Orthotic Management of Common Foot Disorders

medial longitudinal arch of the foot apex

sustentaculum tali

lateral longitudinal arch of the foot

outer arch (5th metatarsals)

transverse arch apex

second ray (metatarsal head and proximal phalangeal base)

Where to put metatarsal pads?

proximal to metatarsal heads

hallux rigidus pathology

<50% extension of big toe

fusion of MTP joint of 1st ray

bony dorsum growth

hallux rigidus mechanism

overuse or injury

arthritis

more prevalent in females

hallux rigidus intervention

footwear - stiff sole with a rocker toe

orthotic - carbon insert

mallet/hammer/claw toes pathology

lesser toe deformities

painful, rigid

blisters and/or redness

mallet/hammer/claw toes mechanism

trauma or disease

muscle imbalance causes tendons and ligaments to shorten

mallet/hammer/claw toes intervention

rigid - extra depth shoe; FO to redistribute pressure; surgery

flexible - splinting, stretching, massage; FO to redistribute pressure

hallux abducto valgus (bunion) pathology

• pain at skin or deep within the 1st metatarsal joint

• limited motion of 1st metatarsal

hallux abducto valgus (bunion) mechanism

excessive pronation after mid-stance unlocks the foot (joint subluxes, alters cartilage)

first metatarsal pushed upwards by the GRF

as the metatarsal moves medially and dorsally, the tendons of the foot pull the great toe laterally

hallux abducto valgus (bunion) intervention

FO - proximal to met heads trimline, medial hind foot posting

dorsal bunions pathology

• formation of an exostosis on the dorsal aspect of the first MTP joint

• mechanically blocks extension of the MTP during third rocker

• pain on dorsum of joint (increase with activity)

dorsal bunions mechanism

• limited motion of MTP, joint is subluxed during pre-swing to achieve the required range of forward motion of the foot

• excessive compressive forces on the dorsal margin of joint

dorsal bunions intervention

• foot orthotics are designed to redistribute weight and unlock the first MTP joint in order to return the normal ROM

• metatarsal bar or rocker bottom

interphalangeal sesamoids pathology

• formation of callous under the IP joint of hallux

• cartilage is naturally present, but with excess force it ossifies and becomes bone

interphalangeal sesamoids mechanism

• first met elevates and locks

• IP joint hyperextends to make up for the missing range

• excess stress on the cartilage beneath the IP joint

• ossification into bone

interphalangeal sesamoids intervention

surgery may be required for removal

FOs can restore proper biomechanics - limit excessive ROM, soft top cover

pinch callous pathology

• Thickening of the skin
  on the medial hallux

• Can be painful, and in
  diabetic population
  can lead to ulceration

pinch callous mechanism

• Limited dorsiflexion at the MTP joint because of over-
  pronation

• To compensate for limited ROM, the foot is externally
  rotated during pre-swing, causing shear forces on medial
  aspect of foot

• Results in thickening of skin

pinch callous intervention

• trimming of callous can help to reduce pressure

• a foot orthotic should be provided to reduce the over pronation & re-establish medial longitudinal arch

• proper footwear fit (width)

stress fracture pathology

pain during WB

increased pain with increased activity

change from a mild pain to a sharp pains

stress fracture mechanism

• mild repeated trauma

• muscles cannot absorb forces, load is taken on the bone due to repetitive stress

stress fracture intervention

• acute: immobilize with a CAM walker or post-op shoe to promote healing

• chronic: FO can be used to transfer weight to the first metatarsal from the lesser metatarsals

  • lateral post

  • lateral heel wedge

mortons neruoma pathology

-pain

-numbness and burning

mortons neruoma mechanism

• excessive pronation or instability of foot

• transverse ligament compresses intermetatarsal nerve

• nerve sheath thickens

mortons neuroma intervention

-cortisone

-surgery

-FO with met pad, rocker or met bar

sub metatarsal bursitis (metatarsalgia) pathology

• pain at met heads

• something in shoe

• callus formation

sub metatarsal bursitis (metatarsalgia) mechanism

• excessive pronation or trauma

• metatarsal drops closer to plantar surface

• poorly distributed loading

• bursa formation (protective)

sub metatarsal bursitis (metatarsalgia) intervention

FO with met pad

tailor’s bunion (bunionette) pathology

• pain at 5th metatarsal head

• overgrowth of bone

tailor’s bunion (bunionette) mechanism

• GRF shifts the 5th metatarsal dorsally and laterally (Wolff’s Law)

• shoe box contact

tailor’s bunion (bunionette) intervention

• FO to reestablish proper loading of foot

• shoe of proper width/heel height

• surgery may be required to remove the bump or straighten the metatarsal if severe

tibialis anterior tendonitis (shin splints) pathology

• pain on anterior aspect of leg that worsens after vigorous activity

tibialis anterior tendonitis (shin splints) mechanism

• Excess pronation
• Tibialis anterior works harder to stabilize the medial arch
of the foot
• Repetitive motion on hard surfaces, hills or overuse

tibialis anterior tendonitis (shin splints) intervention

• FO
- Re-establish mechanical
advantage for the tibialis
anterior
- Decrease the force required
to maintain the arch
• Taping
- PT

accessory navicular pathology

enlarged navicular

accessory navicular mechanism

congenital - 2.5% of the population

accessory navicular intervention

• CAM boot

• FO

  • support medial longitudinal arch

  • move navicular laterally and minimize the protuberance

• surgery

plantar fasciitis pathology

• pain in foot after extended periods of inactivity

• pain in heel

plantar fasciitis mechanism

• inflammation of the plantar fascia

• excess lengthening/torsion on fascia from overpronation

• can create heel spur from excess force

plantar fasciitis intervention

• FO with medial longitudinal arch

  • shorten the length of plantar fascia

  • soft heel cup

• PT for stretching the ligament

• night splint

heel spur pathology

• pain on medial aspect of the calcaneus

• brain present with initial steps in the morning and after extended periods of sitting

heel spur mechanism

• the plantar fascia pulls away from the calcaneus, resulting in an ossification of the bone

• caused by tight plantar fascia

heel spur intervention

• FO with medial longitudinal arch

  • shorten the length of the plantar fascia

  • soft heel cup

• cortisone shots or anti-inflammatories

• physical therapy

• surgery for severe cases

sub-calcaneal bursitis pathology

• inflammation of the bursa that cushions the posterior calcaneus

• burning sensation in middle of heel pad

sub-calcaneal bursitis mechanism

• excess eversion of the calcaneus causes the medial tuberosity to press on the bursa during heel strike, resulting in irritation

• overuse

sub-calcaneal bursitis intervention

• FO to redistribute weight away from heel

  • soft top cover to cushion and accommodate bursa

  • soft heel cup

pes planus pathology

• fallen arches/flat feet when weight bearing

• foot pain and fatigue

pes planus mechanism

• normal in children

  • arch development complete by age 6

• congenital

• acquired

  • PTTD

• secondary to trauma

pes planus intervention

• FO

  • functional if flexible

  • posting for further correction

pes cavus pathology

• high med-long arch

• pain on lateral border and met heads

• calluses at met heads & heel

pes cavus mechanism

• congenital

• associated with NM disorders

• reduces shock absorption

pes cavus intervention

• FO

  • redistribute pressure with intimate arch fit

  • soft top cover for shock absorption