MOBILITY DISORDERS
Definitions:
Immobilization – physical restriction of movement to body or a body segment
Mobility disability is the gap between an individual’s physical ability (eg, muscle strength or balance) and environmental challenges such as walking outdoors on uneven surfaces.
Deconditioning – decreased functional capacity of multiple organ systems, Deconditioning occurs at a faster rate than reconditioning.
Time course of impaired mobility:
Onset: Mobility disorders may be catastrophic (eg, after cerebrovascular accident or hip fracture) or chronic, related to progression of disease and sedentary lifestyle. Sudden onset of mobility limitation usually is a result of a traumatic event, such as an injurious fall; whereas a slow progressive decline in mobility is a consequence of worsening health conditions, such as arthritis
Severity: The disability can range from preclinical (ie, the limitation only exists in highly challenging environments) to severe (as occurs among bedbound individuals)
Patients report difficulty with mobility before the development of actual dependency in activities of daily living and instrumental ADLs, In this preclinical stage, patients have minor abnormalities in performance tests of balance, gait, and lower extremity muscle function. Poorer performance on these tests predicts future disability.
In the early stages, before the onset of task difficulty, older people may be able to compensate for underlying impairments or physiological decrements by modifying their performance and thus maintain their everyday function without strong perception of difficulty
The pathogenesis of mobility disorders can be seen as extrinsic, intrinsic, and situational
- Extrinsic causes include unsafe home or outdoor environment (eg, throw rugs or ice on sidewalks) that may limit mobility.
- Intrinsic causes include any disease that impairs balance, and diseases may negatively affect mobility without impairing balance. These include any diseases causing pain or difficulty with walking, such as arthritis, claudication, lumbar spinal stenosis, and obesity. Fear of falling, anxiety, and depression may also contribute to mobility curtailment.
- Situational factors: lack of an appropriate adaptive aid (bath bench, walker) may lead to unnecessary curtailment of mobility.
Unfortunately: the health-care system tends to promote immobility in patients. Patients are frequently restrained by either physical restraints, chemical restraints (sedatives), or treatment restraints (IV, oxygen, catheters).
CAUSES: Mobility disorders are typically multifactorial, and evaluation should ascertain which factors are potentially reversible
- Physical:
- Musculoskeletal disorders
- Arthritis‘
- Sarcopenia
- Fractures (especially hip and femur)
- Podiatric problems
- Other (e.g., Paget's disease)
- Stroke
- Parkinson's disease
- Other (cerebellar dysfunction, neuropathies)
- Congestive heart failure (severe)
- Coronary artery disease (frequent angina)
- Peripheral vascular disease (frequent claudication)
- Chronic obstructive lung disease (severe)
- Interstitial lung disease severe
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- Acute and chronic pain
- Impaired balance:
- Deconditioning (after prolonged bed rest from acute illness)
- Malnutrition
- Severe systemic illness (e.g., widespread malignancy)
- Acute medical illnesses
- Recent hospitalization
- Drug side effects (e.g., antipsychotic- induced rigidity, Sedatives and hypnotics, by causing drowsiness and ataxia, blurred vision by anticholinergic, postural hypotension diuertics , vasodilators)
- Sensory factors Impairment of vision, hearing, peripheral neuropathy
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3. Psychological,
- Fear (from instability and fear of falling)
- Depression
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Environmental:
- Forced immobility (in hospitals and nursing homes)
- Inadequate aids for mobility.
- Poor lightening.
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Consequences of impaired mobility:
There are profound social, psychological, and physical consequences. No body system is immune to effects of immobility. Effects depend upon general health, age, and degree of immobility
Skin: Pressure ulcers
Musculoskeletal
Muscular deconditioning and atrophy Contractures Bone loss (osteoporosis)
Cardiovascular
Deconditioning
Orthostatic hypotension Venous thrombosis, embolism
Pulmonary
Decreased ventilation Atelectasis
Aspiration pneumonia
Gastrointestinal
Anorexia
Constipation
Fecal impaction, incontinence
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Genitourinary
Urinary infection Urinary retention Bladder calculi
Incontinence
Metabolic
Altered body composition (e.g.,decreased plasma volume)
Negative nitrogen balance Impaired glucose tolerance Altered drug pharmacokinetics
Psychological
Sensory deprivation
Delirium
Depression
Sleep disturbances
Social:
Isolation
Caregiver stress
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Skin:
- Trauma to fragile skin, including ecchymosis and skin tears, occur when elders need more assistance getting up and down;
- Immobility threatens healthy skin integrity and can become severe enough to result in pressure ulcers; The first sign of this is redness that won't blanch
- Dependent Edema Dependent Edema (can predispose to cellulitis) (can predispose to cellulitis
Musculoskeletal:
Muscles:
- Loss of muscle strength1-3% / day, Muscle atrophy (begins after 1 day of immobilization. Muscles may lose half of their bulk after 2 months) larger muscles are more affected than small ones
- Lower limb muscles atrophy occur twice as fast as arm muscles
- Immobility is associated with Decreased oxidative capacity of muscular mitochondria, deceased tolerance to oxygen debt, and earlier accumulation of lactic acid.
- Increased muscle fibers degeneration, increased fat, fibrous content in muscle
- Muscles that cross two joints, such as the hamstring or back muscles, tensor muscles of fascia lata, rectus muscle of the thigh, gastrocnemius muscles, and biceps muscles, are particularly at risk of shortening during immobilization
Bone
- Disuse osteoporosis due to loss of gravitational pull on weight bearing bone (mainly affect spine, lower limb bones)
- Heterotopic ossification: a process by Heterotopic ossification: a process by which the which the soft tissues soft tissues surrounding a bone surrounding a bone forms mature bone forms mature bone.
- Cortical thinning at ligament insertion sites Joints:
- Osteoarthritis: Immobilization can induce cartilage degeneration. The body attempts to repair joints through cartilage proliferation, osteophyte formation, and fibrofatty infiltration of the joint cavity causing contractures.
- Contractures (contributing factors include spasticity, improper bed positioning, and maintaining the limb in a shortened position) Muscles, CT that cross two joints are at increased risk for contractures. development of contractures, further impaired mobility, resulting in more joint tightness and contractures.
- Joint stiffness and pain: if joints are not given adequate full range of motion. The stiffness is due to tightness of the muscles and tissues surrounding the joints.
Gastrointestinal system
- A reduced sense of taste, smell and a loss of appetite, the resulting drop in food intake lead to progressive disuse of the gastrointestinal (GI) tract. Leading to atrophy of the mucosal lining and shrinkage of glandular structures.
- Decreased peristalsis, increased transit times slow the movement of faeces through the colon and rectum, increasing water reabsorption. As a result, stools progressively harden causing constipation, fecal impaction. The associated use of morphine or anticholinergic, loss of privacy and use of bedpans increase risk of constipation
- Gastric bicarbonate secretion may also decrease increasing acidity within the stomach. When patients are in the supine position, these gastric secretions can collect and press against the lower oesophageal (cardiac) sphincter, causing irritation. Patients confined to bed can experience symptoms associated with gastro-oesophageal reflux disease (GERD), such as regurgitation and heartburn
Respiratory effects:
- ↓strength of respiratory muscles→↓tidal volume, minute volume, respiratory capacity
- In a supine person, the weight of the body restricts the