If you have had your bone density scan, you may be confused by what all the information means. You will often be provided with many graphs, diagrams and numbers; however it is not as confusing as you may think! Firstly, lets recap on what our bone density means.
What changes happens to bone density in Osteoporotic bone ?
Your Bone Density is the thickness of the inner spongy part of your bones, you can see how this density changes in bone below with osteopenia and osteoporosis:
Normal bone density is thick, strong and easily resists breaking when put under pressure, for example if you trip your bones will withstand the force of falling. Osteopenic and osteoporotic bone is less able to withstand these forces and are more liable to break with falls.
The DEXA scan and assessing bone density and osteoporosis.
The DEXA scan, or “Dual X-ray Absorptometry”, is a quick and pain free scan that can tell you a lot about your body. It provides you with an in-depth analysis of your fat tissue, muscle mass and bone density.
When looking at osteoporotic change it measures the bone density at the lower back, known as the lumbar spine, and the neck of the femur which is near to the top of the leg bone that creates your hip joint.
Why are the femur and lumbar spine chosen to measure bone density?
The neck of the femur takes a lot of your body weight when you walk, run or carry heavy loads such as a back pack. Your back does a similar job in all movements, particularly when standing/walking.
If your bones have not been under enough pressure over time, then the density will decrease in these areas first.
T-Score, osteoporosis and bone density
T-Score is a value that is given to the quality of bone after being calculated by DEXA scan. As the bones have a honeycomb type structure to them when bone loss occurs, the holes in the bones get bigger. Bigger holes lead to weak and brittle bones. T-score tests are used to help determine how big the holes in the bone are.
T-scores above – 1 are indicators of normal bone density
T-scores between -1 and -2.5 indicate that a person has low bone mass, but it’s not quite low enough for them to be diagnosed with osteoporosis. This is often referred to as osteopenia.
T-scores of -2.5 and lower are designated as being osteoporotic bone.
The good news is that you can change your bone density and T-Score, possibly without medication.
Because bone responds to exercise and can get stronger its not all doom and gloom. The bone density scores can be improved upon greatly with a strength based exercise program.
So how does it actually affect bone density?
When we step or run, the force which goes down into the ground also springs back up into our leg and up to our back. This force applies pressures to the bones and stimulates a release of many hormones which stimulate the bone lay down phase. Normal bones should be laying down, and breaking up bone at an even pace. This generally keeps them healthy and fresh. Of those of us with osteopenia or osteoporosis, it’s this break down phase that tends to be faster, resulting in less bone cells in an area. So to stimulate the laying down, we can perform impact or loaded exercises.
Resistance training works on a similar premise, that the pressure of the weight loads the bone and stimulates the lay down phase of the bones. The muscles pull at their attachments of the bone, stimulating more lay down and therefore thickening the bone.
This is why you will often be prescribed impact or resistance exercises to help with your bone density. Now its important to realise that if your osteoporosis is quite severe, then impact exercises can be dangerous. If your bones are already brittle, doing impact exercises like stomping, jumping or skipping, it can be enough pressure to actually create a fracture. This is why discussing your bone density with your doctor or physiotherapist prior to beginning a new exercise program is important.
Exercises will always depend on your previous history with exercise. If you’ve never done resistance training before, you will most likely start with walking and body weight exercises, and be transitioned onto weights as your body progresses. Some people with a history of resistance training may start with heavier exercises like deadlifts, squats or bench press.
If you’re unsure of exercises to assist with your bone density, visit one of our physiotherapists to come up with an at home or gym program. You can book in here.