Hi, fracture is common in the seniors, especially at your mother's age. The pain, might be just sciatic, I'm just saying you need to think about fracture as one of the possbile causes, also when you walk with her, you need to be very careful. How nice it is when one's mother can be so long-lived and healthy! You know study has showed that daughter of long-lived women will very likely to live long without any serious disease.