Grip strength varies based on age, sex, and hand dominance. The presence of conditions such as arthritis, trigger fingers, or carpal tunnel syndrome can reduce grip strength. The position of your hand can also change the strength during testing.

Grip strength is usually measured using a special tool called a dynamometer. This test is often given by a physical or occupational therapist. Pinch strength can also be measured with a smaller, similar tool. Results from a 1984 study of normal grip strength done at the University of Wisconsin (Milwaukee) Occupational Therapy program can be found at http://www.bleng.com/pdf/grip1.pdf. There is some question whether the newer dynamometers would give different normal values if tested in adults today.