2. Contents :
Definition and principles
Biomechanical and anatomic considerations of hand
Nomenclature
Classification
Diagnostic categories and orthotic devices
3. DEFINITION AND PRINCIPLES
An externally applied device to an existing body part used to modify the structural and
functional characteristics of neuromuscular- skeletal system .
PRINCIPLES:
1) Protection
2) Correction
3) Assistance with function
6. Biomechanical and anatomic
considerations of hand
Relaxed hand position: Wrist acts as base and is in slight flexion , ulnar deviation
MCP, PIP and DIP rest in slight flexion
Thumb is straight and relaxed
Functional hand position: Wrist in 20 degrees extension and 10 degrees ulnar deviation
MCP(45 degrees) PIP(30-45 degrees) and DIP (10-20degrees)flexion
Thumb is partially abducted and opposed with flexion at IP joint
Extension stability at wrist is required for optimal hand function
7. When increasing joint ROM with splinting, the angle of pull needs to be perpendicular to the
axis of bone that is being mobilized.
Total end range time principle, is that the improvement in ROM is directly proportional to the
length of time a joint is held at its end range.
8. ARCH SYSTEM: bone configuration and tension of muscles and ligaments is vital for grasp
and prehensions.
There are 2 transverse arches: the proximal transverse arch formed by the carpal bones and
the distal transverse arch formed by the metacarpal heads of the fingers. The longitudinal
arches are made up of the bones of the 5 digital rays
9. INTRINSIC HAND
Impairment can be due to intrinsic palsy (intrinsic minus hand) or intrinsic contracture (intrinsic
plus hand).
Trauma is the most frequent cause of intrinsic contracture, which can be associated with
metacarpal fractures or increased edema and vascular impairment, as happens with
compartment syndrome. This causes lead to adhesion formation and fibrosis of the intrinsic
muscles and tendons.
Other causes of intrinsic contractures include neurologic or spastic hand secondary to an upper
motor neuron syndrome (cerebrovascular accident, cerebral palsy, traumatic brain injury,
Parkinson’s disease), rheumatoid arthritis, osteoarthritis, and arthrogryposis.
Traumatic injury to the ulnar nerve is the most frequent cause of intrinsic palsy. Other causes
include nervous entrapment along its path in the arm (compression neuropathy), compartment
syndrome, central nervous system diseases, rheumatoid diseases, Leprosy (Hansen disease),
rheumatoid arthritis, Charcot-Marie-Tooth disease, and prolonged immobilization, failure to
splint a crush-injured hand using intrinsic plus posture.
10.
11. Nomenclature
On the basis of : joint they cover , the function they provide, condition they treat, by
appearance, name of the person who designed them.
Mainly three systems:
Common name
International Organisation for Standards(IOS): anatomic region wise name
American Society of Hand Therapists (ASHT): function and body part wise
Example:
Common name ASHT IOS
LONG ARM SPLINT 45 DEGREE ELBOW
FLEXION IMMOBILISATION
SHOULDER-ELBOW-WRIST-
HAND ORTHOSIS
SWAN NECK SPLINT INDEX FINGER PIP
EXTENSION RESTRICTION
FINGER ORTHOSIS
12. CLASSIFICATION
NON ARTICULAR
STATIC: STATIC
SERIAL STATIC
STATIC MOTION BLOCKING
STATIC PROGRESSIVE
•DYNAMIC : DYNAMIC
DYNAMIC MOTION BLOCKING
DYNAMIC TRACTION
WRIST DRIVEN PREHENSIONS
CONTINUOUS PASSIVE MOTION
ADAPTIVE OR FUNCTIONAL USE
13. NON- ARTICULAR
1)Provides support to a body part without crossing any joints and provides protection
Humeral fracture Sarmiento brace
2)Sugar-tong orthosis to immobilize
a proximal radius fracture
3)Gel shell orthosis to exert pressure over
a healing scar to prevent hypertrophic scarring
14. STATIC
STATIC: maintain a position to hold anatomical structures in place at the available end range.
Volar wrist orthosis for acute carpal tunnel syndrome reduces motion and rests injured tissues
15. SERIAL STATIC : A static orthosis that is periodically changed to alter the joint angle
Provides a prolonged gentle stretch to involved structures, helping a stiff joint regain motion
16. STATIC MOTION BLOCKING: The static motion blocking orthosis permits motion in one direction
but blocks motion in another
swan neck splint
17. STATIC PROGRESSIVE Differ from serial orthoses by using non elastic components, such as
static lines, hinges, screws, and turn buckles, to place a force on a joint to induce progressive
change. Once the motion is increased tension is increased progressively.
18. DYNAMIC
Within elastic limits, the stress from a mobilization splint can positively affect the gradual
realignment of collagen fibers (resulting in increased tensile strength of the tissue) without
causing microscopic tearing of the tissue. The ability to alter collagen formation is greatest
during the proliferative stage of wound healing but continues to a lesser degree for several
months during scar maturation.
19. Torque And Mechanical Advantage
Mechanical advantage involves the
consideration of various forces applied by the
splint base and the dynamic portion of the
splint.
Fa refers to the applied force and Fr refers to
the resistance force. Fm is determined by the
sum of the opposing forces (Fa+ Fr)
Length of the lever arm of the applied force
(la)
Length of the lever arm of the applied
resistance (lr)
The goal of a splint is to maintain a mechanical
advantage of between 2/1 and 5/1, meaning
that the lever arm of the applied force is at
least twice as long as the lever arm of the
applied resistance
20. Torque is defined as the effect of force on the rotational
movement of a point.
The amount of torque is calculated by multiplying the
applied force by the length of the moment arm.
A correlation exists between the distance from a pivot
point and the amount of force required.
To achieve the same results, a force applied close to
the pivot point (i.e., short moment arm) must be
greater than the force applied on a longer moment
arm. This force is called torque because it acts on the
rotational movement of a joint.
21. Application Of Force
In dynamic splinting, the force to a joint or
finger is applied through the application of nail
hooks, finger loops, or a palmar bar.
When applying force to increase passive
joint range of motion, the therapist must keep
the direction of pull at a 90-degree angle to
the axis of the joint and perpendicular to the
axes of rotation.
As range of motion increases, the therapist
must adjust the outrigger to maintain the 90-
degree angle
22. Outriggers
nylon string to attach finger loops to the source of tension.
A turnbuckle
Velcro tabs used for static progressive tension
26. WRIST DRIVEN PREHENSION/ TENODESIS: Active extension of the wrist produces controlled
passive flexion of the fingers against a static thumb post through a tenodesis action
27. CONTINUOUS PASSIVE MOTION: Electrically powered devices that mechanically move joints
through a desired range of motion
28. Adaptive or functional use: Adaptive or functional usage devices promote functional use of the
upper limb with impairment resulting from weakness, paralysis, or loss of a body part
29. DIAGNOSTIC CATEGORIES
MUSCULOSKELETAL
Tendonitis (inflammation of the tendon), tenosynovitis (inflammation of the tendon sheaths),
and enthesopathy (inflammation at a muscle or tendon origin or insertion) can all result from
excessive repetitive movement or external stressor.
The goal of fabricating an orthosis for these conditions is to immobilize the affected structures
so as to facilitate healing and decrease inflammation
30.
31. FRACTURES
These devices should immobilize the body part or joint sufficiently to promote healing while
also optimizing function
32. NEUROMUSCULAR CONDITIONS
A distal median nerve injury, a simian hand deformity may occur, and the function most
affected is thumb palmar abduction and opposition.
The orthotic design holds the MCP joints in slight flexion but permits MCP extension. This
orthosis also has a portion to position the thumb in palmar abduction
33. An ulnar nerve palsy orthosis holds the MCP joints of the fourth and fifth fingers in slight
flexion by using a figure-of-eight splint design. The figure of-eight design assists MCP flexion
and permits extension of the MCP joints but blocks hyperextension
34. low median and ulnar nerve injuries, leaves the patient with no or weakened ability to place
the thumb in opposition and palmar abduction
35. With radial nerve injuries distal to the humeral spiral groove, the common presenting condition
is wrist and finger drop. The goal in this case is to enhance wrist and finger extension.
36. BRAIN INJURY AND STROKE
Depending on the area of brain injury and ensuing deficits, particularly if there is a change in
muscle tone, orthotic devices should be designed to prevent deformities and help adjust
muscle tone.
37. Postsurgical and Postinjury Orthoses
Many types of orthoses have been developed to help stiff joints regain motion
Joints that have a soft end feel do well with dynamic orthoses. Those with a rigid end typically
respond better to a static progressive approach that will maintain a constant joint position while
the tissue accommodates gently to the tension without the influence of gravity or motion.
38.
39. EMERGENT TECHNOLOGIES
Concept of neural integration has recently been incorporated into upper limb orthoses.
These devices detect a myoelectric signals from an intact proximal muscle and then send a signal
to distal paralysed muscle.
The paralyzed musc;es are stimulated to contract via surface based electrical stimulation.
40. Orthotic material
Most splinting materials are low temperature thermoplastics.
They become soft and pliable when exposed to low temperatures and can be shaped in water
bath at temperatures 66to 82 degree celsius. Eg:- finger splinting
High temperature thermoplastics are more durable and require oven for heating ~177 degree
Celsius and placement over a mold for shaping. Eg:- management of spasticity.
46. MANUAL FABRICATION METHOD
(A) Creating the negative cast of a person, (B) filling the negative cast with liquid plaster to produce the
positive cast, (C) applying additional plaster modifications, (D) refining plaster modifications, (E) vacuum
forming polypropylene over modified cast, (F) cutting the polypropylene AFO from the cast, (G) finishing the
AFO and (H) fitting the AFO to a person.
Provide compressive forces,traction in controlled manner,
Correcting joint contractures, subluxations, alignment
By compensating the deformity, muscle weakness, or increased tone.
Loss of intrinsic muscle contraction results in impairment of the MCP joint flexion and interphalangeal joint extension, leading to an MCP hyperextension and interphalangeal joints flexion of the fourth and fifth fingers (Duchenne sign). This posture is known as the intrinsic minus or claw posture.
The intrinsic muscles of the hand flex the MCP joints and extend the interphalangeal (IP) joints
After a fracture, a nonarticular Sarmiento brace immobilizes the humerus and allows full range of motion of all the joints involved in the injured extremity
A sugar-tong orthosis is ideal for splinting fractures of the radius, ulna, or wrist. It prevents flexion and extension at the wrist, limits flexion and extension at the elbow, and prevents supination and pronation.
Dynamic finger extension type of orthosis produces extension of the proximal interphalangeal joint of the digits.
Mechanical advantage is determined by the ratio of the lever arm length (la) of the applied force (Fa) to the lever arm (lr) of the applied resistance (Fr). Splint A has a better mechanical advantage than splint B.
In practical terms, we should place the force as far as possible from the mobilized joint without affecting other joints [Brand and Hollister 1993b]. A forearm-based dynamic wrist extension splint is constructed so that its mobilizing force is on the most distal aspect of the palm, while not affecting MCP movement. An exception to placing the force as far from the mobilized joint as possible occurs when rheumatoid arthritis is involved. If the joint is unstable, a force applied too far from the joint will result in tilt rather than a gliding motion of the joint (Figure 11-4) [Hollister and Giurintano 1993]. Therefore, when splinting a hand with rheumatoid arthritis the force should be applied as close to the mobilizing joint as possible.
Orthosis for an intraarticular fracture, such as a hand-based PIP extension orthosis with an outrigger, which gives constant longitudinal traction, although the joint is gently moved
The string is lax when the wrist is released and tightens with wrist extension, bringing the fingers closer to the immobilized thumb and creating three-jaw chuck prehension.
Keeps the joints supple and maintains articular, ligamentous, and tendinous structure mobility during the healing phases after injury or surgery
The universal cuff encompasses the hand and holds various small items such as a fork, a pen, or a toothbrush
1 Forearm-based thumb spica orthosis used for de Quervain
n elbow strap used for lateral epicondylitis.
forearm-based with an outrigger that holds the wrist, fingers, and thumb in extension and allows for flexion of the digits