Stem shifter impalement is something to worry about at times of accidents
So the accidents that could result in this injury is the lesser evil bearing in mind road bikes are heads down speed machines. Broken necks/bones are worse than being spiked by shifters. Never been got by my shifters yet and I have crashed numerous times !
Choose your shifters based on your own preferences and modern STI are probably best and are if the right model is sourced retro by now
Copied from the late great Sheldon Brown's site -
A type of shift lever which mounts on the shaft of the handlebar stem. These were popular in the late '70's and early '80's because they permitted shifting without having to lean down to reach down-tube mounted shift levers. Stem shifters, along with brake extension levers, encouraged riding using only the top of drop handlebars. This riding style was popular at the time, because many casual cyclists bought bicycles with drop bars for reasons of fashion and style, even though drop bars were not suited to their low-intensity riding style.
Unfortunately, this riding position gives rather poor control of the bicycle, mainly because the hands are too close together for good steering control. Also, stem shifters are difficult to shift precisely, because with the shifters behind the stem, there is nothing against which to rest the hand. Most stem shifters are friction shifters, worsening the problem.
Stem shifters also present a danger in a collision. Depending on what gear you have selected, stem shifters can be like having a dull knife aimed at your groin!
If your bike has stem shifters, consider upgrading to something safer and more convenient.'
I must admit that I was thinking of chest rather than groin - that's even worse!!
Today is the yesterday of tomorrow.