I fell hard in my knees when running a week ago. after i was in extreme pain. knees still relatively swollen and painful but i can walk. some numbness in my toe. does this seem serious?

Need evaluation: Swelling of knees with pain may indicate simple sprain or ligamental tear or fracture hence require examination.

Possible fracture: If you fell on your knees and were in 'extreme pain' and are still having pain a week later, you may have a fracture or significant soft tissue injury. It is important for you to see an orthopedist to have your knees properly examined and xrayed.

No: Most direct falls on the knees w/low energy trauma are not serious.Most commonly contusions to the patella(e) and infrapatellar bursitis are the result and resolve w/time.However, if u continue to have pain in one knee(or the other)see your pcp or orthopedic surgeon.Occ. A patellar fracture or injury to the posterior cruciate ligament(pcl) can occur w/ this mechanism of injury.Best of luck.