The effect of hip and knee exercises on pain, function, and strength in patientswith patellofemoral pain syndrome: a randomized controlled trial

Abstract

IntroductionPatellofemoral pain syndrome (PFPS) is often used as an umbrella term for anterior or retropatellar pain. It is a common source of knee pain, especially in the physically active female population (1-6).Treatment methods, such as vastus medialis oblique retraining, open kinetic chain exercises, and isokinetic muscle strengthening, were the most effective over a short period of time; however, they were not more effective than home-based exercise programs (7). Quadricepsstrengthening exercise therapy is commonly recommended for patients suffering from PFPS (7). However, PFPS is associated with decreased hip strength, specifically in the abductors and external rotators (1,2,(8)(9)(10)(11)(12)(13)(14)(15)(16). Since the hip abductors can affect knee valgus by controlling the frontal plane position of the femur, increasing hip abduction strength may help these patients (17).The importance of hip abductors, external rotator muscles, and extensor-strengthening programs for PFPS has received increased attention in recent years (7).Biomechanically, weakness in the hip musculature could lead to increased femoral adduction and medial rotation during dynamic weight-bearing activities, which would increase the lateral patellofemoral joint vector, leading to patellar facet overload (1,2,5,14).However, there are limited numbers of controlled studies on additional hip-strengthening exercises in PFPS (3,4,(18)(19)(20)(21)(22). Sex bias (18,19) and small sample size (3,4,16,19,21) were common problems in most of these studies. Interestingly, specific causes for differential diagnosis of knee pathologies or coexistence of different knee problems confirmed by knee radiographs or magnetic resonance imaging (MRI) were not investigated in the previous studies. Intraarticular lesions, such as meniscus and ligament injuries, were not evaluated in these studies and only clinical PFPS cases were included in these previous reports.This study aimed to indicate the hip exercises in addition to knee exercises with regard to pain, function, and isokinetic muscle strength in young sedentary women with PFPS.Background/aim: The role of hip muscles in the rehabilitation of patellofemoral pain syndrome has recently received interest. The aim of this study was to compare the efficiencies of hip exercises alongside knee exercises versus only knee exercises on pain, function, and isokinetic muscle strength in patients with this syndrome.Materials and methods: Fifty-five young female patients (mean age: 34.1 ± 6.2 years; mean BMI: 25.9 ± 3.9 kg/m 2 ) with patellofemoral pain syndrome were included. The patients were randomized into groups of hip-and-knee exercises and knee-only exercise programs for 6 weeks with a total of 30 sessions at the clinic. Both groups were evaluated before therapy, after 6 weeks of a supervised exercise program, and after 6 weeks of an at-home exercise program. The outcome measures were muscle strength, pain, and both subjective and objective function. Results:The improvements of the patients in the hip-and-knee exe...

Hip and Knee Strengthening Is More Effective Than Knee Strengthening Alone for Reducing Pain and Improving Activity in Individuals With Patellofemoral Pain: A Systematic Review With Meta-analysis

“…The effect of intervention beyond the intervention period was examined in 2 trials. 12,38 No significant change was found in strength of the hip and knee muscles between the groups 4 weeks beyond the intervention period (mean difference, 0.4 Nm/kg; 95% CI: -0.4, 1.3) 12 or 6 weeks beyond the intervention period (mean difference, -2 Nm/kg; 95% CI: -10, 6). [ research report ] activity level was examined by pooling postintervention data from 8 trials 10,12,14,16,17,19,20,38 (n = 471) with a mean PEDro scale score of 6.5.…”

“…7,17,21,25 Eleven trials compared hip and knee strengthening with knee strengthening alone, providing data to answer the second study question. 3,10,12,14,16,17,19,20,27,36,38 Additional information on 8 papers was requested from the authors. Quality The mean PEDro score of the trials was 5.8 (range, 3-8) (TABLE 3).…”

“…Strength The effect of hip and knee strengthening, compared with knee strengthening alone, on strength was examined by pooling postintervention data from 6 trials (n = 359) 10,12,14,19,27,38 with a mean PEDro scale score of 6.7. Hip and knee strengthening did not significantly change strength compared with knee strengthening alone (SMD, 0.2; 95% CI: -0.1, 0.4; I 2 = 0%) (FIGURE 5).…”

“…Hip and knee strengthening resulted in a significant decrease in pain intensity of 1.9 points out of 10 (95% CI: -3.1, -0.7; random effects) compared with knee strengthening alone 12.0 ± 5.7 weeks beyond the intervention period (FIGURE 7). Activity The effect of hip and knee strengthening, compared with knee strengthening alone, on self-reported Pain The effect of hip and knee strengthening, compared with knee strengthening alone, on pain intensity was examined by pooling postintervention/change score data from 10 trials (n = 517) 10,12,14,16,17,19,20,27,36,38 with a mean PEDro scale score of 6.3. There was substantial statistical heterogeneity (I 2 = 82%).…”

“…Maintenance of activity beyond the intervention period was examined by Reduction of pain beyond the intervention period was examined by pooling postintervention/change score data from 5 trials 10,12,16,20,38 (n = 191). Hip and knee strengthening resulted in a significant decrease in pain intensity of 1.9 points out of 10 (95% CI: -3.1, -0.7; random effects) compared with knee strengthening alone 12.0 ± 5.7 weeks beyond the intervention period (FIGURE 7).…”