Are there things in my control that make chiari malformation more likely?

No: This a defect that you are born with. You could not cause it and you cannot prevent it.

No: A chiari malformation is a congenital malformation where part the cerebellum in the back of the brain lies low and slips through the large opening at the base of the skull. Most patients are born with them, and type 1 is usually asymptomatic. Types 2 and 3 are more severe and often require surgery. An acquired chiari can occur following a lumbar shunt procedure, but this is quite rare.