Jan 29, 2015One Step Ahead
An inside look at the Ohio State University Sports Biomechanics Lab reveals how cutting-edge technology is shaping the future of athlete assessment, injury prevention, and training.
By R.J. Anderson
R.J. Anderson is an Assistant Editor at Training & Conditioning. He can be reached at: [email protected]
On his first official day as an Ohio State University Buckeye last June, freshman quarterback Terrelle Pryor looked like an actor on the set of a futuristic science fiction film. Clad only in shorts and covered in small white reflectors, Pryor and 12 of his teammates stepped, squatted, and jumped as high-speed cameras at the school’s Sports Biomechanics Laboratory captured their every move.
The reflectors helped track Pryor’s lower body as he performed simple movements testing his balance, flexibility, and strength in a functional movement screen. As Pryor did overhead squats, lunges with both legs, hurdle steps over a wire, and box drops, information on his biomechanics was transferred to a computer system and used to analyze motor control, joint torque, and strength imbalances–information that could help identify risk for specific injuries. The data was also passed on to strength coaches, who looked at it when designing workouts for him based on his strengths and weaknesses.
The freshman football study is just one project at the Sports Biomechanics Laboratory using cutting-edge technology to improve athlete assessment. Working in concert with the lab’s engineers are medical doctors, physical therapists, and athletic trainers who develop projects to explore the mechanisms behind injury, rehabilitation, and performance.
In less than three years of existence, the OSU lab has become one of the premier biomechanics facilities in the country. It uses data-driven evaluation techniques to reach evidence-based conclusions about many of sports medicine’s commonly held beliefs and practices. It is also working to make advanced assessment methods more accessible down the road, and thus helping to shape the future of sports medicine and athlete development.
MOTION PICTURE MAGIC
If you’ve ever watched a behind-the-scenes breakdown of how video game developers bring superstar athletes to life in games like NBA Live or the popular Madden series, you’ve seen the technology that’s used in the OSU Sports Biomechanics Lab. It’s also what allows real-life actors to perform physically impossible stunts in computer-enhanced films like The Matrix and 300.
But in the Ohio State lab, the goals have nothing to do with special effects. Images captured on camera are converted to simple stick figures or skeletons, mapped out with help from the reflective material attached to the athletes’ bodies.
“Video game developers record a person’s motion so it looks realistic when they apply the animation,” says Ajit Chaudhari, PhD, Director of the Sports Biomechanics Laboratory and Assistant Professor in the Department of Orthopaedics. “But we use it to analyze the subject’s movements and provide objective measurements of their biomechanics.”
Ohio State combines the motion-capture technology with a load-measuring system made up of force plate sensors embedded in a gym floor. The sensors measure the impact created by athletes as they cut while running and performing exercises. “It allows us to calculate force from the floor to the foot up through the leg and estimate the torques placed on an athlete’s joints from the foot to the ankle, knee, and hip,” Chaudhari explains. “That tells us how hard each muscle is working to create motion, what type of loads are being placed on passive structures like the ACL and other ligaments, and how much compression each joint is under during a given movement.”
Located in a 3,500 square-foot gymnasium, the lab’s eight cameras, which film at up to 300 frames per second, are attached to railings nine feet above the floor. They’re configured in a horseshoe shape, with all the lenses focused on the embedded force plates. For cutting drills, athletes approach from the open end of the U, plant on the force plate, and cut in a direction dictated by a signaling board. The cameras and force plates also collect information from a variety of non-running exercises, such as squats, lunges, and box drops. Motion-analysis software then marries the footage collected by the eight cameras, creating 3-D representations of an athlete’s movements.
Chaudhari says analyzing Pryor and his classmates’ biomechanics with the lab’s high-tech tools provides a glimpse of bigger things to come. “At this point we’re laying the groundwork for future projects,” he says. “It takes years to build up a database that can draw solid conclusions on biomechanics. Right now, we’re collecting data to determine which measurements actually matter, because we can measure about 50 different things, from force generated to flexibility to strength. But we don’t know yet which measurements have a relationship with injury risk.”
Janine Oman, MS, PT, ATC, Assistant Athletic Director of Sports Performance at Ohio State, is excited about the opportunities the Biomechanics Lab will create for athletes, coaches, and athletic trainers. “This is something we can add to our toolbox to help identify athletes who need intervention–either for injury prevention or to improve their performance,” she says. “It will give us more objective criteria for making those judgments.”
While Oman acknowledges that the relationship between the Sports Biomechanics Lab and Buckeye athletics is still a work in progress, she says everybody involved recognizes the potential and wants to make progress as a team. “We’re basically trying to figure out how we can best use the information the lab is gathering,” she says. “It’s a collaborative effort between the researchers and our strength coaches and athletic trainers as to what needs to be measured and how we might be able to act on the findings in the future.”
The Sports Biomechanics Lab is also working on a number of studies that address injury prevention and technique validation. A large part of that research is examining the effects of trunk control on injuries within different populations. Currently, Chaudhari and his colleagues are in the early stages of three studies looking at the relationship between trunk control and ACL tears in football players, lower extremity injuries in distance runners, and shoulder and elbow injuries in baseball players.
“There are plenty of anecdotal explanations for how trunk control and core stability help athletes avoid injury and improve performance, but there is no scientific data supporting that yet,” Chaudhari says. “Nobody has ever proven the link or explained the relationship–that’s where we come in.
“To do that, we look at the body as a mechanical system,” he continues. “Just like a machine, if the forces on certain joints are too high, they’re going to break. It can be an acute break, like an ACL tear, or a fatigue failure that plays out over time. We’re looking for some insight into how these injuries occur and how to prevent them.”
The study on football ACL injuries is set to begin this summer and will involve high school players. Funded by a research grant from NFL Charities, it will examine the relationships between core stability, dynamic loading of the knee during cutting, and athletic performance on standardized football-specific tests.
The study will begin with baseline examinations of 20 athletes, during which they’ll wear 79 reflectors–39 on the torso and upper body and 40 on the legs and feet–while going through a battery of running, cutting, and trunk control tests. Cameras and force plates will record each player’s biomechanics during the tests. The players will also perform drills like those used at the NFL Scouting Combine, such as the three-cone drill, the 20-yard short shuttle, and the broad jump, so researchers can examine how the biomechanical measurements from the lab relate to performance on the field.
“We chose the NFL Combine drills because they involve change of direction and upper-body motion to decelerate and then accelerate again,” Chaudhari says. “We think trunk control may have a pivotal role to play in those movements.”
Chaudhari and his staff will look for specific measurements in each player, for example, at what point their knees go into a valgus angulated (knock-kneed) position due to abduction torque–the torque that pushes the knee toward the midline of the body. This torque and the resulting valgus position created by contact from cutting or landing is a fairly accurate predictor of ACL injury risk according to recent studies. Chaudhari wants to determine when the valgus moment occurs for a typical high school athlete.
After the initial evaluations, athletes will be divided into two groups and perform strength and conditioning workouts for six weeks. “We’re still developing the specifics, but we know both groups will participate in a standard high school football summer workout program with general strength and conditioning, agility, and cardio,” Chaudhari says. “The difference is that one group will replace the workout’s standard trunk exercises with ones that concentrate more on stabilization–such as planks, Bodyblade exercises, and Bosu ball work–with a focus on holding and maintaining proper trunk and pelvis position rather than flexing and extending. The other group will perform traditional crunches, med ball tosses, and concentric abdominal work. The trunk exercises will be the only variable between the two groups and will account for about 25 percent of the weightroom activity.”
After six weeks, the athletes will undergo post-testing similar to their earlier baseline screens, and Chaudhari and his team will look at the results from multiple angles. “We expect the trunk stabilization program will lead to greater improvements in general trunk control, but we really aren’t sure,” he says. “If it turns out not to be the case, that could tell us it doesn’t matter how athletes train the trunk–they’ll make stability gains either way.
“Another thing, which is the meat of the study for us, is if we show improved trunk control, does it translate to improved biomechanical measurements and reduced loading on the knee joints and ligaments when those players cut and land?” Chaudhari continues. “If trunk stabilization is as important as we think it is, we expect to see proportional improvements in both. But we don’t know until we do the tests.”
The lab is using similar concepts and technology to evaluate biomechanics and injury thresholds in collegiate and recreational distance runners. Instead of jumping and cutting, the runners will simply have their straight-ahead, normal-speed running biomechanics evaluated. “With these athletes, we’re looking to show a relationship between trunk stability and biomechanical breakdowns resulting in patellofemoral pain, iliotibial band syndrome, and tibial stress fractures,” Chaudhari says. “We feel all these injuries are caused by some type of specific mechanical flaw or pattern.”
The lab is currently collecting pilot data and submitting grant proposals in hopes of securing funding for the study. Chaudhari would like to expand the project to include a larger, more diverse population because of running’s popularity among all age groups.
Another upcoming study will address the relationship between trunk stability and arm injuries among college pitchers. “We’re interested in seeing whether a pitcher who trains for trunk control can reduce stress on his shoulder and elbow, thereby decreasing his risk for a torn rotator cuff or ulnar collateral ligament,” Chaudhari says. “We want to identify any flaws that might contribute to those injuries and correct them. That also means evaluating whether more trunk control work in rehab actually lowers forces and torques in the shoulders and elbows.”
To evaluate pitching biomechanics, Chaudhari is working with some Ohio State mechanical engineering students to outfit a pitcher’s mound with force plate sensors like the ones in the gym floor. “Even though we’re looking primarily at the shoulder and elbow, we also want to measure forces at the feet and how they relate to the torque created by the upper body,” he says. “We’re using a portable fiberglass mound with sensors located under the push-off area in front of the pitching rubber and on the slope where the lead foot lands.”
For this project, Chris McKenzie, PT, SCS, MHS, ATC, CSCS, Rehabilitation Team Leader at the OSU Sports Medicine Center, will bring in several college pitchers who are rehabbing from upper-extremity throwing injuries. His rehab approach concentrates on increasing players’ trunk stability to enhance performance and avoid re-injury, so the lab is a perfect setting to accumulate evidence-based validation.
“My goal is to use the motion-capture technology to expand our understanding of the role pelvic stabilization plays in preventing injury,” McKenzie says. “I also want to find the best way of training for a stable pelvis so we can introduce those methods to younger pitchers and prevent future injuries while improving mechanics.”
Chaudhari believes the Sports Biomechanics Lab today is barely scratching the surface of what it can offer sports medicine professionals and athletes tomorrow. “First, we have to prove that our concepts work and produce some meaningful, practical results,” he says. “Then we’ll start investing in even more advanced equipment and further refine our operations.”
Moving forward, another goal is strengthening the lab’s relationship with the Ohio State athletic department. Chaudhari says his ultimate plan is to some day perform pre-activity screenings for every Buckeye varsity athlete. “We’ll then hand our data over to the strength and conditioning coaches and athletic trainers, who can use it to customize conditioning programs for each individual to address deficiencies and improve strength,” he says.
Oman is excited to have a front-row seat in watching the technology mature. “Our field is in need of more good clinical research,” she says. “We hope these studies will yield data to validate our assessment and treatment techniques so that we can put those techniques into practice for larger populations. I think we’ll also see this type of testing refined so that anybody can afford to do it in some form.”
Chaudhari has similar goals. “A major priority is making our discoveries translatable outside the lab as much as possible, because we’re limited in the number of people we can work with here,” he says. “For example, we’re looking to develop tools that can be taken to baseball fields to determine what deficiencies pitchers have and how they can decrease their likelihood of injury.
“When I first came here, I hoped people would be interested in the kind of work we’re now doing, but I didn’t really know,” he adds. “Fortunately, I’ve found that everyone here is open to new ideas and we all want to talk about what our research is showing and how it can help athletes perform better and stay healthier.”
Sidebar: ON THE LEVEL
The Ohio State University Sports Biomechanics Laboratory is a breeding ground for innovative, data-driven ideas and analysis. One recent example is the Level Belt, a patent-pending training and assessment tool conceived by Chris McKenzie, PT, SCS, MHS, ATC, CSCS, Rehabilitation Team Leader at the OSU Sports Medicine Center, and developed with help from Ajit Chaudhari, PhD, Director of the lab and Assistant Professor in the Department of Orthopaedics.
Worn around the waist while a baseball pitcher practices his delivery, the belt has an accelerometer sensor the size of a matchbox that measures degrees of motion. It’s a new, highly accurate way to assess trunk stability.
“If you tip your pelvis forward, the belt will roll with the pelvis and measure the degrees of displacement,” explains McKenzie, who uses the Level Belt with rehab patients and for performance development. “If the pelvis rolls forward or backward a set number of degrees (usually between five and seven), the sensor provides biofeedback via an audible tone.
“We instruct pitchers on keeping the pelvis stable because proximal stability allows for better distal mobility,” McKenzie continues. “Athletes need that external feedback because five to seven degrees is such a tight range and they often don’t realize what is and isn’t stable.
“Our research is aimed at helping pitchers keep their hips closed longer, allowing more explosion from the push-off leg and better consistency with their arm slot during the delivery,” McKenzie adds. “Our Level Belt provides a measurement of pelvic stability, which helps pitchers improve positioning, mechanics, and pelvic control.”
McKenzie sees this research making the biggest impact on younger athletes, whose mechanics are typically more flawed. “Instead of just monitoring pitch counts and how many innings a pitcher throws, maybe our focus should be on teaching kids how to maintain control of their pelvis and stay closed longer during the pitch cycle,” he says. “Who knows how many elbow and shoulder problems we can prevent that way?