Reliability of Hand-Held Dynamometer in Measuring Gluteal Muscle Rate of Torque Development and Peak Torque: Push and Pull Configurations.

Background: 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/hypothesis: To determine the intra- and inter-reliability of HHD utilizing push and pull configurations to measure hip abduction and extension early (0-100ms) and late (100-200ms) phases RTD and peak torque. We hypothesized HHD with both configurations would be reliable for measuring hip extension and abduction RTD and peak torque.

Study design: Cross-sectional study.

Methods: Twenty healthy adults (10 females) performed three consecutive maximal isometric contraction trials of hip abduction and extension, utilizing an HHD with push and pull configurations by two raters. Each rater's average early and late phases RTD and peak torque of hip abduction and extension were utilized for analysis.

Results: Intra-rater reliability of hip abduction with push and pull configurations ranged moderate-to-good for early and late RTD phases (push: ICC2,1=0.61-0.88; pull: ICC2,1=0.59-0.75). Peak hip abduction torque showed good reliability in both configurations (ICC2,1≥0.79). Hip extension ranged moderate-to-good reliability for early and late RTD phases in push configuration (ICC2,1=0.72-0.87), with good-to-excellent reliability in pull (ICC2,1=0.77-0.91). Peak hip extension torque showed moderate-to-excellent reliability for push configuration (ICC2,1=0.73-0.92) and excellent reliability for pull (ICC2,1≥0.91). Inter-rater reliability for hip abduction showed moderate in push (ICC3,k≥0.72) and good in pull (ICC3,k≥0.78) configurations for both RTD phases, while hip extension showed good reliability in push (ICC3,k≥0.82) and excellent reliability in pull (ICC3,k≥0.95) configurations. Peak torque showed good reliability for hip abduction (ICC3,k≥0.83) and excellent reliability for extension (ICC3,k≥0.94) in both configurations.

Conclusions: HHD with push and pull configurations is a reliable and cost-effective method for assessing RTD and strength of hip abductors and extensors in healthy adults.

Level of evidence: Level 3.