Reliability Of Hand-held Dynamometer In Measuring Gluteal Muscle Rate Of Torque Development And Peak Torque

Belt-stabilized handheld dynamometers (HHD) assess hip rate of torque development (RTD) and strength in research and clinical practice. However, the reliability of HHD with push and pull configurations to measure hip muscles RTD and peak torque is unclear. PURPOSE: To determine the intra- and inter-reliability of HHD utilizing push and pull configurations to measure hip abduction and extension during early (0-100 ms) and late (100-200 ms) phases for RTD and peak torque. METHODS: Twenty healthy adults (10 females; Tegner Activity Scale = 4.8 ± 0.8) performed three consecutive trials of maximal isometric contractions of each hip abduction and extension, utilizing an HHD with push and pull configurations by two raters. The average early and late phases RTD and peak torque of hip abduction and extension for each rater were utilized for analysis. Reliability was classified as poor (<0.50), moderate (0.50-0.749), good (0.75-0.90), and excellent (>0.90). RESULTS: Intra-rater reliability of hip abduction with the push configuration was moderate-to-good for both RTD phases (ICC2,1 = 0.61-0.88), while the pull was moderate for early phase RTD (ICC2,1 ≥ 0.59) and moderate-to-good for late phase RTD (ICC2,1 = 0.63-0.75). Peak hip abduction torque had good reliability in both configurations (ICC2,1 ≥ 0.79). Intra-rater reliability of hip extension was moderate-to-good for the early RTD phase (ICC2,1 = 0.72-0.85) and good for the late phase (ICC2,1 ≥ 0.81) in the push configuration, with good-to-excellent in the pull for both phases (ICC2,1 = 0.77-0.91). Peak hip extension torque had moderate-to-excellent reliability for push configuration (ICC2,1 = 0.73-0.92) and excellent for pull (ICC2,1 ≥ 0.91). Inter-rater reliability for hip abduction was moderate in the push configuration (ICC3,k ≥ 0.72) and good in the pull (ICC3,k ≥ 0.78) for both RTD phases, while hip extension showed good reliability in the push (ICC3,k ≥ 0.82) and excellent in the pull (ICC3,k ≥ 0.95) configurations. Peak torque inter-rater reliability was good for hip abduction (ICC3,k ≥ 0.83) and excellent for hip extension (ICC3,k ≥ 0.94) in both configurations. CONCLUSION: HHD with push and pull configurations is a reliable and cost-effective method in clinical settings for assessing RTD and strength of hip abductor and extensor muscle groups in healthy adults.