Is it normal to have muscle contractions when waking up from anesthesia?

Not unusual: Some patients wake up from general anesthesia with significant shivering. It may be caused by being cold - patient's can get cold fairly quickly if not kept covered (and sometimes warmed with special heated blankets). Warm patients can also shiver. It is thought to be caused by the different parts of the brain and spinal cord "waking up" at different rates. Meperidine (demerol) may help.

Sometimes: One of the medications that we use in anesthesia, succinylcholine, can cause muscle spasms or aches in the post operative period. These usually resolve within hours. Often muscle spasms can be confused with the severe shivering that can occur when a patient's temperature is lowered by being in a cold or with cold IV fluids being given. This resolves once the patient is warmed up.

Shivers : Shivering is a common occurrence after recovering from general anesthesia. It's a response to thermoregulatory changes after anesthesia. Warming patient is the first line of therapy but every patient should be warm after anesthesia and during surgery too.