Orthosis are devices used to support weak joints and correct deformities. They work by applying three point pressure and distributing weight across a wide surface area. Common orthosis include ankle foot orthosis (AFO) which support the ankle and foot, knee ankle foot orthosis (KAFO) which stabilize the knee and lower leg, and hip knee ankle foot orthosis (HKAFO) which provide support from the hip to the foot. Orthosis are made of plastic or metal and their design depends on the joints needing support and the individual's condition.

1. Orthosis

2. Orthosis
 Definition: Orthosis is an orthopedic
appliance or apparatus used to support,
align, prevent, or correct deformities or
to improve function of movable parts of
the body.
 Purpose:
1. To lend stability to a weak joint.
2. Correct or maintain alignment.
3. Correct skeletal deformities, etc.

3. Principles in designing orthosis
 Three point pressure.
 Total contact.
 Partial weight relieving.

4. Three point pressure
 "The sum of the forces and the bending
moments created is equal to zero.“
 A single force is placed at the area of deformity;
two additional counter forces act in the opposing
direction.
 During "quiet" standing, line of gravity (weight
line) passes through:
◦ posterior to hip joint
◦ anterior to knee joint and
◦ anterior to ankle joint

5. Total contact
 “Pressure is equal to the total force per unit area. “
 The greater the area of a pad of an orthosis, the less
force will be placed on the skin.
 P = force
Area of application

6. Partial weight relieving
 “The farther the point of force from the
joint, the greater the moment arm and
the smaller the magnitude of force
required to produce a given torque at
the joint.”
 The greater the length of the supporting
orthotic structure, the greater the
moment or torque that can be placed on
the joint or unstable segment.

7. Types of orthosis
 Upper limb orthosis.
 Lower limb orthosis.

8. Lower limb orthosis
 Purpose: For supporting lower limbs.
 Materials used:
◦ Plastic (recently in demand). e.g. polypropylene,
polyethylene.
◦ Metal: aluminum-light weight, stainless steel, etc.

9. Materials used
 Metal
◦ Traditional orthosis were made from metal.
◦ Metals like aluminum-light wt, stainless
steel-durable.
 Plastic
◦ Plastic orthosis are formed from a single
piece of thermoplastic.
◦ Plastic components like polypropylene,
polyethylene.

10. Types of lower limb orthosis
 Ankle foot orthosis (AFO)
 Knee ankle foot orthosis (KAFO)
 Knee orthosis (KO)
 Hip knee ankle foot orthosis (HKAFO)
 Hip orthosis (HO)

11. AFO
 Ankle-foot orthosis is a brace, usually
plastic, worn on the lower leg and foot
to support the ankle, hold the foot and
ankle in the correct position, and
correct foot drop.
 Purpose:
◦ To control alignment and motion of the
joints of foot and ankle.
◦ For patients affected with muscular
dystrophy, cerebral palsy, etc.
 Construction:
◦ Consists of a shoe attachment, ankle
control, uprights and a proximal leg
band.

12.  Parts:
◦ Calf bands
◦ Metal uprights
◦ Ankle joint
◦ Shoe attachments
◦ Stirrup
Calf band
Metal upright
Ankle joint
Shoe
attachments
Stirrup

13. Types of AFO
 Dorsiflexion assist AFO:
◦ In case of moderate foot drop.
 Plantar flexion assist AFO:
 Posterior leaf spring AFO:
 Patellar tendon bearing AFO:
 Spiral AFO:
 Solid AFO:
◦ In case of severe foot drop.

14. Knee Ankle Foot Orthosis (KAFO)
 A KAFO is a long-leg orthosis that spans
the knee, the ankle, and the foot in an
effort to stabilize the joints and assist
the muscles of the leg.
 Material for fabrication: metals, plastics,
fabrics, and leather.

15. Parts
Hip joints and locks
 Controls for abduction, adduction and
rotation.
 Controls for hip flexion when locked.
 2 position hip locks are also available.
 Pelvic band
 To stabilize the hip joint.
 There are two types unilateral pelvic band
and bilateral pelvic band.
 It adds weight and increases overall energy
expenditure during ambulation.

16. Types of KAFO
 Supracondylar plastic orthosis.
 Scott-Craig orthosis.

17. Knee orthosis
 A knee orthosis (KO) extends above and below
the knee joint.
 Design to control the ligament deficiencies
around the knee.
 Provide functional support and rehabilitation
after injury & surgery of the knee.
 Parts:
 Double uprights
 Free or adjustable knee joint
 Thigh and calf cuffs

18. Types of knee orthosis
 Dynamic patellar orthosis:
 It consist of an elastic sleeve with patellar cutout.
 Its purpose is to prevent the dislocation of
patella.
 Traditional knee orthosis
 It consists of leather thigh, calf cuffs and metal
side bars.
 Pressure pad may be applied to generate medial
or lateral forces.
 Swedish knee cage
 It used in the management of knee
hyperextension.
 Two anterior pads and adjustable posterior
pressure pad at the attachment to the upright .

19. Types of knee joints
 Free motion knee joint:
allows unrestricted flexion & extension.
 Off-set knee joint:
the hinge is located posterior to the
knee joint stabilize knee during stance.

20. Hip Knee Ankle Foot Orthosis (HKAFO)
 Hip joint and pelvic band attached to the lateral
upright of a KAFO converts it to a HKAFO.
 Purpose:
◦ Hip flexion/extension instability
◦ Hip adduction/abduction weakness
◦ Hip internal rotation/external rotation
instability

21.  Parts:
◦ Sole plate extending to the metatarsal
heads with a crossbar added to the
metatarsal heads area for mediolateral
stabilization.
◦ Ankle joint set at 10° of dorsiflexion
◦ Anterior rigid tibial band (patellar tendon
strap)
◦ Offset knee joint with bail lock
◦ Proximal posterior thigh band

22. Types of HKAFO
 Reciprocal Gait Orthosis (RGO)
 It is used for upper lumbar paralysis in
which active hip flexion is preserved.
 RGO consists of bilateral HKAFO with
offset knee joints, knee drop locks,
posterior plastic AFO, thigh pieces,
custom molded pelvic girdle, hip joints,
and a thoracic extension with Velcro®
straps, in addition to the control
mechanism

23. Hip orthosis
 Purpose:
◦ To resist femoral adduction.
◦ Mostly in elderly patients who have had total
hip joint replacement.
 Parts:
◦ Two position lock which permits full extension
and 95 degree of hip flexion and adjustable
adduction stop.