Age 56.6 here.
I actually went through several years of dealing with bilateral carpal tunnel, tendinitis, RSI in upper body in my early 40s. It was a real PITA to have to give up things like softball, racquetball, volleyball, golf, and any manually intensive or repetitive activities in daily life. My grip strength went to hell. It was determined that I had an outcome of a permanent partial disability (10%) in my hands. If I continued to w*rk, it would have worsened.
Besides the nasty politics, it was the
biggest reason for me to quit. I did not get disability retirement.
Present day...8 years after FIRE, I am actually regaining some of my hand strength back and have nowhere near the upper body issues because I am not on the computer stuck in an office chair 8 hours per day.
I do my hand exercises and all over body stretches every day. I use light hand barbells for toning and overall upper body health. I am steadily getting some improvement.