Evidence Of A Conservative Gait Strategy In Athletes With A History Of Concussions

Abstract

A history of multiple concussions, specifically ≥3 concussions, is frequently associated with numerous short and long term neuropathologies. Impairments in postural control are a known acute consequence of concussion; however, limited evidence exists on the effects of multiple concussions on gait. PURPOSE: The purpose of this study was to assess gait stepping characteristics in collegiate aged student-athletes based on concussion history. METHODS: There were 63 participants divided into three even groups based on concussion history: ≥3 concussions, 1 – 2 concussions, and zero concussions. All participants completed 10 gait trials on a 4.9m instrumented walkway. Dependent variables included both gait stepping characteristics and coefficient of variability (CoV) measures and were compared with one-way ANOVAs and Tukey post-hoc tests. RESULTS: There was a significant main effect in the gait stepping characteristics for step velocity (0: 1.43±0.13 m/s, 1–2: 1.25±0.15m/s, and ≥3: 1.32+0.13m/s; P<0.001) and step length (0: 0.73+0.04m, 1–2: 0.68+0.05, ≥3: 0.69+0.06), P=0.011) and post-hoc test identified differences between 0 concussion group and both the 1–2 group and ≥3 groups, but no differences between 1–2 group and ≥3 groups. There was a significant main effect for step width (0: 12.0+3.2cm, 1–2: 10.3+3.2cm, ≥3 14.7+3.5cm, P<0.001) and post-hoc identified >3 significantly different from 0 or 1–2 groups. There was a main effect for step length CoV (p≥0.001) and post-hoc testing identified a significantly higher CoV for the 0 concussion group compared to the 1–2 concussion group (5.5+1.9 and 2.6+0.8 respectively, P<0.001) and the >3 Concussion group (3.6+1.9, P=0.001). There were no differences in the step time (P=0.15) or width (P=0.35) variability. DISCUSSION: This finding provides evidence of subtle impairments in postural control amongst individuals with prior history of concussion which could be an early indicator of future neurological deficiencies. The lack of difference in the variability measures is consistent with prior static stance studies and could suggest the individuals constrain their motor systems to reduce variability. Taken together, these findings indicate a conservative gait strategy being adopted by otherwise healthy young student-athletes with a history of concussions.