An orthosis is defined by the
Organization as ‘‘an externally
applied device used to modify the
structural and functional
characteristics of the
neuromuscular and skeletal
[International Organization for Standardization, ISO
8549-1:1989 Prosthetics and Orthotics - Vocabulary.
General terms for external limb prostheses and orthoses.
1989, International Organization for Standardization:
CLINICAL OBJECTIVES OF
• To relieve pain
• To manage deformities
• To prevent an Excessive ROM
• To increase ROM
• To compensate for abnormalities of
• To protect tissues
• To promote healing
• To provide other effects e.g. placebo,
According to ISO 8549-3:1989 :
• Foot Orthosis (FO)
• Ankle-Foot Orthosis (AFO)
• Knee Orthosis (KO)
• Knee -Ankle-Foot Orthosis (KAFO)
• Hip-Knee-Ankle-Foot Orthosis
• Hip Orthosis (HpO)
PRINCIPLE OF BRACING
•Every orthosis uses force applied to the
limb to accomplish the goals of its design.
An orthosis is most comfortable and
1. The forces are distributed over large
surface areas to minimize pressure on skin
and soft tissue.
2. The forces are applied in such a way
that a large moment arm reduces the
amount of force needed to control the joint.
3. The sum of the primary force and
opposing counter forces of each control
system equals zero.
Principles Underlying Control
Systems in Orthotic Design
1. Pressure = Force/Area
2. Torque = Force × distance
3. Control direction of primary force
direction of counter-forces
4. Equilibrium Σforces = 0
Characteristics of an ‘Ideal’ Orthosis
• Meets the individuals mobility needs and goals.
• Can be worn for long periods without damaging skin or
causing pain & can be easily donned and doffed
• Meets the individual's need to fit in with peers
• Can be made in the shortest period of time
• Can be made with minimal initial cost and cost for
• Transfer body weight to the ground
• Protection, weight bearing surface
• Comfort, function, appearance
• Decrease pressure
• Base for orthotics and bracing
• Blucher shoe style
there is more room
to don and doff the
shoe and the
• Bal shoe style,
The vamp is stitched
over the quarters at
the throat, thereby
limiting the ability of
the shoe to open and
Shoe Modifications Conditions
1. Rocker sole : Traumatic/arthritis
2. Heel Flare : Providing wide heel for
3. ‘T’ or ankle strap : For varus & valgus
4. C & E heel : Pes planovalgus
(Thomas Heel) (Flat Foot & knock knees)
5. CTEV Shoe : Club Foot
Shoe Modifications Conditions
6. Heel Wedge : Valgus/Varus heel
7. Medial Arch Support : To support medial
8. Metatarsal Pad : Fall of M.T. head
Metatarsal Bar Painful toe break
9. Lateral heel & sole : To keep the foot in eversion
10. Excavated heel cushion : Calcaneal spur
Shoe Modifications Conditions
11. Soft lining & Cushioning : Anaesthetic foot
12. Hallux Valgus pad : Hallux Valgus Foot
13. Shoe Filler : Partial Foot Amputation
14. Universal & Equinus shoe : For shortening
Raise <3/8” - accom. inside shoe
>3/8” - full length external
lift to the sole
15. Ext. Orthoses or Prosthesis : If the shortening > 6”
SHOES CHECK OUT
• A practical way of ensuring that a shoe is of
adequate length is to determine whether the
index finger can be placed between the tip of the
great toe and the toe box.
• The presence of calluses indicates areas of
friction from poorly fitting (loose) shoes.
• The presence of corns indicates areas of friction
over bony prominences, most often caused by
• Leather shoes are durable, allow ventilation, and
mold to the feet with time.
PRINCIPLE IN FOOT ORTHOSIS
• For a custom foot
orthosis to be made, the
subtalar joint should be
placed in a neutral
position before casting.
• The subtalar neutral
position is used to treat
including pes planus,
painful RA affecting the
first MTP joint
• Indication subtalar joint instability.
• Controls flexible rearfoot valgus or
varus as well as forefoot abduction
• Holds the calcaneus & supports
the midfoot with high medial and
lateral trim lines.
• It realigns the calcaneus,
improving the angle of pull of the
• Provides a more stable foundation
for the articular surfaces of the
talus, navicular & cuboid bones.
• By limiting movement of the
midfoot & forefoot and holding
the foot in functional position, it
provides a stable base for
postural control during standing
• Redistributes plantar pressures
of spastic equinovarus from the
anterior foot to the heel by
reducing overall stimulation of
• By providing a stable base
during stance phase, it
improves swing limb clearance,
stride length, cadence, and self-
selected walking speed in
diplegic CP children.
Its proximal trim lines are
just superior to the ankle
joint, and its distal trim
lines encase more of the
ANKLE FOOT ORTHOSIS
• Short leg braces used effectively to control ankle motion.
• Provide mediolateral stability as a safety feature.
• Control the amount of dorsiflexion and plantar flexion.
• Plantar flexion creates a knee extension moment and
dorsiflexion creates a knee flexion moment.
• Can also stabilize the knee during gait.
• A cushioned heel move the ground reactive force anteriorly
at the foot and subsequently at the knee and helps stabilize
• A firm heel decreases knee stability via a knee flexion
moment while moving the ground reaction force posterior to
the knee joint e.g. used in genu recurvatum
Three transitional rocker periods occur as the
body moves forward over the foot during stance.
A, During first rocker, the transition from swing into early stance,
controlled lowering of the forefoot ccurs, with a fulcrum at the heel.
B, During second rocker, controlled forward progression of the tibia
over the foot occurs, with motion of the talocrural joint of the ankle.
C, In the third rocker, transition from stance toward swing occurs as
the heel rises, with dorsiflexion of the metatarsophalangeal joints.
FRO Control System
A, When a patient walks in a “crouch gait” pattern, the GRF vector passes behind
the knee at midstance, creating a flexion moment at the knee, which must be
counteracted to maintain upright position.
B, In normal gait, knee stability at midstance is assisted by a ground reaction
moment as the body moves over the foot, and the GRF vector passes anterior to
C, The solid ankle-foot orthosis and the floor reaction orthotic designs use a fixed
ankle position to harness the GRF, creating a large extension moment at the
Plastic ground reaction AFO
The anterior tibial shell closing and 10 degrees of
plantar flexion help create knee extension moments
with weight bearing to add stability to the knees
• Cost effective.
• Good cosmesis.
• Light weight.
• Interchangeability with
• Ability to control varus &
• Provision of better foot
support with the customized
• Solid Plastic Ankle-Foot
• Plastic Ankle-Foot
• Patellar Tendon Bearing
• Charcot Relief Orthotic
• Pressure Relief AFO
• Holds the ankle in as close to
optimal static alignment as
• Mediolateral ankle stability is a
result of trim lines at the
midline of the malleoli.
• The high medial border at the
foot and the slight flaring just
proximal to the medial
malleolus is used to counteract
an abnormal, flexible subtalar
• The crossed Velcro strap
anterior to the ankle helps
position the rear foot
appropriately within the heel
section of the orthosis.
• The posterior position and arc of
the trim lines at the ankle, as
well as the thickness of
thermoplastic material used,
determine the degree of
flexibility of the posterior leaf
• Support the weight of the foot
during swing phase as a means
of enhancing swing limb
• Assist with controlled lowering
of the foot during loading
response in stance as part of
the first/heel rocker.
HINGED PLASTIC AFO
Camber Axis Hinged ankle joint,
allows forward motion of the
tibia through the second/ankle
rocker of stance phase.
Oklahoma orthotic ankle joint,
has a built-in plantarflexion stop
& posterior strapping that can be
adjusted to limit the amount of
• Consists of a proximal
calf band, two uprights,
ankle joints, and an
attachment to the shoe
to anchor the AFO.
• The posterior metal
portion of the calf band
should be 1.5 to 3
inches wide to
• The calf band should be
1 inch below the fibular
neck to prevent a
peroneal nerve palsy.
• The plantar stop is used to control plantar spasticity and is
commonly set at 90 degrees.
• An anterior stop (5 degrees dorsiflexion) is used to
substitute for the function of the gastrocnemius/ soleus
• The posterior spring substitutes for concentric contraction
of dorsiflexors to prevent flaccid foot drop after toe-off.
Patellar Tendon Bearing AFO
• Ulcerations of the
heel of foot,
• Tibial fractures,
• Relief of the weight-
bearing surface in
• Post op ankle
• Charcot joint, and
• AVN of the foot or
• Made of plastic and are bivalved and fit snugly with the
use of Velcro straps or buckles.
• The solid plastic orthosis makes contact with the
ground before the reactive force is absorbed
significantly by the foot and then distributes this force
more proximally along the leg.
• 10% of the weight is transferred to the patellar tendon
and tibial condyles.
• 50% weight-bearing reduction is achieved by custom-
fitted contact distributed throughout the leg.
• Additional weight-bearing reduction is obtained by
eliminating ankle movement via carbon graphite
inserts and/or the use of a rocker bottom.
Charcot Relief Orthotic Walker
• A custom-molded bivalve
plastic AFO that is fully
padded on the inside with
total contact of the foot,
ankle, and leg.
• Purpose is to off-load a
plantar ulcer or stabilize
the progressive deformity
from Charcot joint of the
foot and ankle.
• Has a rocker bottom and
rubber sole for indoor and
• Often used instead of total
contact casting of diabetic
• Lighter weight.
• Lower profile footplate.
• Ability to provide some
substitute for weak
• Fit easily into many shoe
styles and come with
anterior or posterior calf
• Poor mediolateral control
• Lack of adjustability
Stabilize subtalar &
tarsal joints in stance
Control ankle position
Provide stance phase
stability via ankle-
knee coupling & assist
limb clearance in
control at ankle
Type of Orthosis Actions Indications
Stabilize subtalar &
tarsal joints in stance
Preposition foot for IC
or hemiplegic CP
Assist limb clearance
Preposition foot for IC
Apart from above it
of tibia in stance
AFO FOR ANKLE CONDITIONS
FOOT DROP Posterior leaf spring AFO
Hinged plastic AFO with
metal double-action ankle
Hinged midline posterior
stop AFO that is spring-
Hinged AFOs with plantar
stops at neutral (90
LUMBAR SPINAL CORD
AFOs fixed in 10 degrees of
CHECK OUT FOR AFO
• The examination is carried with the patient standing,
sitting, and walking and with the appliance removed.
• The first and most obvious form of a checkout is to
verify that the gait pattern is improved with the orthosis
compared with the gait pattern without the orthosis.
• The patient is to be checked for ease of donning and
doffing the orthosis, and while it is off, observed for
areas of skin breakdown.
• Can the patient sit comfortably with his knee flexed
approx. 105 degrees.
CHECK OUT FOR AFO: STANDING
• Is the shoe satisfactory and does it fit properly.
• Are the sole and heel of shoe flat on the floor.
• Are the mechanical ankle joints aligned so they coincide
approximately with the anatomic ankle.
• Is there adequate clearance for ankle joint and uprights.
• Is sufficient force exerted by the correction T strap.
• Do the uprights or plastic shell conform to the contour of the
leg and are they at the midline of the leg.
• Is the calf band or shell comfortable, of proper width and
provide sufficient clearance for the head of the fibula.
• If PTB brim is used, is there adequate reduction in wt.
bearing at heel.
KNEE ANKLE FOOT ORTHOSIS
• Above knee braces and the components apart from
those of an AFO also include knee joints, thigh uprights,
and a proximal thigh band.
• Indications: severe knee extensor & hamstring
weakness, structural knee instability, and knee flexion
• There are three stabilizers to the knee:
the hamstrings (via eccentric activation at heel strike),
and the plantar flexors (plantar flexion creates a knee
• These stabilizers should all be evaluated carefully by
physical examination before a KAFO is prescribed.
• When maximum strength &
durability are needed
• Significant obesity
• Uncontrolled or fluctuating
ADV: Strong, durable & easily
• Heavy, less cosmetic
• Must be attached to shoe or
• Fewer contact points reduce
•Energy expenditure as weight of
the orthosis is a more
• When control of transverse
plane motion is needed
• For maximum limb control
• For less energy expenditure
• For control of transverse plane
• Lightweight & greater cosmesis
• Interchangeability of shoes
DISADV: Can be hot to wear
• In obese and fluctating edema
intimacy of fit is difficult.
ISCHIAL WEIGHT BEARING (UNWEIGHTING)
The quadrilateral or ischial containment thigh section is designed to permit partial
transfer of the patient’s weight through the KAFO during stance phase. This weight
sift, however small, permits the patient to extend the stance side period on the
ORTHOTIC KNEE JOINT
Straight Set Knee
- Allows free flexion
- Used in combination
with a drop lock, which
keeps the knee in
extension throughout all
phases of gait .
- Uses a double-axis
system to simulate the
movements of the femur
and tibia at the knee
- No proved advantage,
adds bulk & used in
sports knee orthosis.
Posterior Offset Knee
- For patients with weak
- Allows free flexion &
extension of the knee
during the swing phase of
- Helps keep the orthotic
GRF in front of the knee
axis for stability.
A. The knee joint remains extended if the GRF is anterior to
B. A knee flexion moment is created if the GRF is posterior
to the knee.
C. Orthotic GRF at heel strike with posterior offset orthotic
The ratchet lock
Has a catching mechanism
that operates in 12-degree
Useful in rising from seated
to standing & prevents
buckling of knee.
The Bail Lock
Lifting up the bail
posteriorly releases the
knee joint to permit
flexion, allowing the
patient to sit down.
The Dial lock
Used to stabilize the knee
In varying amounts of flexion
Adjusted in 6-degree
increments and is more
precise for the management of
a knee flexion contracture.
• Indications: complete lesion at
L1 or higher SCI for ambulation.
• It consists of
- An ankle joint with a
dorsiflexion and posterior stop.
- A rigid anterior tibial band & a
rigid posterior thigh band for
three point pressure.
- A sole plate extending to the
- A crossbar added to the
metatarsal head area for
mediolateral stabilization, and
- An offset knee joint with a bail
• Mechanical stance-control
• It has lightweight lateral
upright, medial cable,
anterior padded cuffs, and
• The knee unit contains a
cable-driven ratchet that
locks the knee as it extends
in terminal swing in
preparation for stance phase,
and unlocks it at terminal
stance to allow knee flexion
necessary for limb clearance
during swing phase.
• It is a microchip-controlled
and battery-powered SC-
• A pressure-sensing
footplate signals the
microprocessor to lock the
knee joint when the limb is
loaded(regardless of knee
position), and unlock the
unit when unloaded in late
KAFO & HKAFO CHECK OUT
• Should include points mentioned in AFO check out.
• Are the mechanical knee joints aligned so they coincide
approx with anatomic knee and is there adequate clearance.
• Is the knee lock secure & easy to operate.
• Do the uprights provide adequate clearance & are they at
the midlines of leg and thigh.
• Is there satisfactory clearance between the medial upright &
• Is the lateral upright below the head of the trochanter but at
least 1” higher than medial upright.
• Does the ischial tuberosity rest properly on the ischial seat.
• Is the patient free from vertical pressure in the area of the
• Is the centre of hip joint slightly above & ahead of the
• Does the pelvic band fit the contours of the body accurately.
Specialized Knee Orthoses
• Swedish Knee cage:
• provides mild control for excessive
hyperextension of the knee
• Patellar stabilizing braces:
• Improve patellar tracking; maintain
• Lateral buttress or strap positions patella
• A central Patellar cutout may help
positioning and minimizes compression
Sport Knee Orthoses
Uses the standard
distribution system in a
Designed to prevent
stability at the knee
Specialised Knee Orthoses
Unloader knee braces
apply a gentle force to
separate the affected bone
joint surfaces, unloading the
affected area of the knee to
minimise wear and tear
They are proven to relieve
pain and increase
mobility, even amongst
those with moderate and
severe knee ligament injuries
VALGUS (UNLOADING) ORTHOSES
• It unloads the medial compartment of the knee through use of
adjustable tension straps crossing the lateral aspect of the knee joint,
lateral condylar pads, or lateral hinge systems, which are fixed to a
brace shell at the calf and thigh.
• A study by Katsuragawa demonstrated an increase in BMD more in the
lateral tibial condyle than the medial condyle due to the transfer of
forces across the knee joint from the medial to the lateral side after use
of a valgus orthosis. Change of bone density with valgus knee bracing. Int
• A research by Horlick demonstrated a significant reduction of pain when
wearing a valgus brace. Valgus knee bracing for medial gonarthrosis.Clin J Sports Med.
• The age range for
initial use is usually 8
to 15 months.
• It helps balance the
body in space and
allows free use of the
upper limbs for
• Swivel orthosis.
• It is an appropriate for children
(2.5 – 5years) who are unlikely
to become functional walkers.
• The hip and knee joints remain
locked in extension to permit
ambulation in the upright
position but can be unlocked to
• Difficulties include donning and
doffing and rising from a
seated position to a standing
The reciprocal gait orthosis uses a dual cable system to couple flexion of one
hip with extension of the other. This coupling assists forward progression of the
swing limb while ensuring stability of the stance limb.
• Lower limb orthoses are among the most
commonly prescribed biomechanical devices.
• They are intended to assist individuals with
• Orthoses can be rationally prescribed by
specifying the functional outcome desired in
• Ankle–foot orthoses can be designed with
sufficient mechanical lever arms to
effectively control the ankle complex and to
influence the knee joint indirectly
• The recent development of stance
control knee joints has eliminated
several drawbacks associated with
knee-ankle-foot orthoses .
• An appropriate lower limb orthotic
prescription requires a thorough
biomechanical analysis of gait and
knowledge of the available orthotic
• Braddom's Physical Medicine and
Rehabilitation – 5th
• Orthotics & Prosthetics in
Rehabilitation – 3rd
Edition by Michelle
• AAOS Atlas of orthoses and assistive
devices - 4th
edition by John D Hsu