Skeletal muscles are responsible for generating the forces required to maintain posture and to move, thus to perform any kind of activity. Muscle tissue is said to be dynamic because it is able to change its morphological features in relation to certain stimuli. Clearly, these properties change from muscle to muscle, but also within the same muscle with time. These features, especially the shape, can be altered by pathological conditions such as sarcopenia, cerebral paresis, inflammatory myopathies or arthrotic pathologies, but also in the case of a subject practicing a sport that leads to frequent stimulation of specific muscles. The study of muscle shape is therefore useful as it can provide information about a person's state of health or lifestyle.