What Causes Swelling In The Knee After A Fall?

i just fell down from rikshaw 1 month before ,since from then i am almost on rest ,but the only problem which i am facing is that we dont have english type of toilet in our house,apart from this i am always wearing flamingo's Open Patella Knee Cap.i still get swelling whenever i walk much. please suggest me what all precautions should i take further for proper fitness as before i had in busy life.