Biomechanics scientist Ivana Demmel works with clients stuck in recurring injuries and argues that we need to get the foundations right first
Aislinn Kelly chats to Ivana Demmel, a former corporate lawyer turned biomechanics scientist, who explains how chronic injury, postpartum recovery and years of cross-disciplinary study reshaped her understanding of movement. From pressure systems and motor control to pain science and ageing athletes, Ivana argues that most training models assume a level of readiness the body may not yet have.
Aislinn Kelly: You’ve had an uncommon fitness journey – starting out as a corporate lawyer in Belgrade and Amsterdam, and now you’re a biomechanics scientist working with people stuck in recurring injuries. How did you end up there?
Ivana Demmel: Yes, it’s funny. It was injuries that brought me to a career in fitness – a feeling that my body couldn’t keep up my pace. I was not quite a sporty type. Growing up on the autistic spectrum, I was very clumsy and unco-ordinated as a child. It took a while to teach me to catch a ball. In primary school, nobody wanted to have me on their basketball team.
It was just in my twenties that I started discovering physical activity through Pilates, yoga and rollerblading. But it was often challenging to copy movements and it took me a while to master new motor skills. In my late twenties, I developed chronic back pain sitting for long hours in front of my computer, drafting contracts.
I was 29 when my neurologist showed me an MRI scan explaining that the nerves between my lumbar spine and sacrum were permanently damaged and I would have to get used to living in pain. I remember the tingling down my left leg that would fill me with horror, every time I carried anything slightly heavier. The front of my left foot felt numb and I couldn’t feel the big toe at all.
Being autistic, my way of dealing with problems is to throw a lot of learning at them. So, over the years, I studied and studied across various modalities of movement and therapeutic exercise. I learnt how to work with my back pain and, eventually, my symptoms diminished and disappeared completely. And then, I got so passionate about exercise that I couldn’t imagine my life without it.
So, I decided to quit my career in law and retrain as a yoga instructor. I was particularly interested in bodies that didn’t respond to one-size-fits-all approaches to fitness, so I went on to do over 1,000 hours of training, mostly focusing on yoga as therapy.
But then, in my thirties, after two pregnancies close together, my back pain returned. I had a six-finger-wide abdominal separation and my lower back would go into spasm every time I opened a heavy door or lifted my toddler out of the bath. So, I continued learning, across the fields of physiotherapy, women’s health and exercise science.
“Pain read as information keeps them moving while we adjust the variables that actually need adjusting.”
Working with my ‘difficult’ body required digging deeper into understanding intra-abdominal pressure, looking at the torso mechanics and understanding the whole-body biomechanics, especially patterns of loading and injury. And this eventually brought me to an MSc degree course in Sports Biomechanics, understanding mechanisms of injuries in athletes and how to prevent injuries before they happen.
AK: You talk about “back pain as information”. Can you explain that a bit more?
ID: We tend to read pain as a damage report – something is broken, stop moving. But modern pain science treats it more like a signal of mismatch: between the load you’ve asked of a tissue, the context you’re in and what your body is currently ready for. So when pain shows up, I try not to ask, “what’s torn?” I ask what it is telling me.
Has the load outpaced the tissue’s adaptation? Is this someone running on four hours’ sleep and a stressful week? Is there an old fear riding along with a particular movement, long after the tissue has healed? Pain read as damage shrinks a person’s world – they stop, they brace, they avoid and the avoidance becomes its own problem. Pain read as information keeps them moving while we adjust the variables that actually need adjusting.
AK: Working with each client, you start by looking at torso mechanics, breathing and deep core muscles’ timing and co-ordination. Why?
ID: In each movement we do, our bodies need to a) keep themselves together and not fall apart as they are pulled and pushed by gravity and other external and internal forces and b) accomplish the task successfully. So, thinking long term, if we want to keep performing well in the decades ahead, we need to maintain both of these aspects of performance.
And, very often, injuries in a seemingly unrelated part of the body could be related to a lack of strength or co-ordination of deep torso muscles. For example, we know from the research on ACL injuries in football players that the medial collapse at the knee could be about poor neuromuscular control of the hip, pelvis and torso (check out the work of Powers and Zazulak – see the list at the end of the article).
“Let’s find out what we can build” recruits agency, and an agentic body is willing to explore.
This is why modern ACL-prevention programmes – like the widely-used FIFA 11+ – don’t just train the knee; they train the whole chain, with trunk and pelvic stability as a key ingredient. Similarly, in people with chronic back pain, we can find a lot of answers if we look deeper in the torso – at the level of the diaphragm and its co-ordination with the pelvic floor (check out Hodges and O’Sullivan – see list).
I like to start with building strength from the inside out – making sure the body can stay integrated and protect the spine and the internal organs before we load it. Once you have robust foundations, you can keep progressing the training – increasing the challenge with minimum setbacks, even in people with a history of recurring injuries.
AK: You phrase your assessments as “looking for places to build capacity” rather than “finding what’s wrong”. Why does the language matter – and how does it change the work?
ID: Because the words I choose in an assessment set the tone of a person’s nervous system before a single rep is done. “Let’s find out what’s wrong with you” gently recruits a threat-and-defence state – and a guarded body learns guarded patterns. “Let’s find out what we can build” recruits agency, and an agentic body is willing to explore.
“Is the recurring injury a ‘weak link’ or is it the one honest spot where a whole system’s deficit keeps surfacing?”
This isn’t soft framing for its own sake; there’s solid motor-learning and pain-science backing it. How someone feels about their body in the moment you load it genuinely shapes what that body can do. I’m not pretending limitations away – I assess them as carefully as anyone. I’m just choosing the frame that lets a person move towards something rather than flinch away from a fault. The same finding, two different doorways. One opens onto effort; the other onto fear.
AK: If a fitness professional keeps running into clients they can’t quite figure out – same injury coming back, training plateaus, capacity that won’t build – what’s the first thing you’d suggest they look at differently?
ID: Stop trusting the foundation and go and check it. The instinct, when something won’t progress, is to add – more load, more volume, a cleverer exercise. But a capacity that refuses to build is almost always being built on a base that can’t transmit it. So, before I touch the programme, I look underneath it: can this person actually pressurise and brace on cue, or is the load leaking out of a mistimed canister?
Is the recurring injury a ‘weak link’ or is it the one honest spot where a whole system’s deficit keeps surfacing? A symptom that keeps returning isn’t being stubborn – it’s reporting something upstream that nobody has addressed yet. Nine times out of 10, the ceiling you’ve hit is a foundation you assumed was already there.
AK: Your MSc dissertation looked at running biomechanics in elite endurance runners over seven years of ageing. What surprised you about how active bodies actually age?
ID: My mentor and I followed a group of highly trained master endurance runners over seven years – they were in their early 50s when we started and around 60 by the second round of testing – and we re-ran them through the same protocol with force plates and motion capture. We went in half-expecting to document decline. The textbook signature of ageing gait is a loss of ankle power and the body shifting the work upward to the hip joint – the so-called distal-to-proximal shift. Also, in ageing gait, we usually see optimising for safety rather than performance.
What surprised me was how little of that we found. After seven years of ageing, their leg stiffness – essentially how well the leg behaves like a spring on landing – was unchanged. If anything, they appeared to run more like highly trained than aged individuals. This meant: longer strides, shorter ground-contact times and higher forces.
The demand did creep up the chain a little, but only from the ankle to the knee, not all the way to the hip the way it does in less-trained ageing. And the genuinely novel part was that their knees got better at producing stiffness, not worse. These bodies were still optimising for performance – biomechanically, they kept moving like ‘young’ bodies.
AK: The rePower Method – Restore, Rebuild, Reinforce – is your synthesis of everything you’ve learned. What gap in mainstream training did it grow from?
ID: Mainstream training quietly assumes a baseline of readiness that most of my clients simply don’t arrive with. The standard model loads people first and trusts the foundations to sort themselves out along the way. For a body that doesn’t behave to spec – a back that has been in pain, a deep core that lost its timing after pregnancy – that assumption is exactly where the plateaus, the flare-ups and the quiet drop-outs come from. People get loaded before they’re ready, then blame themselves for not progressing.
rePower just names the phase everyone skips. Restore settles pain, rebuilds the pressure system and lays the foundations. Rebuild is honest progressive overload – muscle, load tolerance, building up capacity. Reinforce is about performance: sport-specific work, injury-proofing, training for the decades ahead.
The order matters far more than any single exercise inside it. And what I’d actually offer a fellow coach isn’t “use my exercises” – it’s the structure. Don’t assume the foundation. Build it. Then load it. You can lay that sequence over almost any population you work with.
AK: Your studio is designed to feel like a safe, nourishing kitchen rather than the performance pressure of a gym. What does that environment make possible in the work itself?
ID: A kitchen is the room where you’re allowed to experiment, make a mess, taste as you go and not get it right the first time – and that’s exactly the atmosphere I like to create in my coaching sessions. My studio really is a blend of a kitchen, a gym and a yoga studio.
There is just enough warmth and unhurriedness for a nervous system to feel safe. I try to create a non-judgemental, collaborative atmosphere in my sessions, offering a supportive space for people to get to know their bodies and get stronger on their own terms.
AK: Over 14 years, you’ve gathered an unusual mix of qualifications. From the outside, that can look like generalism. From the inside, what’s the through-line?
ID: I felt none of the disciplines offered a full answer to the needs of my ‘challenging’ body that didn’t seem to respond to training, especially after the babies. This was more than a decade ago, when it wasn’t easy to find fitness – even medical – professionals with experience in working with active female bodies freshly postpartum. I was in pain and I saw three different physios who had no idea how to help me. I had so many questions and very few answers. So, I kept digging across disciplines and each of them offered a slightly different lens to look at my problem.
I was really excited when I discovered the work of Diane Lee on diastasis recti and finding the primary driver between the pelvis and thorax; the work of Julie Wiebe on pelvic health in the context of the whole deep core system; the work of Antony Lo on intra-abdominal pressure and load tolerance in female athletes returning to sport postpartum.
But the more I dug, the more I realised these weren’t islands. Each of them sat on older foundations that I then went back and learnt properly. The pelvic-floor-and-pressure thinking only made sense because of the spinal-stability people before it – Panjabi’s idea of the spine’s “neutral zone”, the deep-core motor-control work of Hodges, the pain-science work of Moseley and Butler.
And because my real job was always to get a ‘difficult’ body strong, not just pain free, I had to take the strength tradition just as seriously: progressive overload going all the way back to DeLorme, periodisation, Jill Cook’s work on how tendons adapt to load, and more recently Stacy Sims on the perimenopausal body specifically.
Threaded through all of it is a more stubborn idea I picked up from the movement-variability researchers – Bartlett, Nigg’s “preferred movement path” – and from my own years in yoga and somatics: that there is no single correct way to move.
So, it was all one long attempt to answer the same question: why won’t this body behave the way the textbook says it should? The synthesis of all those lenses is what eventually became rePower.
AK: You say you start with questions, not answers. What questions are you sitting with right now?
ID: My current preoccupation is perimenopause-specific training. Some questions I’m still pondering are: How much of what we call ageing in women is actually deconditioning plus hormonal shifts we haven’t learned to train around? I’m also wondering how to adapt strength training to ageing bodies and how to continue building muscle as our bodies gradually shift from building-mode to recycling/maintenance-mode.
I’m very excited about training for long-term health and extending the healthspan, especially in women, where there is a more prominent difference between how long we live and how long we maintain a good quality of life.
To dig deeper, check out …
On the knee and the torso
- The FIFA 11+ – a 20-minute, equipment-free warm-up that, run consistently, has been shown to cut football injuries by roughly 30–50%. The manual, posters and pocket reference cards are freely available online (search ‘FIFA 11+ manual’). The foundational trial: Soligard, T., Myklebust, G., Steffen, K., Holme, I., Silvers, H., Bizzini, M., Junge, A., Dvorak, J., Bahr, R. and Andersen, T.E. (2008). Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomised controlled trial. BMJ, 337, p.a2469. doi:10.1136/bmj.a2469.
- Zazulak, B.T., Hewett, T.E., Reeves, N.P., Goldberg, B. and Cholewicki, J. (2007). Deficits in neuromuscular control of the trunk predict knee injury risk: a prospective biomechanical-epidemiologic study. The American Journal of Sports Medicine, 35(7), pp.1123–1130. doi:10.1177/0363546507301585. The study where poor torso control, measured first, predicted who would injure their knee later.
- Powers, C.M. (2010). The influence of abnormal hip mechanics on knee injury: a biomechanical perspective. Journal of Orthopaedic & Sports Physical Therapy, 40(2), pp.42–51. doi:10.2519/jospt.2010.3337. A readable commentary on why the knee pays for what the hip, pelvis and trunk fail to control.
On back pain and the deep core
- Hodges, P.W. and Richardson, C.A. (1996). Inefficient muscular stabilization of the lumbar spine associated with low back pain: a motor control evaluation of transversus abdominis. Spine, 21(22), pp.2640–2650. doi:10.1097/00007632-199611150-00014. The classic, showing the deep core fires late in people with back pain.
- O’Sullivan, P. (2005). Diagnosis and classification of chronic low back pain disorders: maladaptive movement and motor control impairments as underlying mechanism. Manual Therapy, 10(4), pp.242–255. doi:10.1016/j.math.2005.07.005. Why ‘back pain’ is really several different problems wanting different answers.
And a couple of books
Moseley, G.L. and Butler, D.S. (2015). Explain Pain. 2nd edn. Adelaide: NOI Group. The friendliest serious introduction to pain as protection rather than damage; the book behind much of what I said about ‘pain as information’.
Sims, S.T. and Yeager, S. (2022). Next Level: Your Guide to Kicking Ass, Feeling Great, and Crushing Goals Through Menopause and Beyond. Emmaus, PA: Rodale Press. Training the perimenopausal and menopausal body, written for active women and the coaches who work with them.
Ivana Demmel
Ivana Demmel is a biomechanics scientist, MSc, educator and a coach with 14 years of experience working with active people with recurring injuries. She is passionate about women’s health and performance – both biological and athletic – and has published research on slowing down ageing with high levels of training. She created rePower Method, a three-phase system bridging physiotherapy and performance-based training. She values evidence-based solutions and precise, focused training where everything has its ‘why’.
Interested in finding out more about biomechanics? Read Justin Price’s article on functional anatomy on the FitPro blog.
