Beyond Optical Measurement
Dr. Kim Duffy, Vicon Life Sciences Product Manager
Over the past 35 years the use of motion capture has expanded from lower limb analysis to encompass full body analysis and broader biomechanical research. This work covers a huge range of conditions and applications – from working with amputees to cerebral palsy, motor control, neuroscience, and in sport science. This work is fundamentally driving a better understanding of human motion.
For much of the last 35 years motion tracking has relied on optical systems. However, while those systems remain the gold standard in both clinical and sport science settings, we are seeing new devices, such as highly advanced inertial capture sensors coming to market that are changing what is possible when it comes to biomechanical data capture.
At the same time, increased automation of the data processing pipeline – from labelling, to event detection, biomechanical modelling, data export, and post-capture analysis – is helping more research to be conducted more efficiently, benefiting researchers, patients and athletes alike.
There is still so much more value that motion capture can bring to the life sciences though. The question is – what are the key developments we are likely to see in the next few years?
BALANCING THE TRADE-OFF BETWEEN ACCURACY AND ACCESSIBILITY IN LIFE SCIENCES
What distinguishes the life science sector in its use of motion capture is its demand for accuracy. Where the technology is used to inform surgical decisions or to support injury prevention strategies accuracy is clearly non-negotiable.
While this has obviously been necessary, there is still huge potential in making the data collection system simple enough that anyone can ‘self-administer’ a motion sensor. Making the technology easier to use in this way opens up a range of new use cases.
The most obvious example is enabling more continual observations of patients, therefore making it easier to track conditions like Parkinson’s over time. On the sport side, if an athlete can set a sensor up themselves then you open the door to ‘in the moment’ biomechanical feedback, something that has huge potential in injury prevention and performance evaluation.
Ultimately, the easier it is to use the technology, the more monitoring and evaluation you can do – which can only be a good thing. Making the technology more accessible, without compromising on accuracy, is inherently beneficial for patients and athletes.
But what does ‘more accessible’ motion capture really look like?
REALIZING THE POWER OF INERTIAL SENSORS
When it comes to unlocking these new use cases one of the key points to understand is that there are a huge raft of conditions or situations where the full level of accuracy enabled by optical systems is not strictly required. Instead, huge numbers of assessments could be done using wearable inertial sensors.
Body-worn inertial sensors are inherently easier to use – you simply strap it on and it works. This simple fact is a huge tipping point for motion tracking technology.
It means that wearable sensors can be used to support real-time assessments outside of the lab. This is particularly important when it comes to something like injury prevention in sport – no athlete wants to wait weeks to see results when they might be risking injury right now.
Wearables also give us the potential to access more ‘contextual’ data. While lab-based systems still provide the gold standard in precision, capturing motion data in the lab remains inherently ‘unnatural’. As a controlled environment, it is impossible for lab-based motion capture to factor in the more chaotic nature of movements in the real world, which limits the sorts of analysis you can do. The use of wearable inertial tracking promises to fill in those gaps.
The other advantage of inertial sensors is that they be used more broadly because they are cheaper than optical systems. This opens up some interesting possibilities. For example, inertial sensors could be prescribed to patients to capture motion data over an extended period prior to a lab-based consultation, giving clinicians far more real-world motion data to compare with lab assessments and aid the decision-making process.
LOOKING TO THE FUTURE
Alongside wearables, the other key development will be the deployment of artificial intelligence and machine learning (AI/ML) techniques to support the development of markerless tracking systems.
AI and ML will support an even bigger step forward in the accessibility of motion capture – completely removing the need for markers or set up. It offers us the potential to capture detailed motion data direct on a smartphone and instantly analyzed in the moment. Clearly this will significantly accelerate workflows and pipelines.
While in 2020 we are still dipping our toe into the potential for more varied tracking technology to support life and sport science research, over the next few years clinicians and researchers will have a much bigger toolbox to choose from.
Vicon is at the forefront of driving these developments. We are constantly expanding our ecosystem and striving to make our market leading systems even better. Our goal is simply to deliver the highest quality motion capture data, no matter the method.
With the continuing development of the technology and closer collaboration with researchers and coaches, we will continue to extend our understanding of human movement – improving athlete’s and patients’ lives physically, mentally and emotionally.