It may be possible that when your fingers were first stepped on the soft tissue in you hand was damaged. Ligaments and tendons that are injured can become lax, or have looseness in the joints. This can cause the joint to be prone to injury, and cause tendonitis and arthritis down the road.
I would recommend a muscle strengthening program for your hand and fingers. Simple exercises like squeezing a sponge ball or putting a towel on a table and gathering it in a ball with your fingers will help prevent future injury to your hand.
Also, I would try to avoid popping your fingers. This will continue to keep the joints lax.