#IMPULSIVE FORCE MODELS GENERATOR#

For simple pads, a proportional relationship was found between maximum acceleration, which is directly proportional to force, and peak pressure 5. In addition to preventing major fractures, a reduction in local pressure on the impact zone is also desirable. In the elderly, special padding on the hips can reduce the effect of an unexpected fall 4. For athletes, the use of kneepads results in a 56% reduction in the rate of knee injuries 3. dissipation of energy), or temporarily storing energy. This can be achieved by either damping (i.e. To reduce the risk of injury, padding must reduce the impact forces acting on the musculoskeletal system. In some sports, the usage of protective equipment, such as pads, is mandatory. Impact on the knees during a fall is a hazard prevalently occurring during various sporting activities, or in the elderly community 1, 2. Based on this study, future developments in padding might benefit from focusing on the aspect of energy storage and temporarily delayed energy dissipation. The mechanical behavior more closely resembled a spring that temporarily stores energy and consequentially reduces peak forces upon impact.

Contrary to expectations, the knee pad did not act as a mechanical damper. The results from this study illustrate the magnitude of influence that knee pads have on peak forces, transmitted impulse, and energy transfer from a high-force impact in real-life scenarios. Energy dissipation, defined as the difference between kinetic energy pre-impact and peak potential energy post-impact, was higher without a knee pad (no pad: 10.5 J SD: 6.2 J pad: 4.2 J SD: 5.0 J p < 0.001). This effect diminished as drop height was increased. Therefore, the observed impulse was also increased (no pad: 62.2 Ns SD: 17.8 Ns pad: 74.6 Ns SD: 18.6 Ns p < 0.001). The usage of a knee pad led to an average peak force attenuation on impact of 15% (no pad: 5932 N SD: 2472 N pad: 4210 N SD: 2199 N p < 0.001). Eight human knee cadaver specimens were embedded and fixed with a flexion angle of 100 degrees in a custom-made drop testing device (75 kg including the knee).

We hypothesized that knee pads reduce the force and energy transmitted to the bony structures of the knee cap compared with unprotected conditions. This study compares the effect of wearing knee pads to unprotected impact on a hard surface. We also describe preliminary studies of proprioceptive leg force feedback, showing how a reflexive pathway can reinforce the preflexive stability inherent in the system.The mechanics of protective knee padding mitigating injury from a high-force fall have not been investigated in real-life scenarios to date. We show that the model’s response to a lateral impulsive perturbation closely matches that of a cockroach subject to a similar impulse. These modes moderate high frequency perturbations, producing slow heading changes that can be corrected by a stride-to-stride steering strategy.

Although these components of the model are rather complex, neglect of leg mass yields a neuromechanical system with only three degrees of freedom, and numerical simulations coupled with a Poincaré map analysis shows that the feedforward dynamics is strongly stable, apart from one relatively slow mode and a neutral mode in body yaw angle.

#IMPULSIVE FORCE MODELS GENERATOR#

We focus on a hexapedal geometry representative of insect locomotion in the ground plane that includes a neural central pattern generator circuit, nonlinear muscles, and a representative proprioceptive sensory pathway. We describe a hierarchy of models for legged locomotion, emphasizing relationships among feedforward (preflexive) stability, maneuverability, and reflexive feedback.

Impulsive force models