at the University of Pécs and at the University of Debrecen
Identification number: TÁMOP-4.1.2-08/1/A-2009-0011
PHYSICAL ACTIVITY, IMMOBILIZATION
Erika Pétervári and Márta Balaskó
Molecular and Clinical Basics of Gerontology – Lecture 5
at the University of Pécs and at the University of Debrecen
Identification number: TÁMOP-4.1.2-08/1/A-2009-0011
Outline
• The beneficial effects of physical exercise
• Inactivity
• Immobilization syndrome – chronic bedrest
• Pressure ulcers and other consequences
Exercise
• Helps to maintain (reach) a healthy BMI
• Improves body composition, increases BMR
• Trained muscles burn fat
• Active muscles take glucose without insulin (GLUT4)
• Increases the rate of HDL, improves cholesterol profile
• Improves thermal adaptation
• Adrenalin induces vasodilatation in active muscles
• Increases Peak-Bone –Mass, helps prevent osteoporosis
• Reduces stress levels
• Helps prevent depression and dementia (neural growth factor, decreased amyloid production)
• Decreases the incidence of certain types of cancer (colon, breast, uterus, esophagus, prostate) via
maintenance of normal BMI and insulin sensitivity – decreased levels of insulin, estrogen levels and
binding.
Exercise
• Muscle hypertrophy may be elicited by relatively intensive training even in the elderly
(12 weeks – 3 times a week +10%)
Exercise
Inactivity
0 Regular intensive physical exercise, good level of fitness
1 Sedentary lifestyle, only recreational sport
2 Sedentary lifestyle, without recreational sport 3 Moderate immobilization in sitting or horizontal
position
4 Total immobilization (paralysis) 5 Tilting
• MET: metabolic unit
1 MET: 3.6 mlO2/kg/min 3 MET: brisk walking
• A school child has a 7 MET PE lesson 3 times a week for 10 months – 3 × 7 × 10/12 = 17.5
MET/week
• Inactivity increase BMI
(difference between most and least active 30% 2.1 in Caucasians, 2.9 in Afro-americans)
• Maximal activity decreases with age:
from 28-40 → 4-30 MET/week
(3-22 MET/week in Afro-americans)
Inactivity
Immobilization – chronic bed rest
• Short term – beneficial; Long-term – harmful
• Inactivity and somnolence is part of the “sickness- behavior”, besides fever, anorexia, depressed water intake, apathy, lethargy, impaired grooming,
enhanced sensitivity to pain…
• XIXth century: AMI – 6-week bedrest, femur fracture - 6-month bedrest
• Today: a minimum of 12-48 hours of bedrest after AMI
Causes
• Loss of both lower limbs
• Spinal injuries (transection)
• Amyotrophic lateral sclerosis
• Late stages of Parkinson’s disease
• Neuropathies/encephalopathies
• Paralysis due to stroke
• Coma
• Extreme weakness, painful joints, severe COPD, heart failure
• Elderly (depression, isolation, fear from falling, dementia,
tranquillizers, sleeping pills, antihypertensive drugs, diuretics, orthostatic hypotension)
Immobilization – chronic bed rest
Consequences
• Adaptation of the circulation (short term – long term)
• Pressure ulcers
• Depressed ventilation, risk for hypostatic pneumonia
• Increased risk for deep venous thrombosis, pulmonary embolism
• Muscle atrophy, contractures, constipation
• Osteoporosis
• Changes in metabolism, heat adaptation
• Depressed immunity failure
• Psychological changes
Immobilization – chronic bed rest
Earth gravity Normal condition
Zero gravity Acute exposure
Zero gravity Chronic exposure
Earth gravity Upon return Central venous
pool
Immobilization – chronic bed rest
Pressure Ulcers
• Definition
Any lesion caused by unrelieved pressure resulting in damage of underlying tissue (AHCPR, 1994).
• Can occur anywhere on body
Pressure Ulcer Etiology
• Pressure exerted by bony prominences on the body that stop capillary flow to the
tissues.
• Deprives tissues of oxygen and nutrients causing cell death.
• Pressure greater than 32mmHg exerted by bony prominences to disrupt blood flow.
Pressure Ulcers
Causes of Pressure Ulcer
• Prolonged pressure
- duration and intensity of pressure - location of pressure on body
- extended pressure that
blocks flow to the tissue between the source of pressure & the bone
• Shear
• Friction
Function of both time and pressure (hyperbolic curve)
• 70 mmHg pressure for two hours produces irreversible injury
• greater pressure takes less time
• lower pressure takes more time
• obese may be much lower; emaciated may be much higher
• turning schedules must be individualized!!!!
Pressure Ulcer
Pressure Ulcer Staging (depth & tissue type) Stage I Persistent redness
(color pressure insensitive) Stage II Partial thickness skin loss Stage III Full thickness skin loss
(subcutaneous)
Stage IV Full thickness skin loss (fascia)
Pressure Ulcer
Immobilization – chronic bed rest
Epidermis
Subcutaneous tissue
Muscle Dermis
Bone Reddened area
Immobilization – chronic bed rest
Blister
Mortality
• 40% die per year
• 60% die within 1 year after hospital discharge
sources: Thomas DR JAGS 1996; 44:1435.
Brandeis GH JAMA 1990;264:2905-9.
Pain with Pressure Ulcers
• 59% report some degree of pain
• Only 2% receive pain medication within 4 hours of dressing change
• 45% report pain as distressing or horrible
(Ca and hydroxyproline loss)
Time (weeks)
Control Bedrest
Calcium
Change in urinary calcium (mg/day)
-10 -5 0 5 10 15 20
150
100
50
0
-50
OH-Proline
Change in urinary hydroxyproline (mg/day) 20
10
0
-10
VO2max = Qmax x (a-v)O2 Differencemax
Adaptive responses of factors infuencing maximal oxygen uptake (VO2max) in chronic bedrest
Immobilization – chronic bed rest
HR Stroke volume Arterial O2 Venous O2
Sensitivity of the arterial baroreceptor system
Blood volume RBC mass Muscle mass
Symp/parasymp balance
Alpha-adrenergic VC VEmax Perfusion pressure in muscles
Muscle tone V/Q Capillary density
Muscle mass Diffusion Diffusion distance in tissue
Baroreceptor VC
response O2 extraction
Beta-adrenergic activity
Substrate transport
Substrate metabolism
Energy stores
Number of mitochondria
