Physical Disability Evaluation & Disability Diagnosis

MPT Level Answer (20 Marks)

1. Introduction and Definitions (2 marks)

• Impairment - any loss or abnormality of body structure or physiological/psychological function
• Activity Limitation - difficulties an individual may have in executing activities (e.g., walking, self-care)
• Participation Restriction - problems in involvement in life situations (e.g., work, social roles)
• Functional Capacity - maximum ability to perform tasks in a standardized environment
• Functional Performance - actual task performance in real-life settings

2. Models of Disability (3 marks)

A. Nagi's Disablement Model (1965)

B. WHO International Classification of Functioning, Disability and Health (ICF, 2001)

1. Body Functions & Structures - physiological/anatomical integrity
2. Activities - individual-level execution of tasks
3. Participation - involvement in life situations
4. Contextual Factors:
   • Environmental factors - physical, social, attitudinal environment (can be facilitators or barriers)
   • Personal factors - age, gender, coping styles, education

C. Medical Model vs. Social Model

• Medical Model - disability as a deficiency within the individual requiring medical correction
• Social Model - disability as a mismatch between person and environment; society creates disability through barriers
• Biopsychosocial Model (ICF) - integrates both, now the preferred approach in physiotherapy practice

3. Types of Physical Disability (2 marks)

4. Disability Evaluation - Framework and Process (4 marks)

Step 1: Medical History and Review

• Chief complaints, onset, duration, mechanism of injury/disease
• Past medical history, surgical history, medications
• Occupational and social history (essential for contextual factor assessment)
• Review of prior medical records, imaging, investigations

Step 2: Physical Examination

• Postural assessment - static and dynamic alignment
• Range of Motion (ROM) - goniometry (active/passive); standardized to AMA Guides
• Muscle strength testing - manual muscle testing (MMT graded 0-5 by MRC scale), isokinetic dynamometry
• Sensory testing - light touch, pain, temperature, proprioception; two-point discrimination
• Functional movement screen - ability to perform ADL-related tasks
• Neurological evaluation - reflexes, coordination, balance (Berg Balance Scale, Tinetti)
• Gait assessment - observational or instrumented (stride length, cadence, velocity)
• Cardiovascular/pulmonary assessment - for systemic disability (6MWT, VO2 max)

Step 3: Functional Capacity Evaluation (FCE)

• Lifting and carrying capacity (floor-to-waist, waist-to-shoulder)
• Pushing/pulling force
• Positional tolerances (sitting, standing, stooping, kneeling)
• Grip and pinch strength (Jamar dynamometer - 5 positions)
• Fine motor coordination (Purdue Pegboard, Nine Hole Peg Test)
• Aerobic capacity (modified Bruce protocol, Astrand cycle test)
• Consistency and validity of effort testing (Waddell signs, Coefficient of Variation <10% for reliability)

Step 4: Standardized Outcome Measures

Step 5: Contextual Factor Assessment

• Home environment assessment (accessibility, architectural barriers)
• Work environment analysis (job demands, ergonomic review)
• Social support and caregiver assessment
• Psychological screening (PHQ-9 for depression, GAD-7 for anxiety) - important because psychosocial factors influence functional performance

5. Disability Diagnosis - Principles and Methods (3 marks)

1. Impairment-based diagnosis - the anatomical/physiological deficits (e.g., decreased shoulder flexion ROM to 60°, Grade 3 deltoid strength)
2. Functional diagnosis - the impact on activities (e.g., inability to reach overhead, difficulty with ADL)
3. Participation-level diagnosis - the social role restriction (e.g., unable to return to occupation as carpenter)

Impairment Rating (Percentage Method)

• Rates impairment as a percentage of whole-person impairment (WPI)
• Based on diagnosis, clinical findings, and functional history
• Uses a 5-tier classification for most conditions:
  • Class 0: No impairment (0%)
  • Class 1: Minimal (1-13% WPI)
  • Class 2: Mild (14-25% WPI)
  • Class 3: Moderate (26-50% WPI)
  • Class 4: Severe (51-100% WPI)
• Grade Modifiers (0-3) adjust the class based on functional history, physical examination findings, and clinical studies
• Maximum Medical Improvement (MMI) must be reached before final impairment rating is assigned

Indian Disability Certification System

• 21 categories of recognized disabilities
• Benchmark disability threshold: 40% or more of impairment for legal recognition
• Certificate issued by a Medical Authority (government hospital specialist)
• Physiotherapists contribute functional assessments and supportive documentation

6. Specialized Disability Evaluation Techniques (2 marks)

A. Locomotor Disability Evaluation

• Upper limb: ROM at shoulder, elbow, wrist, fingers; grip/pinch strength; sensory testing
• Lower limb: ROM at hip, knee, ankle; leg length discrepancy; manual muscle testing; standing balance
• Spine: Lumbar/cervical ROM; Schober's test; neurological examination; straight leg raise (SLR)
• Amputation: Stump assessment, prosthetic function, K-level classification (K0-K4)

B. Neurological Disability Evaluation

• Stroke: NIHSS (acute), modified Rankin Scale (chronic), Fugl-Meyer Assessment (motor function)
• SCI (Spinal Cord Injury): ASIA Impairment Scale (A-E classification based on sensory/motor levels)
• TBI: GCS, Disability Rating Scale, Functional Assessment Measure
• Cerebral Palsy: GMFCS (Gross Motor Function Classification System, Levels I-V), MACS

C. Occupational/Work-Related Disability

• FCE protocols: Isernhagen Work Systems, WorkWell Systems
• Work capacity categories (Dictionary of Occupational Titles):
  • Sedentary: up to 10 lbs
  • Light: 10-20 lbs
  • Medium: 20-50 lbs
  • Heavy: 50-100 lbs
  • Very Heavy: >100 lbs

7. Goals and Documentation of Disability Evaluation (2 marks)

Goals

1. Determine the nature and extent of functional loss
2. Establish baseline for rehabilitation goal setting
3. Determine return-to-work/activity capacity
4. Provide medico-legal documentation for compensation, insurance, legal proceedings
5. Assist in designing assistive devices, adaptive equipment, and environmental modifications
6. Formulate a prognosis for functional recovery

Documentation Requirements (APTA Standards)

• Demographic data and referral information
• Comprehensive history (medical, functional, occupational, psychosocial)
• All objective findings with standardized measurements
• Validated outcome measure scores
• Impairment rating (if applicable)
• Functional diagnosis (using ICF framework)
• Prognosis and recommendations
• Signature of evaluating physiotherapist with licensure details

8. Special Considerations in Disability Evaluation (2 marks)

Effort and Validity Testing

• A significant challenge in disability evaluation is distinguishing true impairment from symptom magnification or malingering
• Waddell's signs (5 non-organic signs for LBP): superficial/non-anatomic tenderness, simulation tests, distraction tests, regional disturbances, overreaction - positive findings in 3 of 5 warrant attention
• Coefficient of Variation (CV): In grip strength testing, CV <15% suggests consistent, reliable effort
• Rapid Exchange Grip test, Five Position Grip test - for detecting submaximal effort

Psychosocial ("Yellow Flag") Factors

• Fear-avoidance beliefs (FABQ questionnaire)
• Depression/anxiety (PHQ-9, GAD-7)
• Catastrophizing (Pain Catastrophizing Scale)
• Poor social support, litigation involvement

ICF-Based Disability Diagnosis in Practice

1. Identify impairments from clinical tests (ROM, strength, sensation)
2. Link impairments to activity limitations (what the patient cannot do)
3. Identify participation restrictions (social/vocational role limitations)
4. Assess environmental facilitators and barriers
5. Assign an ICF-based functional diagnosis that drives the intervention plan

Summary Table

Key Points Summary

• Disability evaluation uses the ICF framework (biopsychosocial model) as the gold standard
• It encompasses impairment, activity limitation, and participation restriction across body, individual, and societal levels
• AMA Guides provide the most widely used method for impairment percentage rating (WPI%)
• Functional Capacity Evaluation (FCE) is the comprehensive PT tool for work-related disability assessment
• Standardized outcome measures (FIM, Barthel, DASH, ODI, WOMAC, Berg) must be selected based on the population and disability type
• Effort validity testing (Waddell signs, CV%, Five Position Grip) is essential to ensure reliable findings
• Psychosocial yellow flags (fear-avoidance, catastrophizing, depression) significantly modulate functional disability and must be assessed
• In India, RPwD Act 2016 governs disability certification with a 40% threshold for benchmark disability status

• WHO International Classification of Functioning, Disability and Health (ICF), 2001
• AMA Guides to the Evaluation of Permanent Impairment, 6th Edition
• APTA Guide to Physical Therapist Practice
• Rights of Persons with Disabilities Act, India, 2016
• NASEM: Functional Assessment for Adults with Disabilities, 2019

ICIDH-2: International Classification of Functioning and Disability (Beta-2, 1999)

1. Background and Historical Context

The Original ICIDH (1980)

Disease/Disorder → Impairment → Disability → Handicap

• Purely negative and deficit-focused (classified "what was wrong")
• Linear, unidirectional flow - did not account for interactions
• No acknowledgment of environmental or contextual factors
• The word "Handicap" was considered stigmatizing and offensive
• Disability was viewed solely as a consequence of disease (medical model)
• Did not reflect the social model of disability
• Did not recognize that disability can exist without disease (e.g., architectural barriers)

2. What is ICIDH-2?

"ICIDH-2 is a classification of human functioning and disability... ICIDH-2 does not classify people. It classifies domains of functioning." - WHO, Beta-2 Draft, 1999

3. Core Philosophy of ICIDH-2

Key Philosophical Changes from ICIDH (1980):

4. Components of ICIDH-2

A. Body Functions and Body Structures

• Body Functions - physiological and psychological functions of body systems (e.g., muscle power, joint mobility, memory, vision)
• Body Structures - anatomical parts of the body (organs, limbs, their components)
• Negative aspect: Impairment - significant deviation or loss in body structure or function

B. Activities

• Activity - the execution of a task or action by an individual
• Represents functioning at the level of the whole person
• Negative aspect: Activity Limitation - difficulties an individual has in performing activities
• Measured as both capacity (what can be done in a standardized environment) and performance (what is done in the real environment)

C. Participation

• Participation - an individual's involvement in life situations (work, school, recreation, social roles)
• Represents functioning at the level of society
• Negative aspect: Participation Restriction - problems in the manner or extent of involvement in life situations

D. Contextual Factors (New in ICIDH-2)

1. Individual level - immediate physical environment (home, school, workplace), direct contacts (family, peers, caregivers)
2. Service/System level - formal/informal social supports, services, communication, transport
3. Societal level - laws, regulations, attitudes, ideologies, cultural systems

• Facilitators - factors that improve functioning (e.g., ramps, assistive devices, supportive legislation)
• Barriers/Hindrances - factors that restrict functioning (e.g., stairs, stigma, lack of services)

• Not classified in ICIDH-2 due to cultural variability, but identified as influential
• Include: age, sex, education, lifestyle, coping styles, social background, profession, past experience

5. The ICIDH-2 Conceptual Model (Interaction Diagram)

                    Health Condition
                   (Disorder/Disease)
                          |
          ┌───────────────┼───────────────┐
          ▼               ▼               ▼
    Body Functions    Activity      Participation
    & Structures   (Limitations)   (Restrictions)
          ↕               ↕               ↕
          └───────────────┼───────────────┘
                          |
                  Contextual Factors
          ┌───────────────┴───────────────┐
          ▼                               ▼
  Environmental Factors           Personal Factors

• All components are mutually interconnected - change in one affects others
• Disability is not simply caused by a health condition; it emerges from the interaction between health conditions and context
• A person with severe impairment may have minimal participation restriction if environmental facilitators are strong (e.g., wheelchair user who works in a fully accessible office)
• A person with mild impairment may have severe participation restriction if environmental barriers are high

6. Overview Table of ICIDH-2 Components

7. Alphanumeric Coding System

• b = Body Functions (e.g., b730 = Muscle power functions)
• s = Body Structures (e.g., s750 = Structure of lower extremity)
• a = Activities (e.g., a450 = Walking)
• p = Participation (e.g., p850 = Remunerative employment)
• e = Environmental Factors (e.g., e120 = Products for personal mobility)

• 0 = No problem (0-4%)
• 1 = Mild problem (5-24%)
• 2 = Moderate problem (25-49%)
• 3 = Severe problem (50-95%)
• 4 = Complete problem (96-100%)

8. Aims of ICIDH-2

1. Provide a scientific basis for understanding and studying functional states associated with health conditions
2. Establish a common language for describing health and disability across disciplines and countries
3. Permit international comparison of disability data across countries, health disciplines, services, and time
4. Provide a systematic coding scheme for health information systems and statistics
5. Support policy development for disability rights and services
6. Facilitate interdisciplinary communication between physiotherapists, physicians, psychologists, social workers, and policymakers

9. Scope and Universal Application

• Any health condition can be coded using ICIDH-2
• It does not classify "disabled people" - it classifies domains of functioning
• It recognizes that all people experience some degree of functional difficulty at some point in life

10. ICIDH-2 vs ICF (2001) - Final Differences

11. Application in Physiotherapy

• Body function impairment: Reduced right arm muscle power (b730), spasticity (b735)
• Activity limitation: Difficulty with dressing (a540), walking (a450)
• Participation restriction: Unable to return to work as teacher (p850)
• Environmental barrier: No ramp at home (e150)
• Environmental facilitator: Supportive family (e310), physiotherapy services available (e580)
• Personal factors: Motivated, previously active, 45 years old

Summary