Golden Rules of Skeletal Muscle Activity & Terms

Question 1

What are the 4 golden rules of skeletal muscle activity?

Answer 1

1. With a few exceptions, all skeletal muscles cross at least one joint
2. Typically, the bulk of a skeletal muscle lies proximal to the joint crossed
3. All skeletal muscles can only pull → never push!
4. During contraction, a skeletal muscle insertion moves towards the origin

Question 2

Origin

Answer 2

Attachment of a muscle that remains relatively fixed during a muscle contraction

Question 3

Insertion

Answer 3

The movable attachment of a muscle as opposed to its origin

Question 4

Flexion

Answer 4

Bringing 2 bones closer together

Question 5

Extension

Answer 5

Bringing 2 bones further away from each other

Question 6

Hyperextension

Answer 6

Bringing 2 bones further away so that the angle is greater than 180 degrees

Question 7

Rotation

Answer 7

Movement around the longitudinal axis

Question 8

Circumduction

Answer 8

Proximal end is stationary and distal end moves in a circle

Question 9

Dorsiflexion

Answer 9

Lifting motion of the foot

Question 10

Plantar flexion

Answer 10

Depression movement of the foot (towards the ground)

Question 11

Inversion

Answer 11

Sole of foot moving medially

Question 12

Eversion

Answer 12

Sole of foot moving laterally

Question 13

Opposition

Answer 13

Movement of thumb to the tips of the fingers

Question 14

Prime mover

Answer 14

Muscle responsible for causing a particular movement

Question 15

Antagonists

Answer 15

Muscles that react opposite to the movement of the prime mover

Question 16

Synergist

Answer 16

Helps prime movers by producing the same movement or by reducing undesirable movement

Question 17

Fixators

Answer 17

Holds a bone still and stabilizes the origin of the primer mover