title: The effect of hip and knee exercises on pain, function, and strength in patientswith patellofemoral pain syndrome: a randomized controlled trial. The Efficacy of Treatment of Different Intervention Programs for Patellofemoral Pain Syndrome–A Single Blinded Randomized Clinical Trial. Pilot Study Hip posterolateral musculature strengthening in sedentary women with patellofemoral pain syndrome: a randomized controlled clinical trial with 1-year follow-up. Short-term effects of hip abductors and lateral rotators strengthening in females with patellofemoral pain syndrome: a randomized controlled clinical trial. Effects of functional stabilization training on pain, function, and lower extremity biomechanics in women with patellofemoral pain: a randomized clinical trial. Strengthening of the hip and core versus knee muscles for the treatment of patellofemoral pain: a multicenter randomized controlled trial. Posterolateral hip muscle strengthening versus quadriceps strengthening for patellofemoral pain: a comparative control trial. Hip strengthening prior to functional exercises reduces pain sooner than quadriceps strengthening in females with patellofemoral pain syndrome: a randomized clinical trial. Knee complaints seen in general practice: active sport participants versus non-sport participants A Prospective Investigation of Biomechanical Risk Factors for Patellofemoral Pain Syndrome Reliability of the PEDro scale for rating quality of randomized controlled trials. The Effects of Quadriceps Strengthening on Pain, Function, and Patellofemoral Joint Contact Area in Persons with Patellofemoral Pain Physiotherapy for anterior knee pain: a randomised controlled trial Effectiveness of Patellar Bracing for Treatment of Patellofemoral Pain Syndrome Prospective evidence for a hip etiology in patellofemoral pain. 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. The effect of additional strengthening of hip abductor and lateral rotator muscles in patellofemoral pain syndrome: a randomized controlled pilot study
abstract: 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 . MATERIAL S AND METHODS Fifty-five young female patients ( mean age : 34.1 ± 6.2 years ; mean BMI : 25.9 ± 3.9 kg/m2 ) with patellofemoral pain syndrome were included . The patients were r and omized 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 exercise group were better than in patients of the knee-only exercise group in terms of scores of pain relief ( P < 0.001 ) and functional gain ( P = 0.002 ) after 12 weeks . CONCLUSION We suggest additional hip-strengthening exercises to patients with patellofemoral pain syndrome in order to decrease pain and increase functional status Patello-femoral pain syndrome ( PFPS ) is a common knee joint disability . The integration of hip soft tissue regimens are not always emphasized , although current literature implies that there is a significant relationship between the two and there is a lack of r and omized clinical trials to substantiate this relationship in clinical practice . A r and omized controlled assessor blinded trial was design ed to explore different rehabilitation programs related to PFPS . The study was conducted at RAZIEL institute of physical therapy , Netania , Israel with a total of 30 consecutive patients ( mean age 35y ) , diagnosed with PFPS . All patients were r and omly allocated into 3 groups . Group I conventional knee rehabilitation program . Included quadriceps strengthening and Trans Electric Neuromuscular Stimulation ( TENS ) . Group II hip oriented rehabilitation program . included stretching , Hip external rotators strengthening and TENS . Group III a combination of the two above programs .  Pain and function were documented on initial of the program and again 3 weeks later , on the completion . Pain was assessed by a numeric visual analogue scale ( VAS ) ; function was assessed by Patello-femoral joint evaluation scale ( PFJES ) ( 0 - 100 points ) . At end of trial , all groups showed significant improvements in VAS and PFJES ( p<0.0001 ) ; these improvements did not vary significantly between the 3 groups . The conclusions were that the explored different rehabilitation programs showed a similar beneficial effect STUDY DESIGN R and omized controlled trial . OBJECTIVES To determine if adding hip-strengthening exercises to a conventional knee exercise program produces better long-term outcomes than conventional knee exercises alone in women with patellofemoral pain syndrome ( PFPS ) . BACKGROUND Recent studies have shown that a hip-strengthening program reduces pain and improves function in individuals with PFPS . However , there are no clinical trials evaluating long-term outcomes of this type of program compared to conventional knee-strengthening and -stretching exercises . METHODS Fifty-four sedentary women between 20 and 40 years of age , with a diagnosis of unilateral PFPS , were r and omly assigned knee exercise ( KE ) or knee and hip exercise ( KHE ) .  The women in the KE group ( n = 26 ; mean age , 23 years ) performed a 4-week conventional knee-stretching and -strengthening program . The women in the KHE group ( n = 28 ; mean age , 22 years ) performed the same exercises as those in the KE group , as well as strengthening exercises for the hip abductors , lateral rotators , and extensors . An 11-point numeric pain rating scale , the Lower Extremity Functional Scale , the Anterior Knee Pain Scale , and a single-hop test were used as outcome measures at baseline ( pretreatment ) and 3 , 6 , and 12 months posttreatment . RESULTS At baseline , demographic , pain , and functional assessment data were similar between groups . Those in the KHE group had a higher level of function and less pain at 3 , 6 , and 12 months compared to baseline ( P<.05 ) . In contrast , the KE group had reduced pain only at the 3- and 6-month follow-ups ( P<.05 ) , without any changes in Lower Extremity Functional Scale , Anterior Knee Pain Scale , or hop testing ( P>.05 ) through the course of the study . Compared to the KE group , the KHE group had less pain and better function at 3 , 6 , and 12 months posttreatment ( P<.05 ) . For the Lower Extremity Functional Scale , the between-group difference in change scores from baseline at 3 , 6 , and 12 months posttreatment favored the KHE group by 22.0 , 22.0 , and 20.8 points , respectively . CONCLUSION Knee-stretching and -strengthening exercises supplemented by hip posterolateral musculature-strengthening exercises were more effective than knee exercises alone in improving long-term function and reducing pain in sedentary women with PFPS STUDY DESIGN R and omized clinical trial . OBJECTIVE To investigate the influence of strengthening the hip abductor and lateral rotator musculature on pain and function of females with patellofemoral pain syndrome ( PFPS ) . BACKGROUND Hip muscle weakness in women athletes has been the focus of many recent studies and is suggested as an important impairment to address in the conservative treatment of women with PFPS . However , it is still not well established if strengthening these muscles is associated with clinical improvement in pain and function in sedentary females with PFPS . METHODS Seventy females ( average±SD age , 25±07 years ) , with a diagnosis of unilateral PFPS , were distributed r and omly into 3 groups : 22 females in the knee exercise group , who received a conventional treatment that emphasized stretching and strengthening of the knee musculature ; 23 females in the knee and hip exercise group , who performed exercises to strengthen the hip abductors and external rotators in addition to the same exercises performed by those in the knee exercise group ; and of the 25 females who did not receive any treatment . The females of the nontreatment group ( control ) were instructed to maintain their normal daily activities . An 11-point numerical pain rating scale ( NPRS ) was used to assess pain during stair ascent and descent . The lower extremity functional scale ( LEFS ) and the anterior knee pain scale ( AKPS ) were used to assess function . The single-limb single hop test was also used as a functional outcome to measure preintervention and 4-week postintervention function . RESULTS The 3 groups were homogeneous prior to treatment in respect to demographic , pain , and functional scales data . Both the knee exercise and the knee and hip exercise groups showed significant improvement in the LEFS , the AKPS , and the NPRS , when compared to the control group ( P<.05 and P<.001 , respectively ) . But , when we considered minimal clinical ly important differences , only the knee and hip exercise group demonstrated mean improvements in AKPS and pain scores that were large enough to be clinical ly meaningful . For the single-limb single hop test , both groups receiving an intervention showed greater improvement than the control group , but there was no difference between the 2 interventions ( P>.05 ) . CONCLUSION Rehabilitation programs focusing on knee strengthening exercises and knee strengthening exercises supplemented by hip strengthening exercises were both effective in improving function and reducing pain in sedentary women with PFPS .  Improvements of pain and function were greater for the group that performed the hip strengthening exercises , but the difference was significant only for pain rating while descending stairs . LEVEL OF EVIDENCE Therapy , level 1b- STUDY DESIGN R and omized clinical trial . OBJECTIVES To compare the effects of functional stabilization training ( FST ) versus st and ard training on knee pain and function , lower-limb and trunk kinematics , trunk muscle endurance , and eccentric hip and knee muscle strength in women with patellofemoral pain . BACKGROUND A combination of hip- and knee-strengthening exercise may be more beneficial than quadriceps strengthening alone to improve pain and function in individuals with patellofemoral pain . However , there is limited evidence of the effectiveness of these exercise programs on the biomechanics of the lower extremity . METHODS Thirty-one women were r and omized to either the FST group or st and ard-training group .  Patients attended a baseline assessment session , followed by an 8-week intervention , and were reassessed at the end of the intervention and at 3 months after the intervention . Assessment measures were a 10-cm visual analog scale for pain , the Lower Extremity Functional Scale , and the single-leg triple-hop test . A global rating of change scale was used to measure perceived improvement . Kinematics were assessed during the single-leg squat . Outcome measures also included trunk endurance and eccentric hip and knee muscle strength assessment . RESULTS The patients in the FST group had less pain at the 3-month follow-up and greater global improvement and physical function at the end of the intervention compared to those in the st and ard-training group . Lesser ipsilateral trunk inclination , pelvis contralateral depression , hip adduction , and knee abduction , along with greater pelvis anteversion and hip flexion movement excursions during the single-leg squat , were only observed in the FST group after the intervention . Only those in the FST group had greater eccentric hip abductor and knee flexor strength , as well as greater endurance of the anterior , posterior , and lateral trunk muscles , after training . CONCLUSION An intervention program consisting of hip muscle strengthening and lower-limb and trunk movement control exercises was more beneficial in improving pain , physical function , kinematics , and muscle strength compared to a program of quadriceps-strengthening exercises alone CONTEXT Patellofemoral pain ( PFP ) is the most common injury in running and jumping athletes . R and omized controlled trials suggest that incorporating hip and core strengthening ( HIP ) with knee-focused rehabilitation ( KNEE ) improves PFP outcomes . However , no r and omized controlled trials have , to our knowledge , directly compared HIP and KNEE programs . OBJECTIVE To compare PFP pain , function , hip- and knee-muscle strength , and core endurance between KNEE and HIP protocol s after 6 weeks of rehabilitation . We hypothesized greater improvements in ( 1 ) pain and function , ( 2 ) hip strength and core endurance for patients with PFP involved in the HIP protocol , and ( 3 ) knee strength for patients involved in the KNEE protocol . DESIGN R and omized controlled clinical trial . SETTING Four clinical research laboratories in Calgary , Alberta ; Chicago , Illinois ; Milwaukee , Wisconsin ; and Augusta , Georgia . PATIENTS OR OTHER PARTICIPANTS Of 721 patients with PFP screened , 199 ( 27.6 % ) met the inclusion criteria ( 66 men [ 31.2 % ] , 133 women [ 66.8 % ] , age = 29.0 ± 7.1 years , height = 170.4 ± 9.4 cm , weight = 67.6 ± 13.5 kg ) . INTERVENTION(S ) Patients with PFP were r and omly assigned to a 6-week KNEE or HIP protocol . MAIN OUTCOME MEASURE(S ) Primary variables were self-reported visual analog scale and Anterior Knee Pain Scale measures , which were conducted weekly . Secondary variables were muscle strength and core endurance measured at baseline and at 6 weeks . RESULTS Compared with baseline , both the visual analog scale and the Anterior Knee Pain Scale improved for patients with PFP in both the HIP and KNEE protocol s ( P < .001 ) , but the visual analog scale scores for those in the HIP protocol were reduced 1 week earlier than in the KNEE group . Both groups increased in strength ( P < .001 ) , but those in the HIP protocol gained more in hip-abductor ( P = .01 ) and -extensor ( P = .01 ) strength and posterior core endurance ( P = .05 ) compared with the KNEE group . CONCLUSIONS Both the HIP and KNEE rehabilitation protocol s produced improvements in PFP , function , and strength over 6 weeks . Although outcomes were similar , the HIP protocol result ed in earlier resolution of pain and greater overall gains in strength compared with the KNEE protocol OBJECTIVE To compare the efficacy of posterolateral hip muscle strengthening versus quadriceps strengthening in reducing pain and improving health status in persons with patellofemoral pain ( PFP ) . DESIGN Comparative control trial . SETTING Rehabilitation facility . PARTICIPANTS Persons with a diagnosis of PFP ( N=36 ; 18 men , 18 women ) . INTERVENTIONS Patients were alternately assigned to a posterolateral hip muscle strengthening group ( 9 men and 9 women ) or a quadriceps strengthening group ( 9 men and 9 women ) . The posterolateral hip muscle strengthening group performed hip abductor and external rotator strengthening exercises , whereas the quadriceps strengthening group performed quadriceps strengthening exercises ( 3 times a week for 8wk ) . MAIN OUTCOME MEASURES Pain ( visual analog scale [ VAS ] ) and health status ( Western Ontario McMaster Universities Osteoarthritis Index [ WOMAC ] ) were assessed at baseline , postintervention , and 6-month follow-up . RESULTS Significant improvements in VAS and WOMAC scores were observed in both groups from baseline to postintervention and baseline to 6-month follow-up ( P<.001 ) . Improvements in VAS and WOMAC scores in the posterolateral hip exercise group were superior to those in the quadriceps exercise group postintervention and at 6-month follow-up ( P<.05 ) . CONCLUSIONS Although both intervention programs result ed in decreased pain and improved function in persons with PFP , outcomes in the posterolateral hip exercise group were superior to the quadriceps exercise group . The superior outcomes obtained in the posterolateral hip exercise group were maintained 6 months postintervention STUDY DESIGN R and omized clinical trial . OBJECTIVES To determine if females with patellofemoral pain syndrome ( PFPS ) who perform hip strengthening prior to functional exercises demonstrate greater improvements than females who perform quadriceps strengthening prior to the same functional exercises . BACKGROUND Although PFPS has previously been attributed to quadriceps dysfunction , more recent research has linked this condition to impairment of the hip musculature . Lower extremity strengthening has been deemed an effective intervention . However , research has often examined weight-bearing exercises , making it unclear if increased strength in the hip , quadriceps , or both is beneficial . METHODS Thirty-three females with PFPS performed either initial hip strengthening ( hip group ) or initial quadriceps strengthening ( quad group ) for 4 weeks , prior to 4 weeks of a similar program of functional weight-bearing exercises . Self-reported pain , function , and functional strength were measured . Isometric strength was assessed for hip abductors , external rotators , and knee extensors . A mixed-model analysis of variance was used to determine group differences over time . RESULTS After 4 weeks , there was less mean ± SD pain in the hip group ( 2.4 ± 2.0 ) than in the quad group ( 4.1 ± 2.5 ) ( P = .035 ) . From baseline to 8 weeks , the hip group demonstrated a 21 % increase ( P<.001 ) in hip abductor strength , while that remained unchanged in the quad group . All participants demonstrated improved subjective function ( P<.006 ) , objective function ( P<.001 ) , and hip external rotator strength ( P = .004 ) from baseline to testing at 8 weeks . CONCLUSION Both rehabilitation approaches improved function and reduced pain . For patients with PFPS , initial hip strengthening may allow an earlier dissipation of pain than exercises focused on the quadriceps Background Since knee complaints are common among athletes and are frequently presented in general practice , it is of interest to investigate the type of knee complaints represented in general practice of athletes in comparison with those of non-athletes . Therefore , the aim of this study is to investigate the differences in type of knee complaints between sport participants , in this study defined as athletes , and non-sport participants , defined as non-athletes , presenting in general practice . Further , differences in the initial policy of the GP , medical consumption , and outcome at one-year follow-up were also investigated . Methods Patients consulting their GP for a new episode of knee complaints were invited to participate in this prospect i ve cohort study . From the total HONEUR knee cohort population ( n = 1068 ) we extracted patients who were athletes ( n = 421 ) or non-athletes ( n = 388 ) . Results The results showed that acute distortions of the knee were significantly more diagnosed in athletes than in non-athletes ( p = 0.04 ) . Further , more athletes were advised by their GP to ' go easy on the knee ' than the non-athletes ( p < 0.01 ) , but no differences were found in number of referrals and medication prescribed by the GP . The medical consumption was significantly higher among athletes ; however , no significant differences were found between the two groups for recovery at one-year follow-up . Conclusion There are no major differences in the diagnosis and prognosis of knee complaints between athletes and non-athletes presented to the GP . This implies that there are no indications for different treatment strategies applied in both groups . However , athletes are more often advised to ' go easy on the knee ' and to rest than non-athletes . Further , there is a trend towards increased medical consumption among athletes while functional disability and pain are lower than among the non-athletes Background Patellofemoral pain syndrome is one of the most common chronic knee injuries ; however , little research has been done to determine the risk factors for this injury . Hypothesis Altered lower extremity kinematics and kinetics , decreased strength , and altered postural measurements will be risk factors . Study Design Cohort study ( prognosis ) ; Level of evidence , 2 . Methods A total of 1597 participants were enrolled in this investigation and prospect ively followed from the date of their enrollment ( July 2005 , July 2006 , or July 2007 ) through January 2008 , a maximum of 2.5 years of follow-up . Each participant underwent baseline data collection during their pre-freshman summer at the United States Naval Academy . Baseline data collection included 3-dimensional motion analysis during a jump-l and ing task , 6 lower extremity isometric strength tests , and postural alignment measurements ( navicular drop and Q angle ) . Results Risk factors for the development of patellofemoral pain syndrome included decreased knee flexion angle , decreased vertical ground-reaction force , and increased hip internal rotation angle during the jump-l and ing task . Additionally , decreased quadriceps and hamstring strength , increased hip external rotator strength , and increased navicular drop were risk factors for the development of patellofemoral pain syndrome . Conclusion Multiple modifiable risk factors for patellofemoral pain syndrome pain have been identified in this investigation . To decrease the incidence of this chronic injury , the risk factors for patellofemoral pain syndrome need to be targeted in injury prevention programs . Clinical Relevance Prevention programs should focus on increasing strength of the lower extremity musculature along with instructing proper mechanics during dynamic movements to decrease the incidence of patellofemoral pain syndrome BACKGROUND AND PURPOSE Assessment of the quality of r and omized controlled trials ( RCTs ) is common practice in systematic review s. However , the reliability of data obtained with most quality assessment scales has not been established . This report describes 2 studies design ed to investigate the reliability of data obtained with the Physiotherapy Evidence Data base ( PEDro ) scale developed to rate the quality of RCTs evaluating physical therapist interventions . METHOD In the first study , 11 raters independently rated 25 RCTs r and omly selected from the PEDro data base . In the second study , 2 raters rated 120 RCTs r and omly selected from the PEDro data base , and disagreements were resolved by a third rater ; this generated a set of individual rater and consensus ratings . The process was repeated by independent raters to create a second set of individual and consensus ratings . Reliability of ratings of PEDro scale items was calculated using multirater kappas , and reliability of the total ( summed ) score was calculated using intraclass correlation coefficients ( ICC [ 1,1 ] ) . RESULTS The kappa value for each of the 11 items ranged from.36 to.80 for individual assessors and from.50 to.79 for consensus ratings generated by groups of 2 or 3 raters . The ICC for the total score was.56 ( 95 % confidence interval=.47-.65 ) for ratings by individuals , and the ICC for consensus ratings was.68 ( 95 % confidence interval=.57-.76 ) . DISCUSSION AND CONCLUSION The reliability of ratings of PEDro scale items varied from " fair " to " substantial , " and the reliability of the total PEDro score was " fair " to " good . Objective Patellar malalignment is a major cause of patellofemoral pain syndrome ( PFPS ) , but the relationship between clinical symptoms and changes in patellar position and knee muscle strength has not been confirmed . This study examined the effect of weight training on hip and knee muscle strength , patellofemoral joint contact area , and patellar tilt on subjects with and without PFPS , hoping to develop an optimal rehabilitation protocol for subjects with PFPS . Design The study uses a prospect i ve independent group comparison . Fifteen subjects with and without PFPS were assessed for knee strength , patellofemoral joint contact area , and patellar tilt angle using magnetic resonance imaging . The subjects with PFPS were also examined and given a numeric pain rating score and a Kujala patellofemoral score . The subjects performed lower-limb weight training 3 times/wk for 8 wks , and the outcomes were assessed both before and after training . Results Subjects with PFPS have increased their patellofemoral joint contact area after weight training ( P < 0.001 ) . No statistical significant change was found on the patellar tilt angle . The isometric and isokinetic knee strength in subjects with and without PFPS have increased after weight training ( P value increased from 0.007 to 0.05 ) . Both numeric pain rating and Kujala patellofemoral score in the PFPS group improved after training ( P < 0.001 ) . Conclusions Weight-training exercise increased knee muscle strength and the patellofemoral joint contact area , which could reduce mechanical stress in the joint , improving pain and function in subjects with PFPS OBJECTIVE To determine the efficacy of the individual components of physiotherapy in subjects with anterior knee pain . METHODS An observer blind , prospect i ve , factorial design r and omised controlled trial . 81 young adults with anterior knee pain were r and omly allocated to one of four treatment groups : ( 1 ) exercise , taping , and education ; ( 2 ) exercise and education ; ( 3 ) taping and education ; and ( 4 ) education alone . Each group received six physiotherapist-led treatments over three months . Follow up took place at three months using the following outcome measures : patient satisfaction ( discharge/refer for further treatment ) ; a visual analogue pain score ; the WOMAC lower limb function score ; the Hospital Anxiety and Depression scale ( HAD ) ; and quadriceps strength . At 12 months the WOMAC and HAD were assessed by postal question naire . RESULTS All groups showed significant improvements in WOMAC , visual analogue , and HAD scores ; these improvements did not vary significantly between the four groups or between exercising/non-exercising and taped/non-taped patients at three and 12 months . However , patients who exercised were significantly more likely to be discharged at three months than non-exercising patients ( χ2 , p<0.001 ) . Taping was not significantly associated with discharge . Significantly greater improvements in WOMAC , visual analogue , and the anxiety score ( but not the depression score ) were seen in patients who were discharged than in those who were referred . CONCLUSIONS The proprioceptive muscle stretching and strengthening aspects of physiotherapy have a beneficial effect at three months sufficient to permit discharge from physiotherapy . These benefits are maintained at one year . Taping does not influence the outcome Objective : To determine the effectiveness of patellar bracing for treatment of patellofemoral pain syndrome ( PFPS ) . Design : Prospect i ve , r and omized , single-blinded clinical trial . Setting : Subjects recruited from the general population of the city of Calgary . Subjects : A total of 136 subjects ( 79 females and 57 males with a total of 197 affected knees ) diagnosed with PFPS . Intervention : Subjects were r and omly assigned to 1 of 4 treatment groups : ( 1 ) home exercise program , ( 2 ) patellar bracing , ( 3 ) home exercise program with patellar bracing , and ( 4 ) home exercise program with knee sleeve . Outcome Measures : The outcome measurements were knee function ( KF ) and 10-cm visual analogue scale ( VAS ) pain ratings for 3 different situations : knee pain during sport activity , knee pain 1 hour after sport activity , and knee pain after sitting with knees bent for 30 minutes . The outcome measurements were assessed at baseline and at 3 , 6 , and 12 weeks . The investigators were blinded to the treatment group of each subject . Calculations were made for 95 % confidence intervals for the change in KF and VAS pain ratings from baseline measurement to 12 weeks . Results : There was no difference in the 95 % confidence intervals in the change of KF and VAS pain ratings among the 4 treatment groups over 12 weeks . Conclusions : Symptoms of PFPS improved over time in terms of pain and knee function regardless of the treatment group . Patellar bracing did not improve the symptoms of PFPS more quickly when added to a home program of leg strengthening . However , patellar bracing alone can improve the symptoms of PFPS PURPOSE Patellofemoral pain ( PFP ) is the leading cause of knee pain in runners . Proximal and distal running mechanics have been linked to the development of PFP . However , the lack of prospect i ve studies limits establishing a causal relationship of these mechanics to PFP . The purpose of this study was to prospect ively compare running mechanics in a group of female runners who went on to develop PFP compared with healthy controls . It was hypothesized that runners who go on to develop PFP would exhibit greater hip adduction , hip internal rotation , and greater rear foot eversion . METHODS Four hundred healthy female runners underwent an instrumented gait analysis  and were then tracked for any injuries that they may have developed over a 2-yr period . Fifteen cases of PFP developed , which were confirmed by a medical professional . Their initial running mechanics were compared to an equal number of runners who remained uninjured . RESULTS We found that female runners who developed PFP exhibited significantly greater hip adduction ( P = 0.007 ) . No statistically significant differences were found for the hip internal rotation angle ( P = 0.47 ) or rear foot eversion ( P = 0.1 ) . CONCLUSIONS The finding of greater hip adduction in female runners who develop PFP is in agreement with previous cross-sectional studies . These results suggest that runners who develop PFP use a different proximal neuromuscular control strategy than those who remain healthy . Injury prevention and treatment strategies should consider addressing these altered hip mechanics STUDY DESIGN R and omized controlled trial . OBJECTIVES To examine the effectiveness of isolated hip abductor and external rotator strengthening on pain , health status , and hip strength in females with patellofemoral pain ( PFP ) . BACKGROUND Altered hip kinematics result ing from hip muscle weakness has been proposed as a contributing factor in the development of PFP . To date , no study has examined clinical outcomes associated with isolated hip muscle strengthening in those with PFP . METHODS Twenty-eight females with PFP were sequentially assigned to an exercise ( n = 14 ) or a no-exercise control group ( n = 14 ) . The exercise group completed bilateral hip abductor and external rotator strengthening 3 times per week for 8 weeks . Pain ( visual analog scale ) , health status ( WOMAC ) , and hip strength ( h and held dynamometer ) were assessed at baseline and postintervention . Pain and health status were also evaluated at 6 months postintervention in the exercise group . Two-factor mixed-model analyses of variance were used to determine the effects of the intervention on each outcome variable . RESULTS Significant group-by-time interactions were observed for each variable of interest . Post hoc testing revealed that pain , health status , and bilateral hip strength improved in the exercise group following the 8-week intervention but did not change in the control group . Improvements in pain and health status were sustained at 6-month follow-up in the exercise group . CONCLUSION A program of isolated hip abductor and external rotator strengthening was effective in improving pain and health status in females with PFP compared to a no-exercise control group . The incorporation of hip-strengthening exercises should be considered when design ing a rehabilitation program for females with PFP . LEVEL OF EVIDENCE Therapy , level 2b Objectives : To study the effect of additional strengthening of hip abductor and lateral rotator muscles in a strengthening quadriceps exercise rehabilitation programme for patients with the patellofemoral pain syndrome . Design : R and omized controlled pilot trial . Setting : Clinical setting with home programme . Participants : Fourteen patients with patellofemoral pain syndrome . Intervention : The subjects were r and omly assigned to the intervention group ( strengthening of quadriceps plus strengthening of hip abductor and lateral rotator muscles ) or to the control group ( strengthening of quadriceps ) . Both groups participated in a six-week home exercise protocol . Main outcome measures : The perceived pain symptoms , isokinetic eccentric knee extensor , hip abductor and lateral rotator torques and the gluteus medius electromyographic activity were assessed before and after treatment . Parametric and non-parametric tests were used to compare the groups before and after treatment with α=0.05 . Results : Only the intervention group improved perceived pain symptoms during functional activities ( P=0.02—0.04 ) and also increased their gluteus medius electromyographic activity during isometric voluntary contraction ( P=0.03 ) . Eccentric knee extensors torque increased in both groups ( P=0.04 and P=0.02 ) . There was no statistically significant difference in the hip muscles torque in either group . Conclusion : Supplementation of strengthening of hip abductor and lateral rotator muscles in a strengthening quadriceps exercise programme provided additional benefits with respect to the perceived pain symptoms during functional activities in patients with patellofemoral pain syndrome after six weeks of treatment
target: Meta‐analyses showed no significant changes in strength for any of the interventions . •
background: BACKGROUND : The addition of hip strengthening to knee strengthening for persons with patellofemoral pain has the potential to optimize treatment effects .
  OBJECTIVE : To examine the efficacy of hip strengthening , associated or not with knee strengthening , to increase strength , reduce pain , and improve activity in individuals with patellofemoral pain .