Splinting in Occupational Therapy (RSOT408)

Vocabulary practice flashcards covering terminology, biomechanics, anatomy, tool usage, material properties, and ASHT nomenclature for occupational therapy splinting.

Orthosis (Splint)

An external rigid or flexible device applied to a specific body part to protect, immobilize, or restrict motion, fabricated from materials such as wood, metal, plaster, fabric, or tape.

Static Splint

A rigid device with no moving parts designed to immobilize a specific body part, such as a resting hand splint.

Serial Static Splint

A rigid device without moving parts that is repeatedly remolded over time to achieve progressive gains in joint range of motion (ROM), such as a finger gutter.

Dynamic Splint

A splint that incorporates resilient components, such as springs or elastics, to assist, apply traction to, or substitute for motion.

Restriction Splint

A splint classified by purpose that limits a specific joint's range of motion while allowing partial movement, such as a hyperextension block.

Immobilization Splint

A splint designed to stop joint motion completely to provide rest, reduce swelling, and promote tissue healing.

Mobilization Splint

A splint intended to increase range of motion and restore function by applying controlled mechanical forces to soft tissues.

Bar Splints

A narrow splint design constructed from strong, inelastic materials such as stainless steel, aluminum, or thick plastics.

Spring Splints

A design configuration utilizing spring-action and a three-point pressure system to deliver constant mobilizing force to a joint.

Contoured Splints

Splints fabricated from low-temperature thermoplastics that are custom molded directly onto the patient's anatomical contours.

Combination Splints

Splints that blend features from bar, spring, and contoured designs, combining the structural strength of metal with the precise fitting capabilities of moldable plastics.

ASHT Splint Classification System

A standardized, functional nomenclature system developed by the American Society of Hand Therapists to name splints across six descriptive divisions.

ALDPTN

The mnemonic representing the six ASHT divisions: Articular/non-articular, Location, Direction, Purpose, Type, and Total Number of joints.

Articular Splint

A splint that crosses one or more joints and utilizes a three-point pressure system, such as a wrist cock-up orthosis.

Non-Articular Splint

A splint that does not cross a joint and uses a two-point (coaptation) pressure system, such as a pulley ring.

Type (ASHT Nomenclature)

The division in the ASHT system specifying the number of secondary joint levels included in the splint, where '0' indicates no secondary joints are incorporated.

Proximal Carpal Row

The row of carpal bones consisting of the scaphoid, lunate, triquetrum, and pisiform.

Distal Carpal Row

The row of carpal bones consisting of the trapezium, trapezoid, capitate, and hamate.

Metacarpophalangeal (MP) Joints

Condyloid joints formed by the distal heads of the metacarpals articulating with the proximal phalanges, permitting flexion, extension, abduction, and adduction.

Interphalangeal (IP) Joints

True hinge joints of the fingers (PIP and DIP) that permit movement in only one plane: flexion and extension.

Proximal Transverse Arch

Anatomical arch of the hand formed by the carpal bones (scaphoid, lunate, triquetrum, pisiform) that supports wrist stability and mobility.

Distal Transverse Arch

Anatomical arch of the hand created by the metacarpal heads that enables finger adaptability and object grasping.

Longitudinal Arch

Anatomical arch extending from the wrist (distal radius and ulna) to the fingertips, providing structural length and flexibility during grasp.

Dual Obliquity of the Hand

The anatomical principle that radial metacarpals are longer and radial metacarpal heads are positioned higher than ulnar metacarpals, requiring splints to be longer and higher on the radial side.

Hand Creases

Skin creases (wrist, thenar, proximal palmar, distal palmar, and digital) that correlate to underlying joint locations and serve as anatomical landmarks for splint boundaries.

Axis of Motion

An imaginary line around which movement occurs within a joint or body segment.

Torque

The measure of force that produces rotation of a lever around an axis, calculated by the formula $\text{Torque} = \text{Force} \times \text{Distance}$.

Translational Force

A linear force that moves a body segment along a straight path without rotation, resulting in joint compression or distraction.

Cylindrical Grasp

A power grip pattern where an object is stabilized against the palm and flexed fingers, with the thumb providing opposing counterforce.

Spherical Grasp

A power grip used to hold round objects where the fourth and fifth digits are positioned in greater flexion compared to a cylindrical grasp.

Hook Grasp

A grasp pattern excluding the thumb in which the metacarpophalangeal joints are held in extension while the PIP and DIP joints are flexed.

Lateral Prehension

A prehension pattern where the volar pad of the thumb presses against the radial border of the index finger, used when holding a key or credit card.

Tip-to-Tip Prehension

A precision grip involving flexion of the thumb IP joint and the index finger DIP and PIP joints to grasp tiny objects like a pin or coin.

Pad-to-Pad Prehension

A precision handling pattern where the thumb pad is brought into opposition against the pads of the index and long fingers.

Splint Bath

A temperature-controlled water bath used to heat low-temperature thermoplastic materials until pliable for shaping and custom molding.

Heat Gun

A tool that delivers focused streams of hot air to soften splint edges, make localized adjustments, or bond materials like Velcro to thermoplastics.

Fiskars Scissors

Heavy-duty shears specifically designed for cutting warm or partially cooled thermoplastic sheets during pattern fabrication.

Hole Punch

A hand tool used to punch uniform holes through thermoplastic material for attaching components such as straps, rivets, or outriggers.

Resistance to Stretch

The degree to which a heated thermoplastic resists deformation when pulled; high resistance provides greater therapist control and maintains material thickness.

Conformability (Drape)

The ability of a warm thermoplastic material to flow naturally and adapt precisely over anatomical contours with minimal handling.

Memory (Thermoplastic)

The physical property of a thermoplastic material that allows it to return completely to its original, flat dimension upon being reheated.

Bonding

The property of warm thermoplastic material to adhere to itself when pressed together, often prevented by specialized non-stick coatings.

Self-Sealing Edges

Edges of thermoplastic material that automatically round and seal smooth when cut while warm, eliminating the need for post-fabrication finishing.

Cotton Stockinet

A knitted tubular fabric worn over the skin during splinting to protect soft tissues, improve comfort, and ensure a secure fit.

Foam Padding

Cushioning material placed inside an orthosis to relieve pressure over bony prominences and provide shock absorption.

Three-Point Pressure System

A force system featuring three parallel forces where a central corrective force is balanced by two opposing counterforces ($A + B = C$), characteristic of articular splints.

Coaptation Pressure System

A circumferential two-point pressure system that applies equal opposing compressive forces directly to a body segment without crossing a joint.

Pressure Formula in Splinting

The physical relationship governing skin integrity, expressed as $\text{Pressure} = \frac{\text{Total Force}}{\text{Area of Application}}$, indicating that increasing splint surface area reduces localized tissue pressure.

Mechanical Advantage (Splinting)

The efficiency ratio calculated as $\text{Mechanical Advantage} = \frac{\text{Force Arm Length}}{\text{Resistance Arm Length}}$, where longer troughs reduce pressure and improve patient comfort.

High-Profile Outrigger

An elevated dynamic outrigger system that makes it easier to maintain a $90^\circ$ angle of pull and offers superior joint stability during mobilization.

Low-Profile Outrigger

A low-profile outrigger design that is less bulky and cosmetically preferred, primarily indicated for substituting absent active motion rather than stretching stiff joints.

Material Contouring

The biomechanical technique of shaping thermoplastic materials into curves or arches to increase structural rigidity and resistance to bending.

Pistoning

The unwanted shifting or sliding of an orthosis along the limb caused by misalignment between the splint's mechanical axis and the anatomical joint axis, generating shear stress and friction.