Search

Sport-related concussion (SRC) is a functional injury that affects several clinical domains, including balance and cognition. The purpose of this study was, 1) to determine whether a lower limb visuomotor task could identify balance control differences between youth athletes with and without previous SRC; and 2) if balance is affected by training over time. Youth hockey players (n = 34) who reported previous SRC (CONCUSSED; n = 12; mean age = 14.4 yrs., SD = 1.6, mean time from injury = 1.9 yrs., median = 1.7 yrs. [0.6–4.6]) and no history of SRC (CONTROL; n = 22; mean age = 14.7, SD = 1.5) were tested twice over 70 days. Participants stood in single support on a Nintendo Wii Balance board sampled at 100 Hz and performed Go/No-Go tasks with each foot. Five FitLight Trainer™ (Aurora, ON) lights were arranged on the floor at 60°, 30°, and 0° and illuminated in random GREEN (Go) or RED (No-Go). Balance was assessed using root mean square displacement and velocity of CoP in anterior-posterior and medial-lateral directions. CONCUSSED had significantly lower velocity of CoP in the anterior-posterior (F (1, 32) = 13.81, p <.001) and medial-lateral (F (1, 32) = 13.80, p <.001) directions than CONTROL, with no learning effects over time (anterior-posterior: F (1, 32) = 0.30, p =.137: F (1, 32) = 0.91, p =.346; medial-lateral: F (1, 32) = 0.91, p =.346). These findings suggest that CONCUSSED consistently performed the task more conservatively. A lower limb Go/No-Go task may objectively identify differences between youth athletes with and without previous SRC. These visuomotor and balance control deficits may persist beyond clinical recovery. • Tested youth hockey players twice using a novel lower-limb reaching task • 12 of the 34 players reported a previous history of sport-related concussion. • There were no significant learning effects of the task over time. • Centre of pressure velocity was lower in previously concussed players at both time points. • Anticipatory visuomotor impairments may persist beyond symptom resolution. [ABSTRACT FROM AUTHOR]

PURPOSE: To investigate balance control in athletes with and without a previous SRC during a DVA task. METHODS: Athletes (21 ±1.4 years) without (CONT=13) with previous SRC (SRC=13; symptom resolution=22±14.6 months) participated in the study. DVA was assessed using a custom program (V&MP Vision Suite, University of Waterloo) displayed on a 55" monitor viewed from 4m. A moving 'E' target facing left/right/up/down was presented in one of two movement profiles: randomly (RW); or horizontally (H) at speeds of 2.3m/s (30°/s). As participants correctly identify the orientation of the target, it progressively reduced in size. DVA was scored as the log of the minimum angle of resolution (LogMAR), of the smallest target correctly identified. Participants stood on a Bertec force platform during three quiet standing trials; fixating on a target "X" displayed for 30s (QS); RW; and H. Root mean square was calculated for centre of pressure displacement (dCOP) in the anterior/posterior (A/P) and medial/lateral (M/L) directions. RESULTS: No differences for DVA LogMAR scores between groups for RW (SRC= 0.16; CONT=0.15; p=.907) or H (SRC=0.14; CONT=0.18; p=.372). However, there were significant main effects of group for M/L dCOP during QS (SRC=3.4mm; CONT=4.4mm; p< .05, η p² =0.35) and A/P dCOP during RW movement (SRC=3.3mm; CONT=4.5mm; p< .05; ηp²=0.24). Neither number of previous SRC (p= .29) nor time from symptom resolution (p= .94) affected A/P dCOP during RW. CONCLUSION: Reduced dCOP in SRC group was likely due to increased co-contraction of ankle musculature, which may be a top-down neural protective mechanism to compensate for balance control impairments. [ABSTRACT FROM AUTHOR]