I have to agree with the arms in the drive phase. I am at a loss on some of the things stated as they are direct contradictions to sound mechanical principles. One thing I would like to mention is that in curve running, it may be more optimal to extend arms on the downstroke and back to 90 on the upstroke. Anyone have any thoughts on this?
i hear ya. i am currently looking at a jon drummond block start photo and he has about a 150 degree arm angle at toe-off. harnden really made a point to get sprinters to stay at 90 during acceleration. he said a long lever was a slow lever – "fast arms make the legs go faster".