Muscle quality an evolving concept.

Muscle quality concept can be analyzed from a morphological and functional perspectives that include relation between these properties. Morphological muscle quality considers muscle composition, architectural and structural properties. Functional muscle quality has been defined as a ratio between muscle strength or power per unit of muscle mass or area. Biological and adaptative changes to ageing must be considered when interpretation of muscle quality assessment is done in a clinical or research context. One of the conditions that requires an adequate homologation in terminology is sarcopenia, to establish definition and cut-off points.