I did a lot of weight training in my youth and have been training on and off since the age of 16. A good excercise for building strength in the fingers and forearms is the following.<snip>REMEMBER. Do this slowly and with a light weight to avoid injury.
I remember more of what happened when I used the Gripmaster.I pressed down one finger and it had more resistance than normal because of the Griopmaster. So that one muscle and tendon tightened up. It's all a web of muscles connected, so it wasn't very comfortable after a few days.Not that that's a reason to blow it off entirely. I just overdid it I guess within a few days and that was the result. I think it could be useful if it was used carefully. Maybe only a few "pumps" on each finger 2-3 times a week.
Yeah so did I, and most of it was wrong. And your well intentioned low intensity high volume wrist curls are probably not only inefficient but would lead to injury if anyone did them consistently, which fortunately never happens. Light weights are okay for kids, we oldtimers can't afford the injury risk.
If you do any exercise incorrectly it will lead to injury. I don't know why you think the wrist curl is inefficient, (although there is debate about whether forearms need a separate exercise due to the fact they are worked when doing bicep curls). All exercise produces results and as far as I am aware there isn't a precise way of measuring the efficiency. I don’t know if it will improve/help piano playing though, but it will increase the strength of your grip!
https://www.gripmaster.com.au/index1.htmWould this device be a shortcut to strong fingers or injury.