Frames of Reference – Biomechanical Model – Flashcards

The biomechanical model is concerned with the capacity for functional motion. That is, the movement required to perform ones occupations. It is based on mechanistic philosophy whereby the dysfunctional part is analysed.

The model is based on the assumption that voluntary movement and control are the result of muscle strength and function, joint integrity and range, and physical endurance or tolerance (Reed, 1984, p278). The capacity for motion therefore, has three main components (Kielhofner 1997): 1. Joint range of motion 2. Strength 3. Endurance

Each joint is potentially able to move in certain directions and to certain limits of motion due to its bony structure and the integrity of surrounding tissues (Trombly 1995, p73). Muscle Strength has been defined "as the capacity of a muscle to produce the tension necessary for maintaining posture, initiating movement, or controlling movement during conditions of loading of the musculo-skeletal system" (Smidt & Rogers, 1982, in Trombly 1995, p107). Muscle fibres of repeatedly recruited motor units hypertrophy in response to increased resistance or load thereby increasing strength (Downey & Darling, 1971, in Trombly 1995, p413). Endurance is the ability to sustain effort. Energy is needed for a person to produce the required intensity or rate of effort over a period of time necessary to complete a given exercise or activity (Trombly 1995, p153). Factors influencing endurance may relate to oxygen supply from the cardiopulmonary system or to impairment of a muscle or muscle group through localised trauma to the muscle itself or other structure or reduction of innervation to the muscle (Trombly, 1995, p153).

The central concern of this model is a limitation of sustained stability or movement that produces an incapacity to perform occupations (Kielhofner, 2004). That is, inadequate range of motion, Strength, and/or endurance for the requirements of a person's occupational performance (or daily life tasks). A further area often addressed within this model which may impact on the capacity for motion is Oedema . The prognosis for untreated this problem is devastating: permanent loss of ROM, loss of sensation, and compromised nutrition to distal body parts, which may lead to amputation (Dutton 1995). Few occupational therapists would actively assess and treat Oedema alone, but need to know about its assessment and treatment in combination with other deficits addressed

Structural instability (re Joints ) Low-level Endurance Maintaining and improving ROM Maintaining &/or increasing Strength High level endurance

ROM Muscle strength endurance oedema and occupational performance areas: Activities of daily living Work Leisure

Performance Components Range of movement (active [AROM] and passive [PROM]): visual observation goniometer measurements photography/video Jebsen Hand Function Test Muscle strength: manual muscle testing, eg Oxford Scale hand-grip dynamometer Endurance: frequency duration percent of maximal heart rate Intensity eg Metabolic costs of activity- METs. Oedema circumferential measurement volumetric measurement (water displacement) Other components include dexterity and co-ordination, often measured using a peg test of some sort. Also sensation, although not strictly coming under this framework, it is often considered alongside the above. Occupational Performance Areas Activities of Daily Living Barthel Nottingham ADL/Extended ADL Klien Bell AMPS Work assessment Tessa - The Enabling System and Skills Assessment Valpar - Component Work Sample Series

Prevention and Maintenance - to prevent deformity and maintain existing capacity for motion Restoration - to improve diminished capacities for motion, strength and endurance Compensation - to adapt for limited motion

adapted procedures adaptive devices upper extremity orthotics wheelchairs ambulatory devices environmental modifications

Substitute for lost motion Energy conservation Work simplification Consider the use of teaching adapted procedures over issuing equipment, and see what advantages and disadvantages you can come up with. Once you have a list, click below for some hints. Advantages Flexibility Less visible Inexpensive Disadvantages Require habit change Lack external prompts Disadvantages Require habit change Lack external prompts

Consider what you have read, and see what advantages and disadvantages of using equipment you can list. Click on the button below and compare your list with what is here. Advantages Good face validity Placebo effect Technological gadgetry Disadvantages Compliance Stigma Safety Failure experience

Prevention/maintenance Support of painful joints (eg arm slings, arm troughs, playboards) such as a painful shoulder, elbow, wrist or hand Immobilization for healing or protection of tissues Provide stability or restrict unwanted movement/motion Prevention of contractures or normalising tone Restoration Restore mobility to joints

Reduce weight-bearing on lower limbs - either on a temporoary or permanent basis To provide a wider base of support eg the use of a quad walker or a zimmer frame can achieve this Support of unstable joints eg leg braces

fixed toilet frames raised toilet seats grab rails car adaptations ramps widening doorways walk-in showers

b. Approach - restorative although may require some aspects of compensatory in the interim. c. Assessments - dynamometer; observation of functional tasks; interview d. Intervention techs - Stress to muscle tissue can be graded by increasing the speed and/or resistance needed to complete the task and by increasing the number or repetitions of an isotonic contraction or the amount of time an isometric contraction is held (Trombly, 1995, p246). Adaptation of tasks or activities

b. Approach - preventative in respect to the risk of injury to the carer around moving and handling. c. Assessments - carer and client interview, observation of transfer, risk assessment d. Intervention techs - predominately education to the carer around correct body mechanics and moving and handling techniques with the father

b. Approach - preventative in respect to prevention of further injury c. Assessments - client interview, work-site assessment, risk assessment d. Intervention techs - predominately education to the client around correct body mechanics and moving and handling techniques within his workplace (and perhaps at home too regarding moving and handling at home)

b. Approach - predominately compensation (perhaps also prevention/maintenance in respect to positioning of the stump) c. Assessments - interview, functional assessment (showering) d. Intervention techs - environmental modification, education

b. Approach - restorative - early surgery, room for improvement c. Assessments - interview, functional assessment (AMPS); Borg Scale of excursion d. Intervention techs - education, training/retraining principles

b. Approach - compensatory - condition is progressive - will not improve c. Assessments - functional assessment, risk assessment d. Intervention techs - environmental modification, education around manual handling.

Strengths Widely used and documented Easily understood by other professionals Makes good use of problem solving process Can be used in many settings Flexibility in application Quick results / patient sees positive benefits / increased motivation Used for a variety of needs - acute or chronic Limitations Reduced patient choice -reduced opportunity to plan/participate in process/ passive role non-compliant behaviour Programme may become sterotyped/recipe-like Overtly physical bias wider social, environmental issues ignored (reduced holitic approach) also may become a quick-fix of the problem/ over prescribing of equipment