Movement Mechanics - Chapter 4

Question 1

What is biomechanis

Answer 1

the study and analysis of human movement

Question 2

Why is biomechanics so important in exercise theory?

Answer 2

Helps us to evaluate the effectiveness and safety of our programs and activities

Question 3

What are the three types of muscle action?

Answer 3

1. concentric
2. eccentric
3. isometric

Question 4

What is concentric muscle action?

Answer 4

Action which causes the muscle to contract or shorten. The contractual force is greater than the force of resistance

Question 5

What is eccentric muscle action?

Answer 5

Action which causes the muscle to lengthen or extend. The external force is greater than the concentrical force. In eccentric muscle action, the muscle is actually controlling the descent of resistance. The muscle’s origin and insertion point move further apart

Question 6

What is isometric muscle action?

Answer 6

Action which engages the muscle but which does not require it to contract or to lengthen. The muscle becomes tense but length stays the same. Laying over a boca ball and staying flat - your spine and all your back and abdominal muscles are isometric - they are tense but not longer or shorter. Planking is a good example.

Question 6

What are the 4 roles a muscle can assume? (also called movement roles)

Answer 6

1. agonist
2. antagonist
3. stabilizer
4. synergist

Question 7

What is the agonist role of a muscle?

Answer 7

The agonist is the prime mover. It is the muscle that is doing the majority of the work.

Question 8

Are agonist muscles responsible for doing most or least amount of initiation of movement?

Answer 8

Most

Question 9

What is the antagonist role of muscle movement?

Answer 9

The antagonist role is the muscle working to stop the movement. It is also the muscle that assists with joint stability and protection.

Question 10

What role of muscle movement assists with joint protection and stability?

Answer 10

Antagonist role

Question 11

Muscle movement often happens in pairs - agonist and _______

Answer 11

antagonist

Question 12

Muscle movement is often paired together - concentric and ______

Answer 12

eccentric

Question 13

In a bicep curl, the agonist is the bicep and the antagonist muscle is the ______

Answer 13

tricept

Question 14

In muscle movement theory - in a bicep curl, the bicep is ________ and the triceps is ________________

Answer 14

concentric
eccentric

Question 15

What is the synergist role of muscle movement?

Answer 15

The synergistic muscle assists the prime mover. It provides added joint stability.
The synergist muscle is often engaged when we add weight to an exercise

Question 16

What is the stabilizer role of muscle movement?

Answer 16

The stabilizer muscle is responsible for security of a joint or other body movement while another movement takes place. Ie the shoulder muscles functions as stabilizer to bicep curl. The shoulders are isometric in a bicep curl.

Question 17

Key Movements in Exercise.
What muscles and movements are involved in an Abdominal Crunch?

Answer 17

Joint = spine
movement = flexion
against gravity
Action - concentric
muscle used - rectus abdominus

Question 18

Key Movements in Exercise.
What muscles and movements are involved in Push Ups when arms are fully extended and body is lifted - Elbow joint?

Answer 18

Joint = elbow
movement = extension
against gravity
action - concentric
muscle used - triceps brachii

Question 19

Key Movements in Exercise.
What muscles and movements are involved in push ups when arms are fully extended and body is lifted - from the shoulder joint perspective?

Answer 19

joint = shoulder
movement = horizontal adduction
against gravity
action - concentric
muscle - pectorales major

Question 20

Key Movements in Exercise. What muscles and movements are involved in squats - when legs are in bent position - from the hip perspective?

Answer 20

joint= hip
movement =extension
against gravity
action = concentric
muscle - glutes and hamstrings

Question 21

Key Movements in Exercise. What muscles and movements are involved in squats - when legs are in bent position - from the knee perspective?

Answer 21

joint = knee
movement = extension
against gravity
action = concentric
muscle = quads

Question 22

Key Movements in Exercise. What muscles and movements are involved in squats - viewed from front leg bent - hip joint?

Answer 22

joint = hip
movement = extension
against gravity
action = concentric
muscle = glutes and hamstrings

Question 23

Key Movements in Exercise. What muscles and movements are involved in squats - viewed from front leg bent - knee joint?

Answer 23

Joint = knee
movement = extension
against gravity
action = concentric
muscle = quads

Question 24

What is balance?f

Answer 24

anticipating and reacting to outside forces

Question 25

What 5 factors can affect balance and stability?

Answer 25

1. Base of Support
2. Center of Mass
3. Line of Gravity
4. Friction
5. Inertia

Question 26

What is Base of Support?

Answer 26

How much the body is in contact with the supporting surface.

Question 27

The ______ the base of support, the greater the balance and stability.

Answer 27

wider

Question 28

What is the Center of Mass?

Answer 28

An imaginary point where all the weight of the body is centered.

Question 29

Where is the center of mass in most people?

Answer 29

near their belly button/pelvis area

Question 30

What is an easy way to improve the center of mass and increase stability?

Answer 30

bend to a lower position. Move the center closer to the base.

Question 31

What is the Line of Gravity?

Answer 31

An imaginary vertical line straight down through the center of the body.
Standing on 1 foot and holding a heavy suitcase in the opposite hand would be an imbalanced line of gravity.

Question 32

What is friction?

Answer 32

the amount of resistance encountered when one surface meets another.

Question 33

The _____________ the friction, the more effort is required.

Answer 33

Greater

Question 34

True or false - there is more friction required to walk on ice than to walk on carpet?

Answer 34

False - ice has less friction.

Question 35

What is Inertia?

Answer 35

Newton’s Law - those objects in motion will stay in motion; objects at rest will stay at rest unless a force acts upon them.

Question 36

What is an easy way to use inertia principle to make an exercise more challenging?

Answer 36

Reduce the speed in which the exercise is done…….

Question 37

The Human Lever System has 3 parts - name them.

Answer 37

1. Lever - long bones
2. Fulcrum - joints
3. effort - muscles

Question 38

What 4 factors can change the force of an exercise?

Answer 38

1. increase resistance by adding weight
2. changing the speed of an exercise - slower and more controlled movements are more challenging
3. change the length of the lever - difference between push ups on knees vs on toes
4. change the angle of the pull - the wider the angle, the harder the exercise is.

Question 39

Using 5 factors, modify a lunge exercise to affect stability and balance.

Answer 39

1. Change the base of support - lunge onto a boco ball as a base.
2. change the center of mass - do the lunge with arms raised high above the head to increase the center of mass.
3. change the line of gravity - lunge with left foot while holding a weight in right hand.
4. change friction - lunge on a slider to decrease friction and make exercise more challenging
5. inertia - place a bar bell with weights on the shoulders of the participant to increase inertia and make the lunge more difficult.

Question 40

Modify a squat using the 4 factors to change the force of the exercise.

Answer 40

1. add weight - a bar bell with weights on the shoulders of participant
2. decrease the speed of the exercise to make it more challenging
3. change the length of the level - make the squat deeper, challenging the participant to lower their behind as far down towards the floor as they can.
4. Change the angle of the pull - do squats with hands above the head to change the center of mass and angle of the squat