OTPF-4, ICF, and Environmental Factors Vocabulary (Lecture Notes)

Classroom setup and framing

• Students each have a bag with colored paddles to hide answers; bags are personal items for the semester; name your bag to keep track. Instructor can wave answers to check participation and pacing.
• Emphasis on pacing and need for repetition or slower explanations when requested.

Key frameworks: OTPF-4, ICF, WHO

• OTPF-4 (Occupational Therapy Practice Framework, Fourth Edition): focuses on the natural vs human-made products and technology, support relationships, attitudes, and services.
• ICF (International Classification of Functioning, Disability and Health): emphasizes physical, social, and attitudinal factors; less granular split into environmental domains but covers similar ideas.
• WHO perspective: disability resides in society, not solely in the individual; a person with a disability is hindered by social norms, expectations, and environment rather than only by the medical condition.
• Relationship among the three: OTPF-4 and ICF overlap and complement; they describe how environments, supports, attitudes, and services shape participation and functioning.

Distinctions and synthesis among OTPF-4, ICF, and WHO

• Personal factors in OTPF-4: age, education, profession, lifestyle, social background, race, ethnicity, gender, culture.
• Comparison: ICF emphasizes physical, social, and attitudinal dimensions; OTPF-4 lists products/technology, supports, attitudes, services as primary categories.
• WHO statement: disabling conditions are amplified by societal barriers and environments; elimination of barriers and universal design would minimize disability effects.
• Universal design concept: designing environments to be usable by as many people as possible, from the outset; often more cost-effective when built in from the start.
• Accessibility vs negotiability: accessibility enables entry into environments; negotiability enables actual participation and functional use within the environment (e.g., furniture layout, sensor placements, doorways, and everyday reachability).

Personal factors and the context of occupation

• Personal factors range and change over time; they are not static (education level, socioeconomic status, etc.).
• Example: a student’s experiences and preferences evolve from age 8 to age 21; activities enjoyed can shift over time.
• For pediatric and family mealtime evaluations: role of parents/guardians is crucial; consider family dynamics and expectations.
• Attitudes and values: stereotypes and biases toward people with disabilities persist among otherwise independent individuals, affecting participation.
• Real-world example: Dream League Baseball
  • A community program for children and adults with cognitive and/or physical disabilities.
  • 15 years old; buddy system pairs participants with volunteers to assist as needed.
  • Field and facilities designed to be accessible and negotiable; examples include level turf fields, flat dugouts, and absence of lifts, enabling inclusive participation.
  • Observed social benefits: buddies gain awareness and positive social interactions; participants feel recognized and integrated.
• Practical takeaway: ask patients/participants how they previously completed tasks to tailor interventions; avoid judgment; inquiry like, "How did you do it before?" rather than interrogating current practices.
• Personal factors can include orientation, gender, behavioral patterns, psychological assets (e.g., depression, anxiety), education, and socioeconomic status; recognize these as fluid and context-dependent.

The environment and its influence on functioning

• The environment is composed of physical, social, and attitudinal surroundings in which people live and perform activities.
• Environmental factors include products and technologies (e.g., accessible bathrooms with grab bars and wide doors) and daily affordances (e.g., reachability, door mechanisms, light switches).
• Accessibility vs negotiability in practice: an environment can be accessible but not functional due to poor layout or fixtures (e.g., a hotel room with a high bed, inaccessible thermostat, or a rug blocking wheelchair movement).
• Example analysis: a quadriplegic individual in a hotel room again illustrates how accessibility does not guarantee neutrality for independent function; furniture placement, rug, thermostat reach, door weight, and bathroom layout all influence function.
• Natural vs built environment: effects on function are context-dependent and can be positive or negative depending on terrain (gravel surfaces, weather), incline, and available supports.

Environmental factors: natural environment and forces

• Natural environment includes landforms, bodies of water, and physical forces (gravity, weather phenomena like fires/hurricanes).
• Effects can be negative (barriers) or positive (supportive features like ramps) depending on context.
• Forces that influence movement:
  • Internal forces: generated by muscles within the body.
  • External forces: fluid forces, contact forces, gravity.
  • Secondary forces: joint compression, joint traction, and pressure on body surfaces.
• Specific force examples:
  • Gravity: constant downward force; F = m g.
  • Buoyancy (in water): Fb = ρ{f} V_{displaced} g; buoyancy reduces effective weight underwater.
  • Drag in fluids: Fd = frac{1}{2} ρ{f} C_d A v^2; drag increases with velocity and cross-sectional area.
  • Lift: FL = frac{1}{2} ρ{f} C_L A v^2; relevant in movements within water or air (e.g., vertical arm raise in water).
• Contact forces and normal reaction vs friction:
  • Normal reaction force: perpendicular push from a surface.
  • Friction: parallel resistance to motion along a surface; both contribute to movement and stability during isometric and dynamic tasks.
• Gravity and position: gravity effect depends on body position; in a gravity-reduced plane (e.g., horizontal or prone), some movements require less effort against gravity.
• Pressure on body surfaces: prolonged seating or lying can cause tissue breakdown if not redistributed; pressure management is essential in seating/positioning.
• Negotiability and positioning: pressure or contact can be used to guide positioning and movement patterns.

Movement systems and functional anatomy concepts

• Simple machines: Inclined plane, wheel and axle, pulley, screw, wedge, lever.
• Lever basics (three classes):
  • Three components: effort arm (input force), axis (fulcrum), load (resistance).
  • Class I (First class): fulcrum between effort and load; MA =
    MA = rac{d{effort}}{d{load}}. Useful for balance and changing direction of force.
  • Class II (Second class): load between fulcrum and effort; MA =
    MA = rac{d{load}}{d{effort}}. Favors force amplification.
  • Class III (Third class): effort between fulcrum and load; MA < 1; favors speed and range of motion at the expense of force.
  • Factoring lever arms: lengthening the effort arm or shortening the resistance arm reduces the required effort.
• Insufficiency concepts (muscle physiology):
  • Active insufficiency: muscle cannot contract sufficiently across all joints it crosses; movement is limited by the muscle’s own contraction.
  • Passive insufficiency: muscle cannot stretch enough across all joints it crosses; movement is limited when a muscle is stretched across multiple joints.
  • Note: Passive insufficiency implies the muscle cannot lengthen enough; active insufficiency implies the muscle cannot contract enough.
• Open vs closed kinetic chain (KCs):
  • Open chain: distal segment moves freely; single joint can move without affecting others; usually non–weight-bearing (e.g., wrist flexion).
  • Closed chain: distal segment is fixed and weight-bearing; movement of one joint affects other joints (e.g., squats, push-ups).
  • Open vs closed status relates to functional tasks and rehabilitation priorities; open chain allows isolation of joints; closed chain integrates multiple joints and stabilizes proximal segments.
• Open vs closed pack position terminology:
  • Open chain typically corresponds to an open (unpacked) position allowing isolated joint movement.
  • Closed chain corresponds to weight-bearing, often involving multiple joints.
• Functional movement synthesis: Successful movement requires integrating cultural, personal, temporal, virtual contexts, and social/physical environments with factors like insufficiency, kinematic chains, and open/closed chains.

Application activity and ADA-driven exercises

• Group activity design (ADA-based scenario):
  • Group 1: MS patient in a wheelchair; assess access to Admin Building and bathroom.
  • Group 2: Stroke patient with right-side impairment in a wheelchair; assess attending class, bathroom access, and meeting with a teacher.
  • Group 4: Patient with crutches in the Abdomen Building; similar accessibility checks.
  • Each group documents ADA compliance recommendations and presents findings to the class.
• Purpose: reinforce practical assessment of environmental barriers and the importance of universal design and negotiability in real settings.

Ethical, social, and practical implications

• Addressing stereotypes and stigmas: ongoing bias can prevent participation; inclusive environments require active design of spaces and attitudes.
• Role of professionals: OT practitioners must consider both environmental design and personal factors to enable meaningful occupation.
• Real-world impact: inclusive programs (e.g., Dream League Baseball) demonstrate how accessible environments alter social dynamics, increase participation, and reduce stigma.
• Practical approaches: ask open-ended questions about prior methods, tailor tasks to individual contexts, and design environments that support both accessibility and function.

Summary: integrated takeaways

• OTPF-4 vs ICF vs WHO offer complementary lenses: frameworks, environments, outcomes, and social attitudes shape participation.
• Personal factors are dynamic; context matters for occupation and participation.
• Accessibility is necessary but not sufficient; negotiability and universal design ensure real functional participation.
• The natural environment and physical forces interact with internal forces to influence movement; understanding gravity, buoyancy, drag, lift, contact forces, and pressure helps design better interventions and environments.
• Open vs closed kinetic chains, active vs passive insufficiency, and lever mechanics are core concepts for analyzing and facilitating movement in rehabilitation.
• Ethical practice requires addressing barriers, biases, and ensuring environments support independent, meaningful participation for people with disabilities.
• Classroom activities anchored in ADA guidelines bridge theory to practice and illustrate how to evaluate and redesign spaces for accessibility and function.

Quick reference formulas and concepts

• Gravity force: F_g = m g
• Buoyancy: Fb = ho{f} V_{ ext{displaced}} g
• Drag in fluids: Fd = rac{1}{2} ho{f} C_d A v^2
• Lift: L = rac{1}{2}
  ho{f} CL A v^2
• Lever class advantages (conceptual):
  • Class I: MA = rac{d{ ext{effort}}}{d{ ext{load}}}
  • Class II: MA = rac{d{ ext{load}}}{d{ ext{effort}}}
  • Class III: MA = rac{d{ ext{effort}}}{d{ ext{load}}} ext{ (usually }<1 ext{)}
• Open vs closed chain (definition recap):
  • Open chain: distal segment free, typically non-weight-bearing.
  • Closed chain: distal segment fixed on a surface, weight-bearing, involves multiple joints.
• Insufficiency concepts (definitions): active vs passive insufficiency.
• Environmental factors example categories: physical environment, social environment, attitudes, products/technology, services; personal factors include age, education, socioeconomic status, culture, etc.
• ADA-related practical exercise: evaluate access to buildings and bathrooms, and identify barriers that impede functional participation.