Pushing strength in jiu jitsu is key as I highlighted in my article 'Strength Training for Jiu Jitsu - 9 key concepts' although if you're not doing them properly, or other pushing motions you're not getting the full benefit and likely going to develop shoulder problems. This forms your foundation for all pushing strength movements when strength training for Jiu Jitsu, so take the time to get it right.

Have you or any of your training partners ever had shoulders pain from training Jiu Jitsu?

I'd be very surprised if you answered no. The shoulder is a very common injury area in Jiu Jitsu and I'll show you one key detail you must add to the t-plank to build shoulder strength and stability, as well as strength in the elbows, core and thoracic spine. Build up to a 90 second hold on each side.