Instrumenting gait with an accelerometer: A system and algorithm examination

• Published in: Medical engineering & physics Vol. 37; no. 4; pp. 400 - 407
• Main Authors: Godfrey, A., Del Din, S., Barry, G., Mathers, J.C., Rochester, L.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2015; Butterworth-Heinemann
• Subjects: Accelerometer; Accelerometry - economics; Accelerometry - instrumentation; Accelerometry - methods; Adult; Aged; Algorithm; Algorithms; Biomechanical Phenomena; Gait; Gait - physiology; Healthy ageing; Humans; Middle Aged; Monitoring, Ambulatory - instrumentation; Monitoring, Ambulatory - methods; Radiology; Validation; Walking - physiology; Young Adult; Validation; Accelerometer; Gait; Algorithm; Healthy ageing
• ISSN: 1350-4533; 1873-4030; 1873-4030
• DOI: 10.1016/j.medengphy.2015.02.003

•Detailed investigation to explain poor variability/asymmetry agreement between accelerometers and instrumented walkway.•Caution is urged in the choice of reference system for validation studies.•Accelerometers have potential to gather continuous and robust spatio-temporal gait data, representative of normal living.•Further refinement of the gait algorithms are required. Gait is an important clinical assessment tool since changes in gait may reflect changes in general health. Measurement of gait is a complex process which has been restricted to the laboratory until relatively recently. The application of an inexpensive body worn sensor with appropriate gait algorithms (BWM) is an attractive alternative and offers the potential to assess gait in any setting. In this study we investigated the use of a low-cost BWM, compared to laboratory reference using a robust testing protocol in both younger and older adults. We observed that the BWM is a valid tool for estimating total step count and mean spatio-temporal gait characteristics however agreement for variability and asymmetry results was poor. We conducted a detailed investigation to explain the poor agreement between systems and determined it was due to inherent differences between the systems rather than inability of the sensor to measure the gait characteristics. The results highlight caution in the choice of reference system for validation studies. The BWM used in this study has the potential to gather longitudinal (real-world) spatio-temporal gait data that could be readily used in large lifestyle-based intervention studies, but further refinement of the algorithm(s) is required.