I'm 51. I feel like I pulled a lower back muscle on the left side when doing my burpees. They've always been nearly impossible for me since I started 5 months ago at my box. Ever heard of this? Maybe the farther you bring your toes to your hands the more lower back stress it creates or lower back flexibility it requires.
I think one of the issues for me is the flexibility. I usually do step down, step up. But on the step up I can't get my feet up far enough. So, I still end up doing an extra push with my arms to roll back on to my feet solidly before standing and jumping.
I save the quads a bit by instead of jumping the feet up, using the abs to pop up off the ground and letting the hip flexors squeeze the legs up to the hands like a pike. Def requires the mobility for it, though
