Can a one year old child pull a muscle or strain their leg? my daughter is very active and it pains her too walk? any thoughts?

Let me explain: When you child of this age i will assume it is fracture till proven otherwise, take x-ray on him to be sure.

Yes: Yes, an active child can strain a muscle or sprain an ankle. But she should be checked to make sure there is not a fracture. Many fractures in young children are subtle- just a thin line on the xray- and may not be obvious until a few days after the injury. If she's not putting all of her weight on her leg, see your doctor to check it out.

Sprain vs. Fracture: If she is not able to put weight on the leg, she needs to have X-rays taken. There are certain fractures, most notably toddlers' fractures of the tibia, that are often diagnosed clinically even if X-rays are normal. These injuries need to be immobilize to ensure proper healing.