2. Foot Orthoses
The foot orthoses is nothing but a boot that has
components like supports and wedges to manage different
foot symptoms and deformities. These modifications are
made of various material like rubber foam or leather.
The FO can be divided into a lower part and an upper part.
Components of the lower part
sole: it is the part of the shoe in contact with the
ground.The inner part of the sole against which the foot
rests is the insoles.Bar straps and wedges, which are
common attachments to the foot orthoses get there
leverage and attachments through the sole and exert their
forces
3. Ball: Widest part of the sole that id located in the region
of the metatarsal heads.
Shanks: is the the narrowest part of the sole between the
heel and ball.The uprights of the AFO attach themselves to
a stirrup at the shank region.
Toe spring: It is the space between the outer sole and the
floor, which helps to produce a rocker effect during toe off
phase of the gait cycle.
Heel: is the posterior part of the sole, which corresponds to
the heel of the foot. Since it is the portion where most of
the body weight is taken it needs to be resilient and thicker
so that it can prevent shoe components from wearing out
and shift weight to the fore foot.
5. Upper part (Also called shoe upper) components
Quarter: this is the posterior portion of the shoe upper . A
high quarter is referred as a high top and is used by runners
and footballers for greater seensory feedback, and to
prevent retrocalcaneal pain.
Heel counter: In sports shoes there is a reinforcement of
the quarter posteriorly called a heel counter which provides
posterior stability to the shoe and supports the calcaneus .
Vamp:Vamp is the anterior portion of the upper and is
often reinforced with a toe box anteriorly . In front is the
tongue which protects the upper fore foot behind the lace
stays . Extra depth shoes allow more room inside the shoe
for orthotic intervention.
6. Throat: This is the opening of the located at base of
the tongue, through which the foot is inserted.
Toe box: It prevents the toes from suffering trauma
when the person kicks as in football.
Tounge:This is the part of vamp which extends down
in frontof the throat.
Stirrup:This is piece on the outer sole in the shank
region just in front of the heel offering attachment to
metal uprights.
7. Modification of the orthopedic shoe
INTERNAL MODIFICATIONS
The closer the modification is to the foot, the more effective
it is.The insert permits the patient to transfer the orthosis
from shoe to shoe, if the shoe have the same heel height;
otherwise, a rigid insert may rock in the shoe.
Most inserts terminate just behind the metatarsal
head;thus,they may slip forward,particularly if the shoe has
a relatively high heel.Internal modification are fixed to the
shoes interior, guaranteeing the desired placement, but
limiting the patient to the single pair of modified shoes.
9. Inserts made of soft materials, such as the viscoelastic
plastics (e.g, sorbothane and viscolas), reduce sher and
impact shock, thus protecting painful or insensitive
feet.The orthosis slopes anteriorly to reduce load on the
painful heel.In addition, the orthosis has a concave relief to
minimize pressure on the tender area.
Longitudnial arch supports are intended to prevent
depression of the subtalar joint and flattening of the arch
(pes planus).
The orthosis may include a wedge (post) to alter foot
alignment. The minimum support is a rubber scaphoid pad
positioned at the medial border of the insole with the apex
between the sustentaculum tali and the navicular
tuberosity.
12. The metatarsal pad is a convexity that may be
incorported in an insert or may be a resilient domed
component glued to the inner sole so that its apex is
under the metatarsal shafts.The pad transfer stress
from the metatarsal shafts.
Occasionally, modification are sandwitched between
the inner and outer in the front soles ; for examples in
the patient with marked arthritic changes in the front
of the foot probably will be more comfortable if the
shoe has a long steel spring between the sole to
eliminate motion at the painful joints.
13. External modification
An external modification ensures that the patient wears the
appropriate shoes and does not reduce shoe volume, but
will erode as the patient walks and is somewhat
conspicuous.
A heel wedge is a frequently prescribed external
modification. It alters alignment of the calcaneus. A medial
heel wedge , by applying laterally directed force, can aid in
realigning flexible pes valgus or can accommodate rigid pes
varus by filling the void between the sole and floor on the
medial side.A medial wedge is incorporated in a Thomas
heel , intended for flexible pes valgus.
15. Sole wedges alter medial lateral metatarsal alignment. A
lateral wedge shifts weight bearing to the medial side of the
front of the foot. It compensates for fixed forefoot valgus ,
allowing the entire front of the foot to contact the floor.
A metatarsal bar is a flat strip of leather or other firm
material placed posterior to the metatarsal heads. At late
stance , the bar transfers stress from the
metatarsophalangeal joints to the metatarsal shafts.
A rocker bar is a convex strip affixed to the sole proximal to
the metatarsal heads.It reduces the distance the wearer
must travel during stance phase, improving late stance, as
well as shifting load from the metatarsophalangeal joints to
the metatarsal shafts.
19. Ankle-Foot orthoses
The AFO is composed of a foundation, ankle control, foot control , and
a superstructure.
Foundatio of the orthosis of the shoe and a plastic or metal component.
INSERT A plastic or metal insert or foot foundation has several
advantages. Because internal modifications can be incorporated in it,
the insert provides good control of the foot.It must be worn with a shoe
that closes high on the dorsum of the foot to retain the orthosis. The
insert facilitates donning the orthosis because the shoes can be
separated from the rest of the brace.
The orthosis with an insert is relatively lightweight; the is usually made of
a thermoplastic material, such as polyethylene or polypropylene.
20. If the orthosis is placed in a shoes with too low heel, the uprights
would incline posteriorly, increasing the tendency of the wearers
knee to extend. Conversely, if the orthosis is worn with a higher
heeled shoe,the patient might experience knee instability.
STIRRUP the traditional foundation for the AFO is a steel
stirrup , a U shaped fixture, the center portion of which is riveted
to the shoe through the shank. The arm of the stirrup join the
brace uprights at the level of the antomical ankle, providing
congruency between the orthotic and the anatomical joints.
The solid stirrup is one piece attachments that provides
maximum stability of the orthosis on the shoes.
22. The split stirrup has three segments . The central
portion has a transverse rectangular opening on each
side. Medial and lateral angled side pieces fit into the
openings.
The split stirrup simplifies donning the orthosis
because the wearer can detach the uprights from the
shoe. If a central piece is riveted to other shoes can be
interchange.
24. ANKLE CONTROL most AFO are precribed to control
ankle ankle motion by limiting plantarflexion or
dorsiflexion , or by assisting motion. The patient with
dorsiflexior weakness or the paralysis risk draging the toe
durin the swing phase.Dorsiflexion assistance can be
provided by a posterior leaf spring that arises from a plastic
insert.
During the early stance, as the patient applies the force to
the braced foot , the uprights bend backward slightly.
When the patient progress into swing phase, the plastic
recoils forward to lift the foot .
Thinner, narrower plastic permits relatively greater motion.
26. A joint is placed in a plastic hinged solid ankle AFO or
a metal posterior stop can be incorporated in the
stirrup. The posterior stop tend to impose a flexion
force at the knee during the early stance and prevent
the lax knee from hyperextending.
An anterior stop limits dorsiflexion, aiding the
individual with paralysis of the triceps surae to achieve
late stance.
Limiting all foot and ankle motion can be achieved
with a plastic solid ankle foot orthosis its trimline is
anterior to the malleoli.
28. The solid ankle orthosis may be divided transversely
at the ankle, with the sections hinged, creating the
hinged solid ankle foot orthosis.
It provides slight sagittal motion, fostering
achievements of the foot flat position in early stance
and enabling some patients with hemiplegia to walk
with increased stride length and cadence.
30. FOOT CONTROL Medial –lateral motion can be controlled with
a solid ankle AFO. The rigidity of the orthosis can be increased
by using thicker or stiffer plastic, corrugating the plastic,
forming the edges with a rolled contour, or embedding carbon
fiber reinforcements.
A solid ankle AFO or a hinged solid ankle AFO also controls
frontal and transverse plane foot motion.
The valgus correction strap is sewn to the medial portion of the
shoe upper near the sole, and buckle around the lateral upright,
exerting a laterally directed force to restrain pronation.
The varus correction strap has opposite attachments and force
application. Either strap, although adjustable, complicates
donning.
32. Superstructure
The proximal portion of the orthosis, the superstructure, consist of
uprights, and a shell, band, or brim.
Plastic AFO usually have a single uprights or shell. Both the solid ankle
and the hinged solid ankle AFOs have a posterior shell extending from
the medial to the lateral midline of the leg, thus providing excellent
medial-lateral control and a broad surface to minimize pressure.
The sprial AFO is a design in which a single uprights sprials from the
foot plate around the leg, terminating in a proximal band. It may be
made of polypropylene, nylon acrylic, or carbon fiber.The sprial sprial
orthosis controls, but does not eliminate , motion in all plane.
Such AFOs are contraindicated for the individual whose ankle and leg
volume fluctuates markedly, because the orthosis cannot be adjusted
readily.
34. Metal and leather orthosis usually have medial and lateral
uprights to maximise structural stability.
Aluminum uprights are lighter in weight than steel. Carbon
graphite and titanium uprights weight appreciably less than
aluminum and rival the strengthof steel; however, orthoses made
of the newer materials are more expensive.
Most orthoses have aposterior calf band made up of plastic or
leather- upholstered metal. The band has an anterior buckle or a
pressure closure strap. The farther the band from the ankle
joint, the more effective is the leaverage of the orthosis; however,
the band must not impinge on the peroneal nerve.
35. AFO with stirrup attachment, ankle joints, bilateral
uprights and upholdstered metal calf band
36. `An anterior band that is the part of a solid ankle AFO
imposes posteriorly directed force near the knee,
enabling the AFO to resist knee flexion.Such an orthosis
is sometimes known as a floor reaction orthosis.
If the AFO is to reduce the amount of weight
transmitted through the foot, it may have a patellar –
tendon-bearing brim, resembling a transtibial (below-
knee)prosthetic socket.
The brim must be used with an plastic solid ankle or a
steel limited –motion ankle joint.
38. Tone-reducing orthoses are plastic AFOs designed for children
with spastic cerebral palsy and adults with spastic hemiplegia.
The foot plates and broad uprights are designed to modify reflrx
hypertonicity by applying constant pressure to the plantarflexors
and invertors.
They are particularly useful for the individual who have
moderate spasticity with varus instability , but do not have fixed
deformity.
They control the tendency of the to assume an equinovarus
posture; in addition, some versions have a foot plate that
maintains the toe in an extended or hyperextented postion, thus
assisting children with spasticity to walk with better foot and
knee control .
39. Posterior static (or static-progresive or serial-
static) Ankle foot orthosis (posterior AFO)
Common Names : foot drop splint, ankle –foot orthosis.
Objectives : To rest the ankle to relieve pain.
To immobilize or correct ankle contractures.
To prevent or correct ankle contractures.
Indications : For non weight bearing situations when the
clients is in bed , sitting or walking with crutches or walker.
Mild to moderate spastic hemiparesis
Post repair of calcaneal/Achilles tendon.
Musculoskeletal injuries of the distal tibia/ fibula or ankle.
Unconscious client at risk of developing ankle flexion
contractures.
42. Bisurfaced static(serial-static)AFO
Common Name Ankle spastic foot drop splint.
Objective to prevent or reduce ankle flexion
contracture.
To relieve pain.
In weight bearing applications, helps clear the toes
during the swing phase of gait.
Indication Nonweight bearing indications .
Weight bearing indications: weak or paralyzed ankle
dorsiflexors.
44. Circumferential calf Based Dynamic Ankle
Assistive Dorsiflexion Orthosis
Common name Dynamic foot drop splint ankle
extention assist; dorsiflexion splint.
Objects : To passively dorsiflex the ankle to clear the
toe when walking , while allowing planter flexion.
Indications : Weak or paralyzed ankle dorsiflexors
caused by
Cerebral palsy .
Flaccid hemiplegia.
Peroneal nerve injury.
46. REFRENCES
1) Orthotics in rehabilitation, first edition –BY PAT
MCKEE LEANNE MORGAN.
2)Physical rehabilitation, fifth edition- BY SUSAN B
O’ SULLIVAN.
