Spring-like leg dynamics and neuromuscular strategies for hopping on a mini-trampoline in adults and children

Improved balance control is an often-cited potential benefit for trampoline interventions. However, it is unknown whether the soft, elastic surface of a trampoline elicits different motion and neuromuscular strategies between adults and children. Therefore, the purpose of the study was to evaluate the center-of-mass (COM) dynamics and neuromuscular strategies for hopping on a mini-trampoline in adults and children. Fourteen children aged 7-12 years and 15 adults aged 18-35 years hopped on a stiff surface and a mini-trampoline. We evaluated the vertical displacement of COM and leg length, as well as the horizontal displacements between hops. We also assessed muscle activation from tibialis anterior, lateral gastrocnemius, biceps femoris, and vastus lateralis during time periods surround landing and estimated fatigue across the hopping cycles. Our results indicated both groups used spring-like leg dynamics to regulate the COM movement while hopping on a mini-trampoline. Children increased horizontal displacements between hops on the mini-trampoline, requiring greater muscle activation during time-periods associated with proprioceptive input. Moreover, children might not have developed the adult-like ability to appropriately adjust muscle pre-activation for feedforward control. Hopping on a mini-trampoline might increase proprioceptive information and postural demand compared to a stiff surface while reducing neuromuscular fatigue.