Ped immunization

so first off new to peds and being trained but one question I have that isn't being answered in a way I am understanding.

When giving a lot of immuz is to put into the anteior part of the thigh where there is the most muscle.The angle, placement of needle I understand- what I am havingdiffculty getting is the postion between myself and the child.

in this clinic I am suppose to have the child at the end of the exam table to the point the knees bend over the edge, so that my legs press against theirs to the exam table. this is while the parent holds the upper body. The child is squirming and kick or trying to. of course the reasoning of this postioning is to control all this movement during the injection.

before I took this postion I heard of people sticking themselves in this postion or getting hurt by the kicking. the people I know personally: one hurt their back somehow, another bruised leg and the third was a male MA who was kicked in the groin.

after taking this postion I am told that noone has gotten hurt using this position. so confused there.

the idea I had that seemed to work was to have the parent hold the upper body while I held the legs with one hand, while using the needle with theother hand. sitting here writting that it does look/sound more akward but it Is smoother then the wording just used. I do have the strength to pull this off

so there is a gap in understanding here or maybe a better way then either of the ways mentioned. I diffently want to do this in way where no one gets hurt and get it figured out very quickly. if something in all this rambling isn't clear ask- today was bit of a long one and my mind is spinning