Insole Pressure Sensors to Assess Post-Stroke Gait

Objective: To confirm that the simplified insole does not affect the gait speed and to identify objective sensor-based gait parameters that correlate strongly with existing clinical gait assessment scales. Methods: Ten participants with gait impairment due to hemiplegic stroke were enrolled in this study. Pairs of insoles with four pressure sensors on each side were manufactured and placed in each shoe. Data were extracted during the 10-Meter Walk Test. Several sensor-derived parameters (for example stance time, heel_on-to-toe_peak time, and toe_peak pressure) were calculated and correlated with gait speed and lower extremity Fugl-Meyer (F-M) score. Results: The insole pressure sensor did not affect gait, as indicated by a strong correlation (rho=0.988) and high agreement (ICC=0.924) between the gait speeds with and without the insole. The parameters that correlated most strongly with highest beta coefficients against the clinical measures were stance time of the non-hemiplegic leg (beta=-0.87 with F-M and beta=0.95 with gait speed) and heel_on-to-toe_peak time of the non-hemiplegic leg (beta=-0.86 with F-M and -0.94 with gait speed). Conclusion: Stance time of the non-hemiparetic leg correlates most strongly with clinical measures and can be assessed using a non-obtrusive insole pressure sensor that does not affect gait function. These results suggest that an insole pressure sensor, which is applicable in a home environment, may be useful as a clinical endpoint in post-stroke gait therapy trials.