Muscle Fibers, Slow-Twitch

**Definition:** Skeletal muscle fibers characterized by their expression of the Type I MYOSIN HEAVY CHAIN isoforms which have low ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment.

**Tree numbers:** - A10.690.552.500.500.700 - A11.620.249.700

**Synonyms:** - Muscle Fibers, Type I