Status:Closed Asked:Apr 09, 2012 - 07:29 PM
Altered Reciprocal inhibition and what it means
I have a hard time understanding this concept.
From what I understand reciprocal inhibition means when the prime mover (agonist) contract, the antagonist must relax.
But..... I don't understand the definition on the book on page 154. It reads the simultaneous relaxation of one muscle and the contraction of its antagonist to allow movement to take place. AND this contradict with the example of the bicep on the same page. the example read: to perform elbow flexion during a biceps curl, the biceps brachii actively contracts while the triceps brachii (the antagonist muscle) relaxes to allow movement to occur.
So is there a mistake in the textbook or I am not understand why the definition and the example are stating the opposite thing.
Another example on the same page: tight hip flexor would decrease neural drive to the hip extensor. (my interpretation is hip flexor the antagonist is tight and it decrease the hip extensor (the glutes) to fire to activate therefore it's lengthen while hip flexor antagonist is tight.... so from this example.. isn't alter reciprocal is caused by tight ANTAGONIST and not agonist ... the description in red said altered receiprocal inhibition is the concept of muscle inhibition caused by a tight agonist, which inhibits its functional antagonist.
Can someone please explain both concepts to me reciprocal inhibition and altered reciprocal inhibition.
Did the textbook made a mistake? cuz I am not understanding it.. cuz the examples of the biceps curl and tight psaos (hip flexor) doesn't demonstrate the two concepts
This can be confusing sometimes because of the definition of reciprocal inhibition is confused with altered reciprocal inhibition. Think of these two as different things. Reciprocal inhibition is normal and needed for movement to take place. Altered reciprocal is not something that should happen.
When as muscle contracts it is being activated by the nervous system and the opposing muscle is being sent a single to become less activated to allow the movement to take place and this is reciprocal inhibition.
Altered reciprocal inhibition is when a muscle is activated (the agonist) when it should not be and it is decreasing the signal strength to the opposing muscle (the antagonist). Think of the agonist as a muscle being activated even if it is not contracting. The antagonist is the muscle that is opposite of the muscle that is activated.
In the example in the book if a person is standing the hip flexors should not be overactive or tight (activated) if they are then the hip flexor will cause inhibition of the glutes. Inhibition of the glutes should only occur if the person was lifting the leg up using the hip flexor muscles. So when muscles are inhibited due to tightness it is termed altered reciprocal inhibition.
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