The 151 participating athletes were divided into 2 groups: LDD and non-LDD. The LDD group included subjects with at least 1 abnormal disc from L1-2 to L5-S1 of grade III, IV, or V. The non-LDD group included subjects with 5 normal discs of grade I or II. For further assessment, the most damaged disc of the 5 constituted the highest grade of LDD.