Tuesday, May 1, 2007

Muscle actions


Here are a few "different" actions of some muscles that aren't taught in anatomy class.

Latissimus Dorsi: lateral flexion of the torso, extension of the back. Sprint speed. More on this later.

Hamstrings: extension of the knee when the foot is fixed or planted.

Gastrocnemius: knee flexion, knee extension when the foot is fixed or planted.

Pectoralis major: inspiration

External obliques: posterior tilt of the pelvis.

Biceps brachii: shoulder flexion.

Rectus abdominus: resist rotation of the torso.

Adductor magnus: hip extension (3rd most powerful hip extensor), posterior fibers laterally rotate the femur.

TFL and Gluteus maximus: knee stability through the pull of the illiotibial band. Flexion pull when the knee is flexed and extension pull when the knee is extended.

Gluteus medius: anterior fibers flex hip and medially rotate the femur; posterior fibers extend the hip and laterally rotate the femur; both abduct the hip.

Gluteus maximus: hip extension, hip abduction (superior fibers), hip adduction (inferior fibers), lateral rotation of the femur, stability of the knee through the IT band, posterior tilt of the pelvis (bilaterally), rotation of the pelvis (unilaterally), stability of the low back.
Geez, what an amazing muscle! Learn to train it. Train your ass off. (pun intended)

AS

1 comment:

helium said...

Everything makes sense beside:

Hamstrings: extension of the knee when the foot is fixed or planted.

Gastrocnemius: [...] knee extension when the foot is fixed or planted.


How does that work?