antagonistic muscle action Flashcards
muscles can create movement in how many directions
1
muscles can only pull on what
bones
why do muscles come in pairs
they can only create movement in 1 direction, so 2 are needed for 2 directions
when muscles work in pairs its known as
an antagonistic muscles action
one muscle ___ the other ____
contracts
relaxes
agonist is the ___ mover
prime
what does the agonist do
contracts to create movement
what does the antagonist do
relaxes as the agonist contracts
why does the antagonist relax
to allow movement
what is an antagonistic pair
an agonist and antagonistic muscle (when one relaxes and the other contracts)
how are antagonistic pairs positioned
BACK TO BACK
examples of antagonistic pairs
tricep and biceps
hamstrings and quadriceps
gastrocnemius and tibialis anterior
2 ways in which muscles contract
isotonic and isometric
isometric contractions are when
the muscle contracts but stays the same length
example of isometric contraction
olympic weightlifting, holding bar above head
isometric contraction is when
the muscle contracts but changes length
what are the 2 types of isotonic contraction
concentric and eccentric
eccentric isotonic is when
the muscle lengthens when it contracts
example of eccentric contraction
quadriceps lengthen as they contract, allowing flexion of knee in a squat
concentric contraction is when
muscle shortens while it contracts
example of concentric contraction
triceps shorten as they contract, creating extension at the elbow when shooting in basketball
