I FELL ON MY KNEE 4 DAYS AGO & DID NOT BREAK THE SKIN BUT IT SWELLED UP IMMEDICATELY ON TOP, TURNED VERY RED AND LOOKED LIKE IT WAS BLEENDING IN ONE SPOT, BUT UNDER THE SKIN. THE SWELLING IS GONE, BUT IT ALMOST LOOKS LIKE A SCAB, EVEN THOUGH THE SKIN HAS BEEN DRY THIS WHOLE TIME. THERE IS A RED RING AROUND THE SCAB AND IT IS BROWN AND YOLLOW-ISH AND MILDY WARM. MY WHOLE KNEE IS BRUISED AS WELL. COULD THIS BE INFECTION?
Hi, I think it's just a small injury you have had. Kindly try applying hot water fermentation and do little leg exercises like static qua Chat Doctor.  The redness will go slowly and the muscle strength improves.