Inter- and Intra-rater Reliability of a New Wearable Accelerometer in Measuring Hip Flexion Peak Velocity, Mean Velocity, Maximum Range of Motion, and Mean Range of Motion during the Askling H-Test Among Asymptomatic Healthy Adults

Willett, MatthewAlHazmi, Dhuha Saeed S2025-11-292025https://hdl.handle.net/20.500.14154/77224Background: The Askling H-test is recognised as a valid and reliable test to assess hamstring performance during high velocity movement and to guide the return to sport (RTS) decision after hamstring strain injuries (HIS). Key parameters obtained from this test, such as hip flexion angular velocity, along with range of motion, provide critical insights into hamstring eccentric control, flexibility, and potential risk of reinjury. However, evidence on the use of wearable IMUs to capture these parameters remains limited, particularly in sport medicine and rehabilitation settings. Purpose: To evaluate the inter-rater and intra-rater reliability of the Output Sports accelerometer in measuring hip flexion Peak Velocity (Vpeak), Mean Velocity (Vmean), Maximum and Mean Range of Motions (ROMmax, ROMmean) during the Askling H-test among asymptomatic healthy adults under two bracing conditions. Study Design: Cross-sectional Reliability Study. Methods: Four raters utilised the Output Sports accelerometer to capture Vpeak, Vmean, ROMmax, and ROMmean during the Askling H-test on asymptomatic, healthy young males and females under two bracing conditions. Inter- and intra-rater reliability were evaluated using Intraclass correlation coefficients (ICCs) with 95% confidence intervals (CI). Visual estimation of agreement was performed using Bland-Altman Plots. SEM and MDC were calculated to estimate error/change. Results: A total of sixty-eight participants (40 males, 28 females) with a mean age of 24.52±3.86 years were included. A moderate to good inter-rater reliability was observed across both sexes and bracing conditions (ICC=0.69-0.88 males, ICC=0.65-0.89 females), with moderate to good intra-rater reliability for females (ICC=0.59-0.86) and poor to good in males (ICC=0.48-0.74). Conclusion: The Output Sports accelerometer is a reliable device for assessing hip flexion velocities and ROM during the Askling H-test. Bracing further enhanced its measurement consistency, supporting its use in clinical and sports settings. Level of Evidence: Level 3. Key Terms: Askling H-test, Accelerometer, Hamstring Strain Injury, Output Sports, Reliability.30enAskling H-testAccelerometerHamstring Strain InjuryOutput SportsReliabilityInter- and Intra-rater Reliability of a New Wearable Accelerometer in Measuring Hip Flexion Peak Velocity, Mean Velocity, Maximum Range of Motion, and Mean Range of Motion during the Askling H-Test Among Asymptomatic Healthy AdultsThesis