5 year old with low muscle tone and weakness

My 5 year old has a vague diagnosis of generalized weakness and low muscle tone.  He does appear to have hypermobile joints also, just based on what I see in his movememnts.  We have to travel to specilsts, and so far the pediatric neurologist has not given us any guidenece or additional testing options.  Labs have all been negative including choromosomal testing.  We have in a school that provides large amounts of physical activity to help with imporoving his fine and gross motor skills.  I am worried there could be more wrong with him, and I am trying to figure out what tests and providers to try to take him to.  Also any type of indoor/outdoor kids equipment that can help improve his coordination and help strenghthen his muscles?  I just recently purchased Mighty Tykes weights.  any feedback or ideas on tests that could be helpful or doctors that anyone can recommend in the United States.  

If he is hypermobile be careful of weights. I'm in NZ so can't help with specialist. Have you tried swimming for muscle tone? It's tricky when they are so young.

Good luck.

While he does not have a dx of hypermobile it is pretty clear his joints are loose.  I have read all kinds of information some suggest stretching and weights can do harm, while others suggest low weights such as Mighty Tykes can help stablize the joints.  Its very had I have no idea if he is in pain, it just breaks my heart when he cant keep up with the other kids.  We are going to to take him to a new specialist this summer hopefully, not that there is any type of treatment, but i just want to make sure there is not a more serious underlying cause.  I know I have slightly hypermobile joints but it never caused me the delays he is having.  This summer we plan to swim a lot.  We thought about getting a therpy pool if we thought it would help.  

My nephew has hypermobility. He was very uncoordinated and low muscle tone. He also has Asperger syndrome. He has no problems with school work.

How bout a bike? My nephew ended up with a bike that the pedals were more in front of him rather than below him. Seemed to help muscles develop.

It's hard to watch our little ones struggle. Hang in there.

I have jhs as well as my son and nephew.