Severe Leg Muscle Weakness

I'm a 24 year old male. For the past 3 or 4 years I've been experiencing increasing leg muscle deterioration.
As a teenager/high school student I was very active and athletic. For the past few years I've been experiencing this decrease in leg muscle strenght/size. I can't even walk up a set of stairs anymore.
I've seen a number of doctors.
My CPK level was tested in 2007 and came back very high. I've had an EMG and a muscle biopsy in 2007 and was told that there was no answer to the dystrophy. I was also told tehre shouldn't be continued deterioration.
Here I am, a year and a half later and much worse off.
Any suggestions on the type of doctor I should see or a possible solution?

Thanks in advance,