The prevalence of osteoarthritis is increasing globally but current compliance with rehabilitation remains
poor. This study explores whether wearable sensors can be used to provide objective measures of performance
with a view to using them as motivators to aid compliance to osteoarthritis rehabilitation. More
specifically, the use of a novel attachable wearable sensor integrated into clothing and inertial measurement
units located in two different positions, at the waist and thigh pocket, was investigated. Fourteen healthy volunteers
were asked to complete exercises adapted from a knee osteoarthritis rehabilitation programme whilst
wearing the three sensors including five times sit-to-stand test, treadmill walking at slow, preferred and fast
speeds. The performances of the three sensors were validated against a motion capture system and an instrumented
treadmill. The systems showed a high correlation (r2 > 0.7) and agreement (mean difference range:
−0.02–0.03 m, 0.005–0.68 s) with gold standards. The novel attachable wearable sensor was able to monitor
exercise tasks as well as the inertial measurement units (ICC > 0.95). Results also suggested that a functional
placement (e.g., situated in a pocket) is a valid position for performance monitoring. This study shows
the potential use of wearable technologies for assessing subject performance during exercise and suggests
functional solutions to enhance acceptance.