Was there any injury or jerk. Sometimes there is a possibility of joint inflammation due to some osteophyte obstruction following osteoarthritis knee.
Next Steps
She needs to take complete bed rest alongwith brace for support, hot fomentation can be started alongwith analgesic and anti inflammatory medicine. If the pain is persistent, better to get x ray of the joint..
Health Tips
Avoid knee and elbow bending, avoid sitting down, avoid Indian toilet avoid heavy work..