The relation between Hill's equation and individual muscle properties.

In this paper we deal with movement-independent individual muscle properties derived from Hill's equation. Relations between these properties are found by theoretical considerations. We define a dimensionless quantity that turns out to play a major role in characterizing individual muscle properties, and we analyse normalization and symmetry behaviour of the parameters in Hill's equation. This leads to a systematic, transparent, and useful overview of mathematical relations involving muscle parameters. We examine the experimentally determined parameters of 62 subjects to find additional empirical relations between the muscle properties described by the parameters of Hill's equation. In the light of the theoretical end empirical results we investigate the connections between maximum efficiency, endurance, and fibre composition.