The same thing happened to me except it was on T-Bar rows. Everything was going good, kept going heavier until I heard the POP on my left side. I thought for sure I broke something because when I stood I looked like a D. Amazingly doctor said it was a muscle spasm. Got a prescription for Celebrex (the arthritis medicine), went away after about 5 days. I feel for you man because I know what it's like not to be able to sleep or sit.
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