance centre of pressure

Abstract

ObjectiveTo examine how sub-concussive head trauma throughout a contact-sport season affects quiet stance centre of pressure (COP) swayDesignProspective cohortSettingLaboratoryParticipants: Twenty-four elite male football players (age range 18–22) were recruited for the studyInterventionQuiet stance data was collected at the start and at the end of the competitive season. One-minute trials were performed with eyes-open and eyes-closed on a force plate (NDI True Impulse) with feet hip-width apart and hands-on-hips. Biomechanical head-impact exposure was indexed using the xPatch (X2 Biosystems)Outcome measuresCOP measures: Anterior/posterior (AP) and medial/lateral (ML) root-mean-square displacement (RMSd) and mean velocity. Biomechanical head-impact data: For hits above 20g, peak linear acceleration (PLA), and peak rotational acceleration (PRAwere estimated across the competitive season. Independent variables included time (2) and condition (2)ResultsRM-ANOVA reveal an effect of condition (eyes-open vs eyes-closed) in AP-RMSd (p=0.035, 95% CI: 0.006, 0.159), ML-RMSd (p<0.0001, CI: 0.083, 0.250), and ML mean velocity (p<0.0001, 95% CI: 0.111, 0.308). However, despite exposure to a cumulative 8147.2±6215.5 g in linear acceleration and 34.5 x 106 ± 59.0x106 rad/s2 in rotational acceleration, there were no significant differences between conditions for COP measures at post-seasonConclusionsIn contrast to the prolonged COP alterations observed following acute concussions, there were no discernable effects of sub-concussive trauma on COP sway during quiet stance in the same population. This is an important finding as it reveals that participation in contract-sport does not impair quiet stance balanceCompeting interestsNone.