Analysis of outcome measures for persons with patellofemoral pain: which are reliable and valid? Short-term effects of hip abductors and lateral rotators strengthening in females with patellofemoral pain syndrome: a randomized controlled clinical trial. Factors that predict a poor outcome 5–8 years after the diagnosis of patellofemoral pain: a multicentre observational analysis The Effects of Exercise for the Prevention of Overuse Anterior Knee Pain Effects of prefabricated foot orthoses on pain and function in individuals with patellofemoral pain syndrome: a cohort study. Effect of bracing on the prevention of anterior knee pain—a prospective randomized study Prognostic factors for patellofemoral pain: a multicentre observational analysis Comparison of symptoms and clinical findings in subgroups of individuals with patellofemoral pain
OBJECTIVE To examine the test-retest reliability , validity , and responsiveness of several outcome measures in the treatment of patellofemoral pain . DESIGN Evaluation of the clinimetric properties of individual outcome measures for patellofemoral pain treatment , using data collected from a previously published r and omized controlled trial ( RCT ) . SETTING General community and private practice . PARTICIPANTS The data from 71 persons enrolled in an RCT of a conservative intervention for patellofemoral pain were used to evaluate the measures ' validity and responsiveness . A subset of this cohort ( n=20 ) was used to assess reliability . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Three  10-cm visual analog scales ( VASs ) for usual pain ( VAS-U ) , worst pain ( VAS-W ) , and pain on 6 aggravating activities ( walking , running , squatting , sitting , ascending and descending stairs ) ( VAS-activity ) ; the Functional Index Question naire ( FIQ ) ; the Anterior Knee Pain Scale ( AKPS ) ; and the global rating of change . RESULTS The test-retest reliability ranged from poor ( intraclass correlation coefficient [ICC]=.49 ) to good ( ICC=.83 ) , and the measures correlated moderately with each other ( r range,.56-.72 ) . Median change scores differed significantly between improved and unimproved persons for all measures . The effect sizes for VAS-U ( .79 ) , VAS-W ( .88 ) , and the AKPS ( .98 ) were large , indicating greater responsiveness than the FIQ ( .37 ) and VAS-activity ( .66 ) . Similarly , the AKPS and VAS-W were the most efficient measures for detecting a treatment effect when compared with a reference measure ( VAS-U , which was assigned a value of 1 ) . The minimal difference that patients or clinicians consider clinical ly important for the AKPS is 10 ( out of 100 ) points and for the VAS it is 2 cm ( out of 10 cm ) . CONCLUSIONS The AKPS and VAS for usual or worst pain are reliable , valid , and responsive and are therefore recommended for future clinical trials or clinical practice in assessing treatment outcome in persons with patellofemoral pain 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- Background Patellofemoral pain ( PFP ) has traditionally been viewed as self-limiting , but recent studies show that a large proportion of patients report chronic knee pain at long-term follow-up . We identified those patients with an unfavourable recovery ( ‘ moderate improvement ’ to ‘ worse than ever ’ measured on a Likert scale ) and examined whether there is an association between PFP and osteoarthritis ( OA ) at 5–8-year follow-up . Methods Long-term follow-up data were derived from 2 r and omised controlled trials ( n=179 , n=131 ) .  Patient-reported measures were obtained at baseline .  Pain severity ( 100 mm visual analogue scale ( VAS ) ) , function ( Anterior Knee Pain Scale ( AKPS ) ) and self-reported recovery were measured 5–8 years later , along with knee radiographs . Multivariate backward stepwise linear regression analyses were used to evaluate the prognostic ability of baseline pain duration , pain VAS and AKPS on outcomes of pain VAS and AKPS at 5–8 years . Results 60 ( 19.3 % ) participants completed the question naires at 5–8-year follow-up ( 45 women , mean age at baseline 26 years ) and 50 underwent knee radiographs . No differences were observed between responders and non-responders regarding baseline demographics , and 3-month and 12-month pain severity and recovery . 34 ( 57 % ) reported unfavourable recovery at 5–8 years . 48 out of 50 participants ( 98 % ) had no signs of radiographic knee OA . Multivariate models revealed that baseline PFP duration ( > 12 months ; R2=0.22 ) and lower AKPS ( R2=0.196 ) were significant predictors of poor prognosis at 5–8 years on measures of worst pain VAS and AKPS , respectively . Summary and conclusion More than half of participants with PFP reported an unfavourable recovery 5–8 years after recruitment , but did not have radiographic knee OA . Longer PFP duration and worse AKPS score at baseline predict poor PFP prognosis . Education of health practitioners and the general public will provide patients with more realistic expectations regarding prognosis Background : Anterior knee pain ( AKP ) is the most common activity-related injury of the knee . The authors investigated the effect of an exercise intervention on the incidence of AKP in UK army recruits undergoing a 14-week physically arduous training program . Hypothesis : Modifying military training to include targeted preventative exercises may reduce the incidence of AKP in a young recruit population . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : A single-blind cluster r and omized controlled trial was performed in 39 male and 11 female training groups ( median age : 19.7 years ; interquartile range , 17 - 25 ) undergoing phase 1 of army recruit training . Each group was r and omly assigned to either an intervention ( n = 759 ) or control ( n = 743 ) protocol . The intervention consisted of 4 strengthening and 4 stretching exercises completed during supervised physical training lessons ( 7 per week ) . The control group followed the existing training syllabus warm-up exercises . The primary outcome was a diagnosis of AKP during the 14-week training program . Results : Forty-six participants ( 3.1 % ; 95 % confidence interval [ CI ] , 2.3 - 4.1 ) were diagnosed with AKP . There were 36 ( 4.8 % ; 95%CI , 3.5 - 6.7 ) new cases of AKP in the control group and 10 ( 1.3 % ; 0.7 - 2.4 ) in the intervention group . There was a 75 % reduction in AKP risk in the intervention group ( unadjusted hazard ratio = 0.25 ; 95 % CI , 0.13 - 0.52 ; P < .001 ) . Three participants ( 0.4 % ) from the intervention group were discharged from the military for medical reasons compared to 25 ( 3.4 % ) in the control group . Conclusion : A simple set of lower limb stretching and strengthening exercises result ed in a substantial and safe reduction in the incidence of AKP in a young military population undertaking a physical conditioning program . Such exercises could also be beneficial for preventing this common injury among nonmilitary participants in recreational physical activity OBJECTIVES This study evaluated the effects of unmodified prefabricated foot orthoses over a 12-week period on functional performance ; and subjective pain and function in individuals with patellofemoral pain syndrome ( PFPS ) . DESIGN Prospect i ve cohort study over 12 weeks . Each participant was prescribed prefabricated foot orthoses at baseline . PARTICIPANTS Sixty individuals with PFPS ( 18 - 35 years ) . MAIN OUTCOME MEASURES Change in pain and ease of completing a single leg squat ; change in the number of pain free step downs and single leg rises from sitting ; usual and worst pain in the previous week ; the anterior knee pain scale ( AKPS ) ; and the lower extremity functional scale ( LEFS ) . RESULTS At 12 weeks , significant improvements in single leg squat pain and ease , and the number of pain free step downs and single leg rises from sitting were found . Additionally , significant reductions in usual and worst pain , and improvements on the AKPS and LEFS were observed . CONCLUSIONS Functional performance improvements following unmodified prefabricated foot orthoses were greater at 12 weeks that those achieved immediately . Enhanced functional performance over time may have significant implication s for osteoarthritis prevention in some individuals with PFPS . Improvements in subjective pain and function appear to plateau over time There have been numerous reports about the use of knee braces to prevent traumatic knee injuries . Despite the frequent use of braces , very few prospect i ve studies have been performed to study the effect of knee braces for preventing  anterior knee pain syndrome ( AKPS ) . The purpose of this study was to assess the effectiveness of a dynamic patellofemoral brace ( On-Track System , dj Orthopedics ) in the prevention of AKPS .  167 military recruits without history of knee pain were r and omized into two groups prior to the start of their 6-week basic military training ( BMT ) program . The first group ( brace group ) consisted of 54 recruits who  wore the braces for all physical activities during these 6 weeks . 113 recruits served as a control group , and followed the same 6-week strenuous training program . Chi square statistics ( Fisher exact test ) were used to compare the number of AKPS patients in the brace group and in the non-brace group . Our results indicated that recruits in the brace group appeared to develop significantly less anterior knee pain compared to the recruits in the control group ( p = 0.020 ) . Out of the 54 recruits in the brace group , ten ( 18.5 % ) developed anterior knee pain during this study . In the control group ( n = 113 ) , 42 recruits ( 37 % ) developed anterior knee pain . We conclude that the result of the present study suggests that the use of a dynamic patellofemoral brace is an effective way to prevent the development of anterior knee pain in persons undergoing a strenuous training program Objectives Describe proportions of individuals with patellofemoral pain ( PFP ) with an unfavourable recovery over 12 months ; identify clinical predictors of poor recovery at 3 and 12 months ; and determine baseline values of predictors that identify those with poor 12-month prognosis . Methods An observational analysis utilised data from 310 individuals with PFP enrolled in two r and omised clinical trials . Thirteen baseline variables ( participant , PFP , study characteristics ) were investigated for their prognostic ability . Pain , function and global recovery were measured at 3 and 12 months . Multivariate backward stepwise regression analyses ( treatment-adjusted , p<0.10 ) were performed for each follow-up measure . Receiver operator characteristic curves identified cut-points associated with unfavourable recovery at 12 months . Results 55 % and 40 % of participants had an unfavourable recovery at 3 and 12 months , respectively . Longer baseline pain duration was significantly associated with poor 3-month and 12-month recovery on measures of pain severity ( β 11.36 to 24.94 ) , Anterior Knee Pain ( AKP ) Scale ( −4.44 to −11.33 ) and global recovery ( OR : 2.32 to 6.11 ) . Greater baseline pain severity and lower AKP Scale score were significantly associated with poor recovery on multiple measures ( p<0.05 ) . Baseline duration > 2 months and AKP Scale score < 70/100 were associated with unfavourable 12-month recovery . Conclusions A substantial number of individuals with PFP have an unfavourable recovery over 12 months , irrespective of intervention . Knee pain duration > 2 months is the most consistent prognostic indicator , followed by AKP Scale score < 70 . Sports medicine practitioners should utilise interventions with known efficacy in reducing PFP , and promote early intervention to maximise prognosis . Trial registration Australian study : Australian Clinical Trials Registry ( ACTRN012605000463673 ) , Clinical Trials.gov ( NCT00118521 ) ; Dutch study : International St and ard R and omised Controlled Trial Number Register ( IS RCT N83938749 Patellofemoral pain syndrome ( PFPS ) is one of the most common musculoskeletal disorders . However , no consensus on the definition , classification , assessment , diagnosis , or management has been reached . We evaluated symptoms and clinical findings in subgroups of individuals with PFPS , classified on the basis of the findings in radiological examinations and compared the findings with knee-healthy subjects . An orthopedic surgeon and a physical therapist consecutively examined 80 patients clinical ly diagnosed as having PFPS and referred for physical therapy .  The examination consisted of taking a case history and clinical tests . Radiography revealed pathology in 15 patients , and scintigraphic examination revealed focal uptake in 2 patients indicating pathology ( group C ) . Diffusely increased uptake was present in 29 patients ( group B ) . In the remaining 29 patients radiographic and scintigraphic examinations were normal ( group A ) . Knee-healthy controls ( group D ) reported no clinical symptoms . No symptom could be statistically demonstrated to differ between the three patient groups . Knee-healthy subjects differed significantly from the three patient groups in all clinical tests measuring pain in response to the provocations ; compression test , medial and lateral tenderness , passive gliding of the patella , but they also differed in Q angle . Differences in clinical tests between the patient groups were nonsignificant . The main finding in our study on patients clinical ly diagnosed with PFPS is that possible pathologies can not be detected from the patient 's history or from commonly used clinical tests
Of the functional tests , squatting demonstrated the highest sensitivity .
Other useful tests include pain during stair climbing and prolonged sitting .
Conclusion A diagnostic checklist is useful as it provides a structured method for diagnosing AKP in a clinical setting .
Background  Anterior knee pain ( AKP ) or patellofemoral pain syndrome is common and may limit an individual 's ability to perform common activities of daily living such as stair climbing and prolonged sitting .
The diagnosis is difficult as there are multiple definitions for this disorder and there are no accepted criteria for diagnosis .
It is therefore most commonly a diagnosis that is made once other pathologies have been excluded .
Objectives The aim of this study was to create an evidence -based checklist for research ers and clinicians to use for the diagnosis of AKP .