Associations of multiple core stability aspects with drop jump performance

Drop jump performance (DJ) is essential for many ball sports. Core stability (CS) contributes to trunk control and lower-limb capacity during jump movements. The objective of this study was to investigate the relationships between multiple CS aspects and DJ performance.

Eighteen male university basketball players were recruited from a university. Kinematic and kinetic data of DJ were collected using infrared cameras and force plates. Five tests-sit-ups (SU), trunk extensor endurance (EE), trunk flexion-extension range of motion (TFE), dominant extremity single-leg stance time (DLS), and dominant extremity single-leg hop distance (DLH)-were used to assess core strength, endurance, flexibility, motor control, and functionality, respectively. Pearson correlation and multiple linear regression assessed the relationship between CS and DJ performance.

DJ height (H_DJ, r = 0.739, p < 0.001) and joint moment contribution rate (CR) of ankle (CRankle, r = -0.599, p = 0.009) were significantly correlated with DLH. Vertical ground reaction force (vGRF, r = 0.532, p = 0.023), peak joint moment of knee (r = 0.494, p = 0.037), and CR of hip (CRhip, r = -0.554, p = 0.017) and knee (CRknee, r = 0.514, p = 0.029) were significantly correlated with SU. Peak joint moment of knee (PMknee, r = 0.611, p = 0.007) and ankle (PMankle, r = 0.570, p = 0.014) were significantly correlated with DLS, and PMankle was also significantly correlated with TFE (r = -0.470, p = 0.049). Regression models were further explored to explain the H_DJ (DLH, R² = 0.546, p < 0.001), vGRF (SU, R² = 0.283, p = 0.023), CRankle (DLH and TFE, R² = 0. 537, p = 0.001 and p = 0.029), CRhip (SU, R² = 0.307, p = 0.017), CRknee (SU, R² = 0.264, p = 0.029), PMknee (DLS, R² = 0.373, p = 0.007), and PMankle (DLS, R² = 0.325, p = 0.014) by the CS measurements.

Different CS-related characteristics were associated with distinct aspects of DJ performance and lower-extremity biomechanics. Functional capacity was most strongly associated with DJ height, whereas strength- and postural control-related measures were associated with specific biomechanical characteristics. These exploratory findings require confirmation in larger and interventional studies.