Reddit reviews IronMind Expand-Your-Hand Bands 10 Pack: Kiss Elbow Pains Goodbye - Prevent, Rehab, Reduce Pain from Tennis Elbow, Carpal Tunnel. Authentic, Original, Effective.

https://www.ukclimbing.com/articles/page.php?id=6193

This is geared towards climbers but has the best section on rehabilitation that I've seen for joint/pip/pulley injuries. If you have had pain for that long you've likely developed scar tissue...this is going to make things tougher and will require GENTLE stretching and massage to gradually break it up while also strengthening the area.

Similar to climbing, most of typing involves using "finger muscles" (which are actually in your forearm) in only one direction (the one used to close your fingers, not open them). Therefore, one of the best exercises to prevent injuries is to do the reverse exercise, which is finger extension with resistance. This is in the doc, though I have to say rubber bands were never sufficient, and I highly recommend a set with variable "weights," for example this one: https://www.amazon.com/Expand-Your-Hand-Bands-10-Pack-Goodbye/dp/B00083B79M/ref=sr_1_1

I actually have one next to my desk right now. As a bonus, if you play golf or tennis this will also help with "elbow" pain, which is really due to tendon strain as a result of lack of strength in the same muscle group.

While you massage, stretch, and most importantly strengthen, do not be afraid to use the offending area. They DO grow back, but you need to get blood there. That means using it. Good luck :)

If you don't like your friend, get him a hard gripper.

Cheap, easy, and safe things might include expansion bands or a wrist roller.

The most practical solution for someone genuinely wanting stronger hands (and not a fidget toy for when they're bored) would be something like an adjustable Ivanko Super Gripper, though they are not cheap.

I like the bands better than the individual fingers but YMMV. I have the "Ironmind" brand and I love them:

https://www.amazon.com/IronMind-Expand-Your-Hand-Bands-Authentic-Effective/dp/B00083B79M/ref=sr_1_17?ie=UTF8&qid=1527635369&sr=8-17&keywords=finger+resistance+bands

If I recall correctly (and I'm sure someone will point out any error in the comments) there aren't actually any muscles in the fingers.

I would think your standard grip work would do well for you. As for the comparable opening hand movement, I've had these in my wishlist for quite some time.

edit: Yes! Wikipedia for the win!
>Fingers do not contain muscles other than arrector pili muscles. The muscles that move the finger joints are in the palm and forearm. The long tendons that deliver motion from the forearm muscles may be observed to move under the skin at the wrist and on the back of the hand.

Not really gains but for strength: this and this have worked well for me.

Grip training is tricky because compared to most other forms of strength training, there is much more emphasis on tendon strength. And the thing about tendons is that they don't give you the same kind of feedback that muscles do when they get tired. All this means I've found it's easier to overtrain and injure your tendons, and so it's important to throw in extra rest days here and there, especially as a beginner or when upping the resistance.

Take some time off, stretch your hands, and you'll probably be alright.

Also, don't neglect the forearm muscles used to open your fingers. A lot of grip trainers focus solely on squeeze strength to their detriment, the equivalent of exclusively working out your biceps but never your triceps. For the most effective strength t's important to work complimentary muscle groups. I've been using these after a tennis player friend recommended them to me a few years ago and they're excellent.

You should get some kind of wrist extensor training tool to counter the flexor training you are about to do. I use these: https://www.amazon.com/dp/B00083B79M/ref=asc_df_B00083B79M5284604/?tag=hyprod-20&creative=395033&creativeASIN=B00083B79M&linkCode=df0&hvadid=198074695887&hvpos=1o2&hvnetw=g&hvrand=7311871857324905174&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1023191&hvtargid=pla-320458756018

I love the CoC training tools, been using them for a while. Recently closed the 1.5 and now the 2 is what I am aiming for. Busting them out at parties to fuck with people is fun as hell

Ironmind makes a full set for pretty cheap.
https://www.amazon.com/gp/aw/d/B00083B79M/ref=mp_s_a_1_1?ie=UTF8&qid=1482860867&sr=8-1&pi=SY200_QL40&keywords=ironmind+bands&dpPl=1&dpID=51jQMl-rkGL&ref=plSrch

On top of what /u/Glocjt referenced:

Buy these, and get a heavy hammer. Work in some pronator/supinator exercises.

Everyone uses the Captains of Crush. These things are no joke—the Trainer model will be plenty challenging if you're pretty strong. Back off to the Sport or Guide if you're not.

The Expand Your Hand Bands are recommended for working the opposing muscles and warding off tendonitis.

Be careful mixing grip training with serious dry fire. It's real easy to flare up some nasty tendonitis in your elbows.

Dude, thanks so much again for the informative response! Going to shoot for higher reps with the Trainer before moving back to the #1.

While I got you here, quick question (since you seem to know what you're talking about); do you have any thoughts on these expander band things?:

http://www.amazon.com/Expand-Your-Hand-Bands-10-Pack-Goodbye/dp/B00083B79M?ie=UTF8&psc=1&redirect=true&ref_=ox_sc_sfl_title_1&smid=A2T23XKLYNBN84

I'm thinking they might be good to do on days I'm not doing grip training to avoid injury and increase flexibility. I'd imagine one could just use strong rubber bands or whatever but they're cheap enough that I'm thinking about ordering them. I noticed some soreness after using my #1 before I got the Trainer and it seemed expanding my fingers (even without the tension of bands) was helpful in relieving it.