Six Treatments Have Positive Effects at 3 Months for People With Patellofemoral Pain: A Systematic Review With Meta-analysis.

OBJECTIVE: To determine the effects of nonsurgical treatments on pain and function in people with patellofemoral pain (PFP). DESIGN: Systematic review with meta-analysis. LITERATURE SEARCH: We searched MEDLINE, Web of Science, and Scopus databases from their inception until May 2022 for interventional randomized controlled trials (RCTs) in people with PFP. STUDY SELECTION CRITERIA: We included RCTs that were scored ≥7 on the PEDro scale. DATA SYNTHESIS: We extracted homogenous pain and function data at short- (≤3 months), medium- (>3 to ≤12 months) and long-term (>12 months) follow-up. Interventions demonstrated primary efficacy if outcomes were superior to sham, placebo, or wait-and-see control. Interventions demonstrated secondary efficacy if outcomes were superior to an intervention with primary efficacy. RESULTS: We included 65 RCTs. Four interventions demonstrated short-term primary efficacy: knee-targeted exercise therapy for pain (standardized mean difference [SMD], 1.16; 95% CI: 0.66, 1.66) and function (SMD, 1.19; 95% CI: 0.51, 1.88), combined interventions for pain (SMD, 0.79; 95% CI: 0.26, 1.29) and function (SMD, 0.98; 95% CI: 0.47, 1.49), foot orthoses for global rating of change (OR = 4.31; 95% CI: 1.48, 12.56), and lower-quadrant manual therapy for function (SMD, 2.30; 95% CI: 1.60, 3.00). Two interventions demonstrated short-term secondary efficacy compared to knee-targeted exercise therapy: hip-and-knee-targeted exercise therapy for pain (SMD, 1.02; 95% CI: 0.58, 1.46) and function (SMD, 1.03; 95% CI: 0.61, 1.45), and knee-targeted exercise therapy and perineural dextrose injection for pain (SMD, 1.34; 95% CI: 0.72, 1.95) and function (SMD, 1.21; 95% CI: 0.60, 1.82). CONCLUSIONS: Six interventions had positive effects at 3 months for people with PFP, with no intervention adequately tested beyond this time point. J Orthop Sports Phys Ther 2022;52(11):750-768. Epub: 8 September 2022. doi:10.2519/jospt.2022.11359.

Adding muscle power exercises to a strength training program for people with patellofemoral pain: protocol of a randomized controlled trial.

BACKGROUND: Strong evidence supports the proximal combined with quadriceps strengthening for patellofemoral pain (PFP) rehabilitation. However, most reported rehabilitation programs do not follow specific exercise prescription recommendations or do not provide adequate details for replication in clinical practice. Furthermore, people with PFP have power deficits in hip and knee muscles and it remains unknown whether the addition of power exercises would result in superior or more consistent outcomes. Therefore, this study is designed to verify whether the benefits of a rehabilitation program addressing proximal and knee muscles comprising power and strength exercises are greater than those of a program consisting of strength exercises only. METHOD: This study will be a randomized controlled trial that will be conducted at university facilities. A minimum of 74 people with PFP between the ages of 18 and 45 years will be included. The experimental group will engage in a 12-week resistance training program focusing on proximal and knee muscles using power and strength exercises. The control group will engage in a 12-week resistance training program focusing on proximal and knee muscles using strength exercises only. Primary outcomes will be pain intensity and physical function; and secondary outcomes will be kinesiophobia, self-reported improvement, quality of life, peak hip and knee torque, and hip and knee rate of force development. The primary outcomes will be evaluated at baseline, and after 6 weeks, 12 weeks, 3 months, 6 months, and 1 year. The secondary outcomes will be evaluated at baseline and immediately after the interventions. Therapists and participants will not be blinded to group allocation. DISCUSSION: This randomized clinical trial will investigate if adding power exercises to a progressive resistance training may lead to more consistent outcomes for PFP rehabilitation. The study will provide additional knowledge to support rehabilitation programs for people with PFP. TRIAL REGISTRATION: ClinicalTrials.gov NCT03985254. Registered on 26 August 2019.

Telerehabilitation for Knee Osteoarthritis in Brazil: A Feasibility Study.

BACKGROUND: The effectiveness of telerehabilitation for a patient with knee osteoarthritis may depend upon the person's adherence to intervention. Thus, the aim of this study was to investigate whether people with knee osteoarthritis would adhere to exercise-therapy facilitated via multiple media in Brazil, a newly industrialized country. METHOD: This is a feasibility study, pre-post intervention. Middle aged (40-50 years) and elderly (≥70 years) people with knee osteoarthritis received in-person exercise-therapy instructions on the first day, along with a booklet and DVD (videos) to take home. Participants also received six motivational phone calls throughout the 12-week treatment. Satisfaction and adherence were assessed one week after intervention with the Exercise Adherence Rating Scale (EARS), sections B and C. Preference on the method used to adhere to exercises was recorded. CONCLUSION: Telerehabilitation was well accepted by middle-aged and elderly Brazilians with knee osteoarthritis. The preferred media to enhance adherence, was a booklet with descriptions of the exercises, especially for the elderly cohort.

Kinesiophobia, but not strength is associated with altered movement in women with patellofemoral pain.

BACKGROUND: Evidence indicates the presence of both kinesiophobia and knee extension strength deficits in women with patellofemoral pain (PFP). Both impairments may contribute to apparent compensatory gait patterns including reduced cadence and peak knee flexion during stair negotiation. RESEARCH QUESTION: Is kinesiophobia or knee extension strength associated with movement pattern in women with patellofemoral pain? METHODS: Forty women with PFP were assessed with three-dimensional kinematic analyses during stair descent; isokinetic dynamometry of the knee extensors (isometric, concentric and eccentric); and the Tampa scale for kinesiophobia. Pearson coefficients were calculated to determine relationship among variables. RESULTS: Kinesiophobia correlated significantly with cadence (r = -0.62, p < 0.001), and peak knee flexion (r = -0.76, p < 0.001). No significant correlations were found between any knee extensor strength variables and kinematics (cadence or peak knee flexion); or kinesiophobia (p > 0.05). SIGNIFICANCE: Findings of this study could suggest addressing strength impairments alone may not adequately address kinesiophobia and movement pattern impairments in women with PFP. However, high-quality randomised controlled trials are needed to test this assumption. Further value may be added if currently evidence-based knee strengthening exercise is combined with education and/or graded exposure to address kinesiophobia, and consideration to gait retraining to address altered movement patterns at the knee.

Manifestations of Pain Sensitization Across Different Painful Knee Disorders: A Systematic Review Including Meta-analysis and Metaregression.

OBJECTIVES: Previous reviews have reported that manifestations of pain sensitization may play an important role in the pain experienced by people with knee osteoarthritis. However, it is unknown if manifestations of pain sensitization are common features across other painful knee disorders or if sensitization requires targeted intervention. This review aims to synthesize the published research investigating manifestations of pain sensitization in painful knee disorders and to evaluate if the manifestations of pain sensitization change in response to treatment. METHODS: The systematic review protocol was registered with PROSPERO (CRD42015024211). We searched Medline, Embase, CINAHL, Web of Science, Sportsdiscus, and Cochrane Central for studies that investigated between-group differences (knee pain vs pain-free subjects) or the effect of treatment on manifestations of pain sensitization. Two reviewers independently assessed studies for inclusion and quality. Available data were synthesized via predetermined levels of evidence, meta-analysis, and metaregression where possible. RESULTS: Fifty-two studies investigating evidence related to pain sensitization distributed across four different painful knee disorders were identified. CONCLUSIONS: Our meta-analysis provides evidence of pain sensitization in people with knee osteoarthritis (strong evidence), people with patellofemoral pain (moderate evidence), and postmeniscectomy patients (very limited evidence). However, conflicting evidence exists in patellar tendinopathy. Metaregression indicates that pain is associated with pressure pain thresholds in knee osteoarthritis. In people with knee osteoarthritis and patellofemoral pain, several interventions were found to reduce manifestations of pain sensitization. This review highlights that pain sensitization may be amenable to treatment through exercise therapy, mobilization, and pharmacological and surgical intervention.

Clinically measured hip muscle capacity deficits in people with patellofemoral pain.

OBJECTIVE: To evaluate differences in clinical measures of hip abductor and extensor capacity (strength, endurance and power) in people with patellofemoral pain (PFP) compared to asymptomatic controls. DESIGN: Cross-sectional. SETTINGS: Laboratory. PARTICIPANTS: Thirty-two physically active people (16 with PFP and 16 controls). MAIN OUTCOME MEASURES: Strength was evaluated isometrically using a hand-held dynamometer and dynamically using 10 repetitions maximum (10RM) tests. Power was assessed using a linear position transducer. Endurance was assessed using maximum number of repetitions. RESULTS: The PFP group had significant deficits compared to the control group in isometric strength (21-25%) for hip abduction (ES = 0.98) and extension (ES = 0.85); in 10RM (15-18%) for hip abduction (ES = 0.72) and extension (ES = 0.85); and in power (24-31%) for hip abduction (ES = 0.80), and extension (ES = 0.94). No difference was identified for hip abduction and extension in endurance tests. CONCLUSION: Clinical assessments can identify deficits in isometric and dynamic hip strength, as well as power in people with PFP. Hip muscle capacity deficits in people with PFP including strength and power highlight a potential need for more progressive resistance training in this population.

Females with patellofemoral pain have impaired impact absorption during a single-legged drop vertical jump.

BACKGROUND: Females with patellofemoral pain (PFP) have been reported to land with altered biomechanics in some, but not all studies. Kinematic alterations previously reported may indicate, and relate to potential impairments in absorbing impact. RESEARCH QUESTION: To compare vertical ground reaction force (vGRF) and lower limb kinematics during single-legged drop vertical jumps in females with and without PFP; and establish the relationship between vGRF and kinematics during this task. METHODS: Fifty-two physically active females (26 with PFP and 26 controls) participated in the present cross-sectional study. Peak of vGRF was evaluated during landing; and lower limb kinematics in the sagittal and frontal planes during deceleration (landing) and acceleration (take-off) phases were evaluated. RESULTS: The PFP group had 11% greater vGRF (p < 0.01); and 13-24% lower hip, knee and ankle excursion in the sagittal plane during acceleration and deceleration phases (p ≤ 0.02) compared to the control group. No significant between group differences (p > 0.05) for hip, knee and ankle excursion in the frontal plane were identified. Greater impact was significantly correlated with reduced knee (r = -0.56), hip (r = -0.50) and ankle (r = -0.41) excursion in the sagittal plane during the acceleration phase in the control group, but not in the PFP group. No significant correlations were found between vGRF and kinematics variables during the deceleration phase in either group. SIGNIFICANCE: Impaired ability to absorb load and reduced lower limb movement in the sagittal plane during landing in females with PFP may provide separate treatment targets during rehabilitation.

Hip rate of force development and strength are impaired in females with patellofemoral pain without signs of altered gluteus medius and maximus morphology.

OBJECTIVES: To compare rate of force development (RFD) and isometric muscle strength of the hip abductors and extensors; and the thickness and the amount of non-contractile tissue of the gluteus medius and maximus between females with and without patellofemoral pain (PFP). DESIGN: Cross-sectional study. METHODS: Fifty-four physically active females (27 with PFP and 27 healthy individuals) were studied. Hip muscle isometric strength and RFD was evaluated using isokinetic dynamometry. RFD was measured until 30%, 60%, and 90% of the maximal isometric torque (MIT). Hip muscle morphology was evaluated using ultrasonography. RESULTS: The PFP group possessed slower RFD compared to the control group by 33% for hip abductors until 90%MIT (-0.23%/ms, 95%CI -0.44 to -0.02, ES=0.59); by 51% for hip extensors until 30%MIT (-0.42%/ms, 95%CI -0.66 to -0.18, ES=0.97); and by 55% for hip extensors until 60%MIT (-0.36%/ms, 95%CI -0.60 to -0.12, ES=0.81). The PFP group possessed reduced isometric torque compared to the control group by 10% for hip abduction (-16.0Nm/kg×100, 95% CI -30.2 to -1.9, ES=0.61) and by 15% for hip extension (-30.1Nm/kg×100, 95%CI -51.4 to -8.9, ES=0.76). No significant between group differences for the thickness and the amount of non-contractile tissue of the gluteus medius and maximus were identified. CONCLUSIONS: Females with PFP have deficits in isometric strength and RFD in hip abduction and extension. RFD deficits are greater than strength deficits which may highlight their potential importance. Hip muscle strength and RFD deficits do not appear to be explained by muscle thickness or proportion of non-contractile tissue of the gluteal musculature as measured by ultrasound.

Proximal mechanics during stair ascent are more discriminate of females with patellofemoral pain than distal mechanics.

BACKGROUND: Several hypotheses have been proposed to explain the pathomechanisms underlying patellofemoral pain (PFP). Concurrent evaluation of lower limb mechanics in the same PFP population is needed to determine which may be more important to target during rehabilitation. This study aimed to investigate possible differences in rearfoot eversion, hip adduction, and knee flexion during stair ascent; the relationship between these variables; and the discriminatory capability of each in identifying females with PFP. METHOD: Thirty-six females with PFP and 31 asymptomatic controls underwent three-dimensional kinematic analyses during stair ascent. Between-group comparisons were made for peak rearfoot eversion, hip adduction, and knee flexion. Pearson's correlation coefficients were calculated to evaluate relationships among these parameters. Receiver operating characteristic curves were applied to identify the discriminatory capability of each. FINDINGS: Females with PFP ascended stairs with reduced peak knee flexion, greater peak hip adduction and peak rearfoot eversion. Peak hip adduction (>10.6°; sensitivity=67%, specificity=77%) discriminated females with PFP more effectively than rearfoot eversion (>5.0°; sensitivity=58%, specificity=67%). Reduced peak hip adduction was found to be associated with reduced peak knee flexion (r=0.54, p=0.002) in females with PFP. INTERPRETATION: These findings indicate that proximal, local, and distal kinematics should be considered in PFP management, but proximally targeted interventions may be most important. The relationship of reduced knee flexion with reduced hip adduction also indicates a possible compensatory strategy to reduce patellofemoral joint stress, and this may need to be addressed during rehabilitation.

The 'Best Practice Guide to Conservative Management of Patellofemoral Pain': incorporating level 1 evidence with expert clinical reasoning.

IMPORTANCE: Patellofemoral pain (PFP) is both chronic and prevalent; it has complex aetiology and many conservative treatment options. OBJECTIVE: Develop a comprehensive contemporary guide to conservative management of PFP outlining key considerations for clinicians to follow. DESIGN: Mixed methods. METHODS: We synthesised the findings from six high-quality systematic reviews to September 2013 with the opinions of 17 experts obtained via semistructured interviews. Experts had at least 5 years clinical experience with PFP as a specialist focus, were actively involved in PFP research and contributed to specialist international meetings. The interviews covered clinical reasoning, perception of current evidence and research priorities. RESULTS: Multimodal intervention including exercise to strengthen the gluteal and quadriceps musculature, manual therapy and taping possessed the strongest evidence. Evidence also supports use of foot orthoses and acupuncture. Interview transcript analysis identified 23 themes and 58 subthemes. Four key over-arching principles to ensure effective management included-(1) PFP is a multifactorial condition requiring an individually tailored multimodal approach. (2) Immediate pain relief should be a priority to gain patient trust. (3) Patient empowerment by emphasising active over passive interventions is important. (4) Good patient education and activity modification is essential. Future research priorities include identifying risk factors, testing effective prevention, developing education strategies, evaluating the influence of psychosocial factors on treatment outcomes and how to address them, evaluating the efficacy of movement pattern retraining and improving clinicians' assessment skills to facilitate optimal individual prescription. CONCLUSIONS AND RELEVANCE: Effective management of PFP requires consideration of a number of proven conservative interventions. An individually tailored multimodal intervention programme including gluteal and quadriceps strengthening, patellar taping and an emphasis on education and activity modification should be prescribed for patients with PFP. We provide a 'Best Practice Guide to Conservative Management of Patellofemoral Pain' outlining key considerations.