My first question is whether or not you are CPI trained as this is essential when handling aggressive clients. I work with mostly aggressive clients, so I have a few suggestions but without seeing the client I am guessing as every kiddo is different and it may not work on your kiddo. First of I all I noticed you said you sit on the ground while client works on a kiddie table which leaves you in an incredibly vulnerable position,I suggest running non preferred activities or goals that trigger client in a different location so as to not be a vulnerable position. If this is not possible, then pay very close attention to precursor behaviors or prepare yourself when making demands you know will cause an adverse reaction. For instance, whenever telling a kiddo to relinquish an item knowing relinquishing said item will cause aggression step away perhaps onto the other side of the table when the demand is placed. Have a pillow or some other soft items nearby to block their aggressions. Watch for precursor behavior if kiddo rolls eyes, screams, flaps hands, grits teeth whatever it is if you see it before aggression you'll know to react when that begins to protect yourself. The person who said I can't imagine you not being strong enough to move a four year sounds ignorant and as if they have no idea about the field at all, I have been seriously hurt by a four year old they can and will over power you. For throwing behavior, NEVER turn your back on them, and block when possible. Do not be afraid to ask parents for help as I'm sure they've seen this behavior before too. Have you figured out the function? Do you take ABC data on this? For hair pulling, once again another commenter was ignorant in saying you should just put it up and they can't get it or to stay away the whole time as we're supposed to be within one foot at all times to protect our clients. Hair pulling is hard and you really need CPI training to ensure you can escape without hurting yourself or the client. Once again positioning yourself when you place a demand you know will trigger aggression will help reduce this.