I can sit up without using my arms from a lying down position on a firm surface.... I pulled my body out of the HH headfirst using the webbing and did a sort of handstand / tumble / flip to get out (My neighbors were oh-so-amused). Being a female dino I don't have the upper body strength you fellows do, but I can pick up kids up to about 45 - 50 lbs.
i'll try to work on that idea & get back to you. it may or may not be of much help. but we'll see.