occipitofrontalis muscle is the origin of the primary muscle used in a chin up.
occipitofrontalis muscle is the origin of the primary muscle used in a chin up.
what is the origin of the primary muscle used in a chin up?
occipitofrontalis muscle
brachialis is the main muscle used when the elbow is flexed slowly. during rapid and forceful flexion all three muscles are brought into action assisted by the superficial forearm flexors originating at the medial side of the elbow.









































the efficiency of the flexor muscles increases dramatically as the elbow is brought into midflexion (flexed 90°) — biceps reaches its angle of maximum efficiency at 80–90° and brachialis at 100–110°.
elbow
the v-rod muscle was introduced in the summer of 2008 at the harley-davidson dealer show in las vegas for the 2009 production model year. in promoting the muscle, american fashion model marisa miller was hired for an advertising campaign aimed at younger, urban riders. it would be one of only three vrsc models for 2009. like the other two models, the muscle used the revolution engine, a 240 mm wide rear tire, fuel tank, slipper clutch and forward controls. unlike the other models in the vrsc lineup, the muscle had straight shot dual exhausts, with a crossover, one on each side of the bike, unlike the 212 exhaust found on all other vrsc models. additionally, the muscle used an air-box with mock-up air-rams like those found on many american pony and muscle cars. in the production version of the bike the air-rams are cosmetic. the vrscf also had a chopped rear fender with integrated turn signals, and a side-mounted license plate. turn signals were integrated into the rear view mirrors for the first time as a stock feature on a harley-davidson motorcycle. the vrscf provided at the crank a claimed of torque at 6,500 rpm, which was slightly more torque than the other vrsc models, at a slightly lower engine speeds.
harley-davidson vrsc