Test-retest reliability of computerised hand dynamometry in adults with acquired brain injury

Background/aim: The ability to objectively and reliably measure hand performance over time is critical to monitor patient performance and evaluate treatment efficacy. Current spasticity measures are subjective in nature and fail to capture the complexity of the multi-faceted upper motor neuron syndrome. This study examined the test-retest reliability of dynamic computerised hand dynamometry for simultaneously measuring multiple aspects of positive and negative features of the upper motor neuron syndrome during an active grasp and release task. Methods: Community-living adults with upper motor neuron syndrome following acquired brain injury attending metropolitan spasticity clinics for management of upper limb spasticity (N = 36; mean age 50 years ±15) and control participants (N = 27, mean age 40 years ±12) completed a computerised hand dynamometry protocol across two testing occasions 5 weeks apart. Objective measurement of Isometric Force, Cycle Duration and Isometric Grip Work, Force Velocity, was completed during a repeated grasp and release test protocol with a computerised hand dynamometer to evaluate the reliability and reproducibility of hand performance. Results: Kendall Coefficient of Concordance W scores ranged from W = 0.69-0.98 for motor elements of grasp and release, including Isometric Force, Cycle Duration, Isometric Grip Work and Force Velocity. Conclusions: The investigated dynamic computerised hand dynamometry protocol showed fair/good to excellent levels of test-retest reliability in control participants and in subjects with upper motor neuron syndrome following acquired brain injury.