Ergonomic Evaluation in CBR (Community-Based Rehabilitation)

What is Ergonomic Evaluation in CBR?

• Identify harmful postures, repetitive movements, forceful exertions, and awkward positions during daily tasks or occupational activities
• Guide adaptive equipment prescription and workstation modification
• Enable persons with disabilities to participate safely in vocational activities
• Prevent secondary musculoskeletal complications in people who are already physically compromised
• Assess caregivers, community health workers, and rehabilitation workers who are at risk from patient handling and repetitive tasks

Purpose of Ergonomic Evaluation in CBR

1. Vocational rehabilitation - Assessing individuals returning to or entering employment, identifying job demands vs. their functional capacities
2. Home and workplace modification - Using assessment data to redesign workstations, tools, and environments
3. Caregiver safety - Evaluating postures of caregivers who assist disabled individuals
4. Prevention of secondary disability - Identifying ergonomic risks in persons already managing a primary condition
5. Advocacy and policy - Generating data to support workplace accommodations

Common Ergonomic Assessment Methods Used in CBR

• RULA - Rapid Upper Limb Assessment
• REBA - Rapid Entire Body Assessment
• OWAS - Ovako Working Posture Analysis System
• NIOSH Lifting Equation - for manual material handling
• Ergonomic checklists - site-specific screening tools

RULA - Rapid Upper Limb Assessment

Background and Development

• Repetitive movements of the upper limbs
• Static or awkward postures of the neck and trunk
• Force and load handling with the arms and hands

Body Segments Assessed

Group A - Upper Limbs

1. Upper arm - Angle of flexion/extension, abduction, elevation of shoulder
2. Lower arm (forearm) - Angle of flexion, crossing midline
3. Wrist - Flexion/extension, radial/ulnar deviation
4. Wrist twist - pronation/supination

Group B - Neck, Trunk, Legs

1. Neck - Flexion, extension, lateral bend, rotation
2. Trunk - Erect vs. flexed, twisted, laterally bent
3. Legs - Supported/unsupported, walking

RULA Scoring Procedure

• Each body segment in Group A is scored based on joint angle ranges
• Scores are modified by muscle use (+1 if posture is static >1 min or repeated >4x/min) and force/load (+1 for 2-10 kg intermittent; +2 for 2-10 kg static/repeated; +3 for >10 kg)
• Scores are entered into Table A to generate Score A

• Similarly scored for angle ranges and modified for muscle use and force
• Scores entered into Table B to generate Score B

• Score A and Score B are cross-referenced in Table C to generate the Grand Score (1-7)

RULA Action Levels

RULA Scoring Details for Body Segments

Upper Arm

• Score 1: 20° flexion to 20° extension (near neutral)
• Score 2: >20° extension or 20-45° flexion
• Score 3: 45-90° flexion
• Score 4: >90° flexion
• Modifiers: +1 if shoulder raised, +1 if arm abducted, -1 if arm supported/gravity-assisted

Lower Arm (Forearm)

• Score 1: 60-100° flexion (mid-range)
• Score 2: <60° or >100° flexion
• Modifier: +1 if crossing midline or working out to side

Wrist

• Score 1: Neutral position
• Score 2: 0-15° flexion/extension
• Score 3: >15° flexion/extension
• Modifier: +1 if deviated radially or ulnarly

Neck

• Score 1: 0-10° flexion
• Score 2: 10-20° flexion
• Score 3: >20° flexion
• Score 4: Extension
• Modifiers: +1 for rotation or lateral bending

Trunk

• Score 1: Erect/sitting upright
• Score 2: 0-20° flexion
• Score 3: 20-60° flexion
• Score 4: >60° flexion
• Modifiers: +1 for rotation or lateral bending

REBA - Rapid Entire Body Assessment

Background and Development

Key Differences from RULA

Body Segments Assessed in REBA

Group A - Trunk, Neck, Legs

1. Trunk - Flexion/extension, lateral bending, rotation
2. Neck - Flexion/extension, lateral bending, rotation
3. Legs - Bilateral support, unilateral, walking; knee angle

Group B - Upper Arm, Lower Arm, Wrist

1. Upper arm - Flexion/extension, abduction, shoulder raised
2. Lower arm - Flexion angle
3. Wrist - Flexion/extension, deviation/twist

REBA Scoring Procedure

• Trunk, neck, and leg scores combined in Table A → Score A
• Add Load/Force score: +0 (< 5 kg), +1 (5-10 kg), +2 (>10 kg), +1 extra for shock or rapid build-up of force
• Gives Score A (modified)

• Upper arm, lower arm, wrist scores combined in Table B → Score B
• Add Coupling score (quality of grip): 0 (good grip), +1 (fair), +2 (poor), +3 (unacceptable)
• Gives Score B (modified)

• Score A (modified) and Score B (modified) cross-referenced in Table C → Score C
• Add Activity score (+1 for static posture >1 min; +1 for repeated small range actions >4x/min; +1 for rapid large range changes)
• Final REBA Score = Score C + Activity score

REBA Action Levels

REBA Scoring Details for Body Segments

Trunk

• Score 1: Erect (0°)
• Score 2: 0-20° flexion or extension
• Score 3: 20-60° flexion or >20° extension
• Score 4: >60° flexion
• Modifiers: +1 for rotation or lateral bending

Neck

• Score 1: 0-20° flexion
• Score 2: >20° flexion or extension
• Modifier: +1 for rotation or lateral bending

Legs

• Score 1: Bilateral weight, walking, or seated
• Score 2: Unilateral, unsupported, or in an unstable posture
• Modifier: +1 for 30-60° knee flexion; +2 for >60° knee flexion

Upper Arm

• Score 1: 20° extension to 20° flexion
• Score 2: 20-45° or >20° extension
• Score 3: 45-90° flexion
• Score 4: >90° flexion
• Modifiers: +1 for shoulder raised or arm abducted; -1 if leaning/supported/gravity assists

Lower Arm

• Score 1: 60-100° flexion
• Score 2: <60° or >100° flexion

Wrist

• Score 1: 0-15° flexion/extension
• Score 2: >15° flexion/extension
• Modifier: +1 for deviation/twist

Application of RULA and REBA in CBR Settings

Who is Being Assessed?

1. Persons with disabilities in vocational settings - Assessing postures during supported employment (e.g., weaving, tailoring, assembly work, farming tasks)
2. Caregivers - Evaluating postures during patient transfers, bathing, positioning activities
3. Community rehabilitation workers (CRWs) - Screening home-visiting workers for ergonomic risk during assistive device fitting, training, and community activities
4. Self-care tasks - Evaluating postures adopted by persons with physical disabilities during activities of daily living

Practical Steps in CBR Ergonomic Evaluation

1. Observation and task analysis - Observe the individual performing the task; identify the most common or extreme postures
2. Posture recording - Photograph or video-record the task at its most demanding posture; identify the "worst case" posture for assessment
3. Select the appropriate tool - Use RULA for upper limb-dominant or seated tasks; use REBA for tasks involving the whole body, patient handling, or dynamic activity
4. Score each body segment - Using the worksheets or apps
5. Calculate the total score - Follow the scoring tables
6. Interpret the action level - Determine urgency of intervention
7. Implement and reassess - Modify equipment, posture, or task design; re-evaluate after changes

Specific CBR Applications

RULA is preferred for:

• Office and computer work with disability adaptations
• Upper limb prosthetics/orthotics use assessment
• Wheelchair propulsion analysis (upper limb loads)
• Repetitive assembly or craft tasks in supported employment
• Sitting posture assessment during CBR training sessions

REBA is preferred for:

• Manual handling and patient lifting/transfer tasks
• Agricultural tasks (bending, lifting, squatting) in rural CBR programs
• Construction and labor-intensive vocational activities
• Tasks involving unpredictable or variable postures
• Assessment of persons with mobility impairments working in community settings

Comparison: RULA vs. REBA Summary

Limitations of RULA and REBA in CBR

• Both tools capture a snapshot posture and may miss posture variability across a task
• They rely on observer judgment - inter-rater reliability is moderate
• Neither captures cumulative exposure over time or across multiple tasks
• REBA and RULA do not account for individual capacities - especially relevant for persons with disabilities in CBR
• Both tools require training to apply reliably
• In low-resource CBR settings, access to trained ergonomists may be limited

Summary

• Pick RULA if the task is upper limb dominant, repetitive, or sedentary (e.g., wheelchair propulsion, craft work, computer use)
• Pick REBA if the task involves the whole body, dynamic movements, or patient handling (e.g., transfers, lifting, farming)

• Score Group A (Upper arm → Forearm → Wrist) → Table A → add muscle use & force modifier → Score A
• Score Group B (Neck → Trunk → Legs) → Table B → add muscle use & force modifier → Score B
• Cross-reference in Table C → Grand Score (1-7) → assign Action Level

• Score Group A (Trunk → Neck → Legs) → Table A → add Load/Force score → Score A
• Score Group B (Upper arm → Forearm → Wrist) → Table B → add Coupling score → Score B
• Cross-reference in Table C → add Activity score → REBA Score (1-15) → assign Action Level