Understanding Orthoses: Types and Functions

Definition of Orthosis

• An orthosis is an externally applied device
• It modifies the structural and functional characteristics of the neuromuscular skeletal system
• The word "orthosis" is Greek for "making straight"

Functions of Orthoses

• Assist a weak body part or segment with springs, rubber bands, or a flexor hinge hand orthosis
• Resist movement at a joint or part, for example, a foot drop stop to resist plantar flexion
• Support the body by providing rest or immobilizing a joint or part to allow healing
• Prevent deformity and maintain functional position
• Substitute for absent motor function
• Relieve weight with a weight-relieving orthosis, like an ischial or PTB weight-relieving orthosis

Comparison of Static and Dynamic Orthoses

Types of Orthoses by Design

• Simple Shell Orthoses:
  • Non-articular
  • Static
  • Static motion block
  • Serial static
• Orthoses with Outriggers:
  • Static progressive
  • Dynamic
  • Dynamic motion block
  • Dynamic traction
  • Tenodesis

Impact on Joint Mobility by Design Category

Prescription Conditions for Orthoses

• Orthoses are frequently prescribed the following conditions:
• Post-polio paralysis
• Nerve injuries
• Stroke and traumatic brain injury
• Spinal cord injury
• Arthritis
• Deformities
• Congenital limb deficiency
• Burns
• Sports injuries

Factors to Consider Before Prescribing Orthoses

• Joint range of motion
• Muscle strength
• Sensation
• Spasticity
• Deformities
• Shortening
• Pain
• Vocational and avocational needs
• Durability
• Utility
• Simplicity
• Comfortability
• Cosmeticity

Orthoses Types and Their Indications

Elbow and Forearm Disabilities and Orthoses

Tennis Elbow Band

• Indications:
  • Reduction of vibration effects from power tools, hammers, and pneumatic devices
  • Tennis elbow(lateral epicondylitis)

Cubital Tunnel Splint

• Indications:
  • Cubital tunnel syndrome
• Aims to position the elbow at 122 degrees to reduce ulnar nerve prominence, and limits of stretching the ulnar nerve.
• Prevents contracture pain/irritation

Wrist Disabilities and Orthoses

Hand Disabilities and Orthoses

Wrist Orthoses

• Resting Hand Splint: Immobilizes the wrist and hand to reduce symptoms and prevent deformity
• Dynamic Wrist Extension Splint: Substitutes for wrist extension while allowing free finger motion; indicated for drop hand following radial nerve injury
• Dynamic Wrist Flexion Splint: Substitutes for wrist flexion while allowing free finger motion; indicated following flexor tendon repair
• Thumb Spica Splint: Stabilizes CMC, MCP, and IP joints; indicated for De Quervain's tenosynovitis, gamekeeper's thumb, and torn collateral ligaments
• Wrist Cock-Up Splint: Maintains the wrist in a neutral position (0-30° extension) while allowing full MCP flexion and thumb mobility; indicated for carpal tunnel syndrome

Hand and Finger Orthoses

• Dynamic MCP Orthoses: Includes MCP extension and flexion mobilization orthoses
• Static PIP Orthoses: Proximal interphalangeal joint orthoses
• Static DIP Orthoses: Distal interphalangeal joint orthoses
• IP Flexion Orthoses
• IP Extension Orthoses
• Thumb Mobilization Orthoses

Dynamic MCP Orthoses

• MCP extension mobilization orthoses: Extend MCP in flexion contractures, burn, post metacarpal fracture and patients with weak finger extension (radial /brachial nerve injury)
• MCP flexion mobilization orthoses: Flex MCP in case of ( MCP collateral ligament contractures, extensor tendon shortening, median/ulnar lesion, claw hand, postcapsulotomy, post metacarpal fracture)

Static IP Joint Orthoses

• Proximal interphalangeal joint (PIP) Orthoses; for hyperflexion and hyperextension joint deformities, swan neck and Boutonniere deformity correction
• Distal interphalangeal joint (DIP) Orthoses; used to fix DIP in the event of extensor tendons and collateral ligaments repairs, with Gerssy finger and Mallet finger indications

Multiple Choice Questions and Answers

• Primary function of a static orthosis: provide support without movement.
• Characteristic of dynamic orthoses: prevent joint stiffness and assist with movement.
• Purpose of a static motion block orthosis: allows full active ROM in one direction while restricting motion in the opposite direction.
• Orthosis used for carpal tunnel syndrome: wrist cock-up splint.
• Indication for a dynamic wrist extension splint: drop hand following radial nerve injury.
• NOT considered before prescribing an orthosis: patient's favorite color.
• Orthosis used for rotator cuff injuries: shoulder sling.
• Indication for a thumb spica splint: De Quervain’s tenosynovitis.
• Purpose of a functional arm orthosis: allows mobility for patients with proximal arm weakness.
• Indication for a circumferential elbow orthosis: tennis elbow (lateral epicondylitis).
• Goal of a dynamic MCP flexion orthosis: extend MCP joints in flexion contractures.
• Orthosis that applies passive force in one direction while allowing active-resisted motion in the opposite direction: dynamic orthosis.
• Cubital tunnel splint is used to treat: ulnar nerve compression.
• Orthosis designed to stabilize the CMC, MCP, and IP joints: thumb spica splint.
• Primary function of a resting hand splint: reduce symptoms and prevent deformity.
• Crucial factor when prescribing an orthosis: patient’s vocational and avocational needs.
• Condition NOT typically treated with an orthosis is heart disease.
• Orthosis most suitable for treating mallet finger: spiral-based DIP orthosis.
• Indication for using a figure-8 harness/clavicular brace: clavicular fracture.
• The main goal of a dynamic wrist flexion splint is to: substitute for wrist flexion while allowing free finger motion.