hollow-back

1. Kinematic analysis of the Technique of Handspring Forward 1/ 2 Turn and Hollow-back Somersault in Vaulting Horse by Xu Jing The Teaching Method of Forward Handspring Technology in the Floor Exercise
   许婧跳马直体奎尔沃腾越运动学分析自由体操前手翻动作技术教法探析

noun

1. an abnormal inward (forward) curvature of the vertebral column

   Synonym:    lordosis