Each muscle of the skull has a different name, if you want the name of a specific one, you have to indicate where on the skull you are talking about.
Occipital is the term usually used when referring to the base of the skull.
Diastasis
Tetany is the medical term meaning inability to relax the muscles.
Craniotabes (abnormal softening of the skull )It could also be cranimalacia.cranimalaciaDecomposition...craniomalacia
Costochondritis is inflammation of the muscles in the ribs
intercostal muscles - from inter meaning 'between', and costa meaning 'rib'
Colic is the medical term meaning spasm of the visceral muscles.
rigormortis
Myologist is the term meaning specialist in the study of muscles, but an orthopedist is the typical specialist physician who treats muscle problems.
They are called sutures. They vary in specific names depending on which piece of the skull are sutured by them.
Tetany is the medical term continuous spasm of muscles; tetany may result from hypocalcemia.
Contracture or contraction