I hate to think of the damage I would have done to my elbows, had I locked them while shooting all of those big bore Magnums, in the Eighties. In actual practice, my arms tremble if my elbows are straight. I have to shoot with slightly flexed elbows, simply in order to steady the weapon. (And, if forced, my elbows will actually hyper-extend, as some of my police academy firearms instructors discovered, when they tried to “straighten” my elbows.)
The main thing I want to convey: Be sure to shoot powerful handguns, so that the barrel is in line with the forearm bones, if firing one-handed, or with a Weaver-type hold. (An isosceles hold, of course, means that the wrists are slightly bent, but the symmetry of the forearm bones results in good support for all of the joints.) Sadly, I fired N-Frames, with K-/L-/GP100-sized hands and fingers, using an imperfect grip, which got “enough” index finger on the N-Frame trigger, in DA mode. This meant that the base joint of my right thumb was more in line with the force of recoil, which was then transmitted in a way that badly torqued my right wrist. Today, 3+ decades later, if I shoot something as “mild” as a 9mm Glock G19, my right thumb and wrist will swell, and hurt, for more than a week, even though I have not fired a .41 Mag since about 1990, or a .44 Mag since 1985. (I can, in moderation, still shoot full-length-grip pistols, such as a G17, and a full-sized, all-steel 1911, and a revolver with a square-butt grip that reaches all the way to the “heel bone” of my hand.)
Yes, I was the police rookie that thought I had to prove myself, by toting “the (then) most-powerful handgun in the world,” as a duty revolver, and I believed in training with ammo loaded to the same power as my duty ammo. Fortunately, I “down-sized” to .41 Mag, after about a year, but it was still a weapon too big for me to hold properly, while shooting DA. Relief came after five years, when I switched to a Colt Commander duty pistol, which fit my hand. When I did switch back to revolvers, for the duty rig, 1993-1997, I understood proper revolver fit, and understood that .357 Mag was ample for human adversaries. (I made the final switch to duty autos in May 1997.)
One interesting thing, that saved my “dominant” hand, is that I write lefty, and do many other detail-oriented tasks lefty, but throw right-handed, so am right-armed. I started my LE career drawing L-Frame revolvers, from the then-mandated low-slung duty rig, which was not unlike an underhanded throw, so the draw felt natural when done right-handed. Plus, I knew I would mostly be patrolling alone, which meant the right hip would be more-accessible, while seated in the patrol car. So, it made sense to mostly shoot my primary handguns right-handed, and my “back-up” .38 snub-gun lefty, so, my left hand was experiencing .38 recoil, from a gun I could hold in a properly-centered grip. The big-bore Mags, fired with an ergonomically-incorrect grip, happened mostly with my right hand.
I am not trying to type so much that I make this discussion “about me.” I just want to present a complete picture of what can happen, with powerful handguns, held improperly.