Do antipsychotic cause muscle damage or rewire them because of muscle tightening and stiffness? i have trouble crossing legs and bending bc lowerback

Call doctor: There is a such a thing as neuroleptic malignant syndrome where patients can 'get stiff' from these medications. Muscle stiffness is the least of your worries. If you just started these medications, call your doctor and report this immediately.

Not muscle damage: I don't know which antipsychotic you're taking, but all of them at a high enough dose can cause movement problems such as stiffness and tremor, etc. This isn't a muscle problem. Instead it has to do with the balance of neurotransmitters in nervous system pathways affecting movement. Many of these problems can resolve when the med is stopped, but some last much longer.