If his lower body is sinking, it may be because his position in the water is off. Often kids have their heads up, and even when under water will have their head up higher than their chest. That causes the hips to sink and makes it hard to kick well.

Kickboards can encourage that posture. Try having him push off into a streamline with his face in the water, and then kick for as long as he can hold his breath. If he kick is better in that position, work on keeping streamline.

Tell him to squeeze his bottom when kicking. Adults can squeeze their butt cheeks to improve kicks as crazy as it sounds. Have him squeeze his bottom together when kicking. Try it with flutter it’ll show the quickest results and he should then feel comfortable with the other kicks.

I have a mild/moderate low tone kiddo. Tried all the private lessons, exercises, PT. Put said kiddo on a club team that was understanding of their condition. Proper drills/coaching/repetition made ALL the difference.

Practice using a kickboard with straight legs.

Would extra repetition outside of the private swim lessons help build up the muscles? Maybe with a kickboard so that he can focus on the kicking?

Following. My 6 year-old has this problem. It’s called “bicycle kick.” He’s on the spectrum and he’s seeing an OT as well. Instructors have been working with him for a few months now.

Both private swim instructor & group swim instructor mention to me that DS's kick is bad. His lower body is sinking and it is wrong to bend his knee while kicking. He has mild low muscle tone with weak core. How could I as a parent help to improve his kicking form? DS tells me that that his legs are weak. Anything that I could do? Swimming and soccer are his favorite sports even though he is not good at both. The private swim instructor is trying to change his kicking form over next 2 months (is that a waste of money?) , but it is difficult for him to change out of his habit or maybe his physical limitation.

He is seeing weekly OT therapist for other reason. I don't think therapist can help. I am wondering if he should do squat at home to strength his lower body? He is 9.