I am 42 have both knie pains when start to stand up or by upstairs all investigation were normal x-ray mri blood?

Muscle spasms : Your symptoms may be related to muscle spasms from the spinal nerve root irritation in the lower back. You will need to be evaluated by your family doctor and a specialist in physical medicine and rehabilitation.

Knee pain: Bilateral knee pain upon standing or going upstairs could be due to patellofemoral syndrome, itb syndrome, bursitis, or quadricep muscle strain. If your tests are all normal, then it would probably help you to begin physical therapy to move toward a resolution of the pain.