ACL Tears & Stress Fractures: Can DNA Make a Difference?
Sports excite, inspire, and move us in unique ways. We love to follow our favorite athletes as they play through a season. We pay thousands of dollars each year to sweat with dozens of other people in ever-hipper boot camp classes. We can buy the perfect shoe designed for exactly the right kind of impact and movement. Technology helps everyone from athletes to enthusiasts to beginners perform at the top of their game, but there is a downside to all of this activity: the potential for athletic injuries.
Athletic activity puts stress on our bodies and can make us more prone to things like sore muscles, sprains, or worse. Some of these injuries can be painful and challenging to recover from. What’s more, as you’re recuperating, you may slowly lose the level of fitness you’ve worked so hard to achieve. To find the right balance between pushing and protecting ourselves, we need to understand what our bodies are capable of.
An emerging approach to helping athletes avoid sports injuries involves our DNA. Studying how genes can determine one’s susceptibility to these types of injuries is a rapidly growing field in genomics, and new research is beginning to show that there are possible links between certain genetic traits and the likelihood of getting hurt. This field of research has significant potential to help not just elite athletes but really anyone who works out understand how they can keep their bodies healthy along the way.
One line of inquiry involves research into genetic variations and the risk of ACL injury, which can require surgery and months of rehabilitation. The ACL is a major ligament in the knee which helps provide stability to the joint. Ligaments can be thought of as flexible tape that span the gap between bones and provide tension to hold the bones in place. When that tension is released due to a tear, the ACL cannot function as well and the joint is less likely to support everyday use, much less athletic impact.
Tears in the ligaments and tendons are also common injuries, with a particularly high rate among football and soccer players (Agel J et al, 2016). In an effort to predict who may be more susceptible, geneticists are exploring potential links between ligament tears and a variation in the gene coding for a specific protein known as COL1A1. This protein helps build the collagen component in ligaments — a component which can account for as much as 80% of the ligament’s total weight. Different types of collagen, built from a family of similar proteins, can have different physical properties. To balance flexibility with strength, specific combinations of these collagen types get incorporated into the ligament.
COL1A1 is known to have variations that can shift this composition. Researchers hypothesize that some variations can affect the overall strength of the ligament, which means that individuals may be less likely to experience a tear depending on their genetics. This is currently a topic of intense research, and recent papers indicate that there may be an association between this gene variant and specific demographic populations. Further research in the field could one day help athletes stay safer and healthier.
Genetics also plays a role in repetitive stress injuries like stress fractures. Stress fractures can be devastating for athletes because the recovery process is quite lengthy, and athletes may feel healthy before they’ve actually fully recovered, which can lead to further injury. LRP5, a gene that regulates bone mineral density, has been identified to play a role in stress fracture risk; a variation in LRP5 can lead to lower bone density, which can lead to more fractures. Individuals with this variant shouldn’t be discouraged, though, because evidence indicates that mixing up exercise routines can help to reduce chronic stress and reduce injury. Similarly, participating in lower-impact sports — like switching from football to swimming, for instance — could help protect bones.
Our DNA will never be the primary cause of an injury, and knowledge alone can’t keep us from getting hurt. But DNA insights like these can give us an edge when it comes to staying healthy and strong. Genetic testing can help individuals tailor training, stretching, and rest plans to meet specific needs. Being aware of our genetic makeup can give us an enhanced sense of what our bodies may be capable of — and ultimately, motivate us to stick it out when it comes to working out.
Citation: Agel J. Rockwood T. Klossner D. Collegiate ACL Injury Rates Across 15 Sports: National Collegiate Athletic Association Injury Surveillance System Data Update (2004–2005 Through 2012–2013). Clinical Journal of Sports Medicine 2016.