Disability Models Overview

Disability Models

• Disability models describe the impact and consequences of conditions like disease or injury on an individual's functioning.
• These disruptions affect an individual's ability to perform everyday societal roles and functions.
• The process of disablement is not always linear or irreversible and depends on factors like the condition's severity and duration, along with a patient's motivation and desires.

Nagi Model

• The Nagi model breaks down disablement into three levels:
  • Tissue/Cellular Level: Active pathology (e.g. disease)
  • Organ/System Level: Impairment (e.g. reduced function of a system or organ)
  • Personal/Societal Level: Functional limitation & disability (e.g. reduced ability to perform daily activities, societal limitations)

The International Classification of Impairments, Disabilities, and Handicaps (ICIDH) Model

• The ICIDH model categorizes the problem at three levels, like the Nagi model.
  • Tissue/Cellular Level: Disease (e.g. a diagnosis of a condition)
  • Organ/System Level: Impairment (e.g. reduced body function)
  • Personal Level: Disability (e.g. problems performing activities)
  • Societal Level: Handicap (e.g. limitations in social participation/roles or opportunities)

The International Classification of Functioning, Disability, and Health (ICF) Model

• The ICF model places emphasis on a person's overall functioning, not just limitations.
  • Tissue/Cellular Level: Impairment of body structure/function (e.g., anatomical issues or physiological dysfunction)
  • Personal Level: Activity limitation (e.g., difficulty performing specific activities of daily living).
  • Societal Level: Participation restriction (e.g., challenges in social interactions).

Comparison of Models

• Comparing the three models, there is a difference in categories of disablement. Active pathology is used for tissue/cellular level in the Nagi model unlike the other two models that use disease.
• For the individual level, the three models describe limitation in function differently, with functional limitation for the Nagi model, disability for ICIDH Model, and Activity limitations in ICF model.
• At the societal level, disability for disability in Nagi model becomes handicap for the ICIDH model and Participation Restriction in ICF model.

Use of Disability Models in Physical Therapy

• Provides a framework for clinical decision making.
• Enables standardization of terminology ensuring better documentation and communication.
• Can help prevent or reduce the risks of conditions.
• Helps identify effective therapeutic exercise interventions and strategies.

Impact of Therapeutic Exercise on the Disablement Process

• Effective interventions help reduce risk factors and impairments that can impact a person's quality of life.

Key Concepts

• Pathology/Pathophysiology: Disruptions in the body's homeostasis (balance) due to disease or other issues. Includes a range of abnormal findings and symptoms.
• Impairments: The consequences of pathological conditions, manifested in signs and symptoms related to specific body systems. Impairments can be primary and secondary.
• Functional Limitations: The limitations a person faces in performing activities of daily living, often due to impairment.
• Disability: This is the inability of an individual to carry out tasks of daily routines.
• Handicap: Limitations in social participation or opportunities.
• Prevention: Reducing the severity or duration of existing diseases.
• Risk Factors: Influences or characteristics related to disablement.

Common Physical Impairments Managed with Therapeutic Exercise

• Musculoskeletal: Muscle weakness, reduced torque production, decreased muscular endurance, restricted range of motion, joint hypermobility, faulty posture, imbalances in muscle length/strength.
• Neuromuscular: Impaired balance, postural stability, or control, incoordination, delayed motor development, abnormal tone (hypotonia, hypertonia, dystonia), ineffective/inefficient functional movement strategies.
• Cardiovascular/Pulmonary: Decreased aerobic capacity, impaired circulation, pain during physical activity.
• Integumentary: Skin hypomobility (e.g., immobile or adherent scarring).