Muscle Contraction and Human Movement

Question 1

how does human movement occur?

Answer 1

as a result of a force

Question 2

what 2 things can forces that create human movement be?

Answer 2

internal

external

Question 3

what is internal movement?

Answer 3

force individual can control

muscles work to move bones/joints

Question 4

what is external movement?

Answer 4

force from outside an individuals control

Question 5

give an example of an external force?

Answer 5

gravity

Question 6

what is the name given to the most important ‘mover’?

Answer 6

prime mover

Question 7

what is the term given to a muscle creating internal force?

Answer 7

mover

Question 8

what do our muscles to when experiencing external force?

Answer 8

work to counteract (i.e control movement against it)

Question 9

what 3 types of muscle contractions are there?

Answer 9

concentric

isometric

eccentric

Question 10

what is concentric muscle contraction?

Answer 10

muscle shortens during activity (the attachments get closer)

Question 11

what is isometric muscle contraction?

Answer 11

muscle stays the same length

Question 12

what is eccentric muscle contraction?

Answer 12

muscle lengthens during activity (attachments get further away) to a maximum of its full length

Question 13

when do muscles typically experience eccentric contraction (2 ways)?

Answer 13

when resisting a force

because its relaxed (passive)

Question 14

what is an example of isometric contraction?

Answer 14

when a muscle strains against resistance but doesnt change length

e.g. pushing against a wall; it is preventing a movement taking place/stabilising

Question 15

what is an agonist?

Answer 15

mover

Question 16

what is an antagonist?

Answer 16

muscle/other force that can perform the opposite movement to what is occurring

Question 17

what type of movement does an antagonist muscle typically do?

Answer 17

lengthens (usually relaxing but sometimes contracts eccentrically)

Question 18

what is the primary role of most antagonist movement?

Answer 18

slow a muscle down e.g. after throwing a ball- the mover stops creating force and the antagonist works eccentrically to slow the movement

Question 19

when is gravity the mover, and what is the muscle(s) acting against it?

Answer 19

gravity=mover

muscle=antagonist (working eccentrically)

Question 20

what is the stabiliser?

Answer 20

muscle/force stabilising against the prime mover to create more efficient movement at fixed muscle attachment

Question 21

give an example of a stabiliser?

Answer 21

finger flexion= wrist extensor is stabiliser

Question 22

what is a support muscle?

Answer 22

muscles working statically against the pull of gravity

Question 23

what is a neutraliser?

Answer 23

muscle/force preventing unwanted movement when mover can perform more than 1 function at the mobile muscle attachment

Question 24

what is a synergist?

Answer 24

muscle/force working with contracting muscle

Question 25

what is the base of support (BOS)?

Answer 25

area of body in contact with supporting surface and contact between supporting surface and floor

Question 26

what is the BOS when standing?

Answer 26

2 feet + space between them

Question 27

what is the centre of gravity?

Answer 27

point in body where weight and forces acting as a result of limbs/segments of the body are approximately equal

Question 28

where in the human body is the COG regarded as being?

Answer 28

S2 vertebrae

Question 29

what is the line of gravity (LOG)?

Answer 29

a theoretical line from the COG to the ground

Question 30

what happens to the LOG when the body moves?

Answer 30

it moves accordingly

Question 31

why is it important that the LOG is within the BOS?

Answer 31

if not the person will fall