I partially amputated (at the joint closest to the nail) my index finger a decade ago, and it’s been a huge impediment. This has motivated me to seek out some other opinions.

Sent it to some doctor friends and they are floored by the writing style as well.

As an older competitive gamer, I liked the part of this that describes how on injury or amputation the middle finger will quickly take over the index duties - I’ve noticed over the years that when my “trigger” finger on a controller is experiencing tendonitis and I have to rest it, that my middle finger performs just as adequately and I barely notice. This has always surprised me.

The hammer example made me remember something. I did some Aikido long ago, and the instructor spent quite a lot of time showing us how to grip things like sticks. As I remember it, instead of the instinctive way of just forming a fist around it, we should instead start from the little finger, wrapping the fingers one by one, but letting the index finger actually rest more along the handle than wrapping it. That way, supposedly, the grip is just as good, but more flexible and the index finger can help with control.

I’m a violinist (amateur but play regularly). When I have an important note, which is held for a while and needs vibrato, I frequently decide to shift my left hand position so that my middle finger is responsible, rather than the index finger. It feels stronger, easier to nail the intonation (pitch) with precision, and freer to perform the desired type of vibrato. (String players do vibrato by wiggling the left hand finger, which affects the pitch and overtones / oscillation modes of the string.) In fact, I tend to avoid using the index finger on notes that require vibrato.

That preference might be explained here, by the precision/strength combination. I tried holding a hammer as described in the author’s hammer exercise, and there’s similarity, though it requires much more weight-holding. The left hand doesn’t hold the weight of the violin (consider a cello or a guitar with shoulder strap), but a little grip strength is required to securely hold down the string, especially with vibrato.

Overall, fascinating article. I feel quite motivated to read more on hand anatomy and biomechanics.

Makes me think of Tommy Caldwell, top-tier rock climber who created so many of the iconic routes in Yosemite Valley. Despite losing an index finger in his 20s.