Topic 5

Question 1

What is the joint/main action of the Adductor group

Answer 1

Hip adduction

Question 2

What is the joint/main action of the Biceps Brachii

Answer 2

Elbow & shoulder flexion

Question 3

What is the joint/main action of the Triceps brachii

Answer 3

elbow & shoulder extension

Question 4

What is the joint/main action of the pectoralis major

Answer 4

shoulder horiozontal flexion (in the transverse plane)

Question 5

What is the joint/main action of the Deltoid

Answer 5

Shoulder flexion, abduction and extension

Question 6

What is the joint/main action of the Latissimus dorsi

Answer 6

Shoulder adduction

Question 7

What is the joint/main action of the Trapezius

Answer 7

Shoulder girdle elevation (shrugging)and depression

Question 8

What is the joint/main action of the Rectus abdominis

Answer 8

Trunk flexion ( the traditional “6 pack abs”as in sit-ups)

Question 9

What is the joint/main action of the Erector spinae

Answer 9

Trunk extension (keeps us upright/ erect)

Question 10

What is the joint/main action of the Gluteus maximus

Answer 10

Hip extension

Question 11

What is the joint/main action of the Rectus femoris (part of quadriceps group)

Answer 11

Knee extension and hip flexion

Question 12

What is the joint/main action of the Biceps femoris (part of hamstrings group)

Answer 12

Knee flexion and hip extension

Question 13

What is the joint/main action of the Gastrocnemius

Answer 13

Ankle plantar flexion and knee flexion

Question 14

What is the joint/main action of the Tibialis anterior

Answer 14

Ankle dorsiflexion

Question 15

describe the common place a muscles “origin” is found?

Answer 15

Usually at the proximal end of said muscle. it is usually the muscles tendon thats attached to either the least moveable bone OR bone(s) that are closest to the midline

Question 16

what does “insertion mean”? (muscle’s OIA)

Answer 16

is often the distal attachment, it is usually attached to either the more moveable bone(s) OR the bones that are furthest away from the bodys midline

Question 17

list the ANTERIOR major muscles

Answer 17

Trapezius
Deltoid
Pectoralis major
Biceps brachii
Rectus abdominis
Rectus femoris
Tibialis anterior
Quadriceps femoris group
Adductor group (groin)

Question 18

List the POSTERIOR major muscles

Answer 18

Trapezius
Deltoid
Latissimus dorsi
Triceps brachii
Erector spinae
Gluteus maximus
Biceps femoris
Gastrocnemius
Hamstring group

Question 19

What are agonist muscles?

Answer 19

are the prime movers of the action being carried out, they perform the movement that is being described. For example, in a bicep curl, Biceps brachii causes the movement, elbow flexion.

Question 20

What are antagonist muscles?

Answer 20

are the opposing muscles to the movement being carried out. sometimes they do contact with some force to control the movement. In the case above of the bicep curl, the antagonist muscles are Triceps brachii.

Question 21

What are synergist muscles?

Answer 21

These are muscles that help the agonists carry out the movement. In the example of the bicep curl, Brachialis and Brachioradialis assist the Biceps brachii to do elbow flexion.

Question 22

What are stabilizer muscles?

Answer 22

do not contribute to the actual movement visible, but contract isometrically to stabilise the joint around where the muscle is moving to actually cause the movement.
As the Biceps brachii originates from the scapula other muscles around the scapula would be contracting to keep it from moving when it is doing its bicep curl movement causing movement at the elbow

Question 23

what are the main functions of skeletal muscles?

Answer 23

Allow movement
Maintain posture
Stabilise joints
Produce heat

Question 24

What are the five golden rules of skeletal muscle activity?

Answer 24

1. All muscles cross at least one joint.
   (The only exception to this is some of our facial expression muscles which go from skull bones directly onto the deepest layers of the skin.)
2. Typically, the bulk of the muscle lies proximal to the joint crossed.
3. All muscles have at least two attachments: the origin and the insertion.
4. During contraction, the muscle insertion moves towards the origin.
5. Muscles can only pull, they never push.