Hip Strength in Females With and Without Patellofemoral Pain

Abstract

Study Design: Cross-sectional. Objectives: To determine if females with anterior knee pain are more likely to demonstrate hip abduction or external rotation weakness than a similar, asymptomatic, age-matched control group. Background: Diminished hip strength has been implicated as being contributory to lower-extremity malalignment and patellofemoral pain. The identification of reliable and consistent patterns of weakness in this population may assist health care professionals establish a more effective treatment plan. Methods and Measures: Hip abduction and external rotation isometric strength measurements were recorded for the injured side of 15 female subjects with patellofemoral joint pain (mean ± SD age, 15.7 ± 2.7 years; age range, 12-21 years). These were compared with strength measurements from the corresponding hip of 15 age-matched female control subjects (mean ± SD age, 15.7 ± 2.7 years; age range, 12-21 years). All strength measurements were made using hand-held dynamometers. Results: Subjects with patellofemoral pain demonstrated 26% less hip abduction strength (PϽ.001) and 36% less hip external rotation strength (PϽ.001) than similar age-matched controls. Conclusions:The results indicate that young women with patellofemoral pain are more likely to demonstrate weakness in hip abduction as well as external rotation than age-matched women who are not symptomatic. J Orthop Sports Phys Ther. 2003;33:671-676. Key Words: anterior knee pain, hip abduction, hip external rotation, knee, patella P atellofemoral joint pain (PFP) remains one of the most common orthopaedic complaints among adolescents and young adults, with reported incidence rates among athletes greater than 25%. 2,26,31,38 It has also been reported that females, as compared with their male counterparts, are significantly more likely to experience PFP. 9,35 Typically, patients complain of generalized retropatellar symptoms that present insidiously and tend to be exacerbated by prolonged sitting or repetitive weight-bearing activities over a flexed knee. Unfortunately for these individuals, this pain often becomes a chronic condition that may fail to respond to conservative measures. Willson, Joyner Sportsmedicine Institute, 601 Perimeter Dr., Suite 110, Lexington, Current literature suggests that, in the absence of direct trauma, the etiology of PFP is multifactorial. Factors related directly to the patellofemoral joint, including vastus medialis obliquus insufficiency, decreased hamstring, quadriceps, or iliotibial band flexibility, patella alta, and femoral anteversion, have received the most attention.

Hip Strengthening Prior to Functional Exercises Reduces Pain Sooner Than Quadriceps Strengthening in Females With Patellofemoral Pain Syndrome: A Randomized Clinical Trial

“…5 Because we used a relatively unique means of reporting torque that controlled for individual variance due to height and weight, we additionally converted our strength measures for isometric HABD and HER into a percentage of bodyweight for further comparison to studies that did not use these corrections (TABLE 4). 26,38 At the conclusion of this intervention, hip strength values for women in this study were approaching those reported for healthy women.…”

“…Several authors have reported that females with PFPS demonstrate weaknesses of the hip external rotators and hip abductors. 11,17,26,30,31,36,37 During functional activities, especially single-leg activities, the hip muscles prevent hip adduction and internal rotation, which may result in dysfunctional lower extremity joint alignment and can lead to the development of PFPS. 20 …”

Analysis of Hip Strength in Females Seeking Physical Therapy Treatment for Unilateral Patellofemoral Pain Syndrome

“…4,17,29 In spite of the fact that intervention programs for the management of patients with PFPS include exercises aimed at improving the performance of the lateral hip musculature, we are aware of only 2 research reports that have investigated whether differences in hip strength exist between patients with PFPS and a control group. 12,20 Ireland et al 12 found that 15 female subjects with PFPS demonstrated 26% less hip abduction strength and 36% less hip external rotation strength when compared to 15 age-matched control subjects. In contrast, Piva et al 20 reported that there were no statistically significant differences in hip abduction or external rotation strength when 30 subjects with PFPS (17 females and 13 males) were compared with 30 age-and gender-matched control subjects.…”

“…Given the contradictory results from previous reports, 12,20 we also performed a secondary analysis where data from the involved limbs of symptomatic subjects were compared to the corresponding limbs of asymptomatic subjects. We hypothesized that females with unilateral PFPS would exhibit lower LSI values during strength testing compared to asymptomatic subjects.…”

“…This secondary analysis enabled us to compare our results to those from 2 previous studies that employed similar methodology to examine hip abduction and external rotation isometric strength in subjects with PFPS. 12,20 …”