Real-time visual feedback of exerted force does not affect maximal grip force but influences rate of force development

Handgrip strength testing, commonly performed with the Jamar hydraulic hand dynamometer, provides a simple and reliable measure of maximum grip force (GFmax), which is associated with upper limb function, including dexterity and gross motor performance1 in both healthy individuals and those with hand-wrist conditions.2 Although considered the gold standard in clinical and research settings,3 the Jamar does not assess the maximum rate of grip force development (RGFDmax) or provide real-time visual feedback.