Eccentric Hip Muscle Function in Females With and Without Patellofemoral Pain Syndrome

Abstract

Context: Patellofemoral pain syndrome (PFPS) is a common knee condition in athletes. Recently, researchers have indicated that factors proximal to the knee, including hip muscle weakness and motor control impairment, contribute to the development of PFPS. However, no investigators have evaluated eccentric hip muscle function in people with PFPS.Objective: To compare the eccentric hip muscle function between females with PFPS and a female control group.Design: Cross-sectional study. Setting: Musculoskeletal laboratory.Patients or Other Participants: Two groups of females were studied: a group with PFPS (n 5 10) and a group with no history of lower extremity injury or surgery (n 5 10).Intervention(s): Eccentric torque of the hip musculature was evaluated on an isokinetic dynamometer.Main Outcome Measure(s): Eccentric hip abduction, adduction, and external and internal rotation peak torque were measured and expressed as a percentage of body mass (Nm/kg 3 100). We also evaluated eccentric hip adduction to abduction and internal to external rotation torque ratios. The peak torque value of 5 maximal eccentric contractions was used for calculation. Two-tailed, independent-samples t tests were used to compare torque results between groups.Results: Participants with PFPS exhibited much lower eccentric hip abduction (t 18 5 22.917, P 5 .008) and adduction (t 18 5 22.764, P 5 .009) peak torque values than did their healthy counterparts. No differences in eccentric hip external (t 18 5 0.45, P 5 .96) or internal (t 18 5 20.742, P 5 .47) rotation peak torque values were detected between the groups. The eccentric hip adduction to abduction torque ratio was much higher in the PFPS group than in the control group (t 18 5 2.113, P 5 .04), but we found no difference in the eccentric hip internal to external rotation torque ratios between the 2 groups (t 18 5 20.932, P 5 .36).Conclusions: Participants with PFPS demonstrated lower eccentric hip abduction and adduction peak torque and higher eccentric adduction to abduction torque ratios when compared with control participants. Thus, clinicians should consider eccentric hip abduction strengthening exercises when developing rehabilitation programs for females with PFPS.

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

“…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 …”

Trunk, Pelvis, Hip, and Knee Kinematics, Hip Strength, and Gluteal Muscle Activation During a Single-Leg Squat in Males and Females With and Without Patellofemoral Pain Syndrome

“…12,42,45,46 During weight-bearing activities, the hip must contract eccentrically to control the movement of the femur in the frontal and transverse planes. Decreased eccentric hip torque in individuals with PFPS has been reported, 7,10 but sex differences have not been investigated. Decreased hip muscle activation may also contribute to abnormal hip kinematics.…”

“…Testing was performed at an angular speed of 30°/s. 10 All subjects received strong verbal encouragement during eccentric hip abduction and external rotation torque testing. The testing order was randomized to account for ordering bias.…”

“…The evaluated hip was placed superiorly and in neutral alignment in all 3 planes (FIGURE 2A). The rotational axis of the dynamometer was aligned with the hip joint center in the frontal plane, 10 and the lever arm was attached 5 cm above the knee joint line of the evaluated limb. The range of motion of the test was from 0° (neutral position) to 30° of hip abduction.…”

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

“…Impaired hip muscle performance is a common impairment observed in patients with PFP 1,5,17,25,27 and has been shown to be associated with altered hip kinematics in this population. 27,28 A recently published systematic review concluded that there is strong evidence that females with PFP demonstrate impaired strength of the hip musculature, as compared to control subjects.…”