I have lower back pain on the left side and that pain is now in the front. Along with pain down the leg but not pass my knee and numbness in the arm?

Back pain. The low back pain and radiation to the knee suggests a pinched nerve in the low back between the lumbar 3/4 disc. The numbness in the arm is unrelated to the low back. See a neurosurgeon or a neurologist to evaluate your pain and numbness to establish a cause and a treatment plan.