Purpose: Previous research has identified deficient dual-task balance control at the time of return to play (RTP) and possible worsening after RTP in older adolescents/young adults with concussion. We investigated these issues in younger concussion patients, hypothesizing they would have slower walking speed and increased medial-lateral (ML) center of mass (COM) movement, which would normalize by RTP but worsen after resuming activity.
Methods: 13 concussed adolescents (7 male; age 10-17 years) were prospectively evaluated at their initial visit (mean 18, range 4-43 days post-concussion), at RTP clearance (46, range 12-173 days post-concussion), and one month later (26, range 20-41 days post-RTP). Standing balance was assessed using range and root mean squared (RMS) COM motion during 2-leg, eyes open standing while performing audio Stroop, side-to-side head turn (HT), and side-to-side thumb tracking tasks. Dynamic balance was assessed using walking speed and COM ML range and velocity during walking alone and with head turn and verbal fluency (reciting words starting with “F”) dual tasks. Patients were compared to 11 controls (3 male) using t-tests, and changes over time were evaluated using linear mixed-effects regression.
Results: During standing, patients had higher COM ML RMS than controls at baseline during HT and higher COM anterior-posterior (AP) range during thumb tracking. COM ML motion decreased from baseline to RTP (HT range -6.5mm, p=0.058; HT RMS -16.8mm, p=0.002; thumb range 9.2mm, p=0.012) and increased from RTP to 1 month follow-up (HT RMS +10.0mm, p=0.040; Stroop RMS +8.4mm, p=0.086).
Patients walked slower than controls at baseline during all tasks, and COM ML range was higher in patients during verbal fluency at baseline and RTP. Walking speed increased from baseline to RTP during verbal fluency (+7.8cm/s, p=0.044), from RTP to post-RTP in single task walking (+6.1cm/s, p=0.041), and at each successive visit during HT (+6.0cm/s and +6.5cm/s, p<0.07). COM ML range decreased in patients from baseline to RTP with verbal fluency (-14.7mm, p=0.011) and from RTP to post-RTP in single task walking (-4.0mm, p=0.061).
Conclusion: Balance control deficits improved by RTP and only worsened post-RTP during dual-task standing, suggesting that current conservative treatment protocols are appropriate.