His muscles twitched, but he made himself stand a moment longer.

A muscle at the side of his mouth twitched as he said it.

A muscle in the side of his neck was twitching.

Suddenly, a muscle at the corner of his mouth twitched.

A muscle was twitching at the corner of his mouth.

A muscle twitched in his jaw as he turned back to me.

I tried to smile and say hello, but not a muscle twitched.

He didn't answer at first, but the muscles were twitching just below his jaw.

The muscles twitched, the eyes opened, some consciousness, and then back to sleep.

The muscles of his face twitched as if he had been struck a blow.