The other day, I was working out with resistance tubing. I used a lightweight caribeaner to clip the tubing to a metal gate at about the middle of the tubing, and used the handles at either side to stretch the tube out with my arms.

Well, I was facing away from the gate and stretched the rubber out, and the caribeaner slid off the top of the gate and nailed me right in the back of the head. I immediately saw some stars/static and silver streaks, and heard ringing in both ears. These issues dissipated within a few seconds.

After this happened, I promptly put up my things, went back in the house and carried on with my day without any issues. The resistance band was about a 90lb pull, if that matters. I feel fine and I don't believe I experienced confusion, amnesia or headache at all.

Should I be concerned? Was that just one of life's bumps or should I be checked out?