The Effects of Ageing

Physical Effects of Ageing

Height Loss

• Vertebral compression
• Changes in discs
• Muscle tone loss
• Postural slump
• 1cm per decade- 40-50’s
• Accelerates after 60, greater loss in women
• Decrease in physical activity.

Weight

• Trend – weight gain until late middle age mostly due to decline in physical activity and an increase in stress levels.

Body Composition

• Change linked to cardiovascular disease and diabetes
• ↓ in muscle mass – decrease in physical activity, sedentary occupations
• ↑ in body fat – over nourished.

Body Mass Index

• Climbs until age 70 – body composition changes and height loss both contribute.

Bone Loss

• Occurs in mid to late 20’s in everyone
• Causes – hormonal changes, dietary deficiencies, physical inactivity
• More in women – less initial bone and greater hormonal change with age.

Flexibility

• Significantly affected by rheumatoid and osteoarthritis
• Lack of physical activity decreases the range of motion of all joints and affects all activities of daily living.

Cardiovascular Changes

Heart

• Pathways in the heart may develop fibrous tissue and fat deposits and sinoatrial node (the heart’s natural pacemaker) may lose some of its cells – the result is a slower heart rate
• Left ventricle wall thickens, therefore, decreasing amount of blood held in the left ventricle. The heart may fill more slowly
• Abnormal rhythms such as atrial fibrillation more common in older people – the possible cause is heart disease
• Heart muscle cells degenerate slightly, heart valves stiffen and thicken and may result in a heart murmur.

Blood Vessels

• Baroreceptors monitor blood pressure and help to maintain fairly constant BP with positional changes – lose sensitivity with age and can lead to dizziness with changes in position
• Capillary walls thicken and may cause a slower exchange of nutrients, gases, and wastes
• Main heart artery, aorta, becomes thicker, stiffer and less flexible. Probably related to changes in the connective tissue of blood vessel walls. Increases blood pressure, makes the heart work harder and may cause hypertrophy of heart muscle.

Source: http://circresearch.com

Blood

• With age, reduction in total body water, therefore, blood volume decreases.
• Speed red blood cells respond to stress or illness is reduced. Slower response to blood loss and anaemia.
• Level of white blood cells appears to remain similar though certain cells important for immunity decrease in number and therefore reduce the ability to fight off bacteria.

Skeletal Muscle changes

• Sarcopenia – age-related loss of muscle function
• Reduced muscle mass – increase in fat mass and connective tissue
• The total number of muscle fibres decreases – begins at 25 and accelerates thereafter. Type 2 b fibres decrease the fastest resulting in loss of power
• Type 1 fibres increase in area and number
• Loss of motor neurons – 60-year-old has 25% less than a 20-year-old. With the loss of the motor neuron either attached muscle fibres atrophy or are stimulated by a different motor neuron most likely slow twitch / Type 1.

Endocrine Changes in Muscle

Source: https://www.researchgate.net

• Increased insulin resistance – increased fat mass, decreased muscle mass
• Decreased availability of growth hormone – in old age only 20% of peak puberty level is available
• Reduction in oestrogen and testosterone – decrease in muscle mass and bone density
• Vitamin D deficiency – studies show a possible link between lean muscle mass and elevated levels of Vitamin D
• Increased parathyroid hormone – affect calcium and phosphate levels and may contribute to the development of osteoporosis.

Respiratory Changes

• Reduction in number of alveoli, therefore, less exchange of oxygen and CO2
• Reduction in elastic recoil of lungs – decreased capacity of lungs
• Increase in chest wall stiffness and shape of the chest- more difficulty in breathing and greater energy cost to breathe
• Changes in rib- vertebral articulations – stiffness, decreased range of motion- harder to take a big deep breath
• Narrowing in disc spaces in thoracic spine – decreased lung capacity
• Reduction in inspiratory muscle strength – diaphragm
• Reduction in sensitivity of resp. centres in the nervous system

Balance, Posture, Locomotion

Eyes – vision changes so slower processing of sensory information

• Altered perception of body’s vertical orientation – reduced acuity, contrast sensitivity, depth perception and narrowing of the visual field
• Also issues with cataracts, glaucoma and macular degeneration.

Somatosensation – covers touch, joint receptors, and postural control

• A decline in sensitivity of touch and pressure receptors
• Increased vibrational threshold resulting in reduced ability to feel the quality of contact between feet and surface below
• A decline in number and sensitivity of muscle and joint receptors, therefore, less accurate knowledge of limb position particularly while moving
• These impairments require a greater control from other sensory systems for postural control.

Vestibular system – ears

• A decline in density of hair cells that serve as biological sensors of head motion
• Reduction in the vestibule-ocular reflex. This is responsible for stabilising vision when the head moves quickly and determines whether the world or the individual is moving
• Perceptions of dizziness or vertigo add to the perception of instability.

Motor system – nerves

• Loss of large motor neurones, a decline in neurotransmitters and a decline in nerve conduction velocity result in the reduced ability to inhibit inappropriate physical responses to unexpected changes
• There is a decline in execution times so responses are slower
• The resultant decrease in muscular strength, power, and endurance. This loss is reflected in earlier onset of fatigue and increased risk of loss of balance and falls.

Gait

• Speed reductions of around 20% are attributable to reduced stride length
• Other negative consequences are reduced arm swing which normally helps with balance and decreased hip, knee and ankle rotation making gait less fluid and more robotic
• A tendency to walk flat-footed as this increases the amount of time the foot is in contact with the ground – another response to uncertain balance.

Cognitive

• Changes in processes of attention, memory, intelligence which affect the ability to anticipate and adapt to changes in the environment
• Difficulties in storing and manipulating information in working memory while doing a 2nd task, particularly if this requires balance
• Therefore, cognitive impairment is an important risk factor in the likelihood and incidence of falls.

Postural stability

• Spinal changes like kyphosis are often due to inaccurate perceptions of the true vertical so abnormal standing postures occur and are associated with a decline in pelvic and spinal flexibility
• Common kyphotic postures restrict movement and breathing
• Asymmetrical postures are commonly associated with stroke, uncorrected leg length discrepancies and arthritic pain in certain joints
• Postural muscles will need strengthening – soleus, gastrocnemius, tibialis anterior, gluteus medias, tensor fascia latae, erector spinae in thoracic area and abdominal muscles.

Other physical and psychological effects

Other Physical Effects

• ↓ gastrointestinal function – reduced ability to digest protein and Vit B12. There a B12 deficiency can occur
• ↓ ability to break down drugs – taking more than one prescription drug can affect physiological response to exercise
• Urinary incontinence – may discourage people from exercising and a reason to include pelvic floor work into programs
• ↓ liver and kidney function – reduces their ability to remove metabolic waste
• ↓ total body mass with an ↑ in body fat levels – these body composition changes will slow their basal metabolic rate and may lead to further increase in fat mass and muscle wastage
• ↓ recovery ability – decrease in the rate of adaptation to training so any physiological changes will take longer.
• ↑ in heat and cold sensitivity – affected more by temperature changes thereby reducing motivation to be physically active in certain environments.

Psychological Effects

• Ageing requires continual adjustment as there are growing fears and uncertainty as circumstances change
• Being old and ill
• Being poor and becoming a burden to another
• Change and uncertainty
• Dementia, Alzheimers, and other cognitive impairments
• Loss of independence – eg car license or moving into an aged care facility
• Security.