PRELIMS: Intro & Materials Flashcards
What is an orthosis?
: An externally applied device used to modify the structural and functional characteristics of the neuromuscular system.
What are the types of orthoses?
Brace, splint, appliance, caliper.
What is orthotics?
The theory and practice of developing, manufacturing, and using orthoses.
Who are the providers and users of orthoses?
Physicians (physiatrists/orthopedists), orthotists, physical/occupational therapists, and patients.
What are the reasons for orthotic prescriptions?
To support/immobilize, correct/prevent deformities, and assist/restore function.
What does “KAFO” stand for?
Knee-Ankle-Foot Orthosis (Long leg brace).
What is the difference between static and dynamic orthoses?
Static: Control characteristics remain constant.
Dynamic: Control characteristics vary based on external factors.
What are common indications for orthoses?
Pain relief, immobilization, axial load reduction, deformity prevention/correction, and functional improvement.
What are some common conditions requiring orthoses for deformity correction?
Muscle imbalance (UMN/LMN paralysis)
Muscle disease/paralytic conditions
Progressive fibrous tissue diseases (e.g., Dupuytren’s contracture)
Arthritis
Volkmann’s ischemic contractu
What are key principles of orthotic application?
Adequate surface area for pressure distribution
Proper joint positioning
Ease of application and use
Simple and durable design
Cost-effectiveness
What is the role of an orthotist?
An orthotist measures, fabricates, and ensures the proper fit of orthoses, taking into account biomechanical principles, material selection, and patient needs.
What is the role of a physical or occupational therapist in orthotic use?
They train patients to use orthoses, suggest modifications, and fabricate upper extremity (UE) orthoses when necessary.
How do orthoses help in pain relief?
By limiting motion or weight-bearing to avoid stressing injured or painful areas.
Front: How do orthoses help in immobilization and protection?
They stabilize weak, painful, or healing musculoskeletal segments, commonly used in fracture bracing and joint protection.
: How do orthoses help in axial load reduction?
: By redistributing forces to prevent excessive stress on affected areas, such as in scoliosis or Legg-Calvé-Perthes disease.
What are the limitations of orthoses for functional improvement?
Only effective in relaxed limbs
Speed of action must be physiologic
Sensory impairments may reduce effectiveness
Require lightweight, durable materials for lower extremity use
Must be comfortable, cosmetic, and easy to apply
What are the limitations of orthoses for functional improvement?
Only effective in relaxed limbs
Speed of action must be physiologic
Sensory impairments may reduce effectiveness
Require lightweight, durable materials for lower extremity use
Must be comfortable, cosmetic, and easy to apply
What is the primary biomechanical principle of orthoses?
Orthoses apply forces and moments to modify movement and provide support or restriction based on internal force derangements.
What are the key mechanics of orthotic use?
Understanding how external forces can be applied to correct or compensate for abnormal internal forces
What are examples of static orthoses?
Resting splints, immobilizing braces, and fracture orthoses.
What are examples of dynamic orthoses?
Spring-assisted devices, elastic band orthoses, and motorized orthoses.
What are examples of functional orthotic devices?
Wheelchairs, respirators, environmental control apparatus, and driving aids.
What does WHO stand for?
What does WHO stand for?
What are the important properties of materials used in orthotics and prosthetics?
Strength, weight, fatigue resistance, wear resistance, resistance to deformation, and corrosion resistance.
What is an alloy?
A material with metallic properties composed of two or more chemical elements, at least one of which is a metal.
What are the advantages of carbon steels?
Low cost, abundant supply, and ease of working.
What are the disadvantages of carbon steels?
Heavy weight and the need for expensive alloys to prevent corrosion
What elements are present in steel?
Carbon: Imparts strength and hardness.
Manganese & Silicon: Act as cleansing agents to deoxidize steel.
Phosphorus & Sulfur: Undesirable impurities.
What is the main difference between low-carbon and high-carbon steel?
Low-carbon steel (0.05–1.0% carbon): More ductile, lower yield strength.
High-carbon steel (0.9% carbon): Used for springs, stronger but less ductile.
What are the properties of stainless steel?
Corrosion-resistant due to chromium content (≥12%), forms an oxide film, and can be passivated with nitric acid.
What are the two types of stainless steel?
Martensitic: Can be hardened by heat treatment, good corrosion resistance.
Ferritic: Cannot be hardened by heat, not used in orthotics.
: Why is titanium used in orthotics and prosthetics?
Strength comparable to steel but with 60% less density, more corrosion-resistant than aluminum or steel, but expensive and limited in availability.
What are the advantages of magnesium in orthotic applications?
The lightest structural metal.
Excellent strength-to-weight ratio.
High dimensional accuracy and stability.
Good environmental corrosion resistance.
Fully recyclable.
What are the two types of leather tanning?
Vegetable-tanned: Used when great strength is needed.
Chrome-tanned: Used when skin contact is required.
What is butyl rubber, and what are its advantages?
A common synthetic rubber with greater resistance to water, aging, heat, and sunlight.
What are the advantages of neoprene rubber?
Excellent resistance to wear, oxidation, heat, oil, and gasoline compounds.
What are the disadvantages of aluminum?
Lower endurance under repeated dynamic loading, can be damaged by alkalis and acids.
What is polypropylene, and why is it used in orthotics?
: A type of thermoplastic used for its lightweight, high strength, and flexibility
What is acrylic plastic used for in prosthetics?
Acrylic resins are used for prosthetic sockets due to their lightweight and rigidity.
What is Kevlar, and what is its role in orthotics and prosthetics?
A high-strength synthetic fiber used for reinforcement due to its excellent tensile strength and lightweight properties.
