Dear Lorrie
I'm not Cathe, I hope you don't mind me chiming in. I actually came to Cathe and STS after my own head injury.
Depending upon the severity of your concussion, four weeks of recovery sounds about right. Nausea, headache, fatigue, dizziness and balance/coordination issues will be your guide. I eased into it very slowly, doing only 30 min of weight lifting a day and walking. Yoga helped a lot, but I had to be very careful with inverted poses.
With STS you might want to start with Meso 2 just because there is less equipment change - therefore less bending over, again, you will need to go slowly....you might even consider doing one body part a day.
Don't do too much too soon.
I thought I was better after one week, I went shopping with my boys and ended up sitting right down on the floor in the middle of the Macy's men's department....too sick to stand. It scared the bejeezus out of them.
Please take care of yourself.