Trampoline-related injuries in children: a preliminary biomechanical model of multiple users.
BACKGROUND
The recent popularity of domestic trampolines has seen a corresponding increase in injured children. Most injuries happen on the trampoline mat when there are multiple users present. This study sought to examine and simulate the forces and energy transferred to a child's limbs when trampolining with another person of greater mass.


METHODS
The study used a computational biomechanical model.


RESULTS
The simulation demonstrated that when two masses bounce out of phase on a trampoline, a transfer of kinetic energy from the larger mass to the smaller mass is likely to occur. It predicted that when an 80&emsp14;kg adult is on a trampoline with a 25 kg child, the energy transfer is equivalent to the child falling 2.8 m onto a solid surface. Additionally, the rate of loading on the child's bones and ligaments is greater than that on the accompanying adult.


CONCLUSIONS
Current guidelines are clear that more than one user on a trampoline at a time is a risk factor for serious injury; however, the majority of injuries happen in this scenario. The model predicted that there are high energy transfers resulting in serious fracture and ligamentous injuries to children and that this could be equated to equivalent fall heights. This provides a clear take-home message, which can be conveyed to parents to reduce the incidence of trampoline-related injuries.
Menelaws
Simon
S
University of Dundee Medical School, Dundee, UK.
Bogacz
Andrew R
AR
Drew
Tim
T
Paterson
Brodie C
BC
D000328:Adult; D001265:Athletic Injuries / Q000209:etiology / Q000503:physiopathology; D001696:Biomechanical Phenomena; D049628:Body Size; D001835:Body Weight; D002648:Child; D004735:Energy Transfer / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D019876:Sports Equipment / Q000009:adverse effects*