It is fairly well accepted in medical/rehab circles that much of the lateral knee pain felt by runners is related to the IT band. Researchers report that frictional forces are greatest between 20 and 30 degrees of knee flexion (this occurs in the first part of stance phase with running). But what about the differences in hip and knee kinematics between healthy and injured subjects?
I currently train two competitive female marathoners. Both are in their thirties. One has run Boston and the other is training with me to qualify this year (she missed by 36 seconds last year). Many female runners deal with iliotibial band issues during their training. My client trying to qualify for Boston has issues on her right side. My other runner does not. The client affected by this also has some ankle instability which certainly affects closed chain mechanics.
Historically, researchers have felt increased rear-foot eversion has contributed to such injuries. Why? well, increased rear-foot eversion leads to increased tibial internal rotation, and by the ITB’s attachment point distally on the tibia this would in turn increase strain. In addition, it has been postulated that gluteus medius weakness leads to greater hip adduction moments and undue strain.
One recent prospective study done by Noehren et al. concluded that runners who developed ITBS exhibited increased hip adduction and knee internal rotation angles compared to healthy controls. Today, I wanted to briefly update you on a study just published in the Journal of Orthopaedic and Sports Physical Therapy looking at the running mechanics of those with previous bouts of ITBS and those without. The study observed 35 healthy female runners and 35 age matched runners (ages 18-45 who run no less than 30K/week) with a history of ITB issues. They measured:
- Hip, knee and ankle kinematics
- Internal moments during stance phase
So, what did the results say? In a nutshell, the ITBS group did in fact exhibit increased hip adduction angles and peak internal rotation angles at the knee. There was , however, no significant difference among groups with respect to the rear-foot eversion. This particular study did not measure hip abductor strength.
As far as limitations to the study, one primary one was the fact that the ITBS group was healthy during the study (meaning they had some time in the past suffered ITBS). With that said, the results did mirror the prospective study by Noehren.
The practical takeaways for runners and trainers are:
- Prior ITB issues may increase risk for recurrence due to increased strain
- Prior ITB issues indicate atypical hip and knee kinematics may be present
- The rear-foot position may have a lesser role in causation of ITBS
- Addressing hip stability, strength and eccentric control is paramount to injury prevention
- Observing frontal/transverse plane knee mechanics is prudent
In training, I recommmend video analysis or using a mirror independently to observe what I term a single leg hop and stick maneuver. I teach it to all my cutting and impact athletes. Simply begin on the left leg and hop forward onto the right and lower down into a lunge type single leg landing position.
Observe the foot/ankle, knee and hip as the body declerates. This image and sequence of events leaves strong clues about the strength and force dissipation that is or isn’t happening. Perform at least 3 trials and repeat on the other side. This evalaution technique then also becomes a training tool to correct imbalances and improve deceleration mechanics – the very essence of the injury problem to begin with.
I routinely have my athletes with assymetrical or atypical kinematics engage in this drill no less than 2-3 times per week. I have them perform 2-3 sets of 5-10 quality reps on each side (alternate sides). Focus on preventing the femur from adducting too much or the patella moving inward. In addition to this drill, obviously include steady glute max and medius work in your programs to help reduce ITBS. With all that said, happy running!