should the upper arm be parallel at the back of the arm swing or does it differ between sprinters?
The arm should never reach this position- and won’t if the shoulders are fully up. If the shoulders are rolled forward (as some coaches recommend) the natural elastic response which stops backward travel and initiates the elastic response to help shoot the arm forward will be lost. This will lead to a movement of the center of gravity farther and farther back as the race progresses, leading to a loss of top speed and speed end.
to charlie:
how about the elbows at the front of the arm swing, just how far from the body should the elbows be?
I noticed my elbows tends to stay by my side and doesnt move foward much.
I’ve seen several coaches write about having your elbows in front of your body and hands up near your face. Elbows out infront, away from the body to allow the appropriate time to pick your knee up.
Charlie, what arm action is best have have? Is it focus on driving backwards so you can get as much off the track as possible or is it having your arms out in front with elbows away from your body? Also you mentioned in another post about the changes made to Tim’s arm action and focusing on the drive from hands or elbows???
Any clarification would be awesome! 
what is meant by shoulders rolling forward?
Originally posted by bLiNk_mE
what is meant by shoulders rolling forward?
The upper back is curved foward. Look at Matt Shirvington.
Originally posted by THEONE
[quote]Originally posted by bLiNk_mE
what is meant by shoulders rolling forward?
The upper back is curved foward. Look at Matt Shirvington. [/quote]
There’s a post entitled Go PJ Go! Vidcap of his 9.88w in the videos section with Matt Shirvington.
sweet thanx