Originally Posted by vangoes

I had some numbness in my arm before I got into cycling that carried over into my cycling. I had gone to the doctor for a diagnosis and he narrowed mine down to a nerve pinching in front of my shoulder across the chest. He suggested that when I feel it, I stretch back my arm while keeping my chest square to front. I did this and the numbness would reduce.

When I started riding I noticed the numbness again. My seat was too too high and too far back and I was putting too much weight forward. I lowered the seat slightly (as I was straining to touch ground with my toes where it first was) and set it forward so that my knees were over the balls of my feet with the pedal midway (they were slightly behind and I kept trying to slide myself up on the seat) all making me lean too far forward. After the changes my numbness in my arm from riding is gone and my ride is much more comfortable.