The Asymmetries in Straight Jumps on the Trampoline Under Different Sensory Conditions

The trampoline is a popular piece of sports equipment both for recreational use and for Olympic trampolining as a competitive sport. Maintaining body position during jumps is influenced by sensory inputs (visual, auditory, and somatosensory) and symmetrical muscle activity that help athletes to perform consecutive jumps as vertically as possible. To evaluate the effects of these inputs, 15 male and 15 female students (with an average age of 24.4 years, height of 174.3 cm, and average weight of 69.7 kg) performed 10 consecutive straight jumps under four sensory conditions: (1) looking at the edge of the trampoline, (2) without sight, (3) without hearing, and (4) without hearing or sight. Using insoles with integrated pressure sensors (Pedar®, novel GmbH, Munich, Germany), the contact forces on the trampoline during the jump were measured separately for the left and right feet. The results showed that the lack of visual input significantly shortened flight times and increased the asymmetry of ground reaction forces between the left and right legs. For example, in the second series without vision, the average normalized force difference between the legs increased by 0.33 G compared to the control condition. An ANOVA revealed significant differences in the ground reaction forces between sensory conditions, with vision playing a key role in maintaining body control. These results provide practical insights for coaches looking to improve jumping performance and address asymmetries during training by focusing on sensory feedback strategies.