Do you ever get sore knuckles when you knit? I do…It’s also a sharp pain in between my third and fourth knuckles on my left hand. (I knit English.)
I’ve gotten sore hands, but never sore knuckles. Maybe you are holding the needles too tight. Give your hands a rest and then try relaxing your grip.
This might sound kind of odd, but your problem may actually be in your arm. As a massage therapist and a knitter, I sometimes have pain in my hands, generally it is related to my arms. What you may be dealing with could be trigger point pain. When you use your fingers, you are using your arm muscles as well. Try probing the hairy side of your forearm 2 or 3 inches below the elbow. (near the place where your arm bends.) Press there, then raise your 3rd,4th, or 5th fingers, one at a time. You should feel the muscle in your arm contract when you move each finger. This is the area you need to work on. Try stroking that area of your arm with short strokes (about an inch or so in length, only stroke in one direction.) You can also use a tennis ball against the wall to do this. Roll the ball slowly along the muscle from the inside of your forearm to your elbow, leaning hard into the ball that is against the wall. Once again, only go in one direction. Try doing this several times each day, you should notice the difference in a pretty short period of time. I keep a tennis ball in my knitting bag, one in my car, and in my night stand and use them often. My tennis ball, and my knitting needles are both good friends to me. Hope that helps.
KR
Yes, I agree with KnittedRose on the trigger fingers. I just had to have mine released with surgery and it was not fun. My tennis ball has become my friend also. My fingers are still a little stiff but are getting better with time. I also don’t grip my needles as firm as I did either.
Good luck on keeping your fingers pain free.
Yeah. Thanks so much! 
Well, I’ve also noticed it’s only with small needles. :?? Thanks again!!