applied anatomy & physiology - musculoskeletal system and analysis of movement

Question 1

what is an isotonic contraction?
-concentric
-eccentric

Answer 1

isontonic = muscle contracts to create movement
-a muscle causes movement in an isotonic contraction and tehre are 2 type

concentric - muscle shortens under tension
e.g. upwards phases of bicep curl, flexion at the elbow, bicep concentric
eccentric - muscle lengthens nder tension (& doens’t relax)
-acts as a brake in helping control movement of a body [art during negative work
e.g. landing from a jump - bent knee - knee joint is flexed but quadriceps are unable to relax as weight of body ensure that they lengthen under tension

Question 2

what is an isometric contraction?

Answer 2

a muscle can contract without actually lengthening/shortening, as a result there is no movement
-when a muscle is acting as a fixator/acting against resistance

Question 3

what does agonist and antagonist?

Answer 3

agonist= muscle that is responsible for movement that is occuring
antagonist= muscle that works in opposition to the agonist (to help produce a co-ordinated movement)

Question 4

examples of agonist + antagonist
(using bicep)

Answer 4

-the anchor point is on the scapula (shoulder) and other end of muscle attaches on the radium (forearm)
-bicep responsible for flexion of elbow and when muscle contracts, radius moves upwards towards shoulder
-when bicep contracts, responsible for movement that’s occuring = agonist
-can be more than 1 agonist acting on 1 joint
-antagonist muscle is one that works in opposition to agonist
-when bicep contracting, tricep lengthening
-muscles work in pairs to produce rquired movement