I receive a lot of injury emails. Many of which hint at the fact that I’m hiding some secret formula for sustaining healthy running. I’m not—the secret is in plain sight and starts with smart training and my strength workouts.
But when we look to the low hanging injury fruit, it’s obtainable for most of us to reach up and snag a knee injury. Research studies have begun to show injury rates soaring upwards to 79%.1
The knee is by far the most common injury site amongst runners. What if I were to tell you that most knee injuries occur for the same reason. Whether you’re dealing with an irritated joint, raw knee cap (Runner’s Knee), or inflamed outside knee (IT Band Syndrome), the root cause may boil down to a single underlying factor.
At first glance, the knee camouflages itself as a simple hinge joint, much like the elbow. Work your way through the brush and you’ll find smaller, equally important movements. When excessive, these seemingly miniscule movements provide damaging forces to the joint and surrounding tissue.
With such crucial movements lurking in the shadows, one would think that the knee would be equipped to defend itself. One would think…. The knee has muscles that flex (bend the knee) and extension (straightening). Our hamstrings (flexors) and quadriceps (extensors) control for these primary motions, but what about the smaller, damaging motions I eluded to above? The knee has little to no control over how much it spins and thrusts from side to side.
If the knee could write a letter to the foot and ankle it would say “You Suck.”
Our knees are sandwiched between two awful friends. Hip and foot muscles are the primary controllers of knee motion (at least in the sense of the smaller, more damaging forces). Most knee injuries fall at the feet of well… your feet (and hip). Too much knee spin causes a drag on your IT Band, joint, knee cap, etc. It’s Darwinism of your tissues. Whichever tissue is the weakest will breakdown first, ultimately resulting in injury.
One study analyzed 100 female runners and discovered a link to knee injuries (Iliotibial Band (ITB)) in those who had greater knee adduction (knee thrusting inward) and rotation forces at ground contact.2 Another study looking at chondromalacia patella (Runner’s Knee) found that women with pain are more likely to demonstrate weakness in hip abduction (glutes) as well as external rotation (glutes again) than age-matched women who are not symptomatic.3
It may be a strength issue in one runner, while another has diminished mobility through their ankle. They both result in the same thing: the knee picking up the slack.
A good jumping off point is working on hip strength. Understanding that the hip plays a larger role to the knee is nothing new. The real trick lies within targeting the hip, knee, and foot together. Diagnosis is easy. Treatment is difficult.
1. Bobbie R.N. van Gent, Danny D. Siem, Marienke van Middelkoop, Ton A.G. van Os, Sita S.M.A. Bierma-Zeinstra, Bart B.W. Koes. Incidence and determinants of lower extremity running injuries in long distance runners: A systematic review. Br J Sports Med Published Online First: 1 May 2007 doi:10.1136/bjsm.2006.033548
2. Powers, C. M. The Influence of Abnormal Hip Mechanics on Knee Injury: A Biomechanic Perspective. JOSPT. Volume 40 Issue 2. 2010. P. 42-51.
3. Ireland ML, Willson J, Ballantyne B, Davis, I. Hip Strength in Females With and Without Patellofemoral Pain. J Orthop Sports Phys Ther. 2003;33(11):671-676.