My son is 17 months old and he is having hypotonic CP as diagnosed by his neurologist. He doesn’t sit on his own neither he tries to do 4 point crawling. I have tried so many tricks to make him hold the pose of 4 point but he always flattens his legs and make them tight. I really need help to atleast get him in kneeling.
It sounds like working on sitting and core strength would be the first thing to focus on. How does he do on his belly? Is he attempting to push up and reach for things? Is he rolling? How is his head control? Do you have a therapy ball at home? Sorry for all the questions! This post has some ways of using the ball to work on core strength. I would look towards the bottom of the post.
You can also work on reverse pull to sit so starting with him in sitting and slowly lowering him towards the ground. But work in the range where he can hold it.
Sounds like he still needs a lot of core strengthening work to be able to hold a sitting position and then eventually a four point quadruped position.
Lots of tummy time and supported sitting on a therapy ball is great as @Starfishtherapies mentioned.
Check out my post of supporting in quadruped to give you some tips
He does okay with tummy time. Do you have core exercises that i can work with him?
From your description, it sounds like your son would really benefit from direct services with a local pediatric physical therapist. Have you been able to set that up?