I sprained my back two weeks ago, probably from excessive rowing. My last row (72 minutes) was on October 7, 2020, after which the low back pain was too severe for me to do any exercise. In addition to the pain, the back was as stiff as a board from muscle spasm, presumably of the lumbar region of the erector spinae. I wasn’t able to stand up straight for about a week. Therefore, any exercise was out of the question. I went for a 48-minute slow jog on October 19, 2020. I took a break on October 20, 2020 because I was aching a little in the low back and in the lower limbs, and I really didn’t want to inadvertently injure myself further before my medical appointment on October 21 (yesterday). I was feeling generally unwell yesterday, so I took the day off exercise. This afternoon, I did a light row for 60 minutes without any issue. Throughout the row, I was extremely careful to maintain my form. There is some residual pain when rolling in bed but this seems to be improving in the past few days.