Osteoporosis and Movement: How Strength Coaches and Massage Therapists Can Help
- Good Country Physio
- Sep 25
- 6 min read
Have you ever heard of force plates? Join us for a conversation with Michael McBryde who is a Strength and Conditioning coach and massage therapist specialising in advanced biomechanical assessment and performance coaching. Find out about appropriate loads for improving bone density through exercise.
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For people who haven't heard of Hawkin Dynamics and have not seen force plates before, can you describe what they are and what they measure?
Force plates are just essentially a fancy set of scales. Rather than putting things in kilos and pounds, we work in the gold standard, which is in newtons. The goal of it is to measure ground reaction forces. This can range from the force of a sit to stand to assessing ultimate performance for athletes. It’s measuring forces that are applied vertically. Life is force! We try to put a number behind it and help people understand how and what it is they do when they produce their forces. It is useful in injury prevention and management.
From a strength and conditioning perspective, why is loading the bones so important for building and maintaining bone density?
Bones are living tissue and they're consistently being broken down and rebuilt. We need mechanical stimulus to help them stay strong. Every time you're loading and you're moving with some force and intensity, you end up with these tiny micro strains that trigger cells called osteoblasts and they help lay down new bone tissue. Without that stimulus, bones weaken over time. Resistance training and the impact of exercise is so powerful. It tells the skeleton, we need you to be stronger to handle these forces.
Can you explain how the biomechanical analysis and the data from the force plates help to understand the forces that are going through the bones during exercise?
Biomechanical tools like force plates measure ground reaction forces, as we talked about before. We can break out things like asymmetries or landing rates in real time. Instead of guessing, we can quantify exactly how much force travels through the body during a jump, a landing or a lift. So for bones, this helps us see whether the activity provides enough stimulus for adaptation or whether the force that's applied efficiently will be enough to do things like create reduced injury risk. So essentially, we can connect movement patterns with the mechanical load of the skeleton and what the skeleton is actually experiencing.
We know that the amount of loading required to stimulate that bone building process is 4.2 times your body weight. From your experience with the force plates data, what activities stimulate this amount of force and can you rank activities in terms of how much force they put through the bones?
There's some really great studies that have gone into, comparatives between your jump data and things like sprinting. If I was doing a ranking system:
Highest (4-5x bodyweight): Would be sprinting. So moving with high velocity and purpose is one of the best ways of doing that. Then things like jumps, landings and change of direction. So things that we're obviously so familiar with, with AFL, basketball, netball, those good everyday Aussie sports.
Moderate: (2-3 times your body weight) This is heavy resistance lifts, like squats, Olympic lifts. If you're someone who does heavy labouring work, then it's similar to this
Lowest: (1-1.5 x bodyweight) Would be things like walking, loaded carries, really low level plyos and rehab style movements.
We know as well that you can offload the bones also, by doing things like cycling and swimming. Can you tell us a little bit more about this?
When we're doing off leg training, someone's had an injury and we still want them to be fit, but we don't necessarily want them to be loading their ankles or their knees. We're trying to give them that same cardiovascular stimulus, but we don't want to actually be loading the bones. It's super beneficial to the body, but not necessarily the best thing for getting that load if someone is in need of it.
People in rural areas are quite active through farm work. Does this kind of physical activity provide enough stimulus for bone health, or is targeted exercise still necessary?
I personally came from a trade position in my younger years, and I remember feeling like I was at a constant state of good base level strength. As a manual labourer, you're constantly loading and always moving, so hitting our basic load capacities. When I was younger I worked on my uncle's horse farm, and you're doing all those things which are like your downtime, you're keeping the body at that base level strong. However you're rarely reaching that three to four times body weight threshold consistently. So targeted exercise and structured training are going to ensure the bones get the intensity and variability they need to adapt.
Manual work is a great foundation, but it's not always enough for long-term bone health.
For someone who's a little bit cautious about high-impact exercise due to osteoporosis risk, either their age or maybe they haven't trained previously, how would you safely progress them while still creating enough force through their bones?
Build tolerance and load gradually. Start with low-impact strength training like body weight squats, step-ups, those sorts of movements, loading the body efficiently and a little bit more holistically. Then controlled impact activities like drops, hopping, lightweight jump progressions, and then once strength and confidence improve and monitoring this with force plates and other monitoring tools can help ensure that loading is sufficient without being excessive. Then start building towards that progressive overload where we can go to heavier lifts and more dynamic jumping environments, and eventually sprinting.
For people who don't know, what are drop jumps, what role can they have and how much force do they put through the bones? Can you explain from your perspective what drop jumps can do for bone health?
Drop jumps are how well you can absorb and manage your forces when you hit the ground, and that load is between three to five times body weight.
Drop jumps, if we go to the sports science standard, we're talking about a 30 centimetre drop, hitting the ground as hard as you possibly can with as much control and then trying to get off the ground like the floor is lava and jumping as high as you possibly can.
This is managing your forces efficiently, quickly and being explosive. We look at the force weight data to see, what your ground contact time is, what force you're producing, how well you absorb those forces and any asymmetry.
Drop jumps are great for people who aren't as confident to do plyometric training or jump training eg: for the older population to add loading without it being a cardiovascularly intense exercise like skipping.
As Australians, we're an ageing demographic, so movement quality and health is a big focus. A lot of us find, we come off the tools and we're not as active as we once were or not doing our sports as intensely anymore.
From a force plate standpoint, looking at sit to stands, every time we stand up, sit down on a couch or we go to the bathroom, there is a process. Looking at timeline data we can make good decisions around if someone's still able to manage those forces. We can aim for high force in this too by asking people “to stand up as fast as you can with as much intent” and track them over time. We can do six month intervals monitoring if that peak force production slowly declines and start to make great snapshots. This can also be used to assess falls risk. More testing procedures can be conducted such as standing exercises and working on their balance.
In your experience what are the most common misconceptions people have about exercise and bone strength?
‘Walking is enough’ That would be a big one. I know that everybody has this 10,000 step thing just driven into their brains because it's what we've been told for so long. That is great if you're not able to do anything to make sure you get your 10,000 steps in. However it is easy for bone health to decline when you are not hitting those loads.
‘Lifting weights is dangerous for bone health’ is a misconception I hear all the time. We're looking at cultures all around the world and those that use their knees and hips on a consistent basis at full range and are doing labour intensive exercise have hip health equivalent in their 80s to what some people we know in our 20, 30 year olds.
‘I'll have plenty of time to exercise when I'm older’. What are we really aiming for? Why don't we get ourselves ready for our retirement? We're all under the pressures of today's society to make sure you have enough money to retire, but if your body isn’t functioning as well as it should be, then your brain's probably not far behind in terms of functioning capacity.
We know that challenging yourself physically is huge for brain health, but if your bones don't work and you can't move well then you're never going to be able to challenge yourself physically.
Link to Podcast: Search "Good Country Physio" on Spotify
To learn more about Hawkin Dynamics and what they do or to look at some of the research they have published:
Helpful Resources:
Gabrielle Prider and Chelsea Holmes
4th Year Physiotherapy Students at the University of South Australia
Undertaking their Health Promotion placement at Good Country Physiotherapy, supervised by Angela Willsmore
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