Does Specific Footwear Facilitate Energy Storage and Return at the Metatarsophalangeal Joint in Running?

2013 ◽  
Vol 29 (5) ◽  
pp. 583-592 ◽  
Author(s):  
Steffen Willwacher ◽  
Manuel König ◽  
Wolfgang Potthast ◽  
Gert-Peter Brüggemann
Keyword(s):  
Carbon Fiber ◽  
Reaction Force ◽  
Metatarsophalangeal Joint ◽  
Bending Stiffness ◽  
Joint Mechanics ◽  
Running Shoes ◽  
Longitudinal Bending ◽  
Bending Behavior ◽  
Male Subjects ◽  
Positive Work

Longitudinal midsole bending stiffness and elasticity are two critical features in the construction of running shoes. Stiff elastic materials (eg, carbon fiber) can be used to alter the midsole bending behavior. The purpose of this study was to investigate the effects of midsole stiffness and elasticity manipulation on metatarsophalangeal (MTP) joint mechanics during running in 19 male subjects at 3.5 m/s. Midsole bending stiffness and elasticity were modified by means of carbon fiber insoles of varying thickness. Stiffening the shoe structures around the MTP joint caused a shift of the point of force application toward the front edge of the shoe-ground interface. Negative work was significantly reduced for the stiffest shoe condition and at the same time a significant increase of positive work at the MTP joint was found. It seems plausible that the increase in positive work originates from the reutilization of elastic energy that was stored inside the passive elastic structures of the shoe and toe flexing muscle tendon units. Further, an increase in midsole longitudinal bending stiffness seems to alter the working conditions and mechanical power generation capacities of the MTP plantar flexing muscle tendon units by changing ground reaction force leverage and MTP angular velocity.

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.

scholarly journals No effect of cycling shoe sole stiffness on sprint performance

2020 ◽  
Author(s):  
James Warren Hurt ◽  
Rodger Kram
Keyword(s):  
Carbon Fibre ◽  
Metabolic Cost ◽  
Bending Stiffness ◽  
Sprint Performance ◽  
Running Shoes ◽  
Competitive Cyclists ◽  
Longitudinal Bending ◽  
Sprint Cycling ◽  
Shoe Soles ◽  
Power Outputs

Most competitive and recreational road cyclists use stiff-soled shoes designed for cycling and “clipless” pedals that firmly attach to the shoes. There are many unsubstantiated claims by cyclists and industry professionals about the advantages of cycling shoes and clipless pedals. Scientific research has shown that cycling shoes and clipless pedals have no significant effects on the metabolic cost of cycling during submaximal, steady-state efforts. However, a recent study demonstrated that, compared to running shoes, cycling shoes and clipless pedals do provide performance benefits relevant to sprint cycling. Here, we investigated if there was a positive relationship between longitudinal bending stiffness of cycling shoe soles and sprint performance. We measured the mechanical power outputs, velocities, and cadences of 19 healthy male recreational/competitive cyclists during maximal sprint cycling. Participants rode outdoors on a paved asphalt road with a steady, uphill grade of 4.9%. Each subject completed nine 50 m cycling sprints in three (single-blinded) shoe conditions: identical shoe uppers with injection moulded nylon soles, carbon fibre-fibreglass blend soles, and full carbon fibre soles. The same clipless pedals were used throughout all tests. No significant differences were detected between the three shoe soles for: 50 m average and peak 1-second power, average change and peak change in velocity, average and peak cadence, maximal sprint velocity, peak acceleration, and peak crank torque (all p > 0.31). Greater longitudinal bending stiffness of cycling shoe soles had no effect on sprint performance during short uphill sprints.

Neuromuscular changes for hopping on a range of damped surfaces

2004 ◽  
Vol 96 (5) ◽  
pp. 1996-2004 ◽  
Author(s):  
Chet T. Moritz ◽  
Spencer M. Greene ◽  
Claire T. Farley
Keyword(s):  
Center Of Mass ◽  
Reaction Force ◽  
Surface Emg ◽  
Knee Extensors ◽  
Energy Conserving ◽  
Work Done ◽  
Male Subjects ◽  
Positive Work ◽  
Elastic Surfaces ◽  
Ankle Mechanics

Humans hopping and running on elastic and damped surfaces maintain similar center-of-mass dynamics by adjusting stance leg mechanics. We tested the hypothesis that the leg transitions from acting like an energy-conserving spring on elastic surfaces to a power-producing actuator on damped surfaces during hopping due to changes in ankle mechanics. To test this hypothesis, we collected surface electromyography, video kinematics, and ground reaction force while eight male subjects (body mass: 76.2 ± 1.7 kg) hopped in place on a range of damped surfaces. On the most damped surface, most of the mechanical work done by the leg appeared at the ankle (52%), whereas 23 and 25% appeared at the knee and hip, respectively. Hoppers extended all three joints during takeoff further than they flexed during landing and thereby did more net positive work on more heavily damped surfaces. Also, all three joints reached peak flexion sooner after touchdown on more heavily damped surfaces. Consequently, peak moment occurred during joint extension rather than at peak flexion as on elastic surfaces. These strategies caused the positive work during extension to exceed the negative work during flexion to a greater extent on more heavily damped surfaces. At the muscle level, surface EMG increased by 50-440% in ankle and knee extensors as surface damping increased to compensate for greater surface energy dissipation. Our findings, and those of previous studies of hopping on elastic surfaces, show that the ankle joint is the key determinant of both springlike and actuator-like leg mechanics during hopping in place.

Evaluating longitudinal bending stiffness testing for performance footwear

2021 ◽  
Vol 13 (sup1) ◽  
pp. S5-S6
Author(s):  
Laura Healey ◽  
Montgomery Bertschy ◽  
Wouter Hoogkamer
Keyword(s):  
Bending Stiffness ◽  
Longitudinal Bending

Effect of outdoor footwear bending stiffness on metatarsophalangeal joint kinematics, kinetics, and energy balance during level and uphill walking

2021 ◽  
pp. 175433712110087
Author(s):  
Giuseppe Zullo ◽  
Giuseppe Marcolin ◽  
Paolo Mistretta ◽  
Nicola Petrone
Keyword(s):  
Energy Balance ◽  
Motion Capture ◽  
Healthy Subjects ◽  
Force Plate ◽  
Objective Measure ◽  
Metatarsophalangeal Joint ◽  
Bending Stiffness ◽  
Motion Capture System ◽  
Metatarsophalangeal Joints ◽  
Uphill Walking

In outdoor footwear, sole properties must guarantee grip with the ground and support the forefoot without altering the kinematics of the metatarsophalangeal joints (MPJ). The present study aimed to implement an objective measure of shoe bending stiffness and investigate the effect of shoes with different bending stiffness on MPJ kinematics, kinetics, and energy balance during walking. The bending stiffness of four shoes was calculated using a customized flexometer. Then, the influence of each footwear on MPJ biomechanics during level and uphill walking was investigated with a motion capture system and a force plate on 10 healthy subjects. Results showed that MPJ peak dorsiflexion angle, stiffness, and energy balance were affected both by shoe bending stiffness ( p<0.001) and walking slope ( p<0.001). The findings of the study, which quantify the influence of shoe stiffness on MPJ biomechanics, will be helpful in the design of outdoor footwear.

Experimental Investigation on Bending Behavior of Textile Reinforced Concrete (TRC) Plates at High Temperatures

2021 ◽  
Vol 28 (3) ◽  
pp. 88-102
Author(s):  
Assim Arif ◽  
Saad Raoof
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
High Temperatures ◽  
Ultimate Tensile Stress ◽  
Textile Fiber ◽  
Structural Elements ◽  
Textile Reinforced Concrete ◽  
Cementitious Matrix ◽  
Fiber Reinforcements ◽  
Bending Behavior

Textile Reinforced Concrete (TRC) can be used as independent structural elements due to its high loading capacity and proper to product light weight and thin walled structural elements. In this study, the bending behavior of TRC plates that reinforced with dry carbon fiber textile and exposed to high temperatures was experimentally studied under 4-points bending loading. The examined parameters were; (a) number of textile fiber reinforcements layers 1, 2 and 3 layers; (b) level of high temperatures 20°C, 200°C, 300°C, and 400°C. Firstly, the mechanical properties of the cementitious matrix and the tensile properties of TRC coupons at each predefined temperature were evaluated. The results showed that the ultimate tensile stress of the TRC coupons did not affect up to 200°C, however, a significant reduction observed at 300°C and 400°C by 19% and 24% respectively. Regarding the compressive strength and flexural strength of the cementitious matrix, the degradation was not severe until 200°C, while it became critical at 400 °C (23% and 22% respectively). The result of the bending of TRC plates showed that doubling and tripling textile fiber reinforcements layers improved the flexural loading. In general, increasing the level of temperatures resulted in decrease in the flexural capacity of TRC plates. The highest decrease recorded for the specimen reinforced with 1-layer of carbon fiber textile subjected to 400 °C and was 33%.

Carrying loads with springy poles

1991 ◽  
Vol 71 (3) ◽  
pp. 1119-1122 ◽  
Author(s):  
R. Kram
Keyword(s):  
Oxygen Consumption ◽  
Ground Reaction Force ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Reaction Force ◽  
Load Carriage ◽  
Vertical Ground Reaction Force ◽  
Suspension Systems ◽  
Vertical Ground ◽  
Male Subjects

People throughout Asia use springy bamboo poles to carry the loads of everyday life. These poles are a very compliant suspension system that allows the load to move along a nearly horizontal path while the person bounces up and down with each step. Could this be an economical way to carry loads inasmuch as no gravitational work has to be done to lift the load repeatedly? To find out, an experiment was conducted in which four male subjects ran at 3.0 m/s on a motorized treadmill with no load and while carrying a load equal to 19% body wt with compliant poles. Oxygen consumption rate, vertical ground reaction force, and the force exerted by the load on the shoulders were measured. Oxygen consumption rate increased by 22%. The same increase has previously been observed when loads are carried with a backpack. Thus compliant poles are not a particularly economical method of load carriage. However, pole suspension systems offer important advantages: they minimize peak shoulder forces and loading rates. In addition, the peak vertical ground reaction force is only slightly increased above unloaded levels when loads are carried with poles.

scholarly journals Effects of Running Surface Stiffness on Three-Segment Foot Kinematics Responses with Different Shod Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Noor Arifah Azwani Abdul Yamin ◽  
Khairul Salleh Basaruddin ◽  
Ahmad Faizal Salleh ◽  
Mohammad Shahril Salim ◽  
Wan Zuki Azman Wan Muhamad
Keyword(s):  
Plantar Fascia ◽  
Joint Rotation ◽  
Foot Kinematics ◽  
Surface Stiffness ◽  
Flat Base ◽  
Running Shoes ◽  
Stance Time ◽  
Biomechanical Responses ◽  
Artificial Grass ◽  
Male Subjects

Objective. The aim of this study was to investigate the effects of surface stiffness on multisegment foot kinematics and temporal parameters during running. Methods. Eighteen male subjects ran on three different surfaces (i.e., concrete, artificial grass, and rubber) in both heeled running shoes (HS) and minimal running shoes (MS). Both these shoes had dissimilar sole profiles. The heeled shoes had a higher sole at the heel, a thick base, and arch support, whereas the minimal shoes had a flat base sole. Indeed, the studied biomechanical parameters responded differently in the different footwear during running. Subjects ran in recreational mode speed while 3D foot kinematics (i.e., joint rotation and peak medial longitudinal arch (MLA) angle) were determined using a motion capture system (Qualysis, Gothenburg, Sweden). Information on stance time and plantar fascia strain (PFS) was also collected. Results. Running on different surface stiffness was found to significantly affect the peak MLA angles and stance times for both HS and MS conditions. However, the results showed that the joint rotation angles were not sensitive to surface stiffness. Also, PFS showed no relationship with surface stiffness, as the results were varied as the surface stiffness was changed. Conclusion. The surface stiffness significantly contributed towards the effects of peak MLA angle and stance time. These findings may enhance the understanding of biomechanical responses on various running surfaces stiffness in different shoe conditions.

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