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


METHODS
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.


CONCLUSIONS
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.


CONCLUSIONS
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.
Northwestern University Prosthetics-Orthotics Center, Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, USA Jesse Brown VA Medical Center, Chicago, IL, USA matthew-major@northwestern.edu.
Matthew J
MJ
Major
Northwestern University Prosthetics-Orthotics Center, Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, USA.
Pooja
P
Raghavan
Northwestern University Prosthetics-Orthotics Center, Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, USA Jesse Brown VA Medical Center, Chicago, IL, USA.
Steven
S
Gard
D061725:Accelerometry / Q000191:economics* / Q000295:instrumentation; D000671:Amputation, Surgical / Q000534:rehabilitation*; D001186:Artificial Limbs; D005684:Gait / Q000502:physiology*; D006801:Humans; D007866:Leg; D063868:Patient Outcome Assessment; D011474:Prosthesis Design; D015203:Reproducibility of Results
Gait analysis; evaluation studies; gait; prosthetic feet; prosthetics; rehabilitation; rehabilitation of prostheses users; study design