shoulder muscles

Question 1

key points

Answer 1

1. The location & relative size of a muscle may indicate its function
2. Muscles may act to provide both stability & mobility
3. Muscles function together as teams
4. Joint movements can be described in terms of osteokinematics &
   arthrokinematics

Question 2

translation

Answer 2

A force directed through the centre of rotation

Question 3

rotation

Answer 3

A force applied at a distance from the centre of rotation

- this rotation is called moment force

Question 4

moment of force.

Answer 4

When a muscle contraction pulls on a bone, and the bone is fixed at some point (joint), the bone/body segment will rotate around the fixed point.
The force results in a rotation called a moment of force. M= Fd

Question 5

strength

Answer 5

moment of force

Question 6

bones

Answer 6

levers

Question 7

joints

Answer 7

axes / centre of rotation (COR)

Question 8

muscles

Answer 8

provide force = pull

Question 9

line of action

Answer 9

when a muscle contracts it will pull its attachment sites toward the centre of the muscle

Question 10

moment arm

Answer 10

perpendicular distance from the COR to the line of action of the force

Question 11

moment of force simple

Answer 11

the turning effect of a force

= strength of rotation

Question 12

biomechanics

Answer 12

• The joint structural classification indicates the movements possible
• The location of the muscle as it crosses the joint indicates its action
• The PCSA indicates the amount of force the muscle contraction can produce
• Increasing the moment arm increases the strength of rotation caused by that
contraction force
* ability of force to rotate …

Question 13

• The ability of that force to rotate the body segment is determined by 2 things:

Answer 13

1. . The amount of force = PCSA

2. The efficiency of that force = moment arm

Question 14

3 groups of shoulder complex

Answer 14

according to attachment

1. Axioclavicular & Axioscapular
2. Scapulohumeral
3. Axiohumeral