The lack of calcium in the food source, Uv rays both A @ B are known reasons for soft, prone to breaking bones and cramping in the muscles. My question for u is how far from your lighting is your dragon. Your dragon needs to be able to reach with-in a foot of the lighting to get the important uva/uvb rays he needs to help his bones grow and stay strong. The uvb plays a very important role due to giving off Vitamin D3. Lacking these can and will cause M. B. D. ( Metabolic Bone Disease ) which may be the reason for your dragon having a hard time walking/climbing. If he/she is unable to climb towards the lighting, ull have to take the lighting to him / her.
One thing I would highly reccomend u do asap is get your dragon to a vet where they can give him/her an injection of calcium-gluconate which will help boost the calcium levels of your dragon and should put him/her on the right track to recovery. As far as calcium in the food source. Feeding crickets to him/her wont help. U'll have to gut load the crickets with fruits and vegies like apples, grapes, lettuce ( romain ) greenbeans. I cannot stress this enough people.
ABSOLUTELY NOTHING CONTAINING CITRUS. Nothing acidic. Oranges, limes, pineapples, lemons. ect all of these will kill your dragon. The citrus is like carbonation in soda it bubbles and boils like hot water and will eat the stomach liners of the dragon.
U can also dust your crickets with a calcium dust called Cricket dust. Very good stuff man... check it out. If you would like I have links u can have to help with your dragon. If you need help locating a herp vet within your area u can check out
ARAV. Good luck man If you have any other questions let us know.