Comparison of a hand-held and fixed dynamometer in measuring strength of patients with neuromuscular disease.

While numerous studies report acceptable reliability of hand-held dynamometers, very little information is available on factors affecting measurements and comparisons with other force measurement systems. A hand-held dynamometer was compared to a fixed dynamometer to determine if the two systems of force measurement yielded comparable results. Twenty-one patients with neuromuscular disease were measured for maximal isometric strength of 12 muscle groups with both force measurement systems using standardized positioning and stabilization procedures. Only one of the 12 muscle groups tested demonstrated significantly different force measurements between the two systems. Good association was found between both systems in force measurements, with Pearson correlation coefficients ranging from .76 to .90. We conclude that a hand-held dynamometer and a fixed dynamometer yield comparable results in patients with neuromuscular disease, provided that testing is limited to muscle groups producing relatively low forces.