Anterior Knee Pain Scale (AKPS): structural and criterion validity in Brazilian population with patellofemoral pain.

PURPOSE: To identify the best internal structure of the Brazilian version of the Anterior Knee Pain Scale (AKPS), comparing different instrument structures (structural validity) and correlating the scores of the versions (criterion validity). METHODS: We included Brazilian volunteers, aged ≥ 18 years, with patellofemoral pain (PFP) for at least 3 months. We used the confirmatory factor analysis and considered the following fit indices: chi-square/degrees of freedom (DF), comparative fit index (CFI), Tucker-Lewis index (TLI), root mean square error of approximation (RMSEA). We considered the structure with the lowest values of the Akaike information criterion (AIC), sample size adjusted Bayesian information criterion (SABIC), and assessed criterion validity using Pearson correlation coefficient (r) to correlate the long and short versions. RESULTS: The study included 101 participants, mostly women (65.3%), young adults (~ 31 years old), overweight (BMI > 25 kg/m2), incomplete higher education (37.6%), and physically active (64.4%). The original 1-domain, 13-item structure showed adequate fit indices (chi-square/GL < 3.00, TLI and CFI > 0.90, and RMSEA < 0, 08). However, items 11 and 12 had a factorial load of less than 0.23. Therefore, we excluded items 11 and 12 and found adequate fit indices (chi-square/GL < 3.00, TLI and CFI > 0.90, and RMSEA < 0, 08) and lower AIC and SABIC values. We observed a correlation coefficient above the acceptable cutoff of 0.70 (r = 0.966, p-value < 0.001) between the versions. CONCLUSION: The 11-item AKPS (without items 11 and 12) is the version with the most adequate internal structure and correlates satisfactorily with the long version of the instrument.

Home-based exercise program and Health education in patients with patellofemoral pain: a randomized controlled trial.

BACKGROUND: Patellofemoral pain (PFP) is one of the most common disorders of the knee joint. Home-based exercise is an effective intervention to achieve self-management for chronic diseases. This study evaluated the effects of home-based exercise and health education in patients with PFP. METHODS: Patients who had PFP were randomly allocated to an intervention group (IG) or control group (CG). Patients in the IG received a 6-week tailored home-based exercise program with health education via remote support, while patients in the CG group only received health education. Clinical outcomes were compared using the Anterior Knee Pain Scale (AKPS) to measure function and the Visual Analog Scale (VAS) to measure "worst pain" and "pain with daily activity". Muscle strength was measured according to the peak torque of the knee muscles using an isokinetic system. RESULTS: Among a total of 112 participants screened for eligibility, 38 were randomized and analyzed, including 19 participants in the intervention group and 19 participants in the control group. There were no significant differences in baseline characteristics between the groups. At 6-week follow-up, the intervention group showed a greater worst pain reduction (between-group difference, -19.3 [95%CI, -23.2 to -15.5]; P < 0.01) and pain with daily activity (between-group difference, -22.9 [95%CI, -28.3 to -17.4]; P < 0.01) than the control group. Similarly, the intervention group had better improvements in AKPS (between-group difference, 9.0 [95%CI, 4.1 to 13.9]; P < 0.01) and knee extensor strength (between-group difference, 20.1 [95%CI, 14.5 to 25.8]; P < 0.01), compared to the control group. No adverse events were reported. CONCLUSION: Home-based exercise and health education resulted in less pain, better function, and higher knee muscle strength compared with no exercise in patients with PFP. A large randomized controlled trial with long-term follow-up is required to confirm these findings. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2200056224 ( https://www.chictr.org.cn/showproj.aspx?proj=135506 ). Registered on February 1, 2022.

Evaluation and Treatment of Knee Pain: A Review.

Importance: Approximately 5% of all primary care visits in adults are related to knee pain. Osteoarthritis (OA), patellofemoral pain, and meniscal tears are among the most common causes of knee pain. Observations: Knee OA, affecting an estimated 654 million people worldwide, is the most likely diagnosis of knee pain in patients aged 45 years or older who present with activity-related knee joint pain with no or less than 30 minutes of morning stiffness (95% sensitivity; 69% specificity). Patellofemoral pain typically affects people younger than 40 years who are physically active and has a lifetime prevalence of approximately 25%. The presence of anterior knee pain during a squat is approximately 91% sensitive and 50% specific for patellofemoral pain. Meniscal tears affect an estimated 12% of the adult population and can occur following acute trauma (eg, twisting injury) in people younger than 40 years. Alternatively, a meniscal tear may be a degenerative condition present in patients with knee OA who are aged 40 years or older. The McMurray test, consisting of concurrent knee rotation (internal or external to test lateral or medial meniscus, respectively) and extension (61% sensitivity; 84% specificity), and joint line tenderness (83% sensitivity; 83% specificity) assist diagnosis of meniscal tears. Radiographic imaging of all patients with possible knee OA is not recommended. First-line management of OA comprises exercise therapy, weight loss (if overweight), education, and self-management programs to empower patients to better manage their condition. Surgical referral for knee joint replacement can be considered for patients with end-stage OA (ie, no or minimal joint space with inability to cope with pain) after using all appropriate conservative options. For patellofemoral pain, hip and knee strengthening exercises in combination with foot orthoses or patellar taping are recommended, with no indication for surgery. Conservative management (exercise therapy for 4-6 weeks) is also appropriate for most meniscal tears. For severe traumatic (eg, bucket-handle) tears, consisting of displaced meniscal tissue, surgery is likely required. For degenerative meniscal tears, exercise therapy is first-line treatment; surgery is not indicated even in the presence of mechanical symptoms (eg, locking, catching). Conclusions and Relevance: Knee OA, patellofemoral pain, and meniscal tears are common causes of knee pain, can be diagnosed clinically, and can be associated with significant disability. First-line treatment for each condition consists of conservative management, with a focus on exercise, education, and self-management.

Patellofemoral pain in general practice: the incidence and management.

BACKGROUND: Patellofemoral pain (PFP) is a nontraumatic knee problem primarily observed in physically active adolescents. The objective of this study was to determine the incidence and management of PFP in children and adolescents in general practice. METHODS: A retrospective cohort study was conducted using a regional primary care database containing full electronic health records of over 300,000 patients. Patients with a new PFP diagnosis between the years 2013 and 2019 were extracted using a search algorithm based on International Classification of Primary Health Care coding and search terms in free text. Data on the management of PFP were manually checked and analysed. In addition, a sub-analysis for chronic and nonchronic PFP patients was performed. RESULTS: The mean incidence of PFP over the study period was 3.4 (95% CI 3.2-3.6) per 1,000 person years in the age group of 7-24 years. Girls had a higher incidence rate (4.6 [95% CI 4.3-5.0]) compared to boys (2.3 [95% CI 2.1-2.5]). Peak incidence was at age 13 years for both sexes. The most commonly applied management strategy was advice (55.1%), followed by referral to physiotherapy (28.2%), analgesics prescription (10.4%), and referral to the orthopaedic surgeon (8.9%). No differences were found in age, sex, and treatment between chronic and nonchronic PFP patients. CONCLUSIONS: The average Dutch general practitioner sees approximately 1.4 new child or adolescent with PFP per year. Overall management strategies were in concordance with current Dutch general practice guideline on nontraumatic knee problems. More insight should be gained in the population with chronic complaints.

Effect of Tan Tui combined with kinesio taping on the posture control of patients with PFPS: protocol for a randomized controlled trial.

BACKGROUND: Patellofemoral pain syndrome (PFPS) is a chronic disease. Its early symptoms are mild and can be relieved by rest after the pain. If there is no effective rehabilitation, it may develop into patellofemoral arthritis. Physiotherapy and appropriate exercise intervention can improve PFPS and postural control during exercise. Tan Tui (TT) is an effective means to improve postural control. Whether combined kinesio taping (KT) can be used as an effective treatment for PFPS patients' recovery has not yet been confirmed. METHODS/DESIGN: Seventy-two eligible patients with early-stage PFPS will be recruited and randomized into 4 groups: TT + KT group (n = 18), TT + KTp group (n = 18), KT group (n = 18), and CON group (n = 18). The TT + KT group was treated with TT combined with KT intervention; the TT + KTp group was treated with TT and KT placebo technical intervention; the KT group was treated with KT intervention alone; the CON group was treated with routine activities. All 4 groups received 30 min, three times a week, for a total of 6 weeks of intervention training. Measurements will be performed at baseline, mid-intervention (4 weeks), and post-intervention (6 weeks) with visual analog scale/score, (VAS), Knee joint Lysholm function score (Lysholm), UniPedal Stance Test (UST), Star Excursion Balance Test ( SEBT), Relative Peak Torque, (RPT), and Knee joint Position PercePtion (KJPP), to check the maintenance of the effect of any intervention. DISCUSSION: For the first time in this trial, the impact will be evaluated. If the results are the same as expected, they will provide evidence that TT combined with KT sticking intervention can promote the posture control of patients with early PFPS. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2100051166. Registered on 15 September 2021.

Patient-Reported Outcome Measures for Adults and Adolescents With Patellofemoral Pain: A Systematic Review of Construct Validity, Reliability, Responsiveness, and Interpretability Using the COSMIN Methodology.

OBJECTIVE: We aimed to appraise the construct validity, reliability, responsiveness, and interpretability of patient-reported outcome measures (PROMs) used to assess function and pain in adults and adolescents with patellofemoral pain (PFP). DESIGN: Systematic review of measurement properties LITERATURE SEARCH: We searched the PubMed, CINAHL, Scopus, SPORTDiscus, and Cochrane Library databases from inception to January 6, 2022. STUDY SELECTION CRITERIA: We included studies that assessed the measurement properties of English-language PROMs for PFP and their cultural adaptations and translations. DATA SYNTHESIS: Using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology, we determined overall ratings and quality of evidence for construct validity, internal consistency, reliability, measurement error, and responsiveness. We extracted data related to interpretability for clinical use. RESULTS: After screening 7066 titles, 61 studies for 33 PROMs were included. Only 2 PROMs had evidence of "sufficient" or "indeterminate" quality for all measurement properties. The Knee injury and Osteoarthritis Outcome Score patellofemoral subscale (KOOS-PF) had "low" to "high" quality evidence for a rating of "sufficient" for 4 measurement properties. The Lower Extremity Functional Scale (LEFS) had very low-quality evidence for a "sufficient" rating for 4 measurement properties. The KOOS-PF and LEFS were rated "indeterminate" for structural validity and internal consistency. The KOOS-PF had the best interpretability with reported minimal important change and 0% ceiling and floor effects. No studies examined cross-cultural validity. CONCLUSION: The KOOS-PF and LEFS had the strongest measurement properties among PROMs used for PFP. More research is needed, particularly regarding structural validity and interpretability of PROMs. J Orthop Sports Phys Ther 2023;53(8):1-20. Epub: 20 June 2023. doi:10.2519/jospt.2023.11730.

Knee skin temperature response of patients with bilateral patellofemoral syndrome before and after heat and cold stress.

Patellofemoral Pain Syndrome is characterized by the presence of pain in the front area of the knee, which occurs when performing common activities such as climbing stairs, and bending the knees, among others. The objective of this research was to evaluate the detection capability of infrared thermography in patients with Patellofemoral Pain Syndrome, in the baseline state, as well as after the application of thermal stress. The investigation was conducted in 48 patients, who were subdivided into four groups (n = 12). Two subgroups were healthy patients and two with Patellofemoral Pain Syndrome. For the diagnosis of the syndrome, a manual evaluation was performed using the Zohlen test and Q angle measurement. Subsequently, cold stress was applied for 10 min to a healthy subgroup and an experimental subgroup. The remaining two subgroups were subjected to heat stress for 15 min. Thermographic images of the lower extremities were acquired at seven time points, at baseline, immediately after application of thermal stress and then every 3 min until 15 min were completed. It was observed that patients presented Patellofemoral Pain Syndrome bilaterally. After statistical analysis, it was found that there were no significant differences in baseline temperature between the groups. However, for heat stress, a higher temperature was observed in the group with Patellofemoral Pain Syndrome (p < 0.05) in the recovery period, and in the case of cold stress, only a lower temperature in the left knee immediately after the application. In conclusion, it is not possible to detect patellofemoral syndrome bilaterally in the baseline state by thermography and neither is it evident in cold stress. However, after heat stress, thermal recovery is lower for the PFPS group, so it would be susceptible to detection.

Functional tests in women with patellofemoral pain: Which tests make a difference in physical therapy evaluation.

BACKGROUND: Patellofemoral pain (PFP) is characterized by anterior knee, which intensifies during functional activities that require the eccentric action of the quadriceps muscle, specially. In ths way, quantitatively measurable functional tests that simulate these activities should be included in the physical therapy evaluation. OBJECTIVE: To identify which functional tests are most indicated for the evaluation of women with PFD. METHOD: This study evaluated 100 young women (50 with PFP), during the execution of the following functional performance tests: Triple hop, Vertical Jump, Single leg squat, Step Down, YBalance tests, Lunge test and running. Dynamic valgus was also assessed in the tests. The isometric muscle strength of the following muscle groups: hip abductors, extensors and lateral rotators, knee extensors, evertors, and plantar flexors were evaluated. Functional Perception were evaluated by Anterior Knee Pain Scale and Activities of Daily Living Scale. RESULTS: PFP group showed lower performance during the Y-Balance, triple hop, vertical jump tests and running. Was observed an increase in dynamic valgus during Triple Hop, Vertical Jump tests and running in PFP group, besides a poorer perception of function. For all lower limb muscle groups, the PFP group showed a reduction in peak isometric force. CONCLUSION: The YBalance, triple hop, vertical jump tests, and running should be included in the physical therapy evaluation, in addition to aspects of lower limb muscle strength.

Effects of an online program including mindfulness, exercise therapy and patient education compared to online exercise therapy and patient education for people with Patellofemoral Pain: protocol for a randomized clinical trial.

BACKGROUND: Patellofemoral pain (PFP) is a common knee disorder that causes persistent pain, lower self-reported function and quality of life. People with PFP also present with altered psychological factors, which are associated with higher levels of pain and dysfunction. Mindfulness-based interventions (MBI) generally consist of meditative practices developed to provide a holistic approach to chronic conditions. However, the effects of MBI on clinical and psychological outcomes for people with PFP remains understudied. METHODS: This assessor-blinded, parallel, two-arm randomized clinical trial aims to investigate the effects of adding an 8-week online MBI program to exercise therapy and patient education on clinical and psychological factors for people with PFP. We also aim to investigate whether psychological factors mediate changes in pain and function. Sixty-two participants with PFP will be recruited and randomized into one of two treatment groups (Mindfulness or Control group). Both groups will receive an 8-week intervention involving exercise therapy and education delivered through an online platform. The Mindfulness group will additionally receive a MBI component including formal and informal practices. Outcomes will be assessed online at baseline, intervention endpoint (follow-up 1) and 12 months after intervention completion (follow-up 2). Comparisons between groups will be performed at all time points with linear mixed models. A mediation analysis will be performed using a 3-variable framework. DISCUSSION: Exercise therapy and patient education are considered the "best management" options for PFP. However, unsatisfactory long-term prognosis remains an issue. It is known that people with PFP present with altered psychological factors, which should be considered during the evaluation and treatment of people with PFP. Adding a MBI to the current best treatment for PFP may improve short and long-term effects by addressing the underlying psychological factors. TRIAL REGISTRATION: Registro Brasileiro de Ensaios Clínicos (ReBEC) RBR-4yhbqwk, registered in April 6, 2021.

Group- and sex-related differences in psychological and pain processing factors in people with and without patellofemoral pain: correlation with clinical outcomes.

BACKGROUND: People with patellofemoral pain (PFP) exhibit impaired psychological and pain processing factors (i.e., kinesiophobia, pain catastrophizing and pressure pain thresholds [PPTs]). However, it remains unclear whether these factors have different presentations in women and men with PFP, as well as whether their correlation with clinical outcomes differ according to sex. The aims of this study were to: (1) compare psychological and pain processing factors between women and men with and without patellofemoral pain (PFP); (2) investigate their correlation with clinical outcomes in people with PFP. METHODS: This cross-sectional study included 65 women and 38 men with PFP, 30 women and 30 men without PFP. The psychological and pain processing factors were assessed with the Tampa Scale of Kinesiophobia, Pain Catastrophizing Scale, and PPTs of shoulder and patella measured with an algometer. Clinical outcomes assessed were self-reported pain (Visual Analogue Scale), function (Anterior Knee Pain Scale), physical activity level (Baecke's Questionnaire), and physical performance (Single Leg Hop Test). Generalized linear models (GzLM) and effect sizes [Cohen's d] were calculated for group comparisons and Spearman's correlation coefficients were calculated to investigate correlations between outcomes. RESULTS: Women and men with PFP had higher kinesiophobia (d = .82, p = .001; d = .80, p = .003), pain catastrophizing (d = .84, p < .001; d = 1.27, p < .001), and lower patella PPTs (d = -.85, p = .001; d = -.60, p = .033) than women and men without PFP, respectively. Women with PFP had lower shoulder and patella PPTs than men with PFP (d = -1.24, p < .001; d = -.95, p < .001), but there were no sex differences in those with PFP for psychological factors (p > .05). For women with PFP, kinesiophobia and pain catastrophizing had moderate positive correlations with self-reported pain (rho = .44 and .53, p < .001) and moderate negative correlations with function (rho = -.55 and -.58, p < .001), respectively. For men with PFP, only pain catastrophizing had moderate positive correlations with self-reported pain (rho = .42, p = .009) and moderate negative correlations with function (rho = -.43, p = .007). CONCLUSIONS: Psychological and pain processing factors differ between people with and without PFP and between sexes, respectively. Also, correlations between psychological and pain processing factors with clinical outcomes differ among women and men with PFP. These findings should be considered when assessing and managing people with PFP.

The association between kinesiophobia and dynamic balance in patients with patellofemoral pain syndrome.

OBJECTIVE: The aim of the study was to examine the relationship between Kinesiophobia and dynamic balance in patients with patellofemoral pain syndrome (PFPS). PATIENTS AND METHODS: Forty subjects with PFPS [20 Low Kinesiophobia (LK), 20 High Kinesiophobia (HK)], and 20 pain-free subjects (control group) were enrolled in the study. All subjects performed a Y-balance test to measure the dynamic balance. Normalized reach distance and balance parameters were recorded. RESULTS: Our findings indicated that patients with PFPS who have a greater Kinesiophobia showed a poorer dynamic balance. In addition, the HK group showed a significantly lower mean reach distance score in the anterior, posterolateral, and posteromedial directions compared to LK and healthy groups. CONCLUSIONS: Addressing the psychological factors such as Kinesiophobia during examination and treatment of people with PFPS may be important to improve the dynamic balance.

What is the incidence of subsequent adjacent joint injury after patellofemoral pain?

OBJECTIVE: To investigate the incidence of subsequent lumbar spine, hip, and ankle-foot injuries after a diagnosis of patellofemoral pain. DESIGN: Retrospective cohort study. SETTING: Military Health System. PARTICIPANTS: Individuals (n = 92,319) ages 17-60 diagnosed with patellofemoral pain between 2010-2011. INTERVENTIONS: Therapeutic exercise. MAIN OUTCOME MEASURES: Frequency of adjacent joint injuries in the 2-year period after initial patellofemoral pain injury, and hazard ratios (HR) with 95% confidence interval (CI) and Kaplan-Meier survival curves for risk of adjacent joint injury based on receiving therapeutic exercise for the initial injury. RESULTS: After initial patellofemoral pain diagnosis, 42,983 (46.6%) individuals sought care for an adjacent joint injury. Of these, 19,587 (21.2%) were subsequently diagnosed with a lumbar injury, 2837 (3.1%) a hip injury, and 10,166 (11.0%) an ankle-foot injury. One in five (19.5%; n = 17,966) received therapeutic exercise which reduced the risk of having a subsequent lumbar (HR = 0.78, 95% CI 0.76-0.81), hip (HR = 0.93, 95% CI 0.87-0.98) or ankle-foot (HR = 0.86, 95% CI 0.83-0.90) injury. CONCLUSION: The results suggest that a high number of individuals with patellofemoral pain will sustain an adjacent joint injury within 2 years although causal relationships cannot be determined. Receiving therapeutic exercise for the initial knee injury reduced the risk of sustaining an adjacent joint injury. This study helps provide normative data for subsequent injury rates in this population and guide development of future studies designed to understand causal factors.

Patient-Reported Outcome Measures for Adults and Adolescents with Patellofemoral Pain: A Systematic Review of Content Validity and Feasibility Using the COSMIN Methodology.

OBJECTIVE: To assess the content validity and feasibility of patient-reported outcome measures (PROMs) used to assess pain and function in adults and adolescents with patellofemoral pain (PFP). DESIGN: Systematic review. LITERATURE SEARCH: We searched the databases PubMed, CINAHL, Scopus, SPORTDiscus, and the Cochrane Library from inception to January 6, 2022. STUDY SELECTION CRITERIA: We included studies that described the development or evaluation of the content validity of English-language PROMs for PFP, as well as their translations and cultural adaptations to different languages. DATA SYNTHESIS: Using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology, we determined overall ratings and quality of evidence for the relevance, comprehensiveness, and comprehensibility of PROMs. We extracted data related to feasibility for clinical use (eg, administration time and scoring ease). RESULTS: Forty-three studies for 33 PROMs were included. The overall quality of most studies was "inadequate" due to failure to engage stakeholders and/or ensure adherence to rigorous qualitative research procedures. Of all PROMs evaluated, the Knee injury and Osteoarthritis Outcome Score-Patellofemoral subscale (KOOS-PF), was the only PROM with sufficient content validity components. Quality of evidence for content validity of the KOOS-PF was low. Most PROMs were rated feasible for clinical and research purposes. CONCLUSION: Most PROMs used to measure pain and function in patients with PFP have inadequate content validity. The KOOS-PF had the highest overall content validity. We recommend the KOOS-PF for evaluating pain and function (in research and clinical practice) in adults and adolescents with PFP. J Orthop Sports Phys Ther 2023;53(1):23-39. Epub: 18 October 2022. doi:10.2519/jospt.2022.11317.

The effect of a supervised online group exercise program on symptoms associated with patellofemoral pain syndrome in women.

BACKGROUND: Patellofemoral pain syndrome (PFPS) is one of the musculoskeletal system pathologies frequently encountered especially in women. OBJECTIVE: The aim of the current study was to compare the efficacy of an online exercise program with a home exercise program including the same exercises, and a control group planned for females with PFPS. METHODS: The study included 60 females with PFPS aged 33.17 ± 6.84. Participants were randomly divided into 3 groups. One of the groups was given a 6-week home program consisting of evidence-based exercises. Exercises consisting of the same exercises were supervised online to another group. The third group did not receive any intervention. Pain, knee joint range of motion, muscle strength in flexion and extension and hip posterolateral muscle group, patellofemoral joint functionality, quality of life, recurrence of injury and fear of movement were measured at preintervention and postintervention. RESULTS: Participation in the online supervised exercise group was seen to result in a greater decrease in pain during activity and kinesiophobia, and a greater increase in the quality of life mental health sub-dimension compared to the home exercise group. CONCLUSION: Online supervised exercise groups could be an alternative telerehabilitation method for exercise programs established for women with PFPS.

Are there neuromuscular differences on proximal and distal joints in patellofemoral pain people? A systematic review and meta-analysis.

We aim to determine the neuromuscular differences in proximal and distal joints between patellofemoral pain (PFP) and healthy participants. Relevant articles were selected through seven databases. Studies comparing electromyography (EMG) or morphology parameters of trunk, hip, ankle/foot joints in PFP people compared to a healthy control group (CG) were included. 1458 studies were identified, from which 36 were included in the systematic review [PFP, n = 655; CG, n = 649] (31 involving EMG) and 32 in the meta-analysis (27 involving EMG). 75% of studies presented moderate to high methodological quality. The meta-analysis demonstrated that, compared to CG, PFP have: (i) similar transversus abdominis/internal oblique and erector spinae muscle onset, independently of sex; (ii) similar EMG amplitude of gluteus medius and gluteus maximus, independently of sex or task performed; (iii) similar gluteus medius muscle onset, independently of sex or task performed; (iv) similar gluteus maximus muscle onset, independently of sex; (v) a small effect for a shorter activation duration of gluteus medius (0.50; 95% CI [0.07; 0.93]; p = 0.02); (vi) a medium effect for a shorter activation duration of gluteus medius during stair/step down task (0.81; 95% CI [0.18; 1.45]; p = 0.01); (vii) similar external oblique, gluteus maximus, tensor fascia latae, tibialis anterior and fibularis muscle thickness and (viii) a small effect for a smaller gluteus medius muscle thickness (0.52; 95% CI [0.22; 0.82]; p = 0.007). We were not able to perform meta-analysis for EMG at distal joints. Neuromuscular differences in PFP seems to occur only in the gluteus medius muscle. Due to high heterogeneity and several methodological concerns observed, mainly in EMG studies, the interpretation of these results needs caution.

Talonavicular joint mobilization and foot core strengthening in patellofemoral pain syndrome: a single-blind, three-armed randomized controlled trial.

BACKGROUND: Patellofemoral pain syndrome (PFPS) is defined as pain around the patella while performing activities such as squats, running, and climbing steps. One of the inherent risk factors for PFPS is an excessively pronated foot posture. The aim of this study was to investigate the effect of foot intervention, talonavicular joint mobilization (TJM) and foot core strengthening (FCS), on PFPS. METHODS: Forty-eight patients with PFPS (mean age, 21.96 ± 2.34 years; BMI, 22.77 ± 2.95 kg/m2) were enrolled in the study. Participants were randomly assigned in a 1:1:1 ratio to three groups, and received 12 sessions of TJM, FCS, and blended intervention at university laboratory for 4 weeks. The primary outcomes were pain while the secondary outcomes were lower extremity function, valgus knee, foot posture, and muscle activity ratio measured at baseline, after 12 sessions, and at the 4-week follow-up. RESULTS: The two-way repeated-measures ANOVA revealed significant interactions in all groups (p < 0.05). TJM reduced pain more than the FCS at post-test (mean difference, - 0.938; 95% Confidence interval [CI], - 1.664 to - 0.211; p < 0.05), and blended intervention improved lower extremity function (mean difference, 6.250; 95% CI, 1.265 to 11.235; p < 0.05) and valgus knee (mean difference, - 11.019; 95% CI, - 17.007 to - 5.031; p < 0.05) more than the TJM at 4 weeks follow-up. TJM was more effective in post-test (mean difference, - 1.250; 95% CI, - 2.195 to - 0.305; p < 0.05), and TJM (mean difference, - 1.563; 95% CI, - 2.640 to - 0.485; p < 0.05) and blended intervention (mean difference, - 1.500; 95% CI, - 2.578 to - 0.422; p < 0.05) were more effective in foot posture than the FCS in 4 weeks follow-up. Blended intervention displayed greater improvement in muscle activity than the TJM (mean difference, 0.284; 95% CI, 0.069 to 0.500; p < 0.05) and the FCS (mean difference, 0.265; 95% CI, 0.050 to 0.481; p < 0.05) at 4 weeks follow-up. CONCLUSIONS: Our study is a novel approach to the potential impact of foot interventions on patellofemoral pain. Foot intervention including TJM and FCS is effective for pain control and function improvement in individuals with PFPS. TRIAL REGISTRATION: KCT0003176 , 16/08/2018 (retrospectively registered).

Clinicians' experience of the diagnosis and management of patellofemoral pain: A qualitative exploration.

BACKGROUND: Patellofemoral pain (PFP) is common and has a poor long-term prognosis. There is a lack of clarity about the clinical reasoning of recognised inter-disciplinary experts in the published literature. OBJECTIVES: To help identify best practice by exploring the clinical reasoning of a range of inter-disciplinary experts that regularly diagnose and treat PFP. DESIGN: Qualitative study with semi-structured interviews. METHOD: Recruitment resulted in a convenience sample for semi-structured interview, which were recorded and transcribed verbatim. Data were analysed until theoretical saturation, as determined by multiple investigators. FINDINGS: Interviews with 19 clinical experts (15 men, 4 women; mean experience 18.6 years ± 8.6) from four broad professions yielded four themes. Firstly, the assessment and diagnosis process should include a thorough history and examination to rule in PFP. Secondly, information provision should aim to increase patients' understanding, aid in controlling symptoms, and facilitate behaviour change. Thirdly, active rehabilitation, which was a salient theme and included advocacy of combined hip and knee exercise that is adapted to the individual. Finally, treatment adjuncts, which can be used selectively to modify symptoms, may include running retraining, taping, or foot orthoses. CONCLUSIONS: PFP should be diagnosed clinically, and tailored treatment programmes should be prescribed for people with PFP. Exercise was considered the most effective treatment and underlying psychological factors should be addressed to improve prognosis.

Confidence and Knowledge of Athletic Trainers in Managing Patellofemoral Pain.

CONTEXT: Patellofemoral pain (PFP) is prevalent and challenging to manage. Most patients with PFP are unsatisfied with their knee function at 6 months after treatment and report ongoing pain up to 16 years after diagnosis. The confidence and knowledge of athletic trainers (ATs) in providing evidence-based care to people with PFP is unknown. OBJECTIVE: To investigate the confidence and knowledge of ATs in the diagnosis, risk factors, prognosis, and treatment with current evidence for PFP. DESIGN: Cross-sectional study. SETTING: Online survey. PATIENT OR OTHER PARTICIPANTS: A random sample of 3000 ATs were invited to participate; 261 completed the survey (10% participation rate, 88% completion rate). MAIN OUTCOME MEASURES(S): We surveyed AT demographics, confidence in PFP management, and knowledge related to diagnosis, risk factors, prognosis, and treatment. The confidence and knowledge of ATs in managing PFP was assessed. Their beliefs about evidence were compared with the available evidence (ie, consensus statements, position statements, systematic reviews). RESULTS: Of the ATs surveyed, 91% were confident that their management of PFP aligned with the current evidence, but only 59% were confident in identifying risk factors for PFP development. In addition, 91% to 92% of ATs agreed that quadriceps and hip muscle weakness were risk factors for PFP, which aligns with the current evidence for the former but not the latter. Moreover, 93% to 97% of ATs' responses related to therapeutic exercise aligned with current evidence. However, 35% to 48% supported the use of passive treatments, such as electrophysical agents and ultrasound, which did not align with the current evidence. CONCLUSIONS: Most ATs were aware of supporting evidence for therapeutic exercise in PFP management and were confident providing it, creating a strong foundation for evidence-based care. However, varying levels of awareness of the evidence related to risk factors and passive treatments for PFP highlight the need for professional development initiatives to better align ATs' knowledge with the current evidence.

The 45-second anterior knee pain provocation test: A quick test of knee pain and sporting function in 10-14-year-old adolescents with patellofemoral pain.

OBJECTIVE: To test 1) if the 45-second Anterior Knee Pain Provocation Test (AKPP-test) could differentiate between adolescents with patellofemoral pain (PFP) and pain-free controls and; 2) whether improvements in the AKPP-test over 12 weeks were associated with improvements in self-reported knee function and pain. DESIGN: Prospective cohort. PATIENTS: 151 with PFP and 50 pain-free controls (age 10-14 years). OUTCOMES: The AKPP-test was performed at baseline, 4- and 12-week follow-up. Pain and function were collected using Knee Injury and Osteoarthritis Outcome Score (KOOS). RESULTS: At baseline, the AKPP-test provoked pain to a median of 5 points (IQR: 3-7) on the 0-10 Numeric Pain Rating Scale in adolescents with PFP, compared to 0 (IQR 0-0) in controls. Higher pain during the AKPP-test was associated with worse KOOS-Sport/Rec (r = -0.33, P < 0.001), worse KOOS-Pain (r = -0.47, P < 0.001), and pain intensity (worst pain last 24 hours) (r = -0.39, P < 0.001) at baseline. Improvements in the AKPP-test over 12 weeks were associated with improvements in KOOS Pain (r = 0.48, P < 0.001) and KOOS Sport/Rec (r = 0.40, P < 0.001). CONCLUSIONS: Improvements in the AKPP-test were associated with improvements in self-report knee pain and limitations in sports, suggesting the AKPP-test may be a clinically responsive test of knee pain and sporting function in adolescents with PFP.