Stay On Target: A Technology in Sports series Leaders in Sport feature, brought to you by Target3D, the Home of Motion Capture
In their second feature on technology in sports, Target3D’s Biomechanics Specialist Stephanie White discusses how technology is changing the way we approach injury prevention and recovery, and goes on to explain how VR is changing the rules of sport.
“Winning and losing can be determined by a fraction. Think of a football that’s literally millimetres off the goal. Equally, the minutest change of angle or foot position can quickly cause injury.
My career stemmed from an intense fascination into how people use their bodies. I’m interested in how people perform. There are many ways to perform, to move and there’s always someone who’s doing it better!
With technology now playing a much bigger role in the world of sport than I ever anticipated, everyone involved - from the coaches to the players to the spectators - is becoming used to tracking each aspect of the game and is still getting used to technology making decisions.
As I moved through my MA studies in Clinical Exercise Science, researching upper limb motor control at the time, the tech side became more interesting to me too - mocap and EMG specifically. How something as human, as ancient, as the movement of the body can be changed, adapted and affected by technology that has only been around for a few decades.
But, as sports become more competitive, so do the technologies working to create stronger, more resilient athletes. In sport performance terms, motion capture aims at tracking and recording athletes’ human motion in real time to analyse physical condition, athletic performance, technical expertise and injury mechanism, prevention and rehabilitation.
Undergoing vicious training programs and endless travel, athletes constantly face the menacing prospect of a serious injury. Research shows young athletes who sustain an injury are more likely to be re-injured, or experience a new injury in the future. Evidence suggests that some injuries can have long term impacts that limit athletic activity and daily function, resulting in chronic pain and disability, even in young adults.
“A lack of symmetry in motion, muscle strength, flexibility, and mechanics between both sides of the body, is an underlying risk factor for sport injury.”
As well as identifying weaknesses and asymmetries in the athlete’s movements to reduce risk of injuries, incorrect or poorly setup technology can have a detrimental effect on a player’s performance.
There are two ways of tracking symmetry - using markers and without.
Let’s look first at the world of elite cycling, who look to advanced technology to provide precise fitting calculations. A proper bike fit is one of the single most important factors for optimal performance, efficiency, injury prevention and comfort on the bike. It provides the rider with the most economic means of expending energy, while helping prevent pain that is common in the knees, hips, and lower back. STT System’s Cycling 3DMA software provides the ergonomics that fits to the individual’s body, through the use of markers. Template reports are generated to check for range of motion, joint alignment, posture and symmetry in elation to the bike to ensure the bike and rider work together in a harmonious way. This type of data cannot accurately be captured with 2D video, static fitting, or fitting by ‘eye’, so eliminates the guesswork and assumptions of bike fitting. The result is that the rider will have a true fit to their bike, maximizing efficiency and performance while reducing the risk of injury.
A marker-less motion capture system was piloted in a study at the Winter Park Competition Centre using Captury Live, to observe asymmetry during shoulder movements, spite rotation, bilateral squats, single leg squats and a series of jumps and balancing movements in adult athletes. Full-body musculoskeletal images were produced to analyse strength, flexibility and dysfunction. “If we can see an athlete compensating, then being able to address that asymmetry ahead of time could help prevent injury and we’re going to see performance enhancement,” according to researcher Stephanie Zavilla. This means they would be able to identify the athlete’s weaknesses and asymmetries, to reduce the risk of injury, while maximizing efficiency and performance.
“For assessing athletes during recovery time after an injury, 3D motion analysis is a useful high precision method.”
So how has Motion 3D software been used in rehab applications to look at athletes’ range of movement and symmetry? Professional Red Bull F1 driver Mark Webber used this to assess his gait after he broke his leg in a serious cycling accident. His biomechanist prescribed effective interventions based on the data collected from motion analysis. Effective interventions rely on accurate observations. Traditional assessments involve 2D visuals and eye-balling how the athlete moves, but with a 3D perspective you can look at the body from any angle helping to identify factors contributing to sports injury.
Interestingly, science through kinematic methods has presented strong evidence that athletes continual high loading during landing are likely to suffer from knee joint pain and ruptures due to poor control of the knees bilaterally. A 2019 study concluded that athletes returning to sport after anterior cruciate ligament reconstruction (ACLR) are still at risk of re-injury following return to play. 3D analysis showed that ACLR demonstrates significant 5 degree valgus angles during cutting turns which forces again stress on the ACLR. This suggests that physical therapy should address mechanics and motor control of the lower extremities, especially during specific sport performances such as changing directions. I fully expect, with the advancement of technology, new and more effective treatments will be developed to ensure that the player is ready to return to the game and stay in longer.
One of the things I love about competitive sport is the surge of adrenaline that helps push the human body past its limits. But sometimes athletes and coaches are so focused on the performance that it’s easy - tempting perhaps - to overlook the danger factor. ”Besides contributing to high performance, tech has been used to monitor and anticipate high-risk scenarios to prevent certain serious injuries and even death.” Head injuries and heart failure are understandably taken seriously and technology is being used to try to make the players safer…
In rugby, where players can experience an average impact of 22Gs, sensors are showing up in the shoulder pads of players, with Sansible’s LiveSkin system used in rugby for feedback on player performance. Briefly, the pads directly measure the force load and coaches can monitor the forces experienced during tackles, track statistics across high-energy-cost events and recognise abnormal patterns. This also gives insight as to whether the player has fully recovered from injury. In the future, it will become more common for collision sports to wear such pads to make the players safer.
I noticed that sensors have also made it into the racing gloves of Formula 1 drivers, who have to endure heat and lateral G forces for long periods while balancing broad and narrow focus. With this sensor, medical crews are able to monitor the driver’s oxygen levels, heart rate, and motion from a single device remotely throughout the entire race. The biometric feedback is so valuable to the medical crew, especially when an accident occurs and they have lost communication to the driver.
“While it’s agreed that technology serves for good when it comes to the players health and safety, there is a growing debate about the role of technology in influencing the game itself.”
Although now widely accepted in rugby, tennis and cricket, Video Assistant Referees (VAR) have become a hot topic in professional football. Although sensor systems, such as HawkEye, have been put into the goal posts and inside the ball, some goals are still in the grey area. The VAR system is designed to assist human referees in making decisions on penalties, red cards, and player identification to ensure transparency throughout the game in some circumstances.
Remember the controversial handball decision on Man City’s Gabriel Jesus that contributed to the handball law being changed earlier this year? Before that, it was ultimately the referee’s discretion to decide if the handball was a deliberate act. VAR has provided clear examples of what should and should not be penalised for handball with the final word going, not to a human but to the technology.
Of course, the technology is there to ensure the game is transparent and to reduce errors, yet it also challenges the referees and players who are exposed praise and criticisms on their performance. The fans’ reactions are instant after something big happens, which can be unnerving when the VAR system takes 2-3 mins to replay and make the final decision. At the moment teams, referees and fans are unsure if this best for the game, but the technology is here to stay and it will be up to the professionals to use their knowledge and skills on how they can use it for their advantage.
I’m absolutely sure mocap will continue to be a valuable resource to improve performance and efficiency as it educates us more about the science of the human body and allows professionals to think strategically and play smart. The challenge for authorities is to maintain the balance between elite performance and the unpredictability that makes sport so compelling, whilst never compromising on safety. In the end, the goal is to use technology to highlight the best parts of the game, not to take the human aspect out of what is fundamentally a human performance.
Meet Stephanie and the Target3D team at the Leaders in Sport Performance Summit, where they’ll be hosting a live mocap demo and answering your questions about motion capture, VR and AI for sports performance.