Running Footwear Development

To influence and control the physiology and psychology of athletes to help them achieve their targets.

• shock absorption at initial contact (IC) —> reduce ground reaction force

• protection against roigh ground surface

• alignment of the forefoot —> even distribution of force at key chronic injury sites

1. Pronation Control

2. Impact Force Modification

3. Habitual Joint (motion) Path

4. Comfort Filter

   
   

• Bottom

• Middle

• Top

Sprenung = Heel-Toe-Drop

• high differenz between Heel and Toe withe the shoe

• infuence the running

• the most shoes have a higher Heel —> this support Heel stricker by reducing the load form muscels and Joints while running (because there is a bigger cushioning at the Heel) —> because the cushioning isnt that big at the front of the shoe, the foot stands like an Ramp

• depence on your running style, you sould choose your sprnegung

• light weight

• Responsiveness (Ernegy Return)

• Highly compliant

• Durable

• Cost efficient (material & process)

  
  

—> PEBA(x), TPU, TPEE, PU

• TPU Capsiles = Thermo-Plastic Polyurethane Capsules

• Midosle ist the “engine” of the show

• delivers the most perceived comfort, measured performance and visual pn a product —> therforethe material of this Part ist very important

Material: TPIU

• TPU particels are getting expanded in an autoclave process (heat & pressure) and become foamed cells

• eTPU for expanded thermoplastic polyurethane

• this eTPU Boost capsuled get fused tigether to create a midsole

• midsole is used in running footwear because of its unique combination of comfort-cushioning an denergy return

1. lactate threshold

2. maximum rate of oxygen uptake (VO2max)

3. running economy

—> running economy —> mainly dempent on running footwear —> the lower the energetic cost of running the longer and faster marathoners can run —> low cost of transportation = high running economy —> footwear creators can make elite runners run faster for longer through footwear design

1. Energy return

2. Deformation

3. Bending stiffnes

4. Shoe Mass

5. Comfort / Fit

—> Mainly midosle related

1. Low weight

2. Geomety: Stack-Heights, Drop, Width, Sidewall, Heel-Toe Drop, Toe Spring

3. Hardness (surface)

4. Compression stiffness (total midsole)

5. midsole construction: Foam, Torsion-Bar, Plate, Gel, Insert,..

6. Bending Stiffness: Midfoot and Forefoot

7. Torsion-Ability: Between fore and rearfoot

8. foram resilience: Energy-Return (relative and sbsolute)

9. foram durability (longevity)

• Footwear Mass, longitudinal bending stiffness and sushioning impact running economy

• cushioning means —> cushioning the impact, deformation, storage and return of mechanical energy

• the amount of energy stored depends on the compliance —> the extend of compression when loaded with a cretain force

• foams are viscoelastic —> that menas they dissipate some energy as heat

• compliant fomes are usually perceived as soft

• the percentage of stored mechanical energy that is returned is called resilience

• plates increase longitudinal bending stiffness and, if shaped correctly, hace the potential tp reduce energetic cost

1. by using machine tests (lab)

   • deformation

   • energy return

   • absolute energy return

   • weight

   • stiffness

2. by using biomechanics (athlete in lab-conditions

   • ground reaction force

   • kinematics and kinetics of joints

   • joint power comparsion

   • EMG

   • VO2max

3. athlete testing

   • Perception, comfort, and sensation qunatification

   • race time comparison

= the most relevant Test setup fpr running shoe performance

he foot-form compressed the midsole in the vertical direction to matchj the displayed general time history of the vertical ground reaction force, producing insile pressure similar to those recorded during running at 18Km/h

• vertical stamp —> compress material

• 0N to 2000N —> Force controlled

• speed of 18kM/h

• results shown in dorce-displacemnet curve

• loading curve: compression (deforms) - absolut energy in

• de-loading curve: recoils - absulute energy return

• hysteresis = emnergy loss (heat): area between loading - de-loadning curve

• absolut energy return: absolute energy in minus energy loss (grey area under the curve)

• relative energy return: absolute energy in / absolut energy out * 100

• elastic emergy that is returned

• deformation energy

• linear spring force

Last = starting point of shoe making

Last = human (runners) foot

• it is important for building a silhouette of the foot and therefore to build a suitable shoe

• is th emost essential part in performnce shoe making —> the basis for the shell pattern

What: 2D Version of the actual Last

Why: to cut the material used for the shoe in the right dimension

How: Manually (with tape, etc.) and digital

• Last Copy is a model of the foot, from witch the measurements for the shoe are evaluated

• the shell patter is used to produce the upper of a shoe —> it refers to the last copy (the measurments needed) and the design (how the shoe will look like)

—> consists of differen Parts

—> is making of different panel, which will be formed together at the end

= is a post treatment

• functional print using screen printing

• increases stiffness of the tectile (fabric) in lateral-medial direction

• optimizes fir & performance due to restriction the material elongation (strech) around the MTP area

• helps to keep camp shape

• Shoe-Making skills

• Shoe costing responsibility

• shoe performance & quality responsibility

• Project Management

• Biomechanics in running footwear

• classic development tasks

• soft skills

• 
  

—> 2 main process steps

Stock-Fitting:

• Footwear specific term of combining all parts of the bottom unit (tooling) in the mass-production process

• Building the bottom unit out of the outsole, midsole(s), heel counter (varies), torsion bar, plates, other elements

Assembly:

• shoe assembly i sthe process of brining the upper and the bottom unit together

• Midsole absolute height in the forefoot minus the midsole absoult height in the rearfoot

• midsole usually the key influencer of the stack-height since outsole and sockliner usually are kept constant in thickness

speed technology = footwear geometry, based on varaibels like foam, plates, stack heigth, and misole shape

—> helps give the runner more power (forward)

• during running the leg are compressed during the first half of the stance (—> to slow down the body)

• in the second half of the stance it rebounced to speed up again

—> this cyclic allowed a effectiv force production (because of the stretch-shortenic ,uscel action)

CoM = center of mass

—> combination of soft material and stiff plate provides a harmonious interaction, making it easier to fell the shoe bounce away with each running stride

—> can enhance how the human foor acts like a lever

• often plates or Rods (Carbon) are incorporated in the midsole —> thereby increasing the longitudinal bending stiffness —> such plates can reduce the energetic cost of running by 1%

= Footwear mass, cushioning, and longitudinal bening stiffness

• lighter running shoes reduce the enercetic cost of running

• foam, that cushioning impact, store and return mechanical energy

• plates increased longitudinal bending stiffness

• at the moment al modern running shoes have midsoles made from varios foam materials, that to various degrees, cushioning impact, store an dreturn mechanical energy

• amount of the energy stored by foam materials depends on its compliance - the amount of compression that accurs when loaded with a certain force

• all foams are viscoelastic —> they dissipate some energy as heat

• compliant foams are commonly describt as soft

·      Provide a clean, general characterization of midsole mechanical energy storage and return capabilities in a direction relevant to the spring-mass behavior of runners

·      Reproducible results

·      To properly execute a force-constrained mechanical test, the compression force and regional distribution of force needs to resemble that of human running

·      mounted a rigid foot-form (shoe last) to a material testing machine and snugly fit the foot-form into the fully constructed shoes

·      The material testing machine compressed the midsole in the vertical direction by matching a general time history of the vertical ground reaction force measured during running

·      As vertical force is applied, the shoe midsole deforms (upper trace in each graph)

·      Then, as the shoe is unloaded, the force returns to zero as the midsole recoils (lower trace in each graph)

·      The area between loading and unloading curves indicates the mechanical energy (J) lost as heat

·      The area below the lower traces represents the amount of elastic energy (J) that is returned

·      A last has over 100 measuring points and everyone determines with their individual ball, heel and instep measurements how the later shoe will look like

·      The shape of the shoe last is later responsible for the perfect fit of the shoe

·      Reflects the arch of the foot and the width of the ball of the foot as well as the distance between the toe and heel area

= perforated elastic structur, witch is designed to enhance the energy return effects of the midsole

• also designed to strech and flexing in responce to your unique foot strike

• the grip arranged across the bottom of the foot correspond withe the key pressure points as the foot moves through a stride, ensuring the most used areas are als the hardest wearing

• for running that means: having a outsole that works withe the midsole, adapting to you unique foot stricke & make for a far more confortable run

• the grip pattern provides traction without averdoing it

—> stability strech web sole: grip pittern os closer (specally at the medial9, therefore the outsole has more stability and a higher grip

—> neutral strech web sole: grip pattern has lager gaps

= seves to support the footbed —> allow the fore- and rearfoot to move indepently

• is placend between the midsole and outsole

• designed to allow independent movement of the heel and the front of the foot —> to prevent injuries or stains —> espacally on uneven ground

• lightweight bridge between forefoot and heel

• by supporting the midfoot, the torsion system serves as a platform which helps to combat improper flexing of the arch

• is vervy respansive

• provides stability, comfort and a supportiv fit

—> neutral boost midsole:

—> stability boost midsole: is wider tahn the neutral one, therfore it provide extra stability

= an exoskeletan taht wraps around the outside of the heel

• often made of rigid material which hold up against the impact taht area of the foot experience when running

• helps the shoe keeps its shape and stabilizies the integnty

= quard rail for the foot

• this technology guides the foot to the ideal push-off-point when rolling

• stabilizies and guid the foot

= Heel-Toe Drop

= total height underneath the foot wehen on is wearing footwear (imncludes all type of layers)

= is defined: midsole absolute height in the forefoot minus the midsole absolut height in the rearfoot

• by sprengung the foot stands like on a ramp —> support the rolling movment and cushion the heel area at the same time

• most pronounced effects are seen at the metatarsophalangeal (MTPJ) and ankle joints

• Stiffening the shoe limits the bending of the MTPJ, which causes a reduction in negative work —> This means that less energy is wasted at the joint, and more can be used for propulsion

• Furthermore, running in stiffer shoes causes the point of application of the ground reaction force to shift more anteriorly, creating a longer lever arm around the ankle and MTPJ —> A longer lever arm permits the muscle tendon units surrounding the joint to generate higher joint moments —> As the ankle is responsible for propulsion during the end of the push-off phase of the gait cycle, you should be able to run faster in stiffer shoes as long as your calf muscles are strong enough.