Although the relations between body size and some standard tests of muscle strength and movement performance represent a well-documented phenomenon in the literature, the normalization for body size has been used both inconsistently and arbitrarily. This problem is exacerbated when
muscle strength is tested to assess functional capabilities or when movement performance is tested to estimate muscle strength. The reason is that both muscle strength and movement performance can be influenced by body size. Moreover, these relations can differ for the particular muscle strength and movement performance tests.