Sport-related Concussions Have A More Conservative Stepping Pattern During Instrumented Tandem Gait Performance

Abstract

Tandem gait has emerged as a dynamic and clinically viable test of dynamic motor control following sport-related concussion (SRC). A myriad of tools are available to objectively assess gait kinematics. One piece of equipment, the Tekscan Strideway, uses individual load cells on a series of connected force platform tiles to quantify gait. No data exists that examines the performance of SRC using this device. PURPOSE: The purpose of this study was to evaluate the differences in center of pressure (CoP) performance during single-task (ST) and dual-task (DT) tandem gait within 24-48 hours post-SRC. METHODS: 18 Division I [SRC (age: 19 ± 1.00 yr. Male=7, Female=11)] and 18 nearly matched controls [CON (age: 19.88 ± 1.05 yr. Male=7, Female=11)] completed the vestibular ocular motor screening test (VOMS) and 3 trials of ST and 1 trial of DT (serial 7s) using the Tekscan Strideway (30Hz, Boston, MA). The raw CoP trajectory for the best tandem gait trial of each condition (fastest overall) was exported and further analyzed using a custom MATLAB code. All turns during the tandem gait trials were removed and each straight path walking was composed together. The raw CoP data in the AP and ML directions were smoothed using empirical mode decomposition and then excursion and velocity data were calculated. T-tests compared the time to complete ST and DT while two multivariate ANOVAs compared CoP in the AP and ML directions. RESULTS: SRC took significantly longer to complete the ST trial (p=.006; SRC=14.2±4.4s, CON=10.8±2.1s) but not the DT trial (p=.279). The SRC group had a larger VOMS near-point convergence (NPC) (p=.007; SRC=9.5±5.5cm, CON=5.2±2.9cm) and a higher VOMS change score (p<.001; SRC=19.7±6.4, CON=0±0). A significant omnibus effect was noted in AP direction (p=.015) but not in the ML direction (p=.996) for the tandem gait CoP data. Follow-up comparisons noted that in the AP direction during ST, SRC had slower CoP excursion (p=.003; SRC=1.6±0.2cm, CON=1.9±0.4cm) and lower CoP velocity (p=.004; SRC=54.2±7.7cm/s, CON=66.1±14.2cm/s) but no differences during DT. CONCLUSIONS: These results suggest that during instrumented ST tandem gait, SRC have a more conservative and slower heel-to-toe stepping pattern.