Inter-rater and intra-rater reliability and validity of a parallel robotic system with musculoskeletal model-based feedback for monitoring the proprioceptive system in healthy individuals.

Background: Knee proprioception is essential for injury prevention, stability, and performance improvement. Reliable proprioception measurement tools are crucial for accurate assessment and effective rehabilitation. Thus, the aim of the present study was to determine the validity and reliability of a parallel robotic system with musculoskeletal model-based feedback to assess knee joint position sense (JPS) in healthy people.

Material/methods: Fourteen healthy participants (7 men and 7 women) (mean (SD) age = 35.21 (9.32) years) volunteered for the study. The validity, inter-rater and intra-rater reliability of a parallel robotic system for measuring JPS were evaluated.

Results: The results indicate moderate to strong reliability in the 30° JPS test (ICC = 0.41-0.66; SEM = 0.27-0.37), and strong to excellent reliability in the 50° JPS test (ICC = 0.64-0.87; SEM = 0.31-0.45). Significant concurrent validity with correlations of variable strength was detected between the inclinometer and the robot in the 30° JPS tests (Pearson's correlation = 0.52-0.66; SEM = 0.30-0.43), and in the 50° JPS tests (Pearson's correlation = 0.55; SEM = 0.44) but only for the passive motion in closed kinetic chain.

Conclusions: A parallel robotic system with musculoskeletal model-based knee measurement provides a valid and reliable method for assessing knee JPS in healthy people. Its precision makes it a promising tool for both clinical use and future research applications.