Abstract
Background Inertial measurement units (IMUs) have potential to be inexpensive, portable sensors for collecting gait parameters and joint kinematics. Current validation protocols generally do not investigate IMU accuracy in measuring altered gait; therefore, they cannot assess an IMU’s ability to detect pathologies. The Stridelink IMU-based gait analysis device is intended for use in detecting and monitoring gait abnormalities, thus there is a need to evaluate the device’s accuracy under abnormal gait conditions.
Research question How well do measurements from the StrideLink IMU agree with motion capture (MoCap), particularly when gait is mechanically altered to simulate pathology?
Methods Twenty-eight healthy participants (ages 18-40) were analyzed during a one-minute tread-mill walk with Vicon MoCap and StrideLink. Tests were performed under normal and mechanically induced abnormal conditions (knee brace, walking boot). Equivalence testing and correlation analysis evaluated StrideLink’s accuracy against MoCap.
Results StrideLink showed statistical equivalence (within 5%) for average cadence, stride, swing, and stance times but not double support time. Many metrics were statistically equivalent (p < .001) despite induced abnormalities. Correlation analysis showed almost perfect agreement with MoCap for stride times, cadence, and stance. However, the abnormal gait protocol revealed nuances not observed in normal gait; specifically, the device underestimated swing time by ∼10 ms in knee brace restricted limbs.
Significance This study utilized mechanically induced gait abnormalities to assess the robustness of IMU measurements. Results indicate StrideLink yields valid temporal gait measurements comparable to reference systems, even under conditions of significant deviation, supporting the utility of using induced abnormalities for sensor validation.
Competing Interest Statement
This work was funded by StrideLink Inc., and co-author Cassandra McIltrot is a co-founder of StrideLink Inc.
Funding Statement
This study was funded by StrideLink, Inc. (Contract M2300371 at Texas A&M University).
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
The IRB of Texas A&M University gave ethical approval for this work
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Data Availability
All data produced in the present study are available upon reasonable request to the authors
