Summary of the project
Running training with specially sprung jumping shoes is a relatively unknown sport. In a comparison with normal jogging and trampoline jumping, the acceleration forces, along with the effects of these different pieces of sports equipment on the body, were examined together with the VDIni-Club Bremen (a technology children’s club run by the Association of German Engineers).
The results show which acceleration forces act on the ankle, the back, and the head of an athlete. Unsuitable jogging footwear, as well as disproportionately high jumps with special jumping shoes, lead to strain with a risk of injury. The trampoline, on the other hand, allows jump training with optimal cushioning. For the comparison between jogging with running shoes, running on jumping shoes, and trampoline jumping, accelerations were measured at the ankle, the back, and the forehead.
A device from the German manufacturer bellicon was used as the therapeutic trampoline. The special product feature of this model is the spring-based jump-mat suspension using rubber ropes. In this test, accelerations were measured at the ankle, at the back at the level of the lumbar vertebrae, and at the head (forehead).
Comparison of impact loads when jogging with running shoes, spring shoes, and gentle trampoline jumping:
Building on existing research by sports scientist Jens Heidenfelder, a phase model was introduced to better understand the measurement results, consisting of an impact phase (1), a contact phase (2), and a propulsion phase (3).
Phase 1 describes the initial contact with the ground, in phase 2 the foot continues to roll, and in phase 3 the foot is propelled forward, meaning it continues moving until the next ground contact.
During gentle trampoline jumping, without lifting significantly off the jump mat, almost identical acceleration values of nearly 3g were measured at the foot, back, and head. It becomes clear that there is no impact shock at all. Since the jumping happens simultaneously with both feet and without forward movement, this phase received a new name. During this flight phase, meaning as long as the feet do not touch the jump mat, acceleration was 0g. Here, the athlete reaches a state of weightlessness.
Trampoline jumping on the bellicon® is free of impact shocks. The risk of injury is therefore low. Surprisingly evenly, all parts of the body experience a gentle, shock-free change in strain.
In summary, the therapeutic trampoline is the healthiest piece of sports equipment.