DETERMINING THE REQUIRED BODY FUNCTIONS

Body functions

Physiological functions of the body systems, including psychological functions (WHO, 2001)

Body Function Categories

Six broad categories of body functions used in occupational analysis, based on the ICF

Mental functions

Category covering higher level cognitive, attention, memory, perception, thought, and emotional functions

Sensory functions

Category covering vision, hearing, vestibular, taste, smell, proprioception, touch, interoception, pain, and temperature/pressure sensitivity

Neuromusculoskeletal and movement-related functions

Category covering joint, muscle, and movement functions

Cardiovascular, hematological, immune, and respiratory system functions

Category covering blood pressure, heart rate/rhythm, immune protection, and respiration

Voice and speech functions; digestive, metabolic, and endocrine system functions; genitourinary and reproductive functions

Category covering vocalization, digestion/metabolism/hormones, and reproductive/urinary functions

Skin and related structure functions

Category covering protection, repair, hair, and nails

Specific Mental Functions

Category under mental functions covering higher level cognitive, attention, memory, perception, thought, mental functions of sequencing complex movement, emotional, experience of self and time

Global Mental Functions

Category under mental functions covering consciousness, orientation, psychosocial, temperament/personality, energy, sleep

Higher level cognitive functions

1) Judgment

2) Concept formation

3) Metacognition

4) Executive functions

5) Praxis

6) Cognitive flexibility

7) Insight

Judgment

Mentally examining different options and discriminating between them to form an opinion or belief, using past experience to weigh implications for oneself and others

Concept formation

The ability to organize information and develop ideas based on common qualities of objects or situations, linking pieces of information to understand something not concrete; tied to abstraction and generalization

Metacognition

Awareness of one's own mental processes and the ability to reflect on one's own mental state; "thinking about thinking," important for learning, life planning, and communication

Executive functions

Frontal-lobe-reliant functions including decision making, abstract thinking, planning and carrying out plans, mental flexibility, and deciding which actions are appropriate in certain circumstances

Praxis

The brain's ability to plan, organize, and carry out sequential, novel movements with correct timing and transitions; also called motor planning

Cognitive flexibility

The ability to change strategies when confronted with a problem or a change in thoughts, shifting from one concept to another as new information is presented

Insight

Self-awareness and understanding of one's own behavior, abilities, strengths, and weaknesses; needed for safe decisions, correcting errors, and adapting to problems or disability

Attention (mental function)

1) Sustained attention

2) Shifting attention

3) Divided attention

4) Concentration

5) Distractibility

Sustained attention

Maintaining focus on one activity or stimulus for a sustained amount of time BUT requires vigilance towards maintaining thought and receiving sensory information

Concentration

Maintaining focus on one activity or stimulus for a sustained amount of time

Distractibility

Focusing on one or more stimuli while ignoring all other stimuli in the environment; demand increases as external stimuli increase

Divided attention

Focusing on two or more stimuli at one time, dividing attention between different motor movements, cognitive processes, or both

Shifting attention

Attending to one task at a time for limited periods, refocusing concentration from one stimulus to another and back

Memory (mental function)

Short-term, long-term, and working memory; closely linked to sensory processing, since information must be registered before it can be stored

Short-term memory

Memory that stores information temporarily, for about 30 seconds; used for small chunks of information needed only briefly

Working memory

The ability to hold and manipulate information from short- and long-term memory during complex tasks, such as problem solving

Long-term memory

Information about past events, language, and sensory experiences stored for long periods (hours to years), including personal information, events, facts, and procedures

Perception (mental function)

Discrimination of sensations (e.g., auditory, tactile, visual, olfactory, gustatory, vestibular, proprioceptive); the brain's ability to recognize and understand different sensations

Auditory perception

The brain's ability to discriminate between different sounds, tones, and pitches, distinct from the ear's ability to transmit sound

Tactile discrimination

The perceptual ability to distinguish different textures by touch (e.g., smooth vs. rough), relying on the brain to interpret what is felt

Visual discrimination

The ability to perceive and interpret visual information, discriminating between shapes, objects, colors, and other visual stimuli

Olfactory discrimination

The ability to distinguish differences in smells, alerting a person to smells that require action

Gustatory Discrimination

Ability to distinguish different taste sensations

Vestibular perception

A function of the inner ear that determines the position of the body in space, direction of movement, speed, and head position

Proprioception (perception)

Detecting the position of body parts, including muscle lengthening/shortening and limb direction, even without seeing them

Thought (mental function)

1) Control and content of thought

2) Awareness of reality vs. delusions

3) Logical and coherent thought

Control/content of thought

Having volitional control over thoughts so they relate appropriately to the activity or topic at hand

Awareness of reality

The ability to distinguish between what is real and what is fiction or imagined, understanding what is feasible given the environment

Logical and coherent thought

Thought that is reasonable, explainable in words or symbols, and used for sound reasoning based on factual information

Mental functions of sequencing complex movement

Regulating speed, response, quality, and time of motor production; the mental control over movements as they occur (execution), separate from understanding what movement is needed

Emotional functions

1) Regulation and range of emotions

2) Appropriateness of emotions

Regulating emotions

Controlling actions and decisions during difficult, dangerous, or catastrophic situations

Appropriateness of emotions

The match between the situation and the affect/display of feelings during an activity

Experience of self and time

Awareness of one's identity (including gender identity), body, and position in the reality of one's environment and time

Self-concept

Awareness of one's roles and identity in the world, beyond physical appearance, including gender identity

Body image

Awareness of the physicality and image of one's own body, including size, shape, height, and weight

Consciousness (global mental function)

State of awareness and alertness, including the clarity and continuity of the wakeful state

Continuity of wakeful state

Continuous or sustained alertness and awareness required for activities demanding constant vigilance and quick reactions

Orientation (global mental function)

Orientation to person, place, time, self, and others

Orientation to self

Awareness of one's own identity, understanding one's name and who one is in relation to others

Orientation to place

Awareness of one's own location, including type of place and geographic location

Orientation to time

Awareness of current date, month, day of week, year, and approximate time of day

Psychosocial functions

Integration of mental functions to form personal and interpersonal skills to establish reciprocal social interactions

Temperament and personality

1) Extroversion

2) Introversion

3) Agreeableness

4) Conscientiousness

5) Emotional stability

6) Openness to experience

7) Self-control

8) Self-expression

9) Confidence

10) Motivation

11) Impulse control

12) Appetite

Extroversion

Being outgoing, demonstrative, and readily engaging with others

Agreeableness

Being easily pleased, accommodating, and cooperative

Conscientiousness

Being careful, particular, and governed by principles and a strong work ethic

Emotional stability

An even-tempered, calm, composed temperament, also called easygoing

Openness to experience

A personality trait allowing acceptance of new, controversial, or surprising experiences as learning opportunities

Self-expression

The ability to express one's feelings and emotions, seen in art, style, and personal communication

Confidence

Belief in oneself; being self-assured, assertive, or bold

Motivation

The internal incentive to act or take action; drives people beyond basic needs

Impulse control

The ability to resist sudden urges to do or say something

Appetite

A natural desire for things, physiologically and psychologically driven (e.g., desire for food, touch)

Energy (global mental function)

Energy level, motivation, appetite, craving, impulse control; mental stamina and vigor rather than physical/aerobic capacity

Craving

A drive toward action related specifically to consuming substances

Sleep (global mental function)

Physiological process, quality of sleep; physical and mental disengagement from the immediate environment, required only during activities of going to sleep

Visual functions

1) Quality of vision

2) Visual acuity

3) Visual stability

4) Visual field

Quality of vision

The ability to detect light, contrast, and color among visual stimuli

Visual acuity

The ability to detect form and contour, seeing things clearly near and far

Visual stability

The ability to perceive objects/environment as stable even though the eyes are moving rapidly (saccades)

Visual field

Visual awareness of the environment, including detection of everything within the area when gaze is fixed straight ahead

Hearing functions

Sound detection and discrimination; awareness of location and distance of sounds

Vestibular functions

Sensation related to position, balance, and secure movement against gravity, relying on the inner ear's semicircular canals

Taste functions

Association of taste qualities of bitterness, sweetness, sourness, and saltiness, based on chemical signals from taste buds

Smell functions

Sensing of odors and smells, requiring the nose to perceive chemicals in the air

Proprioceptive functions

Awareness of body position and space, controlled by sensory receptors in muscles, tendons, and joints

Touch functions

Feeling of being touched, touching various textures; perceiving contact with skin or mucous membranes

Interoception

Internal detection of changes in one's internal organs, involving signals from the hormonal, immune, and autonomic nervous systems (e.g., hunger, thirst, alertness)

Pain

Localized and generalized pain; identifying potential or actual bodily damage and its location

Localized pain

Pain identified as coming from a specific body part, via pain receptors at the site of injury

Generalized pain

Pain occurring in nonspecific, larger areas, providing information about overall bodily dysfunction (e.g., flu-related pain)

Sensitivity to temperature and pressure

Thermal awareness (hot and cold) and sense of force applied to the skin (thermoreception)

Joint mobility

Joint range of motion; the ease with which a joint moves through motion

Joint stability

Structural integrity of joints; physiological stability related to structural integrity, keeping bones in proper alignment

Muscle power

Strength; the force with which a body part must move or hold an object

Muscle tone

Degree of muscle tension; the natural tension present in muscles at rest, creating resistance to passive movement

Muscle endurance

Sustainability of muscle contraction; required when a contraction must be maintained for a prolonged period or repeated over time

Motor reflexes

Involuntary contraction of muscles automatically induced by specific stimuli (e.g., the stretch reflex, which prevents overstretching)

Involuntary movement reactions

Postural reactions, body adjustment reactions, supporting reactions; automatic responses that restore the body to an upright position when balance is threatened

Control of voluntary movement

Eye-hand and eye-foot coordination, bilateral integration, crossing of the midline, fine and gross motor control, oculomotor function

Eye-hand/eye-foot coordination

Using visual information to control and contract muscle groups in a coordinated fashion to guide reaching or stepping movements

Bilateral integration

Using both sides of the body (arms or legs) collaboratively to complete a task, either actively together or with one as a stabilizer

Crossing midline

When the right side of the body crosses into the left side's space (or vice versa), requiring trunk muscles to collaborate with limb movement

Fine motor movements

Movements utilizing the smaller muscles of the hand, fingers, and thumb for precise manipulation of small objects

Gross motor control

Coordination of movements using the larger muscles of the body (e.g., throwing, jumping, kicking), without demand for small precise control

Oculomotor control

Motor control of the eye muscles allowing detection of visual information, including saccades, pursuits, accommodation, and binocularity

Gait patterns

Gait and mobility in relation to engagement in daily life activities; normal gait uses both legs interchangeably, shifting weight from one to the other

Cardiovascular functions

Blood pressure, heart rate and rhythm; maintaining pressure exerted by blood on vessel walls and appropriate heart contraction rate