M easurement o f dynamic strength There is no universally accepted single measure of dynamic strength and various devices, as well as free weights, have been used for dynamic strength testing. These devices include the Incremental Lift Machine (ILM) (Stevenson et al., 1990), and a hydrodynamometer (Pinder and Grieve, 1997). Fixed loads and isoinertial devices such as the ILM have constant resistance to acceleration. In a hydrodynamometer, motion itself is resisted by a drag force caused by the movement of a body through water. In such a device the relationship between velocity and effort can be preset.