Getting a knee up on injury
Our knees do a lot for us: they propel us forward, pivot us backward, lower us to the ground and raise us to sky. It’s a complicated joint, says Alberta Innovates clinician researcher Ryan Lewinson.
Lewinson is pursuing a combined MD/PhD program at the University of Calgary and has completed the PhD portion of his studies. “It has many structural components such as muscle, bone, cartilage and ligament, and we put it through a variety of movements every day.”
He compares the knee to a hinge: it flexes and extends. Unlike a hinge, the knee also moves forward and backward, and bends and rotates from side to side. These many abilities also decrease the knee’s stability, making it prone to injury from trauma such as a fall; sudden movements such as changing directions; high-impact sports such as running; and wear and tear from age. This is why nearly one in every eight runners develops pain around or behind the knee cap, a condition known as runner’s knee, or patellofemoral pain syndrome. And one in 10 adults over age 60 develop osteoarthritis of the knee, which is caused by the breakdown of cartilage and results in pain and stiffness.
Lewinson says custom-made orthotic inserts placed inside shoes can prevent pain from a number of knee injuries by changing how the foot connects with the ground. When the foot lands, its bones and muscles transfer impact to the knee. “If we want to change the biomechanics at a joint such as the knee or hip, we can usually do this by changing the way the foot hits the ground.”
Orthotics can do this, but only work when perfectly customized to a person’s body. The gold standard for fitting orthotics is a gait analysis, which requires specialized equipment used in research laboratories. Clinicians don’t have such equipment and typically rely on observing a person’s posture to determine the right orthotic.
Lewinson has developed a simple, accurate and affordable way to customize orthotics for knee pain using basic equipment. The system could also help customers at shoe stores choose ready-made orthotics.
Calgary researcher Matt Jordan, a PhD and director of Strength and Conditioning at the Canadian Sport Institute Calgary (CSIC), is also working to reduce knee injuries. His recent work focuses on the anterior cruciate ligament (ACL), a band of tissue that helps stabilize the knee joint. ACL injuries are common in sports with sudden twists and turns; these movements can cause the ligament to rip in half or disconnect from the bone. “Normally, a person feels a ‘pop’ in their knee and, usually, a lot of pain,” Jordan says.
Surgery and physiotherapy can repair these injuries and make such an injury a thing of the past. But 40 to 45 per cent of people do not fully return to their sport and many who do may have a second ACL injury in either knee.
The high risk of reinjury makes it hard for athletes and their coaches to know when or if it’s safe to resume training and competition. Right now, athletes’ knees and movements are evaluated to determine if they are ready to train. This only offers a rough idea of their recovery.
Jordan has developed a simple new method for assessing athletes’ knee strength after ACL surgery. It measures and compares the functional strength of the injured and healthy leg by having athletes jump vertically on force plates.
If the force of the landing varies significantly between the legs, that suggests the athlete needs more physical training to strengthen the injured knee and supporting muscles. The method can also help athletes fine-tune their rehabilitation strategy (one of the CSIC’s specialties).
Jordan notes that the research focuses on competitive skiers and could be used to help athletes in any sport and level of competition. A long-time coach and athlete himself, he hopes his research helps more athletes return to the sports they love.
“There’s nothing worse than getting injured and not being able to play your sport again.”
Written by Debby Waldman (originally appeared in Apple Magazine – Summer 2017)