My Mom is in constant pain (her left leg) feels burning and in calf and foot. Any advice?

Please take the advice already given and have her see a Neurologist. I have neuropathy in my left foot and it used to shoot horrible pain up into my leg. It wasn't until I was diagnosed with Fibromyalgia and a serious back injury to my spine, that the pain went away. It left for two reasons---taking Neurontin twice a day, and doing water aerobics three times a week. Exercising in the warm water was so instrumental in helping the pain go away.

I also was going to suggest neuropathy. Is she diabetic? Has she seen a neurologist?

It sounds like she may have neuropathy. If she does, there are some medications that could help. Have her doctors prescribed anything for her?

An appointment with Orthopedic doc is in order - could be nerve, tendon or muscle related. Possibly just some physical therapy needed but that is all for a doctor to determine.