Effects of ball position on landing mechanics after completing a 180-degree jump in female netball players

Netball presents a high incidence of anterior cruciate ligament (ACL) injuries, with evidence suggesting that catching a ball overhead, and lowering it below the pelvis, may exacerbate injury risk. This study investigated the biomechanical effects of ball position on landing mechanics during a 180° rotational countermovement jump. Sixteen female participants (mean age: 17 ± 1 years; height: 167 ± 5.87 cm; weight: 74 ± 17.57 kg) performed jump-landing tasks while holding a ball in four conditions: Down towards the leading limb (Down Leading), trailing limb (Down Trailing), chest-height, and centrally low. Portable VALD force plates and dual-plane video captured landing kinetics and kinematics. Variables included rate of force development (RFD) (N/s/cm), impulse (N.s/cm), and peak vertical ground reaction force (PvGRF) (N/cm), normalised to jump height. Repeated-measures ANOVAs with post hoc tests and Greenhouse-Geisser/Bonferroni corrections determined significance. The Trail limb exhibited consistently higher RFD (1158.17 N/s/cm) and PvGRF (97.55 N/cm) compared to leading (1012.84 N/s/cm, 90.49 N/cm), possibly due to participants braking with their trailing limb when rotating clockwise. Impulse did not differ significantly across conditions. Video analysis suggested low ball positions may have increased valgus knee collapse, trunk rotation, wider landing stance, and temporary loss of balance that required saving actions. A high incidence of failed jumps in moderately experienced (∼8yrs of exposure) players indicates potential need for further training of controlled jump rotation actions. Similarly, the findings highlight the importance of bilateral turning training to mitigate asymmetrical loading and indicates avoiding excessively low-ball positions, which may affect trunk control and balance.