A muscle that has a shape of spindle, which is being wider in the middle and narrowing towards both ends.
Example of fusiform muscle is the biceps brachii.
Fusiform muscles are arranged in a strap-like fashion to provide the greatest degree of shortening, thus, enabling the muscle to produce quick and wide range of motion. However, compared with penniform muscle, they are not a very powerful type of muscle.
Word origin: Latin, fusus
Synonym: musculus fusiformis, spindle-shaped muscle.
Compare: penniform muscle.
See also: muscle.