Research implicating excessive hip adduction as a possible cause for running knee ionjuries is mounting. Importantly, prospective research indicates excessive peak hip adduction during running is a risk factor for both illiotibial band syndrome (ITBS) and patellofemoral pain (PFP). To address these faulty hip mechanics, clinicians frequently prescribe hip strengthening protocols. Promisingly, these exercise programs have been reported to effectively reduce pain in individuals with ITBS and PFP.[5-7] Considering these therapeutic outcomes, implementing hip strengthening in runners with ITBS and PFP is recommended. However, is a strength program enough to correct the faulty mechanics which may have led to the development of these conditions in the first place?
Effects of hip strengthening on peak hip adduction during running
Three recent studies[5 8 9] have investigated the effects of hip strengthening protocols on hip motion during running. Despite reporting increased hip strength, these studies do not indicate hip strengthening programs (between 3 and 8 weeks duration) will reduce peak hip adduction during running. Interestingly, two of these studies were completed on individuals with PFP and did reduce pain.[5 9] This indicates their programs were still therapeutic, but the positive results may be from a different mechanical change (i.e. not hip motion) – we will save this discussion for another post. Put together, these findings indicate hip strengthening may reduce pain and improve strength, but not change a known risk factor for running related ITBS and PFP, i.e. excessive peak hip adduction. [2 3] Considering this, it is likely that hip exercise protocols need to focus on more than just strength in order to reduce the risk of symptom development or exacerbation in the future.
Effects of neuromuscular retraining on peak hip adduction during running
Willy et al evaluated the effects of combining hip strengthening with neuromuscular retraining during single legged squatting over six weeks. Their cohort consisted of 10 asymptomatic females possessing excessive hip adduction (i.e. greater than 20⁰) during running. The neuromuscular retraining involved the use of visual (i.e. a mirror) and verbal feedback to reduce the amount of hip adduction/internal rotation during the completion of single legged squat exercises. The findings from this study highlight the importance of exercise and neuromuscular retraining specificity during clinical practice. Here they are:
- During single legged squatting, peak hip adduction reduced from 10.6⁰ to 3.9⁰ following the six week program
- During running, there was no significant difference in peak hip adduction(20.7⁰ compared to 20.0⁰) following the six week program
Importantly, the findings from Willy et al show that adding neuromuscular retraining to a hip strengthening exercise program is needed to facilitate changes to hip motion, but these changes are likely to be task specific. Clearly, if you want to change hip motion during running, you need to complete a specific neuromotor retraining during running, similar to that previously reported to be effective in PFP.[11 12] Hip strengthening alone will certainly not get the job done.
1. Powers CM. The influence of abnormal hip mechanics on knee injury: a biomechanical perspective. J Orthop Sports Phys Ther 2010;40(2):42-51
2. Hamill J, Miller R, Noehren B, et al. A prospective study of iliotibial band strain in runners. Clin Biomech (Bristol, Avon) 2008;23(8):1018-25
3. Noehren B, Hamill J, Davis I. Prospective evidence for a hip etiology in patellofemoral pain, 2013.
4. Beers A, Ryan M, Kasubuchi Z, et al. Effects of Multi-modal Physiotherapy, Including Hip Abductor Strengthening, in Patients with Iliotibial Band Friction Syndrome. Physiother Can 2008;60(2):180-8
5. Ferber R, Kendall KD, Farr L. Changes in Knee Biomechanics After a Hip-Abductor Strengthening Protocol for Runners With Patellofemoral Pain Syndrome. Journal of Athletic Training 2011;46(2):142-49
6. Khayambashi K, Mohammadkhani Z, Ghaznavi K, et al. The effects of isolated hip abductor and external rotator muscle strengthening on pain, health status, and hip strength in females with patellofemoral pain: a randomized controlled trial. J Orthop Sports Phys Ther 2012;42(1):22-9
7. Dolak KL, Silkman C, Medina McKeon J, et al. Hip strengthening prior to functional exercises reduces pain sooner than quadriceps strengthening in females with patellofemoral pain syndrome: a randomized clinical trial. J Orthop Sports Phys Ther 2011;41(8):560-70
8. Snyder KR, Earl JE, O’Connor KM, et al. Resistance training is accompanied by increases in hip strength and changes in lower extremity biomechanics during running. Clin Biomech (Bristol, Avon) 2009;24(1):26-34
9. Earl JE, Hoch AZ. A Proximal Strengthening Program Improves Pain, Function, and Biomechanics in Women With Patellofemoral Pain Syndrome. American Journal of Sports Medicine 2011;39(1):154-63
10. Willy RW, Davis IS. The effect of a hip-strengthening program on mechanics during running and during a single-leg squat. J Orthop Sports Phys Ther 2011;41(9):625-32
11. Willy RW, Scholz JP, Davis IS. Mirror gait retraining for the treatment of patellofemoral pain in female runners. Clin Biomech (Bristol, Avon) 2012;27(10):1045-51
12. Noehren B, Davis I. The effect of gait retraining on hip mechanics, pain, and function in runners with patellofemoral pain syndrome… Patellofemoral pain syndrome: proximal, distal, and local factors, an international research retreat, April 30-May 2, 2009, Fells Point, Baltimore, MD. Journal of Orthopaedic & Sports Physical Therapy 2010;40(3):A40-1