Are motor tics associated with sexual abuse as a child?

No: Motor tics are, generally speaking, a biological condition, responsive to behavioral techniques, and medication.

Not necessarily: Tics can be worsened by stress. So sexual abuse can trigger anxiety, and possibly tics. But motor movement disorders and tourette's are not caused by environmental factors. A more likely result of sexual abuse are symptoms consistent with post traumatic disorder, withdrawal, sexual precocity, aggression, and aloofness.