• sole: bottom of shoe
– insole: interior bottom of a shoe
• some models have removable insoles
– outsole: material in direct contact with ground (tread)
– midsole: material between insole and outsole (made of EVA or PU)
• upper: top of shoe that holds shoe to foot
• Low-cut, mid-cut and high-cut uppers
– toe box: area that holds toes and heads of metatarsals
– vamp: material over the instep
– heel counter: specialized area at heel that is relatively rigid in running shoes
• last: form for shaping shoe (straight, semicurved, curved) and footprint
Biomechanics Laboratory, School of Human Kinetcs

• walking:
– long duration
– double “active” peaks
– +/-20% body weight
• running/sprinting/jumping:
– brief durations
– single “active” peak
– 3 times BW
– heel-toe landing
• landings:
– brief duration
– up to 10+ times BW
– forefoot landing
3xBW
2xBW
1xBW
0
Biomechanics Laboratory, School of Human Kinetcs

• ground reaction forces are high (3x body weight)
• impact is brief therefore little time for muscles to dissipate forces
• some people’s anatomy may predispose injury (leg length discrepancy, excessively pronated/supinated feet or varus/valgus knees)
• running surfaces are rigid (roads, sidewalks, frozen earth)
• people tend to over-train (amount per day, no recovery days)
• warm-up and stretching are often neglected
Biomechanics Laboratory, School of Human Kinetcs

• plantar fasciitis
– anatomical, excessive heel impacts, poor running mechanics
• heel spur, hammer toes, bunions
– poor shoe fit
• ankle and foot sprains
– mechanically caused by landing off balance or on an obstacle
• tibial stress syndrome/fracture
– overuse injury, training on hard surfaces, old or poor footwear
• knee/back pain
– anatomical differences (leg length, abnormal Q-angle)
• shin splints
– mechanically caused by rapid changes in training surfaces and overuse
Biomechanics Laboratory, School of Human Kinetcs

• protection from:
– sprains (high cut shoes may help but reduce flexibility)
– cuts and abrasions (strong uppers may increase weight and decrease mobility)
– punctures from nails, rocks, slivers etc. especially for road running (thick soles help but reduce efficiency)
• traction or prevent slippage
– tread helps especially on wet surfaces
– spikes and studs (check rule books)
• cushioning
– in midsoles (reduces efficiency)
• ventilation
– air circulation, water drainage or waterproof?
Biomechanics Laboratory, School of Human Kinetcs

• low cut
– greatest mobility
• mid cut
• high cut
– may help to control ankle sprains
Biomechanics Laboratory, School of Human Kinetcs

• Cushion:
– for high-arch feet, underpronator
– extra cushioning in the midsoles to help absorb shocks; their soles have a curved or semicurved shape (last) that promotes a normal running motion
• Motion control:
– for flat feet or feet that pronate after landing
– straight last and a more rigid midsole than other running shoes, these help keep your feet properly aligned.
• Stability:
– for normal or neutral feet
– semicurved last, but the less rigid midsoles allow feet to strike the ground naturally
Biomechanics Laboratory, School of Human Kinetcs

• measured by durometer (hardness)
• mainly in midsole
• cushioning is helpful for hard surfaces
• especially as muscles start to fatigue
• greater cushioning means less efficiency
• may cause ankle instability and sprains
• gel or air cushions cause landing instability
• cushioning columns are better
• breaks down over time
• impact testing for endurance
Biomechanics Laboratory, School of Human Kinetcs

• all shoes absorb and dissipate energy
• cushioned running shoes absorb the most energy
• the greater the cushioning the more lost energy
• sprinters’ shoes have the least cushioning and are therefore the more efficient
• bare feet are most efficient but traction may be compromised and they offer little protection from stones, heat or sharp objects
Biomechanics Laboratory, School of Human Kinetcs

• basketball/volleyball
– sturdiest with thick midsole cushioning
– for wooden floors and high impacts
• cross-trainers
– most versatile athletic shoes available
– less cushioning
• spiked for track & field
– greatest traction on rubberized tracks
– lightest and fastest
• studded for soccer or rugby etc.
– greatest traction of grass or artificial turf
Biomechanics Laboratory, School of Human Kinetcs

• of hand:
– one-dimensional rotation
– turning palm upwards is supination, downwards is pronation
• of foot
– three-dimensional motion
• inversion, plantiflexion and internal rotation
– supination is turning foot so that plantar surface (bottom of foot) is directed medially (towards midline)
– pronation is turning foot so that plantar surface (bottom of foot) is directed laterally (away from midline), this is most common motion when a foot lands during running
Biomechanics Laboratory, School of Human Kinetcs

• foot is supinated at landing pronates during loading
• orthotics help to reduce rates of pronation during landings
(Bates et al.
1979; M ündermann et al., 2003; Stackhouse et al .,
2004) but it is unclear how they affect the kinetics (MacLean et al., 2006)
Biomechanics Laboratory, School of Human Kinetcs

• orthosis
– device added to support an anatomical structure
– i.e., brace or wedge
– e.g., custom foot orthotic (CFO) appliances (“orthotics”), ankle-foot orthoses (AFO) and knee braces
Biomechanics Laboratory, School of Human Kinetcs

• orthotic with medial forefoot post for forefoot supination (varus)
• orthotic with lateral forefoot post for forefoot pronation (valgus or plantiflexed first ray)
• orthotic with medial heel post for subtalar varus
Biomechanics Laboratory, School of Human Kinetcs

• Bates B et al. Amer J Sports Med 7:338-342,1979.
• Huberti HH & Hayes WC. J Bone Jnt Surg 66A :715-724,1984.
• Insall J, Falvo KA & Wise DW. J Bone Jnt Surg 58A :1-8,1976.
• MacLean C, McClay Davis, I & Hamill J. Clin Biomech 21:623-
630 , 2006.
• Mündermann A et al. Clin Biomech 18:254-262 , 2003.
• Stackhouse CL, McClay Davis, I & Hamill J. Clin Biomech
19:64-70 , 2004.
Biomechanics Laboratory, School of Human Kinetcs

• valgus: outward angulation of the distal segment
– distal segment is rotated
L aterally
– distal means farther away from the body’s centre
– “knock-kneed”
– common in women
Biomechanics Laboratory, School of Human Kinetcs

• inward angulation of the distal segment
– “bowlegged”
– common in horse riders
Biomechanics Laboratory, School of Human Kinetcs

• “quadriceps-angle” is formed in the frontal plane by two line segments:
– from tibial tubercle to the middle of the patella
– from the middle of the patella to the anterior superior iliac sine (ASIS)
• in adults is typically 15 degrees
• Increases or decreases in the Q-angles are associated with increased peak patellofemoral contact pressures (Huberti &
Hayes, 1984).
• Insall, Falvo, & Wise (1976) implicated increased Q-angle in a prospective study of patellofemoral pain.
Biomechanics Laboratory, School of Human Kinetcs

• prosthesis
– device that replaces an anatomical structure
– i.e., an artificial limb
– e.g., solid-ankle, cushioned-foot (SACH) foot,
FlexFoot, C-knee, Mauch leg
Biomechanics Laboratory, School of Human Kinetcs

•
LAUSANNE, Switzerland --
Double-amputee sprinter Oscar
Pistorius won his appeal Friday and can compete for a place in the
Beijing Olympics.
•
Olympic Rule: For the purpose of this Rule the following shall be considered assistance, and are therefore not allowed:
– e) use of any technical device that incorporates springs, wheels or any other element that provides the user with an advantage over another athlete not using such a device.
It's a great day for sport. I think this day is going to go down in history for the equality of disabled people.
-- Oscar Pistorius
Biomechanics Laboratory, School of Human Kinetcs