Knee pain is the most common pain reported in runners and no one has contributed more to our understanding of this pathology than Irene Davis. I’m a huge fan of researchers that really sink their teeth into a topic and doggedly work to methodically shed more and more light on the subject. Dr. Davis is one of those rare individuals. Working out of the Gait Lab at the University of Delaware, Davis started exploring the biomechanics of the knee in the mid-90s, and has a formidable list of publications that numbers well over 40. Recently, she moved on to the Spaulding National Running Center at Harvard University.
One of the common observations of several studies on patellofemoral pain (PFP) has been that weakness of the hip abductors and external rotators is correlated with, and also predicts PFP. The solution to the problem then seems to be very straightforward…strengthen the muscles that are weak in controlling the valgus knee during gait and all will be splendid. Indeed, were the findings in some studies, but others were less promising. What could be the missing variables?
Last year, an elegant study co-authored by Davis indicated that perhaps the solution is as much related to software as it is to hardware. Brian Noehren, et al, demonstrated one of the most impressive effects on chronic anterior knee pain in runners ever published. And they did it using gait re-training without strength training. They took a small cohort (n=10) of runners (at least 6 mi/week, avg of 16 mi) who had at least 4/10 pain in the anterior knee with running. The average chronicity was 75 months!! They did a gait analysis as well as single leg squat, and measured kinematics including contralateral pelvic drop, peak hip adduction and internal rotation. They also measured vertical impact forces.
Intervention was verbal coaching while running in 8, 30 minute sessions on a force plate treadmill and with live gait analysis. As the runners implemented the coaching cues, they got real-time feedback via the gait analysis software which showed a representation of their peak hip adduction. After 2 weeks, pain was reduced by 86%. On follow up one month later, ALL WERE RUNNING PAINFREE! For more details, here’s a link to that study.
Here are the 3 verbal cues the coaches used to help the runners change their gait:
- Contract the gluteal muscles (or as I tell my patients, pretend you are pinching a coin between you butt cheeks. Don’t crush it, but don’t drop itj!)
- Run with the knee pointing straight ahead.
- Keep the pelvis level (or as I tell my patients, don’t run like a supermodel!)
Dr. Irene Davis’ Bio: