Assessing a low-cost accelerometer-based technique to estimate spatial gait parameters of lower-limb prosthesis users.

Abstract

Inexpensive methods for characterizing lower-limb prosthetic gait allow clinicians to monitor gait quality. This study assessed an established method for estimating step length using a low-cost accelerometer to estimate distance walked in lower-limb prosthesis users and explore the use of subject-specific correction factors. A three-axis accelerometer was attached to participants using straps. Validity and test-retest reliability of step length was assessed in able-bodied individuals using a motion capture system. Validity of distance walked was assessed with lower-limb prosthesis users. A regression equation was developed for prosthesis users to estimate a correction factor that minimized error. The system demonstrated excellent reliability and minimal mean error for both participant groups, but subject-specific correction factors did not provide substantial benefit. Estimate variability was high, suggesting the need for further refinement. Estimating distance walked and step length from low-cost accelerometers may be a valid, clinically accessible method for characterizing prosthetic gait. The use of a low-cost accelerometer may provide valid means for estimating step length and distance walked of lower-limb prosthesis users in a clinical environment for monitoring patient outcomes.