My son is 6 and he has been using his scooter (regular one shaped like L with wheels), he is happy and he knows kids his age uses them too for fun so keep him on it as long as you can, easy to travel with even at airports.
Our son refused to be in the medical stroller as he thought it made him look like a "baby" and he loved go go scooter. He is on his 3rd go go scooter and also now at age 19 has a power chair. The scooter works well for him when we travel on a plane and when his power chair is in for repairs. Good luck! Cheri
ps We also wore out 2 double strollers when the kids were younger. Jacob was our middle child of 3, he has an older non DMD brother and younger sister. We had a fround to back double stroller and a side by side one for when they got older.
I have to with DMD..they are now 16 and 13. When they were little up until my oldest was about 7 or 8 I pushed them around in a double jogging stroller. My 16 yr old started using an electric scooter in 6th grade..Also get a handicap placard for your car so you can park as close as possible to everything. As they got older, i would sometimes rent or borrow a manual wheelchair and push them.
I'm so sorry. I can only imagine how hard the last year has been for you.
I only have one boy with DMD, but we used a sit and stand stroller, and it worked great. The older kid (our DMD boy) can hop on and off the back, and he never felt like a baby because he was in control. Now that he's older (8), he uses a scooter that he can drive himself, but then your younger two could use the sit and stand?
It's like this one: