Sensory seeking Proprioceptive input

by BigToe
(California)

My son is 3 1/2 yrs old and was diagnosed with severe autism , non verbal last year . he also has sensory processing disorder. My son likes to lean his body one side when I am holding his hand while we are walking, almost like he likes traction on his shoulder, he will deliberately lean forward and put all his weight or bend his knee and fall on the ground when we are walking. This only happen when I hold his hand when we are walking outside but if his walking inside the house he does not do it . But he also likes to bounce in his mini couch and body slam on the couch. he has deep pressure vest that I put on when he seek deep pressure and it seem to calm him down after 20 minutes of wearing it.

any tips on what should I do to prevent my son from leaning on opposite side of his body when we are walking when I am holding his hand. example is when i am holding his right hand he will lean on the left side of his body putting all his weight and the speed of his walking is slow and all of a sudden fast walking then deliberately landing on his knees on the ground and if my husband and I are holding both of his hands each side , he will lean his body forward and put his weight while walking.