Accelerometers can correctly count orthopaedic patients' early post-operative steps while using walking aids.

Area of Science:

• Orthopaedic rehabilitation
• Wearable technology
• Biomechanical monitoring

Background:

• Effective post-orthopaedic surgery rehabilitation is crucial.
• Outpatient management necessitates objective progress monitoring like step counts.
• Accuracy of commercial wearables for step counting in early post-operative conditions is uncertain.

Purpose of the Study:

• To evaluate the accuracy of commercial wearables and accelerometers in counting steps during early post-operative conditions.
• To determine if accelerometers are more accurate than wearables for step counting in this context.

Main Methods:

• A case series of 20 healthy subjects simulated post-operative gait patterns with walking aids.
• Four commercial wearables and one accelerometer (AX6) were tested at wrist, hip, and ankle locations.
• Relative error (RE) was calculated against manual and video step counts.

Main Results:

• The AX6 accelerometer and Fitbit showed RE < 0.1 for most walking aids.
• AX6 demonstrated the lowest standard deviation in accuracy.
• Accuracy generally improved with gait speed, except for AX6; the ankle was the optimal sensor location.

Conclusions:

• Commercial wearables have limitations in accurately counting steps during early post-operative rehabilitation.
• Accelerometers, with appropriate algorithms, show potential for reliable step monitoring in this phase.
• Cautious use of wearables is advised for monitoring post-operative rehabilitation progress.