What is the normal range for two-point discrimination in the hand?

The normal range for two-point discrimination in the hand is considered to be less than 7 mm. This test assesses the sensory function of the skin and can indicate the density of sensory receptors in a given area. In the fingertips, the two-point threshold can be as low as 3 mm, but on average, areas of the hand have a two-point discrimination threshold around 5 to 7 mm. This sensitivity allows individuals to distinguish between two closely applied stimuli, which is crucial for tasks that require fine motor skills and sensory processing.

Two-point discrimination can vary significantly in different parts of the body due to factors such as the density of nerve endings. The fingertips, for instance, have a higher density of mechanoreceptors compared to other areas like the back or arms, which usually demonstrate a much higher two-point discrimination threshold. In clinical settings, testing for two-point discrimination can help identify neurological issues or peripheral nerve damage. Thus, a result of less than 7 mm falls within the expected normal range for hand function.