‘Osteo’ means bone and ‘pore ‘means hole – it can be explained simply by ‘holes in the bone’.
Osteoporosis is a bone disease where there is loss of minerals and break down of the normal healthy bone structure so the bones become fragile and brittle.
“Over the next 10 years, the total cost of osteoporosis and associated fractures is estimated to be $33.6 billion.” – Osteoporosis Australia
Did you know that by the time you are 35 your skeleton would have remodeled 5 times?
Over a 7-year period cells called ‘osteoclasts’ break down and clean out old bone tissue and cells called ‘osteoblasts’ build new bone. This is due to the mechanical stresses and strains on the skeletal system by gravity and muscle activity.
The process is also influenced by other factors such as genetics, age, hormones, medication (corticosteroids for example), excessive alcohol intake, smoking and nutrition (adequate vitamin D and calcium for example) and conditions such as diabetes and rheumatoid arthritis and prolonged inactivity.
After the age of 35, bone reabsorption starts to exceed bone deposition and we start to lose up to .5 to .75% of bone density per year. Men generally lose bone density at a slower rate until the age of 65 when the rate of bone loss equals that of women.
Osteopenia
This is thinning of the bone and a precursor to osteoporosis. Having osteopenia does not mean you will get osteoporosis but without intervention you are at high risk of progressing.
What does ‘Osteogenic’ mean?
Osteogenic describes something that is important for building and maintaining bone density.
Some interesting and relevant facts
- Currently 4.75 million Australians over 50 have osteoporosis or Osteopenia.
- This figure will increase over the next 10 years to 6.2 million.
- There is one fragility fracture every three and a half minutes – this figure is also likely to increase.
- It is estimated that fractures related to osteoporosis occurs once in every four fractures for men and twice in every five for women over 50. One of the most serious outcomes of osteoporosis is a fracture of the hip.
- In 2011-12 19,000 people over 50 were hospitalized for an osteoporosis related hip fracture. 72% were aged 80+ and 72% were women (Australian Institute of Health and Welfare).
What do bones do?
- They provide attachment for ligaments, tendons and muscle (ligaments join bone to bone and tendons join muscle to bone).
- They Support and protect internal organs eg heart, lungs, bladder, brain.
- Red and white blood cell formation occurs in bone marrow.
- They provide a storehouse for minerals.
Bone density in women
A decline in bone density is a normal part of the ageing process – like getting wrinkles! This bone loss is accelerated in menopausal women who may lose 20-30% of bone over a five-year period. This is thought to be due to the decline in oestrogen during this period of their life. Oestrogen is a stimulant for bone, tendon and muscle health and function. As soon as a woman has reached a plateau in menopause symptoms (usually marked by a resolution of hot flushes and other symptoms) the bone reabsorption will tend to stabilise.
Bone density and smoking
It is important to mention here that smoking causes leaching of calcium from the bones because smoking causes less calcium to be absorbed from the diet. AS calcium is required for many other functions in the body the bone then becomes a source. Women who smoke also tend to have lower oestrogen levels and experience earlier menopause and weaker bones than non-smoking women.
Normal bone loss vs excessive bone loss
During the ageing process we lose muscle, skin tone and bone – this is normal. What many people don’t realise is that just as we can do things to protect and improve our skin condition as we age, we can also be proactive in minimizing the loss of bone and muscle mass through exercise, diet and lifestyle choices.
We know from research that bone remodelling occurs at different rates during different stages of life. As a child your bones are rapidly remodeling responding aggressively to exercise and growth hormone with peak bone density (90%) occurring at around 20 years of age. A further 10% increase in bone density can occur in the next 15 years to age 35. The more active you are as a child the greater the peak of bone density at age 35 and the lower the risk of developing osteoporosis later in life.
Testing for Osteoporosis
The Gold Standard test for detecting osteoporosis or osteopenia is the DEXA (bone densiometry) scan.
As osteoporosis advances the bony bridges within trabecular become thinner and break down and the ‘holes’ become bigger. The bone becomes more fragile and susceptible to deformation or fracture with what was once ‘normal loading’.
Did you know we have two types of bone in our body?
- Cortical bone – long heavier bones, like in your arms and legs – make up 80% of skeletal mass but only 20% of total bone turnover occurs in these bones. They are less likely to develop significant osteoporosis due to the nature of the bone being denser.
- Trabecular or ‘spongy’ looking bone makes up 20% of skeletal mass and yet 80% of bone turnover occurs in this bone, which is more susceptible to fracture. This spongy looking bone is lighter and reduces skeletal weight and is highly responsive to metabolic rates and stress. It is found in the vertebral bodies of the spine and neck and in the ends of long bones such as the end of radius at the wrist. These areas are much more susceptible to fragility fractures wills.
T – Scores
- T-scores compare your bone mineral density (BMD) with that of young healthy adults of the same sex.
- Osteoporosis is diagnosed when the T-score is -4 (or less) to -2.5 standard deviations (SD’s) below that of a young healthy adult of the same sex. This indicates porous bone that can lead to fractures.
- A T-score of -1 or higher is considered normal compared to an average 30 year old of the same sex.
- A T-score of -2.5 to -1 is considered ‘borderline’ and a warning sign where life style management is important to reduce further loss even of no increase occurs.
- A T-score indicating Osteopenia would be -2.5 to -1. This is considered a ‘high risk’ zone and again a very important signal to become proactive in management.
Z – Scores
Z-score compares the patient’s BMD with that of adults of the same age and sex. It is the number of standard deviations (SD’s) of the BMD measurement above or below that of adults of the same age and sex. Z-score is a useful indicator of possible secondary osteoporosis. Whereas Primary osteoporosis is considered directly related to aging and accelerated at menopause, Secondary osteoporosis has a direct cause. This type of osteoporosis is ‘secondary to’ or caused by, something else. For example, osteoporosis caused by the use of prednisone is a very common form of secondary osteoporosis.
A Z-score of -2.0 or below should trigger investigations for underlying disease to exclude other causes of bone mineral loss. Medications such as anti-depressants and anti-coagulants such as warfarin can also predispose to secondary osteoporosis.
Do medications help?
Do Medications Help Certain medications such as bisphosphonates (Fosomax, Boniva, Actone) inhibit the activity of the osteoclasts, which clean out old bone. They are believed to help reduce fragility fractures in up to 30 to 50% of those who have already experienced one fragility fracture. The results vary according to each study and have more recently been challenged.
There are side effects of these drugs – informed decision is always required when deciding the best option for you. A ‘load management’ approach is a more proactive and less invasive approach.
It may be worthwhile considering a change in lifestyle and taking up osteogenic exercise for a year. You should of course discuss this with your doctor. The more informed you are the better you can make the right decision for you.
Exercise for bone health
We know from research that two types of exercise are ‘Osteogenic’ – meaning important for building and maintaining bone density:
- Weight bearing or exercises on land against the resistance of gravity (anti-gravity) that help build stronger bones; tennis, power walking, jogging or running, stair climbing, dancing and team sports such as netball (high impact weight bearing exercise).
- Muscle strengthening or resistance exercise such as weight or resistance band training, functional exercises that lift your own body weight are also osteogenic and provide the stimulus of both ‘compression’ on the bone from gravity and ‘traction’ on the bone from the attached muscles to promote stronger and healthier bones; heel lifts, lunge squats, weight bearing yoga, resistance based Pilates.
These exercises also improve overall quality of life as we get older by making the normal activities of daily living – such as getting in and out of bed or a chair or car, climbing stairs, vacuuming and cleaning – easier and with a reduced risk of injury.
Poor bone and muscle condition as well as poor balance are associated with increased risk of falls. If you are unable to stand on one leg for greater than 10 seconds you have a very high risk of falling. Test yourself!
Some kinds of exercise DO NOT help bone health
It may surprise you to learn that low impact weight bearing exercise such as walking, while better than no exercise, has minimal effect in maintaining bone density. When high impact exercises are contraindicated for any reason (for example sub optimal pelvic floor strength, illness etc) low impact exercises combined with some resistance work is recommended.
Swimming and cycling, while good for cardio-vascular health, are not osteogenic and swimming, due to it being ‘weightless’ may have a detrimental affect on bone density – astronauts return from time in space with significant bone loss due to a prolonged period of weightlessness.
How much exercise do you actually need?
The current Australian Guidelines (see link below) regarding exercise to promote bone health is that it must be regular, progressive and varied. The following tips are also recommended;
- Regular smaller bursts of exercise each day are better than one long session a day.
- Lifting heavier weights are better – if you can lift a weight for 10 repetitions comfortably then the weight is too light to be osteogenic.
- Lifting weights quickly may be more beneficial than slowly (there is some controversy about this).
- Rapid short bursts of movement such as jumping or skipping are more beneficial than slow ones. You may need to address any pelvic floor issues before taking up these higher impact activities.
- Variety is important – change of direction, altering sequencing, avoiding routine is important and maximizes the physiological effects of exercise.
- For those with suboptimal pelvic floor strength or those who have had a fragility fracture – you will need to be guided by your doctor or physio as high impact exercise may be contraindicated and you will need a graduated resistance training program.
The Age Factor
When we are young we tend to be more physically active and this level of activity declines as we age. Knee and hip pain in older individuals will often inhibit exercise and it becomes a real struggle to maintain bone density and independence.
Did you know that more than 80% of joint stability comes from the surrounding muscles?
Yet the usual response to pain is to avoid using these muscles with the outcome being further instability, uncontrolled shearing forces and further damage to the joint.
Exercise is of vital importance as we age to reduce loss of muscle function and bone and reduce overall loss of function and risk of injury from falls etc. In 2012 the estimated incidence of osteoporosis (most likely underestimated and didn’t include osteopenia) was 25% of women over 50 and 6% of men over 50.
The Osteoporotic Spine
With low bone mass we need to think about precautions when exercising. Forced movements into flexion (bending forward), side bending and rotation can place excessive anterior loads on the fragile vertebrae resulting in ‘squashing the bone’ or a ‘wedge fracture’. Wedge fractures tend to occur at the front of the spine. Compression fractures can occur when lifting heavy weights, even carrying a lot of body fat. The downward pressure causes the fragile vertebrae to flatten.
The Vertebral bodies most at risk are T6, 7 and 8 – right between the shoulder blades. These vertebra are most at risk with flexion such as toe touches, crunches etc. Such exercises can be very dangerous if not done in a very careful way. That’s where Clinical Pilates can help. In clinical Pilates exercises are modified and varied according to pathology. Touching toes forcefully is not a good idea without good muscular control and lengthening the spine in the process. Clinical Pilates emphasizes controlled extension activities.
Osteoporosis is often called the silent disease because fragility fractures can happen over time in the spine and may not be detected – or detected incidentally when a more serious fracture such as a hip fracture occurs.
Once one vertebrae changes shape into a wedge – the following cascade effect occurs.
- Progression of a kyphotic (rounded) spine.
- Reduced height, stiffer rib cage and reduced volume of breath.
- Reduced appetite and discomfort in the abdomen.
- Poor elimination – constipation.
- Poor neck posture resulting in neck tension and headaches.
- Shoulder problems due the change in position of the bones that form the shoulder joint and abnormal loading of the supportive muscles all resulting in shoulder pain and impingement.
Good balance reduces the risk of falls
Apart from appropriate strength training for healthy bones it is also important to improve your balance to minimize your risk of falling and sustaining a fracture.
If you are unable to stand on one leg for 10 seconds or more – lightly touch a wall or bench and gradually withdraw this assistance as able.
Once you can balance unsupported for 30 seconds or more close your eyes and repeat the exercise until you can balance for over 10 seconds.
Gradually progress to more challenging balancing exercises with guidance from your physiotherapist. Balance exercises can be done incidentally throughout the day for example, when cleaning your teeth, waiting for the kettle to boil, or while talking on the telephone.
Maintain the Correct Posture
Good erect posture can minimise the effect of gravity on your spine.
We all tend to slouch at times particularly with a more sedentary lifestyle. This leads to postural changes such as; rounded shoulders, poke chin, sway back and rounding of the spine. These changes cause our centre of gravity to move forward resulting in more compressive loads on the spine, shoulders and head due to gravity. This increased compressive load can be enough to cause wedge fractures of the thoracic spine. There are many exercises that, over time, can realign your spine and restore healthy posture.
Exercises that work your spine in extension should be a part of your healthy bones routine.
