After a long-running fascination with athletics and injury mechanisms, Prof. Thomas Kernozek has implemented many motion capture systems to fuel his work in physical therapy and the study of movement-related conditions. Using two systems at the University of Wisconsin, LaCrosse, where he is a Professor in the Health Professions—Physical Therapy faculty, Thomas’s teaching gives students valuable experience with advanced motion capture technology, while also gaining evidence-based data for his own clinical research.
We caught up with Thomas to discover more about his specializations; his experience using real-time feedback and which future mocap features can help nurture the next generation of talent for biomechanics in sports medicine.
Like many people that grew up being active and enjoying many forms of sport and exercise—or becoming injured!—I was driven to understand why some injuries may occur and how it gets examined in a clinical setting. That led to a career in biomechanics, where my research specializes in some common lower extremity injury types: anterior cruciate ligament (ACL) injury, patellofemoral joint and Achilles tendon injuries.
Physical therapy was once a Bachelor’s degree here in the US but the professional knowledge base has changed drastically since. It became a Master’s degree when I was hired at LaCrosse in 1996, and I now teach and work alongside entry-level clinical students in the doctoral program in physical therapy. Our university laboratory spaces allow our students to engage fully with robust technology, which really helps them develop their own perspectives on how they understand and treat movement-related injuries. I always aim to craft students into striving to become scholarly clinicians by using our mocap systems in my teaching and scholarship.
I discovered Motion Analysis while visiting other universities and medical institutions during a sabbatical. When I was “growing up as a biomechanist”, video technology was just in the beginning stages and the use of high speed film was phasing out. I’d used an earlier video based motion capture system before joining LaCrosse that did not have the same capabilities as the Motion Analysis system, so I jumped at the chance to implement this equipment once we had opened the Strzelczyk Clinical Biomechanics Laboratory in our new Health Science Center.
Its compatibility is a huge plus, as the software and hardware can be upgraded and integrated with existing systems easily. Older Motion Analysis camera models we purchased are still operational and compatible with our software but the overall evolution of these systems has been great to see. We now use mostly Kestrel cameras and Cortex for both systems we have set up in two laboratories—one surrounding an instrumented treadmill—for examining physical activities with human subjects and using data gathered to inform computer models to estimate joint and soft tissue loading.
We work with collegiate athletes in jumping sports here at the university, including volleyball and basketball. We’ve also targeted female athletes because we see ACL injuries and related maladies being more prevalent in those performers. We also study a lot of runners. Ultimately, we want to prevent these athletes from getting hurt.
Our students get practical first-hand access to advanced mocap in classes, so it is used in teaching and research, which is somewhat unique to our physical therapy curriculum. The mocap cameras help identify, measure and track movement, which supplies evidence to inform answers to clinical research questions related to physiotherapy.
One thing we’ve done with Motion Analysis systems is use musculoskeletal models to measure Achilles tendon stress or patellofemoral stress related to running performance. These data are particularly useful for clinical research, as we attempt to drill down to the anatomical structures and tissues to examine how varied athletic movements (such as stride patterns) affect loading. Excessive loading may be associated with the performer’s pain symptoms. We have also used biomechanics within a motor control paradigm to provide augmented feedback to participants to alter their movement performance.
A notable project involved test subjects with patellofemoral pain (pain around the knee cap) performing squats. After a physical therapist made sure that these test participants met certain criteria following a clinical assessment for patellofemoral pain, we streamed their motion capture data into a musculoskeletal model while they were performing squats. The load data between the patella and the femur during the exercise was displayed as augmented feedback. Participants were able respond to this augmented feedback to alter their squat performance to reduce loading.
Our capabilities are still evolving, and mocap technology not only shapes our understanding of therapeutic exercise and injury, but contributes to medical literature in the physical therapy profession. Computer modeling approaches informed by Motion Analysis data helps to get a clearer picture of injury mechanisms during movement, and we’re excited to see modeling and motor control capabilities grow quite rapidly.
Wearables and other portable systems are another exciting market to inform clinical practice and provide testing opportunities outside the lab. From a teaching point of view, we’re proud to inform our clinical students on the power of these new technologies and how they may open opportunities for them. We’ve had our students go on to study PhDs or work in residency or clinical practice where they are adept at using motion capture.
If Thomas’ use of innovative mocap technology has inspired your own biomechanics testing, talk to our team to find out how Motion Analysis can help you achieve your own goals.