L9: Movement

Question 1

What are the four structural levels in the body?

Answer 1

Cells > Tissues > Organs > Body Systems

Question 2

What are body systems?

Answer 2

Systems are comprised of organs which function cooperatively and have a common purposes.

Question 3

What is flexion and extension?

Answer 3

• Flexion: Decreasing the angle between two bones

- Extension: Increasing the angle between two bones

Question 4

What are the terms for muscle functions and the roles muscles play during movement?

Answer 4

• Agonist/prime mover: causes a desired motion
• Antagonist: opposes the action of the agonist
• Synergist: assists the agonist, may act as joint stabilizers, neutralize rotation, or be activated when the agonist is fatigued.

Question 5

Which muscles are stabilizers?

Answer 5

When the agonist and antagonist contract together, and a joint must be stabilized. The muscles that co-contract to protect a joint and maintain alignment are called stabilizers.

Question 6

What are the different types of muscle actions?

Answer 6

Shortens (come together), Lengthen (away from the middle), or remains the same length.

Question 7

What are the different types of movement?

Answer 7

• Static (Isometric) Action: Muscle tension = Resistance
• Concentric (Shortening) Action: Muscle overcomes resistive force
• Eccentric (Lengthening) Action: Returning to resting length from a shortened position, muscle is overwhelmed by resistive force

Question 8

What is a closed-chain movement?

Answer 8

The end of the chain furthest from the body is fixed, while the rest of the chain moves. e.g. Squat where feet are planted on the ground. Emphasises compression of joints which helps stabilise the joints.

Question 9

What is an open-chain movement?

Answer 9

The end of the chain furthest from the body is free, e.g. Seated leg extension. Emphasises shearing forces at the joints.

Question 10

Where is the body’s centre of gravity (COG)?

Answer 10

The point where its mass is considered to concentrate and where it is balanced on either side in all planes (frontal, sagittal, transverse). Gravity is also enacting its constant downward pull through this point. GENERALLY located at the level of the second sacral vertebra.

Question 11

What does muscular balance refer to?

Answer 11

The symmetry of interconnected components of muscle and connective tissue.

1. Equal strength and flexibility on both sides
2. Proportional strength ratios in opposing muscle groups (agonist/antagonist)
3. Balance in flexibility: normal ROM is achieved not exceeded