Please enable JavaScript.
Coggle requires JavaScript to display documents.
45-1 Describe the types of muscle action - Coggle Diagram
45-1
Describe the types of muscle action
Muscle action or contractions are
described as
Isometric contraction
constant length
eg: deltoid maintains steady
contraction, holding arm in
abducted position
resistance & gravity is equal
no movement
events
Both the distal and proximal bony levers are fixed
No visible motion occurs when the muscle develops active tension
Sarcomere does not change length
Eg: Holding the weight without changing the joint angle
Dynamic contractions
Concentric contractions
shortening of
muscle under load
eg: deltoid shortens to
raise arm in abduction
force generated by muscle
exceeds force of gravity
so arm moves up n away
events
Muscle shortens while continuing to produce active tension
Sarcomere shortens
Cross-bridges are formed, broken and reformed
1 more item...
Eccentric contractions
lengthening of
muscles under load
eg: deltoid lenthens to
lower arm in adduction
muscle relaxes,
force generated becomes
less than gravity
gravity pulls limb down
as muscle resistance decreases
events
Muscle elongates while continuing to produce active tension
Sarcomere lengthens
Cross bridges are broken, reformed and broken again
1 more item...