Computerised pinch dynamometry in the assessment of adult hand spasticity

Background/aimThe hand engages with the environment through the grasp, stabilisation, manipulation and release of objects during everyday tasks, activities and routines. Upper motor neuron syndrome following acquired brain injury may negatively impact hand function, reducing strength, range of motion and motor control. It is important for clinicians to reliably measure such impacts, particularly for the impact of intervention and to monitor change in performance over time. Therefore, the aim of this study was to investigate the test-retest reliability and construct validity of Dynamic Computerised pinch Dynamometry for measuring fine hand motor performance following acquired brain injury. MethodsThe Dynamic Computerised pinch Dynamometry protocol was completed by 36 community dwelling adults and 27 healthy adults using a simulated pinch and release task in lateral and pincer grip positions. Measurements were conducted over two testing occasions approximately five weeks apart. Dynamic Computerised pinch Dynamometry output was evaluated to determine the test-retest reliability and construct validity of the measure. ResultsTest-retest reliability scores using Kendall coefficient of concordance ranged from W=0.61-0.94. Dynamic Computerised pinch Dynamometry discriminated between participants with and without acquired brain injury (z=4.97-6.50, P<0.05) and between the affected and non-affected hand of participants with acquired brain injury (z=3.37-5.22, P<0.001). ConclusionsDynamic Computerised pinch Dynamometry in both lateral and pincer positions had fair to excellent test-retest reliability, and had good construct validity for discrimination between participants with and without acquired brain injury as well as between the affected and non-affected hand of participants with acquired brain injury.