Objective
The purpose of this study was to investigate anticipatory postural adjustments (APA) during the transitional movement task of gait initiation (GI) in individuals acutely following a concussion.
Design
Cohort Study.
Setting
University Research Center.
Participants
A population based sample of 84 participants divided into two equal groups of acutely post-concussion (CONC) and healthy student athletes.
Intervention
Participants were tested on two occasions – a pre-injury baseline test and then the CONC group was retested acutely post-concussion and the control group again at a similar time. All participants completed 5 trials of GI on 4 forceplates.
Main Outcome Measures
The dependent variables were the displacement and velocity of the center of pressure (COP) during the APA phase and initial step kinematics. Comparisons were made with a 2 (Group) × 2 (Time) repeated measures ANOVA.
Results
There was a significant interaction for COP posterior displacement (P<0.001) and lateral displacement (P<0.001). Posteriorly, post-hoc testing identified a significant reduction in CONC (PRE: 5.7 ± 1.6 cm and POST: 2.6 ± 2.1 cm, P<0.001), but no difference in Control (PRE: 4.0 ± 1.6 cm and POST: 4.0 ± 2.5 cm, P=0.921). Laterally, post-hoc testing identified a significant reduction in CONC (PRE: 5.8 ± 2.1 cm and POST: 3.8 ± 1.8 cm, P<0.001), but no difference in Control (PRE: 5.0 ± 2.5 cm and POST: 5.2 ± 2.4 cm, P=0.485).
Conclusions
The results of this study suggest difficulty in the planning and execution of GI acutely post-concussion and posterior APA displacement and velocity are highly effective measures of impaired postural control. Finally, the APA phase is linked to the supplementary motor area which suggests a supraspinal contribution to post-concussion impaired postural control.