4.2 Joint Movement and Muscle Contraction

Question 1

Outline the movement of synovial joints.
4.2.1

Answer 1

->

Question 2

Extension of a joint is best described as..
4.2.1

Answer 2

Increasing the angle between the two bones involved in a particular movement.

Example:
When the quadriceps contracts, knee extension increases the angle between the femur and tibia.

Question 3

Flexion of a joint is best described as…
4.2.1

Answer 3

Decreasing the angle between the two bones involved in a particular movement.

Example:
When the hamstrings contract, knee flexion decreases the angle between the tibia and the femur.

Question 4

Outline the movement of synovial joints.
4.2.1

Answer 4

->

Question 5

What is the difference between between ….?
-Protraction & retraction
-Inversion & eversion
-Elevation & depression
-Dorsiflexion & plantarflexion
4.2.1

Answer 5

->

Question 6

Explain the movements: Abduction & Adduction. Provide an example
4.2.1

Answer 6

Abduction- the movement of a limb away from the midline of the body.

Adduction- the movement of a limb towards the midline of the body.

*Adduction-> “adding” the limbs to the body

Question 7

What is this movement called?
-> picture attached
4.2.1

Answer 7

Horizontal adduction & abduction
(also known as horizontal flexion & extension)

Question 8

What is pronation & supination?
Give an example
4.2.1

Answer 8

The ‘twist’ movement in a limb.
Example: Pivot joint between ulna and radius allowing the hand to be palm up to palm down.

Question 9

What is a synergist muscle?

Answer 9

Synergist muscles assist the prime mover/agonist during an exercise.

Question 10

What is a fixator muscle?

Answer 10

Fixator muscles stabilize the origin to maintain a correct and stable position when the agonist is working.

Question 11

How does circumduction differ from rotation of a joint?

What joints allow circumduction?
4.2.1

Answer 11

Circumduction is the movement of a limb in a circle. Rotation is when a limb moves around its long axis, turning like a screw.

Ball and socket joints -> shoulder, hip

Question 12

Outline the types of muscle contraction.
4.2.2

Answer 12

Question 13

Explain the concept of reciprocal inhibition.
4.2.3

Answer 13

A muscle can only pull on a bone, they cant push a bone back to its original position. This is why muscles work in antagonistic pairs.

These antagonistic pairs work with the concept of reciprocal inhibition. The agonist muscle contracts, while the antagonist muscle relaxes.

Example: Bicep Curls
Biceps Brachii (agonist) contracts
Triceps Brachii (antagonist) relaxes

Question 14

Analyze movements in relation to joint action and muscle contraction.

Which antagonistic pair is involved in Shoulder flexion, and extension. Mention eccentric & concentric contraction

4.2.4

Answer 14

Flexion

AGONIST (prime mover) = Anterior Deltoid & Pectoralis Major -concentric

ANTAGONIST (relaxed) = Posterior Deltoid & Latissimus Dorsi -eccentric

Extension

AGONIST (prime mover) = Posterior Deltoid & Latissimus Dorsi -concentric

ANTAGONIST (relaxed) = Anterior Deltoid & Pectoralis Major -eccentric

Question 15

Analyze movements in relation to joint action and muscle contraction.

Which antagonistic pair is involved in Elbow flexion, and extension.
4.2.4

Answer 15

Flexion

AGONIST (prime mover) = Biceps Brachii -concentric

ANTAGONIST (relaxed) = Triceps Brachii -eccentric

Extension

AGONIST (prime mover) = Triceps Brachii -concentric

ANTAGONIST (relaxed) = Biceps Brachii -eccentric

Question 16

What does DOMS stand for?
What is it?
When does it peak?
4.2.5

Answer 16

Delayed Onset Muscle Soreness

• Muscle soreness following exercise
• Sub-cellular damage and inflammation

In general peaks 1-2 days after but can last 10 days.

Question 17

What type of muscle contraction is DOMS typically associated with?
4.2.5

Answer 17

eccentric contractions
- it places more stress on the muscle since you go against gravity