Angular momentum generation and control during a back handspring step out on the balance beam performed by female...

The back handspring step out (BHS) is a foundational skill in gymnastics balance beam routines that requires the generation of significant sagittal plane angular momentum while tightly regulating frontal plane momentum to control their balance. However, which body segments are critical for generating this momentum and successfully performing the BHS and whether skill level influences this generation remains unknown. Twenty-five gymnasts with a range of skill levels performed a BHS on a balance beam. The BHS was scored, and segmental contributions to whole-body angular momentum were analyzed during the take-off, flight, hand contact and landing phases. Angular momentum has previously been used to assess balance control, where higher ranges of frontal plane angular momentum are indicative of poorer balance control. There were no differences in segmental contributions to angular momentum during the take-off phase between high- and low-scoring groups. However, the low-scoring group had higher trunk contributions to frontal plane angular momentum after the take-off phase. The trailing leg was also found to be a large contributor to frontal plane angular momentum, and thus more likely than the leading leg to cause deviations in balance control. In the sagittal plane, momentum generation and skill level were weakly correlated, suggesting as gymnasts become more skilled, they produce larger sagittal plane motions and are more adept at generating angular momentum. Because the trunk and trailing leg had high contributions to frontal plane angular momentum, controlling the trunk and trailing leg should be a focus in training regimes to improve BHS performance.