Mastering the use of hand-held dynamometry in clinical practice

Measures of muscle performance, such as strength and the rate of force development (RFD), are important for function, rehabilitation, and successful aging. Clinicians seeking to use objective measurement methods of muscle performance in support of their assessments and rehabilitation programs have many affordable dynamometry options. However, substantive differences exist between devices on important characteristics such as sampling frequency, load capacity and determining force onset, which dramatically affect the ability to obtain accurate estimates of muscle performance. The assessment environment and setup also require careful consideration. Busy clinicians are often unaware of the extent to which methodological variability and inconsistencies in testing protocols can inflate measurement error and render tests insensitive to change. Where data inform treatment and return-to-play decisions (vs. motivational aid), ensuring validity and reliability is paramount, particularly given that clinicians typically assess individual, not group performance. This is because ascertaining change or difference in intra-individual performance demands a greater level of measurement precision compared to assessing performance between groups of people. This evidence-informed Masterclass will exemplify some of the critical technical and methodological factors that intrude on measurement accuracy. It will provide readers with the knowledge: how to critically evaluate the utility of dynamometers, answering the question, which to buy and why? How to construct assessment protocols to improve quality data collection, and how to understand what constitutes real change in performance beyond "differences" caused by measurement error.