"Careful with that axe Eugene...."
As a guitarist I've spent many years making sure my hands are kept in tip top condition for playing guitar and keyboards. At times I've played as much as five hours per day 5 days a week and the toll on limbs is incredible, you just wouldn't think your fingers would become so worn out, but they do and long term damage can occur if you're not careful.
I've worked with and sourced the best advice from some of the most experienced of hand surgeons and osteomyologists, who in turn have worked with the world's 'name' musicians. My hope is that I can pass on this benchmark advice to those who might not be able to afford ££££'s/ $$$$$$'s to make their career a better place. Learning the best methods for ensuring hand and ultimately your finger movements are maximised for playing is vital, especially for you that 'shred' the fret board wheat. So many players hit a wall where no matter what they do to remedy a sore hand or finger it just won't stop hurting; I might just have the answer/s you're looking for.
Trapped nerves are the usual suspect, it can occur at the tip of a finger (often the middle/ longest finger as due to it's length that presses on the fret board first). Prolonged playing can inflame joints, fingertips and all in between. Some sports injuries and domestic falls also interfere with musicians playability and cause nerve pathways to become blocked, so if you have any injuries, even older ones, then these can impact on your playing.
The 'middle' finger on the fret hand is also an 'interval' finger, it tends to hammer on or hammer off or latch together movements between the 1st and 3rd finger. Finally, a callous can actually cause your nerve to become 'trapped as the callous inflates inwards and against the nerve. Anti-inflammatory drugs might help, however it might still require more manipulative work to free up that joint.
Working out the pain from joints and muscles can take some time, so patience is needed; too many aggressive hand stretches can exacerbate the problem; a day of stretching, a day of adjustment and so on. If you 'force' the injury, try to make it better before time, you will exacerbate the problem; another culprit is the musician who 'tests' the ailment, by trying to play when he/ she knows they are still in pain always leads to further heartache. Some of you may have been running the gantlet with the same injury for years, I can assure you that you can, at the very least, remove the pain while you play and get back to where you once were.
Please get in touch if you're at your wits end, I might be able to offer valuable, common sense advice without the need to go to a specialist.
I can be contacted via john@bidstonhill.com or phone: 0151 324 9741