I found this off of wikpedia. I wish people would write more of these for more runners in more events. this is the best biomechanical analysis I've read. I enjoyed reading it but I've never seen anything of this quality for other runners of other events.
http://en.wikipedia.org/wiki/Asafa_powell#Physiology_and_running_style
"Physiology and running style
Asafa Powell is 190 cm (6 ft 3) tall and weighs 88 kg (14 stone). Despite his height, he has an explosive start, which is unusual for big runners. His long legs give him a mechanical advantage, and his maximum stride length has been recorded at 2.60 m (8½ feet). He is a mid-foot striker: he puts much of his foot on the ground for maximum friction to push off. This enables him to increase his turnover, or rate of stepping. His psoas major muscle, which lifts the leg for the next stride, has four times the normal cross-sectional area. His tendons are extremely stiff: it takes 43 kg of muscular force to stretch the average man's thigh tendons 1 cm, 59 kg for Japanese champion sprinter Nobuharu Asahara; but for Powell it takes 114 kg of muscle strength.[6] These extremely stiff tendons increase the amount of force that is elastically stored and then restored to momentum at each stride. However, the most impressive aspect about his running is his technique and how he combines that with immense power when he runs. He has remarkable leg extension and clawing, and his back-kick is very short and low."
To tell the truth, I wish I had the ability to analyze biomechanics like this.