scholarly journals Effect of the Construction of Carbon Fiber Plate Insert to Midsole on Running Performance

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5156
Author(s):  
Fengqin Fu ◽  
Ievgen Levadnyi ◽  
Jiayu Wang ◽  
Zhihao Xie ◽  
Gusztáv Fekete ◽  
...  
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Finite Element Simulation ◽  
Independent Effect ◽  
Marathon Running ◽  
Joint Mechanics ◽  
Long Distance ◽  
Running Performance ◽  
Element Simulation ◽  
Fiber Plate

In this paper, to investigate the independent effect of the construction of the forefoot carbon-fiber plate inserted to the midsole on running biomechanics and finite element simulation, fifteen male marathon runners were arranged to run across a runway with embedded force plates at two specific running speeds (fast-speed: 4.81 ± 0.32 m/s, slow-speed: 3.97 ± 0.19 m/s) with two different experimental shoes (a segmented forefoot plate construction (SFC), and a full forefoot plate construction (FFC)), simulating the different pressure distributions, energy return, and stiffness during bending in the forefoot region between the SFC and FFC inserted to midsole. Kinetics and joint mechanics were analyzed. The results showed that the footwear with SFC significantly increased the peak metatarsophalangeal joint (MTPJ) plantarflexion velocity and positive work at the knee joint compared to the footwear with FFC. The results about finite element simulation showed a reduced maximum pressure on the midsole; meanwhile, not significantly affected was the longitudinal bending stiffness and energy return with the SFC compared to the FFC. The results can be used for the design of marathon running shoes, because changing the full carbon fiber plate to segment carbon fiber plate induced some biomechanical transformation but did not significantly affect the running performance, what is more, reducing the peak pressure of the carbon plate to the midsole by cutting the forefoot area of the carbon fiber plate could be beneficial from a long-distance running perspective for manufacturers.

Longitudinal bending stiffness does not affect running economy in the Nike Vaporfly

2020 ◽  
Author(s):  
Laura Healey ◽  
Wouter Hoogkamer
Keyword(s):  
Carbon Fiber ◽  
Energy Savings ◽  
Metatarsophalangeal Joint ◽  
Bending Stiffness ◽  
Running Economy ◽  
Independent Effect ◽  
Joint Mechanics ◽  
Negative Power ◽  
Longitudinal Bending ◽  
Fiber Plate

Objectives: To determine the independent effect of the curved carbon-fiber plate in the Nike Vaporfly 4% shoe on running economy and running biomechanics.Methods: Fifteen healthy male runners completed a metabolic protocol and a biomechanics protocol. In both protocols participants wore two different shoe conditions, an intact Nike Vaporfly 4% (VFintact), and a cut Nike Vaporfly 4% (VFcut). The VFcut had 6 medio-lateral cuts through the carbon-fiber plate in the forefoot to reduce the effectiveness of the plate. In the metabolic protocol participants ran at 14 km/h for 5-minutes, twice with each shoe, on a force-measuring treadmill while breathing into an expired gas system. In the biomechanics protocol participants ran across a runway with embedded force plates at 14 km/h. We calculated running economy, kinetics, and joint mechanics of the lower limb.Results: Running economy did not significantly differ between shoe conditions (0.5% higher in the VFcut compared to the VFintact). Biomechanical differences were only found in the metatarsophalangeal joint (MTP) with increased MTP dorsiflexion angle, angular velocity, and negative power in the VFcut. Contact time was 1% longer in the VFcut.Conclusion: Cutting the carbon-fiber plate and reducing the longitudinal bending stiffness did not have a significant effect on the energy savings in the Nike Vaporfly 4%. This suggests that the plate alone plays a limited role in the 4% energy savings, and instead those likely result from a combination and interaction of the foam, geometry, and plate.

scholarly journals Longitudinal bending stiffness does not affect running economy in Nike Vaporfly shoes

2021 ◽  
Author(s):  
Laura Healey ◽  
Wouter Hoogkamer
Keyword(s):  
Carbon Fiber ◽  
Energy Savings ◽  
Metatarsophalangeal Joint ◽  
Bending Stiffness ◽  
Running Economy ◽  
Independent Effect ◽  
Joint Mechanics ◽  
Negative Power ◽  
Longitudinal Bending ◽  
Fiber Plate

Objectives: To determine the independent effect of the curved carbon-fiber plate in the Nike Vaporfly 4% shoe on running economy and running biomechanics.Methods: Fifteen healthy male runners completed a metabolic protocol and a biomechanics protocol. In both protocols participants wore two different shoe conditions, an intact Nike Vaporfly 4% (VFintact), and a cut Nike Vaporfly 4% (VFcut). The VFcut had 6 medio-lateral cuts through the carbon-fiber plate in the forefoot to reduce the effectiveness of the plate. In the metabolic protocol participants ran at 14 km/h for 5-minutes, twice with each shoe, on a force-measuring treadmill while breathing into an expired gas system. In the biomechanics protocol participants ran across a runway with embedded force plates at 14 km/h. We calculated running economy, kinetics, and joint mechanics of the lower limb.Results: Running economy did not significantly differ between shoe conditions (0.5% higher in the VFcut compared to the VFintact). Biomechanical differences were only found in the metatarsophalangeal joint (MTP) with increased MTP dorsiflexion angle, angular velocity, and negative power in the VFcut. Contact time was 1% longer in the VFcut.Conclusion: Cutting the carbon-fiber plate and reducing the longitudinal bending stiffness did not have a significant effect on the energy savings in the Nike Vaporfly 4%. This suggests that the plate alone plays a limited role in the 4% energy savings, and instead those likely result from a combination and interaction of the foam, geometry, and plate.

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