Muscle architecture for pennate muscles. Pennate muscles can be further divided into uni-, bi- or multipennate. Unipennate muscles are those where the muscle fibers are oriented at one fiber angle to the force-generating axis and are all on the same side of a tendon. The pennation angle in unipennate muscles has been measured at a variety of resting length and typically varies from 0° to 30°. The lateral gastrocnemius of wild turkeys is an example of this muscle architecture. Muscles that have fibers on two sides of a tendon are considered bipennate. The stapedius in the middle ear of humans, as well
Supinator muscle the most active muscle in forearm supination during unresisted supination, while biceps becomes increasingly active with heavy loading. Supination strength decreases by 64% if supinator is disabled by, for example, injury. The term "supinator" can also refer more generally to a muscle that causes supination of a part of the body. In older texts, the term "supinator longus" was used to refer to the brachioradialis, and "supinator brevis" was used to describe the muscle now known as the supinator. Supinator muscle In human anatomy, the supinator is a broad muscle in the posterior compartment of the forearm, curved around the