I am sorry to hear about your symptoms, and it sounds like they are limiting your ability to enjoy your hobbies. I encourage you to raise your concerns with an orthopedic surgeon
. It is not possible to provide an accurate diagnoses without performing a thorough medical history and physical exam, and an orthopedist can help determine if you need any additional testing.
The knees are complex joints involving bones, muscles, ligaments, and cartilage. Volleyball can place a great deal of stress on these joints, either exacerbating a prior injury
or leading to a new one. Tears in the meniscus, or cartilage lining the knees, can cause pain. Damage to any one of the knee ligaments, such as the ACL or MCL, can cause pain. Syndromes such a patellofemoral syndrome and iliotibial band syndrome can cause pain through overuse. It is also possible that your leg muscles are generally de-conditioned, which is causing pain now that you have resumed playing volleyball.
Your back pain could be due to muscle strain
from you compensating from a knee injury. It is also possible you have a separate issue related to the muscles or bones of your back. I strongly encourage you to see an orthopedic surgeon, who can help determine the most appropriate tests to assess your symptoms.