Three months ago I could not, now I can. My flexibility and mobility had been diminishing, my posture, while not horrible, was not good and the tightness in my lower back, which I've had for several years, just wouldn't ease up. As fate would have it my wife had been going to this place called StretchLab and I thought what the hell, I'll try it. Twice a week for the past 3 months and I also doing a morning routine myself every day now. Took about 4-6 weeks to feel some appreciable results, but it has worked quite well for me. I have also gravitated much more towards bodyweight exercises. I still left weights twice a week, one day upper, next day lower, every other workout day is bodyweight only. Considerably less joint and tendon soreness as a result. No real loss in overall strength, muscle tone is actually better, and my balance has improved quite dramatically. Physical balance, mental balance is still a crapshoot.
Human backs are not designed to be flat, so I wouldn't worry too much about failing the test. https://www.mayoclinic.org/healthy-lifestyle/adult-health/multimedia/back-pain/sls-20076817?s=2 https://www.mayoclinic.org/healthy-lifestyle/adult-health/multimedia/back-pain/sls-20076817?s=4