should ACh (acetylcholine) fail to be release in muscle contraction?
Are you asking what happens when ACh is not released? The steps of a muscle contraction are as follows, 1. ACh is released from the somatic motor neuron. 2. ACh initiates an action potential in the muscle fiber. 3. The muscle action potential triggers Ca2 release from the sarcoplasmic reticulum. 4. Ca2 combines with troponin and intitates contraction.
This is called excitation contraction coupling, with no ACh the Action potential will not reach the ttubule to begin the chain of events that is muscle contraction.