I've been doing box squats as my max effort lower body lift under WS4SB3 for the last 2 weeks. Yesterday, I upped my weight significantly, and found that my lower body could handle it, but my upper back hurt after the workout.
When I first unrack the barbell, I don't have an arch until I set up. So my question is: should I have an arch the full time that I'm loaded with weight? And I did have a belt on, and used the traditional block method to tense my core, so my lower back is fine. Does anyone know how to prevent this upper back potential injury?
And finally, when I have more weight than I'm used to off the rack, I can't really TELL if my arch is in deep or not. It seems odd, but I feel more overwhelmed just holding it.