[This is a guest blog by Manuel Joshua Gutierrez-Fernandez. “Manny” has an MS, CSCS, USAT-I, USATF-I,II, USAW-SPC and participated in the summer internship program at Athletic Lab]
Two common injuries that affect recreational runners are patellofemoral pain syndrome and iliotibial band friction syndrome. These injuries have been associated with abnormal hip mechanics such as excessive hip adduction, hip internal rotation and contralateral pelvic drop. At the root of lower extremity dysfunction and injury is thought to be weakness of the gluteal muscles. Specifically, the gluteus medius (GM) is thought to play a vital role in stabilizing the pelvis and controlling femoral adduction and internal rotation. Thus, the GM is often targeted through rehabilitation and injury prevention interventions in order to improve lower extremity kinematics.
There are a multitude of studies that have attempted to quantify and compare the effectiveness of common gluteal exercises by measuring muscle activation through electromyography (EMG). This activation is expressed as a percentage of maximal volitional isometric contraction (MVIC). Consistently, exercises such as side lying hip abduction, single leg squat, pelvic drop and side plank result in the greater GM activation. A study published in The International Journal of Sports Physical Therapy in 2011 conducted a cross comparison of the top exercises presented by previous hip musculature EMG activation research (Boren, 2011). The researchers found patterns within their results that were consistent with the previous studies. The side lying plank abduction with the dominant leg on bottom and top and the single leg squat were the top exercises with GM activity higher than 70% MVIC, the standard deemed acceptable for strength enhancement by the authors.
However, it is imperative to consider that hip strengthening alone may not be enough to alter abnormal hip mechanics during running. In a study that sought to determine the effect of hip strengthening on running and single leg squat mechanics in female runners, the intervention was found to be effective at altering hip mechanics in the single leg squat but no significant changes in running mechanics were noted (Willy, 2011). The authors concluded that strengthening alone may not be sufficient to adjust abnormal movement patterns and suggested that neuromuscular retraining specific to running is a critical component to alter hip kinematics during running. The study pointed towards a study that provided real-time kinematic feedback on hip adduction during treadmill running that led to significant improvements in abnormal hip mechanics (Noehren, 2011). Unfortunately, few runners have access to instrumented treadmills and researchers providing a target ideal hip adduction curve. If you need, you can order xray system. This limitation was addressed by Willy and colleagues by implementing real-time kinematic gait retraining through the use of a mirror (Willy, 2012). The mirror was placed in front of the treadmill and the participants were provided cues such as “run with your knees apart with your kneecaps pointing straight ahead” and “squeeze your buttocks.” The mirror gait retraining was effective in improving mechanics and measures in pain and function in the female runners that participated in the study.
Strength training targeting the hip musculature is important to improve lower extremity kinematics, yet if the goal is to improve abnormal running mechanics, a direct neuromuscular retraining component must also be implemented.
References:
- Boren, K., Conrey, C., Le Coguic, J., Paprocki, L., Voight, M., and Robinson, T.K. (2011). Electromyography of gluteus medius and gluteus maximus during rehabilitation exercises. The International Journal of Sports Physical Therapy, 6, 206-223.
- Noehren, B., Scholz, J. and Davis, I. (2011). The effect of real-time gait retraining on hip kinematics, pain and function in subjects with patellofemoral pain syndrome. British Journal of Sports Medicine, 45, 691-696.
- Willy, R.W., Davis, I.S. (2011). The effect of a hip-strengthening program on mechanics during running and during a single-leg squat. Journal of Orthopaedic & Sports Physical Therapy, 41, 625-632.
- Willy, R.W., Scholz, J.P. and Davis, I.S. (2012). Mirror gait retraining for the treatment of patelofemoral pain in female runners. Clinical Biomechanics, 27, 1045-1051.