Validity and reliability of a single-unit inertial measurement unit: a real-time adapted sports assessment tool for handcycling-based activities.

Purpose: Single-device wearable inertial measurement units (SWIMU) have been used to quantify able-bodied sports movement in real-time but have not been adequately validated for use in adapted sports. Access to the kinematic profile of adapted sport athletic movements may be important for understanding the effect of technique on performance, fatigue and injury risk. The purpose of this study was to assess the validity and reliability of a SWIMU during upper-body sports movement in people with physical disabilities.

Materials and methods: Seven people with disabilities completed three handcycling sessions while wearing a SWIMU on their right wrist. During session 1, motion capture markers were also placed on participants where they completed three (3) 15-s trials at a self-selected cadence. Kinematic data from Motion Capture System was compared to SWIMU data. During sessions 2 and 3, participants cycled at 10 mph for 20 revolutions. SWIMU data was compared across sessions 2 and 3 to determine its reliability.

Results: Linear acceleration measured through a SWIMU and Motion Capture System was highly correlated in the x-axis (r = .80) and moderately highly correlated in the y-axis (r = .70) and z-axis (r = .68; p<.001). SWIMU had excellent intraclass correlation (ICC) across all axes (ICC > .75; p<.001).

Conclusions: A SWIMU is valid and reliable during ergometry-related movement in people with disabilities. SWIMU have the potential to provide real-time feedback to adapted sports participants and trainers on sports-specific technique during a single training session and across multiple sessions.