This video is not me but a friend. He says after doing this for 15 minutes he can really tell his core was working. I'm in a power chair and can't stand up without assistance but do practice walking with a walker. I recently bought a electric hoist and safety harness to help me get on and off the floor but realize I can also use it to practice standing safely like this. To start I will need to hold the walker, but if I started practicing this regularly, what muscles would be worked and if those muscles are worked, what functional improvements could happen?