1.4 Musculoskeletal System

Question 1

Role of agonists and antagonists

Answer 1

Agonist = responsible for the movement, contracting

Antagonist = works in opposition to the agonist, lengthening and acting as the antagonist

Question 2

Agonist and antagonist for ‘elbow flexion and extension’.

Answer 2

Flexion:
Agonist = biceps
Antagonist = triceps

Extension:
Agonist = triceps
Antagonist = biceps

Question 3

Agonist and antagonist for ‘ankle plantar and Dorsi-flexion’

Answer 3

Plantar flexion:
A = gastrocnemius
AN = tibialus anterior

Dorsi-flexion:
A = tibialus anterior
AN = gastrocnemius

Question 4

Agonist and antagonist for ‘knee flexion and extension’

Answer 4

Flexion:
A = hamstrings
AN = quadriceps

Extension:
A = quadriceps
AN = hamstrings

Question 5

Agonist and antagonist for ‘hip flexion and hip extension/hyper-extension’

Answer 5

Flexion:
A = hip flexors
AN = gluteals

Extension:
A = gluteals
AN = hip flexors

Question 6

Agonist and antagonist for ‘hip adduction and abduction’

Answer 6

Adduction:
A = adductors
AN = gluteus medius

Abduction:
A = gluteus medius
AN = adductors

Question 7

Agonist and antagonist for ‘hip horizontal adduction and abduction’

Answer 7

Horizontal adduction:
A = adductors
AN = gluteus medius

Horizontal abduction:
A = gluteus medius
AN = adductors

Question 8

Agonist and antagonist for ‘shoulder flexion and extension/hyper-extension’

Answer 8

Flexion:
A = anterior deltoid
AN = latissimus dorsi

Extension/ hyper-extension:
A = latissimus dorsi
AN = anterior deltoid

Question 9

Agonist and antagonist for ‘ shoulder horizontal adduction and abduction’

Answer 9

Horizontal abduction:
A = latissimus dorsi
AN = pectorals

Horizontal adduction:
A = pectorals
AN = latissimus dorsi

Question 10

Agonist and antagonist for ‘shoulder adduction and abduction’

Answer 10

Adduction:
A = latissimus dorsi / posterior deltoid
AN = middle deltoid / supraspinatus

Abduction:
A = middle deltoid / supraspinatus
AN = latissimus dorsi / posterior deltoid

Question 11

Isotonic muscle contractions

Answer 11

Isotonic = a muscle contracts to create a movement

Eccentric = muscle lengthens under tension; acting as a brake in helping control the movement of a body part during -tive work.

Concentric = muscle shortens under tension.

Question 12

Isometric muscle contractions

Answer 12

Isometric = when a muscle can contract without lengthening or shortening; as a result no movement occurs.

Occurs when a muscle is acting as a fixator or acting against a resistance.

E.g. crucifix in gymnastics