Into my 40s, I was still a fool who thought pushing through pain and adversity, and taking the craziest, bumpiest, twistiest, most challenging road possible, was a mark of honor and valor and the only way to live. Among loads of other stupidities, I developed severe elbow tendonitis and ulnar nerve damage, which disrupted most everything in my life.
The point is that light, bent shaft, smallish-blade paddles, seem to be, for me anyway, much less stressful on my joints, nerves and tendons, especially on a long day on flat water. Something to think about, especially as one gets older. (I can still act foolish from time to time but I am much less crazy nowadays. I think.)
I specifically avoid any carbon fiber shafted paddles for just that reason. The stiffer shafts (sorry) tend to exacerbate any tendonitis tendencies (seriously).
I have found that the more flexible wooden shafts are much better for my joints. And to those that will complain about the lost energy to shaft flex, just remember that as your effort reduces at the end of the stroke, the paddle shaft deflection also reduces to zero. So that "lost" energy isn't lost at all, only slightly purloined.