I read your answer to a grandmother who had a grand son or grand daughter at the age of 34 months that was falling a lot. I have been trying to find something about this issue online and that's how I ended up on your web page.
I am a guardian of a toddler who is 29 months and he has the same problem. He falls and stumbles over the smallest things and a lot of times he will walk into things like a table or the doorway etc. We have baby gates in the house to protect him from falling in any stairs and the house is really kid safe. He walks normal, seems to have a normal hearing and he is talking well for his age.
He has a sister that is 4 years old and she is very athletic and she never had any problems falling or walking into things like he does. The two kids spend one week with their mom and one week with their dad and are also in preschool five days a week when they are with dad. The toddlers preschool teacher asked me if we had noticed that he is always bonking into things and falls a lot. He also comes home from his mom with bruises so we know this happens here, at his mom's and in preschool.
He is also showing early "warning signs" of learning disability. He is left handed, his fine motor skills are not quite there , and he can't put a 4 piece puzzle together even if the picture of the shape is on the puzzle board. We know that he cant be diagnosed until he hits second grade, but we have been made aware of early warning signs. His dad has learning disability so we don't think it is unlikely that one or both of his kids could end up with some sort of a learning disability as well. The toddlers dad and I are doing things to try to prevent this from ever happening and we are doing it in form of fun play. The toddler loves to try to thread beads on a string, he has a box with different shaped blocks that has to go in one certain hole, we have easy wooden puzzles and building blocks to boost his imagination. And he plays the games only as long as he has fun doing it. I don't know if this can be a part of him always falling or walking into things as far as his motor skills goes.
we would be very happy if you have any ideas of what we could or should do if anything to help the "little guy" from hurting himself so much.
If you could please send me a mail back we would be very thankful.
On reading of your grandson's problems, the first thing I thought of was "Has his vision been checked?" This was because he is walking into things but as you noted he may have a muscle problem predominantly affecting his legs.
An optometrist or an ophthalmologist can check his vision while his muscles can be assessed by a physiotherapist who can also show you exercises to help any problem detected. If necessary your local doctor can refer your grandson to the above specialists - ones with expertise in assessing children would be best.
Please let me know how things turn out.