Which spine condition did Bolt say made his right leg slightly shorter? The answer is scoliosis.
In his autobiography, Bolt wrote that he had scoliosis, a condition involving an abnormal sideways curvature of the spine. He said the condition made his right leg about half an inch shorter than his left. The difference contributed to an uneven stride and became part of the physical challenge he managed throughout his sprinting career.
Bolt’s back problems and recurring injuries became a particular concern after he began working with coach Glen Mills in 2005. His training was adjusted to strengthen his back and improve his running mechanics. Rather than preventing an elite career, the condition became one factor his coaching and conditioning had to accommodate.
Scoliosis is often confused with kyphosis or lordosis, which describe different spinal-curvature patterns. Spina bifida is also distinct: it is a neural-tube birth defect, not simply a sideways spinal curve. Bolt’s account concerns scoliosis specifically, and it should not be taken to mean that every person with scoliosis has a measurable leg-length difference.