Wearable approaches for non-invasive monitoring of tendons: A scoping review

Objectives: The objective of this review is to explore and analyse current research on the use of wearable sensor technologies to evaluate rehabilitation and prevention strategies for tendinopathies and tendon injuries, and assess tendon biomechanics. Design: Scoping review. Data sources: PubMed, IEEE and Scopus were searched from database inception to March 2024. Eligibility criteria: Studies were included if they used wearable technologies to assess tendon biomechanics directly, for predicting tendon injuries, or monitor tendon rehabilitation. Studies were only included if they evaluated patients during functional movements, rehabilitation exercises, or daily life activities. Data extraction and synthesis: Data extracted included year of publication, target measurement parameter, sensor specifications, data analysis methodology, study population, tendons assessed and exercises/movements evaluated. Results: Fifty-eight studies were included. Thirty-four studies were based on kinematic measurements from inertial measurement units (IMUs), accelerometers or GPS technology. Nine studies used wearable pressure-sensitive insoles. Eleven studies used techniques to track shear waves (vibration) in Achilles and patellar tendons. Five studies used techniques to track ultrasound compression waves. Two studies proposed flexible sensors for assessing tendon biomechanics. Conclusions: There is a predominant use of IMU devices for measuring kinematics during rehabilitation exercises, everyday movements and sports activities, underlining the versatility of the technique. Wearable insoles can measure ground reaction forces and provide insights into Achilles tendon loading and foot mobility. Recently proposed technologies aim to directly measure Achilles and patellar tendon biomechanical features by tracking induced waves propagating along the tendon tissue.