Fluctuation in grip and pinch strength among normal subjects.

Grip and pinch strength testing are commonly used to evaluate hand strength for disability ratings and to assess responses to various forms of therapy. This study determined the variations in grip and pinch strength in normal individuals. Ninety-five healthy subjects--61 women and 34 men--were examined prospectively by use of a Jamar dynamometer and a Preston pinch gauge. Grip and pinch were measured in the morning and afternoon twice a week for 3 weeks, giving a total of 12 testing periods. Mean grip strength fluctuated between 5.1 and 8.4 kg, or between 19.2% and 23.7%. Mean lateral pinch strength fluctuated between 2.6 and 3.8 pounds, or between 13.8% and 17.6%. There were no differences between the morning and afternoon values. Grip and pinch strength fluctuate over time. Repeat testing is necessary to accurately assess hand strength. Grip and pinch strength do not vary from morning to afternoon.