Ambulation and Shoes

BIOL 313 Final Exam

How many young drivers believe it is illegal to drive barefoot

2/3

what are the two sources for facts

personal experience and the word of other (authority)

why do we believe that shoes are required by law or health codes?

thats what we’ve always been told

How do shoes harm your feet? (4 main ways)

1. Alter the skeleton of the feet

2. Alter the muscles of the feet

3. Alter the fascia of the feet

4. Alter the biomechanics of standing, walking, and running

Where in the body do shoes have acute and chronic affects?

the feet, ankles, knees, hips, and back

How many women a year are hospitalized for high heels

over 20,000

how many shod children suffered psuedomonas infections after nail puncture?

50%

What happens when a nail enters your foot through a shoe?

shoe particulate matter is embedded in the wound

how many barefoot children suffered pseudomonas infections after nail puncture?

0%

Shoes are…

incubators for growing bacteria and fungi and the leading cause of athlete’s foot

what is the most prevalent skin infection

athlete’s foot

how many people in the general population have athletes foot

15%

how many male marathon runners have athletes foot?

24%

How many female marathon runners have athlete’s foot

6%

Ratio of men to women with toenail fungus

2:1

why is athlete’s foot so prevalent?

foot sole has a high density of sweat glands but closed-toe shows don’t allow the sweat to evaporate

what is the cause of foot odor?

the breeding ground of microorganisms in your shoes

only field of medicine in which a healthy body part is considered insufficient to perform its function without support

podiatry

what do support structures do

weaken body parts

shoes _________ the foot

immobilize

shoes reduce _____ and ______ flow

blood and lymph

shoes cause ________ of the muscles

atrophy

shoes weaken what three things

ligaments, tendons, soft tissues

shoes change the biomechanics of what three things

standing, walking, running

what are the four unnatural ways shoes immobilize the foot?

toes compressed, toes elevated, arch lifted, heel elevated

what are the most damaging features of shoes?

elevated heel, thick hard outer sole, thick inner sole, toe spring, tapered toe box, arch support, curved last, large sole surface area, instep support panels, cinching features (laces)

what is hallux valgus

an abnormal deviation of the great toe (hallux) laterally toward the other toes

What is this called?

hallux valgus

bunion

an abnormal enlargement of the first MTP joint

hallux valgus is caused by

skeletal remodeling

what is hammer toe

the extensor tendons are too long and/or flexors are too short and pull too tightly

what causes hammer toe?

shoes with short narrow toe boxes and/or shoes with toe springs

hammer toe

ingrown toenail

what often causes ingrown toenails?

excess pressure on the toes by shoes

flatfoot affects how much of the population?

25%

Shoes impede what by fixing the arch with an arch support?

the windlass mechanism

the windlass mechanism

a biomechanical process in the foot where the plantar fascia (a band of connective tissue) acts like a rope or cable to raise the medial longitudinal arch during the push-off phase of walking

shoes harbor _________ bacteria

pseudomonas

the narrow toe box of shoes

reduces the efficacy of the great toe during push off by shifting it laterally to the 2nd and 3rd toes

a narrow toe box eventually pushes

the hallux laterally

elevated heels shift body weight what direction?

anteriorly

90%

of the body’s weight is supported by the metatarsal heads in 3-inch heels

in heels…

the toes are kept hyperextended and the windlass mechanism is disengaged

elevated heels engage what muscles to keep the body from falling forward

triceps surae and gluteus maximus

when wearing heels the pelvis

is tilted 15 degrees

how does wearing heels affect the knee?

body weight is shifted forward in the knee

knee osteoarthritis in women and men

4x higher in women

toe springs are required because

of the stiff nature of the shoe sole

shoes encourage

overpronation

orthotics

arch support

processes dramatically reduced by immobilization and arch support

windlass mechanism, shock absorption, and spring action

what is the most common foot complaint in the US?

plantar fasciitis (PF)

what characterizes plantar fasciitis

sharp heel pain, especially in the morning

treatments for plantar fasciitis

steroid injections, physical therapy, orthotics

-itis

inflammation

-iosis

dead tissue

plantar fasciitis

inflammation of the plantar fascia

tissue death of the plantar fascia

plantar fasciosis

cause of plantar fasciosis

permanently hyperextended toes reduced blood perfusion of plantar fascia leading to necrosis

running shoes

dramatically reduce tactile feedback from foot sole

shoe running

over-striding, over-extended knee, dorsiflexion, and heel striking

barefoot running

flexed hip, knee, and ankle; flatfoot landing

GRF

ground reaction force

running in shoes creates a sharp

GRF that is absent when barefoot

when running barefoot

impact forces on the knee and hip are zero

foot arches take _______ years to fully develop

8-10

little muscle activity is required to

stand at ease

when standing what is true of our hips and knees

they are in the most stable positions and fully extended

the body’s center of gravity is

slightly anterior to the rotational pivot point of the ankle

muscles counter the forward sway of our body

gastrocnemius and soleus

two phases of the gait cycle

stance phase and swing phase

stance phase

60%

swing phase

40%

one gait cycle

heel strike of one foot to the next heel strike of the same foot

one step

heel strike of one foot to heel strike of other foot

both feet on the ground

double support

one foot on the ground

single support

20% of the stance phase

must be double support

ambulation

one of the most complex biomechanical achievements of the body

standard terminology for stance phase

heel strike

foot flat

midstance

heel off

toe off

standard terminology for swing phase

acceleration

midswing

deceleration

Rancho terminology for stance phase

initial contact

loading response

midstance

terminal stance

preswing

Rancho terminology for swing phase

initial swing

midswing

terminal swing

heel strike/initial contact

foot flat/loading response

midstance

heel off/terminal stance

push off

what is push off

most forceful part of gait, just before toe off (a Howell introduction)

toe off/preswing

initial swing/acceleration

midswing

terminal swing/deceleration

What terminology was focused on single vs double support?

Richard terminology

the four phases of Richard terminology

first double support, single support, second double support, swing

the single support and swing phases of Richard terminology have what three phases?

early, middle, late

vertical CoM is about

5cm at 1.8m/s

tallest part of gait cycle

midstance

mediolateral displacement when walking

2 cm left and right