I woke up yesterday with a lot of stiffness and ache in my back, middle of the back, just below the shoulder blades. I had done legs the day before, including some squats that were fairly heavy by my standards (not maxing or anything though). Anyways, would that be an area that would likely be related to working out the day before? The ache is higher on the back than what I think of as being worked with squats but I'm no expert. Also, it feels a lot better today but still noticeable. Do I need to take any time off?