1) Orthotic knee joints mimic the function of the anatomical knee and are used in leg braces to support or assist a person's knee. 2) They can be concentric or eccentric and are made of materials like steel to provide stability while allowing flexion. 3) Different knee joint designs provide varying levels of stability, flexibility, and locking mechanisms depending on the needs of the person.

1. AIIPMR Notes – basic orthotic knee joints

2.  Mimics the function of anatomical knee.
 Orthotic knee joints are the joints which are used
in KAFO’s, HKAFO’s, KO’s etc
 It supports or assist the anatomical knee.

3.  They can be classified according to the axis:
1) CONCENTRIC
2) ECCENTRIC

4.  Axis of the joint placed centrally.
 Made out of three parts: Joint unit,
Upper and Lower upright.
 Made up of die cast steel.
 Weight of joint is less.
 Give less flexion to knee.
 No positive locking and unlocking
system of joint.

5.  Male part of joint protrudes or project outwards.
 Cost is more.
 Joint is not very durable.
 Difficult to give shape as it is vulnerable to break .
 E.g. : ALIMCO JOINT

6.  Axis is not placed centrally.
 Made up of mild steel.
 Weight is more.
 Provide positive locking system.
 Made out of two parts: Male and
Female upright.
 Male part does not project out.
 Gives more flexion at knee.

7.  More durable joint.
 Cheap in cost.
 Ex : AIIPMR JOINT.

8.  Also known as straight
knee joint or free knee.
 Permits unrestricted
movement into flexion
and extension to 180
degrees.
 Mild to moderate genu
varum or valgum.

9. Mechanical axis is located
posterior to the weight line.
Stable without a lock.
Free to bend during swing
and allows sitting.
Moderate genu recurvatum.
Contraindicated to knee and
hip flexion contracture.

10.  Follow the natural motion at knee more
accurately.
 Principal designs of PKJ:
i) Two meshing gears
ii) A plate with two pivots
(genu-centric)
 Aids in patient’s comfort while
sitting.

12.  Fall with gravity or
are manually locked.
 Requires that each side
be unlocked independently.
 Simplest lock.
 Most secure lock.
 Paralysis, severe genu varum/
valgum or recurvatum.

13.  Also known as a Dial lock
or Adjustable position locking
knee joint.
 Simple, effective and sturdy.
 Can be locked while
accommodating knee flexion
contracture.
 Provides external mechanical
stability.
 Spastic paralysis, KFC.

14.  Also known as Bail, Pawl or French
lock.
 Permits unlocking of both joints
simultaneously.
 Easier to lock and unlock.
 Can unlock accidentally if bumped.
 Allows the medial and lateral knee
locks to be disengaged at the same
time by posterior pressure as
against the edge of seating surfaces.
 Useful for paraplegics.

17.  Designed for patients with quadriceps weakness.
 Its arrangement permit the patient with lower limb
paralysis to have more closely natural gait pattern.
 Advantages:
 Stance phase stability.
 Swing phase freedom
 Decrease need for compensatory strategy.
 Reduced energy expenditure.
 Less stress and strain applied to patient’s lower back
while walking

18.  Fix knee deformity
 Hip flexion deformity
 Hip contracture.
 Poor balance and in co-ordination.

19. 1. Stance control orthotic knee joint (Horton)
2. UTX Swing knee joint
3. Swing phase lock orthotic knee joint.
4. Load response KJ.
5. G – Knee
6. E – Knee.

20. STANCE
KNEE
JOINT
G - KNEE
E - KNEE

21. UTX KNEE
JOINT
SWING KNEE
JOINT
LOAD
RESPONSE
KJ

22.  Track the instantaneous anatomical knee center.
 Eliminates the mechanical joint as a source of
pistoning, slippage or undesirable forces upon the
knee.
 Excellent sports knee joint.
 Minimizes effect of error in joint replacement.
 Made up of stainless steel, and is low profile.
 Successfully used by snow-skiers, foot-ball
players, runners etc.