It looks like you have pre patellar bursitis - what this is an inflammation of the fluid sac (bursa) that is present in front of the knee cap. Being compressed against hard ground caused it to get inflamed and thats why you feel it squishy. Treatment is rest, ice, and non steroidal anti inflammatory drugs (over the counter Ibuprofen 800 mg three times daily- always take these medicines with or after food). Do not take Ibuprofen if you have a history of kidney problems or have had bleeding from your gut or have severe reflux. In that case you can take Acetaminophen (Tylenol) 325-650 mg every 4-6 hours. No more than 3,000 mg of Tylenol should be taken in a 24 hour period. If symptoms still persist, then you should see a primary care doctor