David is twenty-five years old and lives in supported accommodation. He has ASD. He has no expressive communication other than a few signs that are used idiosyncratically, so that only people who know him can understand them. However he understands verbal communication and sign at a concrete level, and has good self-care skills. David is extremely tactile defensive. If he is touched, even accidentally, by another person, he becomes very anxious and needs to perform repetitive rituals, sometimes for a couple of hours. Interruption of these can result in a full-blown panic attack from David, during which he may lose control to the extent of becoming aggressive. David needs to attend surgery as he has been limping and may have injured his foot.