Hip strengthening prior to functional exercises reduces pain sooner than quadriceps strengthening in females with patellofemoral pain syndrome: a randomized clinical trial

Effects of high frequency strengthening on pain sensitivity and function in female runners with chronic patellofemoral pain

OBJECTIVE

To investigate the effects of a high frequency strengthening program on function, pain, and pain sensitization in female runners with chronic patellofemoral pain (PFP).

DESIGN

Cross-sectional study.

SETTING

University laboratory.

PARTICIPANTS

Thirty female runners (mean age 32 ± 8.1 years) with chronic PFP completed an 8-week home strengthening program.

MAIN OUTCOME MEASURES

Variables assessed at baseline, 8-weeks, and 12 weeks included single leg step down test (SLSD), pain, Anterior Knee Pain Scale (AKPS), University of Wisconsin Running Injury and Recovery Index (UWRI), and quantitative sensory testing.

RESULTS

There was large and statistically significant improvement at 8 and 12 weeks for average knee pain (ηp2 = 0.334, p < 0.001), worst knee pain (ηp2 = 0.351, p < 0.001), SLSD (ηp2 = 0.161, p = 0.001), AKPS (ηp2 = 0.463, p < 0.001), and UWRI (ηp2 = 0.366, p < 0.001). A medium to large effect and statistically significant improvement in pressure pain threshold testing was found for all local and remote structures (ηp2 range, 0.110 to 0.293, range p < 0.001 to p = 0.009) at 8 and 12 weeks.

CONCLUSIONS

There was a significant decrease in local and remote hyperalgesia via mechanical and thermal pain sensitivity testing in female runners with chronic PFP. There was a large effect and significant improvement in self-reported pain and function.

Effect of adding short foot exercise to hip and knee focused exercises in treatment of patients with patellofemoral pain syndrome: a randomized controlled trial

BACKGROUND

Patellofemoral pain syndrome is considered a common cause of anterior knee pain that could disturb function and limit daily activities. The purpose of the study was to investigate the effect of adding short foot exercise on pain, function, balance, and hip abductors, and quadriceps muscles strength in the treatment of patients with patellofemoral pain syndrome.

METHODS

Twenty-eight male and female patients with patellofemoral pain syndrome with age ranged from 18 to 35 years old participated in this study. They were equally and randomly assigned into two groups; the study group which received short foot exercise in addition to hip and knee exercises (n = 14) and thecontrol group which received hip and knee exercises only (n = 14). Participants received their interventions during 6 consecutive weeks (12 sessions). Pain intensity, function, abductors quadriceps muscle strength, and balance were assessed using the Visual Analog Scale, anterior knee pain scale (AKPS), hand-held dynamometer, and the Biodex Balance System respectively. All measurements were taken before and after 6 weeks of intervention in both groups. Multivariate analysis of variance was performed to compare the within and between groups effects for measured variables.

RESULTS

The within-group comparison showed significant improvement in pain severity, function, balance, and hip abductors, and quadriceps muscles strength in both groups post-treatment compared with pre-treatment. Between groups analysis, however, showed no significant statistical difference between both groups in all variables, except in pain, function, and mediolateral stability which showed better improvement compared to the control group.

CONCLUSIONS

Adding short foot exercise to hip and knee exercises improved pain, function, and mediolateral stability in patients with patellofemoral pain syndrome.

TRIAL REGISTRATION

clinicaltrials.gov. NO: NCT05383781. Date 19/ 5/2022.

Effects of hip abductor with external rotator strengthening versus proprioceptive training on pain and functions in patients with patellofemoral pain syndrome: A randomized controlled trial

BACKGROUND

Strengthening the hip muscles, particularly the abductors and rotators, has been reported beneficial for treating Patellofemoral pain syndrome (PFPS). Proprioceptive training (PT) is also shown to improve musculoskeletal pain and function in PFPS. The most appropriate treatment from these 2 is unclear. This study aimed to compare the effects of hip abductors and external rotator strengthening exercises along with conventional physical therapy (CPT) vs the proprioceptive training of the knee along with CPT in patients with PFPS.

METHODS

Forty-five participants were divided into 3 groups, experimental group 1 (EG 1), experimental group 2 (EG 2), and control group (CG), with fifteen participants in each group. EG 1 received hip abductor and external rotator strengthening exercises in addition to CPT. EG 2 received proprioceptive training and CPT. CG received CPT alone. Intervention programs lasted for 4 weeks. The pain was measured by Kujala Anterior Knee Pain Scale (AKPS). The study was registered retrospectively in the protocol registration and results system (clinicaltrials.gov, ID: NCT05698797 on 26/01/2023).

RESULTS

AKPS scores significantly (P < .001) improved in all 3 groups. A significant (P < .05) difference was also observed between all 3 groups. The greatest improvement was observed in EG 1, followed by EG 2 and CG.

CONCLUSION

The addition of hip abductor and external rotator strengthening exercises to a 4-week CPT program showed a more significant improvement in AKPS scores than the addition of proprioceptive training in patients with PFPS.

Persons with patellofemoral pain exhibit altered hip abductor muscle recruitment while performing hip abductor exercises

INTRODUCTION

Strengthening of the hip abductors has been advocated for persons with patellofemoral pain (PFP). It is not clear if these individuals activate the hip abductor muscles appropriately to achieve the desired therapeutic effects.

OBJECTIVE

To compare activation of the hip abductor muscles between persons with and without PFP during the performance of hip abductor exercises.

METHODS

Thirty-two individuals participated (12 with PFP and 20 without PFP). The average age (± standard deviation) was 29.7 ± 5.9 years for the PFP group and 28.1 ± 6.9 for the control group. Electromyographic (EMG) signals from the gluteus medius (GMED), superior gluteus maximus (SUP-GMAX), and tensor fascia lata (TFL) were obtained using fine-wire electrodes while participants performed 11 different exercises. Normalized EMG activity of each muscle was compared between groups across all exercises.

RESULTS

When averaged across all exercises, persons with PFP exhibited significantly greater EMG activity of TFL (mean = 25.3% MVIC; 95% CI = 19.2, 31.3) compared to those without PFP (mean = 17.6% MVIC; 95% CI = 12.8, 22.4) and significantly lower EMG activity of SUP-GMAX (mean = 16.4% MVIC; 95% CI = 11.0, 22.0) compared to those without PFP (mean = 25.4% MVIC; 95% CI = 21.0, 29.8). Persons with PFP exhibited lower EMG activity of GMED, but only for 3 out of the 11 exercises evaluated (hip abduction, hip hike, step-up).

CONCLUSION

Compared to persons without PFP, those with PFP exhibited activation differences during the performance of exercises used to target the hip abductors. Our results highlight the need for activation training prior to the initiation of strengthening exercises to achieve desired therapeutic effects.

Āsana for Back, Hips and Legs to Prevent Musculoskeletal Disorders among Dental Professionals: In-Office Yóga Protocol

Dental professionals are exposed to significant unavoidable physical stress, and theoretical ergonomic recommendations for a sitting workplace are inapplicable in many dental activities. Work-related musculoskeletal disorders (WMSDs) represent a serious health problem among dental professionals (prevalence: 64-93%), showing involvement of 34-60% for the low back and 15-25% for the hips. Muscle stress; prolonged sitting; forward bending and twisting of the torso and head; unbalanced working postures with asymmetrical weight on the hips and uneven shoulders; and others are inevitable for dental professionals. Therefore, the approach for the prevention and treatment of WMSDs must be therapeutic and compensatory. This project was conceived to provide a Yoga protocol for dental professionals to prevent or treat WMSDs from a preventive medicine perspective, and it would represent a Yoga-based guideline for the self-cure and prevention of musculoskeletal problems.

METHODS

Specific Yoga positions (āsana, such as Virāsana, Virabhadrāsana, Garudāsana, Utkatāsana, Trikonāsana, Anuvittāsana, Chakrāsana, Uttanāsana, Pashimottanāsana) have been selected, elaborated on and adapted to be practiced in a dental office using a dental stool or the dental office walls or a dental unit chair. The protocol is specifically devised for dental professionals (dentists, dental hygienists and dental assistants) and targeted for the low back, hips and legs (including knees and ankles). The protocol includes Visranta Karaka Sthiti (supported positions) in sitting (Upavistha Sthiti) and standing (Utthistha Sthiti) positions, twisting/torsions (Parivrtta), flexions/forward bend positions (Pashima) and extensions/arching (Purva) for musculo-articular system decompression and mobilization.

RESULTS

Over 60 Yogāsana-specifically ideated for back detensioning and mobilization, lumbar lordosis restoration, trunk side elongation, hip release and leg stretches and decontraction-are shown and described. The paper provides a meticulous description for each position, including the detailed movement, recommendations and mistakes to avoid, and the breathing pattern (breath control) in all the breath-driven movements (āsana in vinyāsa). An exhaustive analysis of posture-related disorders affecting the lower body among dental professionals is reported, including low-back pain, hip pain and disorders, piriformis syndrome and quadratus femoris dysfunction (gluteal pain), iliopsoas syndrome, multifidus disorders, femoroacetabular and ischiofemoral impingement, spinopelvic mobility, lumbopelvic rhythm, impairment syndromes, lower crossed syndrome, leg pain, knee pain and ankle disorders.

CONCLUSIONS

A detailed guideline of āsana for low-back decompression, hip joint destress, piriformis and gluteal muscle release, lumbar lordosis recovery and a spinopelvic mobility increase has been elaborated on. The designed Yogāsana protocol represents a powerful tool for dental professionals to provide relief to retracted stiff muscles and unbalanced musculoskeletal structures in the lower body.

Quadriceps or hip exercises for patellofemoral pain? A randomised controlled equivalence trial

OBJECTIVE

To assess effectiveness equivalence between two commonly prescribed 12-week exercise programmes targeting either the quadriceps or the hip muscles in patients with patellofemoral pain (PFP).

METHODS

This randomised controlled equivalence trial included patients with a clinical diagnosis of PFP. Participants were randomly assigned to either a 12-week quadriceps-focused exercise (QE) or a hip-focused exercise (HE) programme. The primary outcome was the change in Anterior Knee Pain Scale (AKPS) (0-100) from baseline to 12-week follow-up. Prespecified equivalence margins of ±8 points on the AKPS were chosen to demonstrate comparable effectiveness. Key secondary outcomes were the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire pain, physical function and knee-related quality of life subscales.

RESULTS

200 participants underwent randomisation; 100 assigned to QE and 100 to HE (mean age 27.2 years (SD 6.4); 69% women). The least squares mean changes in AKPS (primary outcome) were 7.6 for QE and 7.0 for HE (difference 0.6 points, 95% CI -2.0 to 3.2; test for equivalence p<0.0001), although neither programme surpassed the minimal clinically important change threshold. None of the group differences in key secondary outcomes exceeded predefined equivalence margins.

CONCLUSION

The 12-week QE and HE protocols provided equivalent improvements in symptoms and function for patients with PFP.

TRIAL REGISTRATION NUMBER

NCT03069547.

Dose-response effect of lower limb resistance training volume on pain and function of women with patellofemoral pain: A systematic review and meta-regression

OBJECTIVE

Analyze whether the effects of lower limb resistance training on pain and self-reported function were associated with the exercise volume prescribed for women with patellofemoral pain (PFP).

METHODS

A systematic search was undertaken in four databases from inception to May 2023. Eligible trials examined the effects of resistance training programs on pain (visual analogue scale or numerical pain scale) and function (Anterior Knee Pain Scale) in women with PFP. Meta-analysis was undertaken with a random-effects model. The association of resistance training volume-related variables with mean difference effects on pain and function were tested by exploratory univariable meta-regression models.

RESULTS

From 1,404 estudies retained for screening after duplicate removals, 16 studies (579 patients) were included. Changes in knee pain were inversely associated with weekly training frequency (β = 0.5 ± 0.2, P = 0.012). No associations were found between the amount of resistance exercise prescribed per session or per week and effects on pain. Changes in function were associated with the number of sets per week (β = 0.1 ± 0.1, P = 0.044) and number of sets per session (β = 0.6 ± 0.2, P < 0.001) over the intervention. Most favorable results were achieved with 17 to 27 sets per session and >45 sets per week.

CONCLUSIONS

The amount of prescribed resistance exercise does not seem to be critical for pain reduction in women with PFP. However, our findings support a dose-response effect in terms of improving function.

Rehabilitation of anterior knee pain in the pregnant athlete: Considerations and modifications by trimester

BACKGROUND

Anterior knee pain is a common symptom many females experience during pregnancy. There are several musculoskeletal changes that occur in anatomy and physiology throughout the course of pregnancy that impact the lower extremity kinetic chain. Pregnant athletes, recreational through competitive, who attempt to maintain a high activity level through each trimester may be at increased risk for anterior knee pain due to a greater demand for lumbopelvic and hip stabilization.

CLINICAL QUESTION

What are the evidence-driven rehabilitation guidelines and specific modifications needed to treat anterior knee pain in the female athlete during each trimester of pregnancy?

KEY RESULTS

We aim to provide an overview of rehabilitation treatment guidelines for pregnant females with anterior knee pain, presenting specific physiological changes and rationale for modifications, discussed by trimester. We recommend our program be conducted under the supervision of a physical therapist working closely with the athlete's obstetrics and sports medicine team.

CLINICAL APPLICATION

The number of women who are active during pregnancy is increasing. We provide an overview of the guidelines and considerations for treating women with anterior knee pain during a healthy and uneventful pregnancy.

Exercise-Induced Changes in Femoral Cartilage Thickness in Patients With Patellofemoral Pain

CONTEXT

Rehabilitative exercises alleviate pain in patients with patellofemoral pain (PFP); however, no researchers have analyzed the cartilage response after a bout of those athletic activities in patients with PFP.

OBJECTIVE

To determine if a single session of rehabilitative exercises alters femoral cartilage morphology.

DESIGN

Crossover study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twelve participants with PFP (age = 21.0 ± 2.0 years, height = 1.72 ± 0.1 m, mass = 68.7 ± 12.6 kg) and 12 matched healthy participants (age = 21.3 ± 2.8 years, height = 1.71 ± 0.1 m, mass = 65.9 ± 12.2 kg) were enrolled.

INTERVENTION(S)

Participants completed treadmill running, lower extremity strengthening exercises, and plyometric exercises for 30 minutes each.

MAIN OUTCOME MEASURE(S)

Patient-reported outcomes on the visual analog scale, Anterior Knee Pain Scale (AKPS), Knee injury and Osteoarthritis Outcome Score (KOOS), and Knee Injury and Osteoarthritis Outcome Score for Patellofemoral Pain and Osteoarthritis were collected. Femoral cartilage ultrasonographic images were obtained at 140° of knee flexion. Ultrasound images were segmented into medial and lateral images using the intercondylar notch. Medial and lateral cartilage cross-sectional area (mm2) and echo intensity (EI), defined as the average grayscale from 0 to 255, were analyzed by ImageJ software. The difference between loading conditions was calculated using repeated-measures analysis of variance. The Spearman correlation was calculated to find the association between the cartilage percentage change (Δ%) and patient-reported outcomes.

RESULTS

Pain increased in the PFP group after all loading conditions (P values < .007). No differences were found in cartilage cross-sectional area or EI alteration between or within groups (P values > .06). The KOOS was negatively associated with the Δ% of the lateral femoral cartilage EI after plyometric loading (ρ = -0.87, P = .001), and the AKPS score was positively correlated with the Δ% of lateral femoral cartilage EI (ρ = 0.57, P = .05).

CONCLUSIONS

Ultrasound imaging did not identify cartilaginous deformation after all loading conditions. However, because lateral cartilaginous EI changes were associated with the AKPS and KOOS score, those questionnaires may be useful for monitoring changes in femoral cartilage health.

Effect of hip abductors and lateral rotators' muscle strengthening on pain and functional outcome in adult patients with patellofemoral pain: A systematic review and meta-analysis

BACKGROUND

Even though literature indicates presence of weak hip abductors and lateral rotators' in Patellofemoral Pain (PFP), studies evaluating the effect of hip abductors and lateral rotators strengthening to improve knee function and quality of life in PFP are limited.

OBJECTIVE

This study systematically reviews and meta-analyzes the best evidence on the therapeutic value of strengthening hip abductors and lateral rotators muscles for treating PFP with a presumptive hypothesis that strengthening hip muscles stabilizes the patellofemoral joint, relieves pain, and enhances knee functions.

METHOD

Medline, EMBASE, CINAHL, PEDro and PubMed Central databases were searched between January 1994 and September 2019 using the PICOS tool. The methodological quality of the selected studies were appraised individually using the 20-item McMaster Critical Review Form for Quantitative Studies. Supplemental quality appraisal of randomized controlled clinical trials performed using the Cochrane Collaboration's 'Risk of bias' quality criteria. Data on patient population demographics, interventions, duration of intervention, and outcome measures were extracted and summarized in evidence tables and descriptive analysis. Meta-analyses under both fixed and random-effects models determined pooled effects size from appropriate RCTs.

RESULTS

All fourteen studies demonstrated that hip muscle strengthening improved pain and knee function. All RCTs, except one, demonstrated that hip muscle strengthening is superior to quadriceps strengthening. Of the five RCTs assessing the additional effect of hip-quad versus quadriceps strengthening, four suggested that hip-quad strengthening is superior to standard quadriceps strengthening alone to improve PFP and knee function.

CONCLUSION

In adult patients with PFP, strengthening hip abductors and lateral rotators' have beneficial therapeutic effects than the conventional quadriceps exercises in improving knee pain and function both in the short- and long term. However, the present review data can be used to develop a standardized hip-quad protocol in the future.

The Relationship between Patellofemoral Pain Syndrome and Hip Biomechanics: A Systematic Review with Meta-Analysis

(1) Background and purpose: Muscular control and motor function in a patient with Patellofemoral pain syndrome (PFPS) have not yet been investigated systematically. Therefore, this review synthesis the previous results about the association of PFPS with gluteus muscle activation, hip strength, and kinematic characteristic of the hip and knee joint, to deepen understanding of the PFPS etiology and promote the establishment of an effective treatment strategy. (2) Methods: A literature search was conducted from January 2000 to July 2022 in four electronic databases: Medline, Embase, Google scholar, and Scopus. A total of 846 articles were initially identified, and after the screening process based on the inclusion criteria, 12 articles were eventually included. Means and SDs of gluteus medius (GMed), gluteus maximus (GMax), hip strength, and kinematic variation of hip and knee were retrieved from the present study. (3) Results and conclusion: Regarding kinematic variation, moderate evidence indicates that an increased peak hip adduction was found in PFPS groups during running and single leg (SL) squat activities. There is no difference in the GMed and GMax activation levels between the two groups among the vast majority of functional activities. Most importantly, strong evidence suggests that hip strength is weaker in individuals with PFPS, showing less strength of hip external rotation and hip abduction compared to the control group. However, without prospective studies, it is difficult to determine whether hip strength weakness is a cause or a result of PFPS. Therefore, further research is needed to evaluate the hip strength level in identifying individuals most likely to associated with PFPS development is needed.

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.

Patellofemoral Pain Syndrome Risk Associated with Squats: A Systematic Review

Patellofemoral pain syndrome (PFPS) is highly prevalent; it can cause severe pain and evolve into progressive functional loss, leading to difficulties performing daily tasks such as climbing and descending stairs and squatting. This systematic review aimed to find evidence, in the literature, of squat movements that can cause or worsen PFPS. This work was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, and its protocol was registered in PROSPERO (CRD42019128711). From the 6570 collected records, 37 were included. From these 37 articles, 27 present a causal relationship between knee flexion and PFPS, 8 describe a relationship, considering the greater existence of muscle contractions, and one article did not describe this relationship in its results. The main limitations stem from the fact that different studies used different evaluation parameters to compare the force exerted on the patellofemoral joint. Furthermore, most studies are focused on sports populations. After analysing the included works, it was concluded that all squat exercises can cause tension overload in the knee, especially with a knee flexion between 60° and 90° degrees. The main causal/worsening factors of PFPS symptoms are the knee translocation forward the toes (on the same body side) when flexing the knee, and the muscle imbalance between the thigh muscles.

Comparison of the Superiority of Quadriceps Strengthening Isometric and Isotonic Exercises with Respect to Pain, Quality of Life, and Functional Capacity of Patients with Chondromalacia Patellae

Purpose: This study aims to investigate the superiority of different exercise modalities, including isotonic and isometric strengthening for quadriceps, over each other and their effect on pain, quality of life and functional capacity in patients diagnosed with chondromalacia patellae (CMP). Methods: This study was designed as a prospective study in 30 patients(15 patients in isometric, 15 patients in isotonic group) and 15 healthy volunteers aged 20–50 years who were diagnosed with CMP based on physical examination and magnetic resonance imaging and had pain complaints. Pain level was evaluated with Visual Analogue Scala (VAS), functional capacity with Lysholm scale, and quality of life with Short Form-36(SF-36). Q-angle, and thigh circumference were evaluated before and after exercise in all patients. Results: In patients with CMP, there were significant differences in Q-angle, pain, functional capacity, and some subcomponents of the SF-36 quality of life after performing isometric or isotonic exercises compared with the control group (p0,05). In the evaluation of the isotonic and isometric exercise groups, there were no significant difference in the assessment of Q-angle, thigh circumference, pain, functional capacity, and quality of life of patients with CMP (p>0,05). Conclusion: Isometric and isotonic quadriceps strengthening exercises are not superior to each other in terms of pain, functional capacity, and quality of life in CMP treatment.

Strength, Flexibility and Postural Control of the Trunk and Lower Body in Participants with and without Patellofemoral Pain

Patellofemoral pain (PFP) is a frequent knee condition. The aim of this study was to investigate strength, flexibility and postural control in people with and without PFP. Fifty-five participants between 14 and 54 years of age (PFP = 18, control group = 37) were included. Strength and flexibility for all trunk, hip, knee and ankle muscle groups were measured along with postural control outcomes. Analyses were conducted based on the “affected” and “non-affected” leg within-group and between-groups. Between-groups analysis demonstrated a statistically lower strength of trunk muscles (range: 35.8–29.3%, p < 0.001), knee extensors (20.8%, p = 0.005) and knee flexors (17.4%, p = 0.020) in PFP participants. Within-group analysis proved an 8.7% (p = 0.018) greater hip internal rotation strength and ankle extension flexibility (p = 0.032) of the “affected side” in PFP participants. This was, to our knowledge, the first study to investigate the strength of all trunk muscle groups. The results indicate that participants with PFP exhibit impaired strength of trunk muscle groups, along with knee muscle deficits, which may present a rehabilitation target. Clinicians should consider implementing trunk strengthening exercises into PFP programs along with knee-targeting exercise programs.

Optimizing Rehabilitation and Return to Sport in Athletes With Anterior Knee Pain Using a Biomechanical Perspective

Anterior knee pain represents one of the most common athletic knee conditions and arguably also one of the most complex. The patellofemoral joint is at the center of several forces, and alterations in any of these force vectors due to muscular imbalance, soft-tissue tightness or laxity, and altered functional movement patterns can all combine to create a painful anterior knee. While typically anterior knee pain is not a surgical entity, the orthopaedic surgeon with an understanding of these biomechanical intricacies is best positioned to provide comprehensive evidence-based care for the patient with anterior knee pain.

Level of Evidence

V, expert opinion.

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 NCT 03985254. Registered on 26 August 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05748-x.

Autoregulation in Resistance Training for Lower Limb Tendinopathy: A Potential Method for Addressing Individual Factors, Intervention Issues, and Inadequate Outcomes

Musculoskeletal disorders, such as tendinopathy, are placing an increasing burden on society and health systems. Tendinopathy accounts for up to 30% of musculoskeletal disorders, with a high incidence in athletes and the general population. Although resistance training has shown short-term effectiveness in the treatment of lower limb tendinopathy, more comprehensive exercise protocols and progression methods are required due to poor long-term outcomes. The most common resistance training protocols are predetermined and standardized, which presents significant limitations. Current standardized protocols do not adhere to scientific resistance training principles, consider individual factors, or take the importance of individualized training into account. Resistance training programs in case of tendinopathy are currently not achieving the required intensity and dosage, leading to high recurrence rates. Therefore, better methods for individualizing and progressing resistance training are required to improve outcomes. One potential method is autoregulation, which allows individuals to progress training at their own rate, taking individual factors into account. Despite the finding of their effectiveness in increasing the strength of healthy athletes, autoregulation methods have not been investigated in case of tendinopathy. The purpose of this narrative review was 3-fold: firstly, to give an overview and a critical analysis of the individual factors involved in tendinopathy and current resistance training protocols and their limitations. Secondly, to give an overview of the history, methods, and application of autoregulation strategies both in sports performance and physiotherapy. Finally, a theoretical adaptation of a current tendinopathy resistance training protocol using autoregulation methods is presented, providing an example of how the method could be implemented in clinical practice or future research.

Is Isolated Hip Strengthening or Traditional Knee-Based Strengthening More Effective in Patients With Patellofemoral Pain Syndrome? A Systematic Review With Meta-analysis

Background:

Focus on the importance of hip muscle strength in patients with patellofemoral pain syndrome (PFPS) has recently increased. It is unknown whether patients with PFPS will benefit more from hip strengthening compared with traditional knee-based strengthening.

Purpose:

To compare the efficiency of isolated hip strengthening versus traditional knee-based strengthening for patients with PFPS.

Study Design:

Systematic review; Level of evidence, 2.

Methods:

We conducted a search for studies comparing isolated hip strengthening and knee-based strengthening by using the MEDLINE, Embase, and Cochrane Library electronic databases. The methodological quality of included studies was assessed using the PEDro scale. Predetermined variables from each study were extracted and analyzed.

Results:

A total of 5 comparative studies were included in this review; all studies were of moderate to high quality and reflected good internal and external validity. Pain (visual analog scale [VAS]) and function (Anterior Knee Pain Scale) scores improved in both the hip and knee groups after strengthening intervention, although no statistically significant differences were seen between groups in the pooled analysis. In 2 studies, VAS pain scores were reduced earlier for patients in the hip group than for those in the knee group (P < .05). In 1 study, improvement in Western Ontario and McMaster Universities Osteoarthritis Index function scores in the hip group was statistically superior compared with those in the knee group after intervention and at 6-month follow-up (P < .05). In 2 studies, patients in the hip group exhibited statistically greater hip abductor and extensor strength than did those in the knee group after intervention (P < .05).

Conclusion:

The best-available evidence suggests that overall, isolated hip strengthening and knee strengthening were equivalent for treatment of PFPS.

Effects of a Targeted Exercise Program on Inter-Leg Asymmetries in Patients with Patellofemoral Pain

Patellofemoral pain (PFP) is often associated with impaired muscle strength, flexibility, and stability. It has been suggested that inter-leg asymmetries have an important role in increasing the risk of musculoskeletal injuries, including PFP. Thus, the aim of this study was to identify significant asymmetries and determine the effects of a symmetry targeted exercise program in patients with PFP. Eighteen patients aged 13 to 54 years (24.17 ± 12.52 years) with PFP participated in this study. Strength, flexibility and stability outcomes of the trunk, hip, knee and ankle muscles were assessed. A single-group pretest–posttest design was used to assess changes in inter-leg and agonist–antagonist asymmetries resulting from the 8-week period of the supervised exercise program. Results indicated a significant improvement in inter-leg symmetry regarding bilateral stance in a semi-squat position (p = 0.020, d = 0.61, df = 17) and ankle plantarflexion (p = 0.003, d = 0.32, df = 17) and ankle dorsiflexion strength (p < 0.001, d = 0.46, df = 17). In addition, the ratio of ankle dorsiflexion/plantarflexion (p = 0.036, d = 1.14, df = 17) and hip extension/flexion (p = 0.031, d = 0.94, df = 16) changed significantly during the intervention period. To our knowledge, this was the first study to evaluate inter-leg asymmetries resulting from a period of a supervised exercise program. The results indicate that an exercise program focusing on individual asymmetries may influence specific deficits and contribute to better rehabilitation outcomes.

Trunk, Hip and Knee Exercise Programs for Pain Relief, Functional Performance and Muscle Strength in Patellofemoral Pain: Systematic Review and Meta-Analysis

Objective

Previous research suggests that muscle strength exercise is the most effective rehabilitation methods in patients with patellofemoral pain (PFP). This systematic review with meta-analysis compared the effects of Hip&Knee, Hip-only and Knee-only exercise programs on pain relief, muscle strength, and functional performance in patients with PFP.

Methods

Literature searches of PubMed, PEDro and CINAHL databases revealed twenty-one studies included in the final descriptive review, thirteen of which were included in the meta-analysis. Data extraction included baseline and post-intervention means and standard deviations of all eligible outcome measures both for the intervention and control groups, participants baseline demographics and intervention characteristics.

Results

The results showed that Hip&Knee and Hip-only exercise programs were comparatively effective, while the Knee-only exercise programs proved to be inferior to the above-mentioned approaches. The Hip&Knee exercise programs showed the greatest pain relief (mean difference = -1.71 (-3.11, -0.30); p = 0.02; I² = 96%) and functional improvement (standardized mean difference = 1.28 (0.45, 2.12); p = 0.003; I² = 84%), although the subgroup analysis did not show any significant difference compared to Hip-only exercise programs (p > 0.05).

Conclusion

Overall, Hip&Knee exercise programs appear to reduce pain and improve function more than other exercise programs and could be used as a primary rehabilitation approach in patients with PFP. However, the difference between the subgroups in most outcome measures suggests that Hip&Knee exercise programs are no more effective than Hip-only exercise programs.

Combined Hip Abductor and External Rotator Strengthening and Hip Internal Rotator Stretching Improves Pain and Function in Patients With Patellofemoral Pain Syndrome: A Randomized Controlled Trial With Crossover Design

Background:

Active rehabilitation has an important role in the management of patellofemoral pain syndrome (PFPS). Although some studies have shown the benefit of hip-muscle strengthening, the effect of combining hip-muscle stretching with strengthening has not yet been defined.

Purpose:

To evaluate the effect of combined strengthening of the hip external rotators and abductors and stretching of the hip internal rotators on pain and function in patients with PFPS.

Study Design:

Randomized controlled trial; Level of evidence, 2.

Methods:

A total of 109 patients with PFPS (75 female and 34 male; mean age, 31.6 ± 10.8 years) were first randomly assigned to protocol A (n = 67) of the A-B arm (AB group; standard rehabilitation) or protocol B (n = 42) of the B-A arm (BA group; standard rehabilitation with strengthening of the hip external rotators and abductors and stretching of the hip internal rotators). Each protocol consisted of 3 sessions a week for 4 weeks. After a washout period, corresponding to a symptom-free period, rehabilitation programs were crossed over. A visual analog scale (VAS) evaluating perceived pain, the Functional Index Questionnaire (FIQ), and the Kujala score were administered at baseline, the end of each rehabilitation protocol, and 12 weeks after the completion of the second protocol for each group.

Results:

Until the final follow-up, VAS, FIQ, and Kujala scores were significantly improved in both the A-B and B-A arms (P < .05 for all). Compared with protocol A, protocol B provided significant improvement in terms of pain and function in both the BA (VAS and Kujala; P < .001) and AB (VAS and Kujala; P < .001) groups.

Conclusion:

Combined strengthening of the hip abductors and external rotators with stretching of the hip internal rotators provided better outcomes, which were maintained for at least 12 weeks, in terms of pain and function in patients with PFPS.

Short-term effectiveness of an intervention targeting lower limb range of motion on pain and disability in patellofemoral pain patients: A randomized, non-concurrent multiple-baseline study

INTRODUCTION

Patellofemoral pain (PFP) is a common and often long-standing musculoskeletal condition. Evidence of the effectiveness of interventions addressing soft tissue flexibility is conflicting and of inconsistent scientific quality. However, reduced soft tissue flexibility can negatively affect patellofemoral joint kinematics. Lower limb range of motion (LLROM) reflects soft tissue flexibility throughout the kinetic chain. The aim was to evaluate the short-term effectiveness of an intervention targeting LLROM on pain and disability in patients with PFP.

METHODS

A randomized, non-concurrent, multiple-baseline single-case design with a two-week intervention phase and baseline and postintervention phase with varying length was conducted. Eight participants (5 females, 3 males) of age 19(±1.6) years, weekly sports participation 12(±3.1) hours and 17(±14) months symptom duration were included. The Anterior Knee Pain Scale - Dutch Version (AKPS-DV) and the Patient Specific Complaint Scale (PSCS) were administered twice a week. After allocating participants to one of four subgroups of reduced LLROM the intervention was applied. The intervention consisted of soft tissue techniques (mobilization, taping, and stretching).

RESULTS

Participant 3 and 6 showed a medium and small but statistically significant positive effect on the AKPS-DV. Participant 2 showed a large and statistically significant positive effect on the PSCS.

CONCLUSIONS

This study provides moderate evidence that an intervention targeting LLROM in patients with PFP reduces pain and disability in the short-term. Further research is needed to evaluate the long-term effectiveness and optimize individual treatment outcomes.

Fatigue-Induced Hip-Abductor Weakness and Changes in Biomechanical Risk Factors for Running-Related Injuries

CONTEXT

Despite overlap between hip-abductor (HABD) weakness and fatigue-induced changes in running, the interaction of these theorized contributors to running injuries has been underevaluated.

OBJECTIVE

To assess the effects of a fatiguing run on HABD torque and evaluate the correlation between HABD torque and previously identified running-related injury pathomechanics while participants were rested or fatigued.

DESIGN

Crossover study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 38 healthy, physically active males (age = 21.61 ± 4.02 years, height = 1.78 ± 0.08 m, body mass = 76.00 ± 12.39 kg).

INTERVENTION(S)

Data collection consisted of rested-state collection, a fatiguing treadmill-run protocol, and fatigued-state collection. For the HABD measures, side-lying handheld-dynamometer isometric tests were performed and converted to torque using femur length. For the gait analysis, kinematic (240 Hz) and kinetic (960 Hz) running (4.0 m/s) data were collected for 3 trials. The fatigue protocol involved a graded exercise test and 80% o2max run to exhaustion. Immediately after the run, fatigued-state measures were obtained.

MAIN OUTCOME MEASURE(S)

Variables of interest were HABD torque and peak angles, velocities, and moments for hip and knee adduction and internal rotation. Differences between conditions were compared using paired t tests. Pearson correlation coefficients were calculated to evaluate relationships between HABD torque and biomechanical variables.

RESULTS

Fatigue decreased HABD torque and increased hip-adduction angle, knee-adduction velocity, and hip and knee internal-rotation velocities and moments (all P values < .05). In the rested state, HABD torque was correlated with hip-adduction velocity (r = -0.322, P = .049). In the fatigued state, HABD torque was correlated with hip-adduction velocity (r = -0.393, P = .015), hip internal-rotation velocity (r = -0.410, P = .01), and knee-adduction angle (r = 0.385, P = .017) and velocity (r = -0.378, P = .019).

CONCLUSIONS

Changes in joint velocities due to fatigue and correlations between HABD torque and hip- and knee-joint velocities highlight the need to consider not only the quantity of HABD strength but also the rate of eccentric control of HABDs.

Update on Patellar Instability

Patellar instability is a multifactorial clinical condition that affects a significant number of patients and occurs due to morphological variations of the joint and patellofemoral alignment. The present literature review study aimed to identify and summarize current concepts on patellar instability, in relation to associated risk factors, diagnostic criteria, and the benefits and risks of conservative and surgical treatments. For this purpose, a search was conducted in the following electronic databases: MEDLINE (via Pubmed), LILACS and Cochrane Library. It is concluded that the accurate diagnosis depends on the detailed clinical evaluation, including the history and possible individual risk factors, as well as imaging exams. The initial treatment of patellar instability is still controversial, and requires the combination of conservative and surgical interventions, taking into consideration both soft tissues and bone structures, the latter being the most common reason for choosing surgical treatment, especially lateral patellar instability.

Effects of whole body vibration with exercise therapy versus exercise therapy alone on flexibility, vertical jump height, agility and pain in athletes with patellofemoral pain: a randomized clinical trial

Background

Patellofemoral pain (PFP) is the most prevalent orthopedic problem in active young adults. Due to its multifactorial etiology, a variety of therapeutic measures have been adopted to treat PFP, including exercise therapy, electrotherapy, and manual therapy. It has also been suggested that whole body vibration (WBV) can improve neuromuscular function in persons with knee problems. The aim of the present study was to evaluate the effects of adding WBV to routine exercise programs on flexibility, vertical jump height, agility and pain in athletes with PFP.

Methods

Twenty-four male athletes with PFP were randomized into two groups of WBV + exercise (n = 12) or exercise only (n = 12). Participants received their interventions during 4 consecutive weeks (12 sessions). Pain intensity, flexibility and agility were assessed respectively as score on a numerical rating scale, the sit-and-reach test, and a modified T-test, and vertical jump height was measured to the nearest centimeter. The tests were done before and after the interventions, and the results were compared between the two groups. Independent t-tests and paired t-tests were used for between- and within-group comparisons, respectively.

Results

After the interventions, all variables for vertical jump height, flexibility, agility and pain intensity improved significantly in both groups (p < 0.05). The flexibility test showed significantly greater improvement in the WBV + exercise group (p<0.001), whereas for vertical jump height, agility and pain intensity, there were no statistically significant differences between groups (p>0.05).

Conclusions

The present findings showed that exercise therapy with and without WBV can significantly decrease pain and increase agility, vertical jump height and flexibility in athletes with PFP. Adding WBV to routine exercise therapy, however, can augment the effects of the latter on flexibility.

Trial registration

IRCT, IRCT20090831002391N39. Registered 7 February 2018, https://en.irct.ir/search/result?query=IRCT20090831002391N39.

Do exercises for patellofemoral pain reflect common injury mechanisms? A systematic review

OBJECTIVES

Current best evidence has reported that therapeutic exercise programs that are designed to treat patellofemoral pain (PFP) should include both hip and knee specific exercises. The purpose of this review was to (1) examine the quality/comprehensiveness of exercise reporting in this field; (2) quantify the extent to which individual exercises comprised task-specific elements (single limb stance; eccentric control of the hip; rotational z-axis control) most likely to address key pathomechanics associated with PFP.

DESIGN

Systematic review: a systematic survey of RCTs.

METHODS

PubMed, CINAHL, Medline, Physiotherapy Evidence Database (PEDro) and SPORT Discus databases were searched for randomized controlled trials that addressed PFP utilizing a proximal control hip focused rehabilitation paradigm. The therapeutic exercise programs were evaluated, and each individual exercise was extracted for analysis. Quality assessments included the PEDro Scale and the Consensus on Exercise Reporting Template (CERT) was utilized to score the reporting of the interventions.

RESULTS

19 studies were included in the final analysis. 178 total exercises were extracted from the proximal hip and knee rehabilitation programs. The exercises were analyzed for the inclusion of elements that align with reported underlying biomechanical mechanisms.

CONCLUSIONS

The vast majority of the exercises were sagittal plane, concentric, non-weight bearing exercises, whereas multiplanar exercises, single limb weightbearing, and exercises where loading was directed around the longitudinal z-axis, were considerably under-represented. Current exercises for PFP utilize simplistic frameworks that lack progression into more task specific exercise, and are not reflective of the complex injury etiology.

The immediate effect of lumbopelvic manipulation on knee pain, knee position sense, and balance in patients with patellofemoral pain: A randomized controlled trial

BACKGROUND

Patellofemoral pain (PFP) is a common musculoskeletal disorder. Quadriceps and core muscle neuromuscular control impairments are frequently associated with PFP. Lumbopelvic manipulation (LPM) has been shown to improve quadriceps and core muscle activation and decrease their inhibition, but changes in balance and knee joint position sense (JPS) after this intervention remain unknown.

OBJECTIVE

To determine whether LPM decreases knee pain and JPS error and increases balance performance in patients with PFP.

DESIGN

Randomized controlled trial.

SETTING

Biomechanics laboratory at a rehabilitation science research center.

METHODS

Forty-four patients with PFP participated in this study that randomly divided into two equal groups. One group received LPM and the other received sham LPM (positioning with no thrust) in a single session. At baseline and immediately after the intervention, the outcomes of pain using a visual analog scale, balance using the modified star excursion balance test (mSEBT), and JPS at 20° and 60° of knee flexion using a Biodex dynamometer.

RESULTS

There was a statistically significant improvement in pain, balance control (anterior direction) and JPS in the LPM group immediately after the intervention. In addition, we observed significant differences between groups in pain, balance control (anterior direction) and JPS at 60° of knee flexion immediately after the intervention.

CONCLUSION

A single session of LPM immediately improved balance control, knee JPS, and pain in patients diagnosed with PFP.

CLINICAL REHABILITATION IMPACT

Findings suggest that LPM may be used as a therapeutic tool for immediate improvement of symptoms of PFP. However, more research is needed to determine long term results.

Effects of Trigger Point Dry Needling on Neuromuscular Performance and Pain of Individuals Affected by Patellofemoral Pain: A Randomized Controlled Trial

Purpose

To investigate the effects of trigger point dry needling (TrP-DN) on exercise-induced patellofemoral pain syndrome (PFPS).

Patients and Methods

In this randomized, single-blind, parallel-group trial, 50 patients with PFPS were randomly allocated to the following two groups: the TrP-DN group (n = 25) and the Sham needling group (n = 25). Patients in both groups were asked to perform a stretching exercise of the quadriceps daily after needling. The needling group received a single session of TrP-DN to trigger points (TrPs) in the vastus medialis oblique (VMO), vastus lateralis (VL), and rectus femoris muscles (once a week for 6 weeks), and the Sham group received placebo needling. Visual analogue scale (VAS) for pain intensity and Kujala questionnaire for the functional status were assessed before treatment, 3 and 6 weeks after treatment, and at the 3-month follow-up. The ratio of the myoelectric amplitude of the vastus medialis oblique and vastus lateralis muscles (VMO/VL) was assessed before treatment and 6 weeks after treatment.

Results

There was no significant difference in the general data between the two groups. The VAS scores and Kujala scores in the TrP-DN group were significantly improved and increased at the 3-week treatment visit, 6-week treatment visit, and 3-month follow-up compared to the scores before treatment; and the scores in the Sham group were only significantly improved at the 3-week treatment visit, and 6-week treatment visit. VAS scores in the TrP-DN group were significantly lower and Kujala scores were significantly higher at the 6-week treatment visit and the 3-month follow-up compared to those in the Sham group. The VMO/VL ratio in the TrP-DN group was significantly increased at the 6-week treatment visit compared to that before treatment.

Conclusion

TrP-DN at the quadriceps combined with stretch can reduce the pain, and improves the clinical symptoms and function, the VMO/VL ratio, and the coordination of VMO and VL in patients with PFPS.

Comparison of Protonics™ Knee Brace With Sport Cord on Knee Pain and Function in Patients With Patellofemoral Pain Syndrome: A Randomized Controlled Trial

CONTEXT

Protonics™ knee brace has been suggested as an intervention for patients with patellofemoral pain syndrome. However, the effectiveness of this knee brace compared with traditional conservative methods knee rehabilitation is lacking.

OBJECTIVE

To compare the effect of Protonics™ knee brace versus sport cord on knee pain and function in patients with patellofemoral pain syndrome.

DESIGN

Randomized controlled trial.

SETTING

Loma Linda University.

PARTICIPANTS

There were 41 subjects with patellofemoral pain with a mean age of 28.8 (5.0) years and body mass index of 25.6 (4.7) kg/m2 participated in the study.

INTERVENTION

Subjects were randomized to 1 of 2 treatment groups, the Protonics™ knee brace (n = 21) or the sport cord (n = 20) to complete a series of resistance exercises over the course of 4 weeks.

MAIN OUTCOME MEASURES

Both groups were evaluated according to the following clinical outcomes: anterior pelvic tilt, hip internal/external rotation, and iliotibial band flexibility. The following functional outcomes were also assessed: Global Rating of Change Scale, the Kujala score, the Numeric Pain Rating Scale, and the lateral step-down test.

RESULTS

Both groups showed significant improvement in the outcome measures. However, the Protonics™ knee brace was more effective than the sport cord for the Global Rating of Change Scale over time (immediate 1.0 [2.1] vs post 2 wk 3.0 [2.2] vs 4 wk 4.6 [2.3] in the Protonics™ brace compared with 0.0 [2.1] vs 1.3 [2.2] vs 3.0 [2.3] in the sport cord, P < .01), suggesting greater satisfaction.

CONCLUSIONS

Both study groups had significant improvements in the clinical and functional symptoms of patellofemoral pain. The Protonics™ knee brace group was significantly more satisfied with their outcome. However, the sport cord may be a more feasible and cost-effective method that yields similar results in patients with patellofemoral pain syndrome.

Investigation of different application techniques for Kinesio Taping® with an accompanying exercise protocol for improvement of pain and functionality in patients with patellofemoral pain syndrome: A pilot study

BACKGROUND

Patellofemoral pain syndrome (PFPS), characterized by retropatellar and peripatellar pain, is a common disorder affecting young women. Treatment has included exercise-based therapy and taping techniques for rapid reduction of symptoms and pain. Although Kinesio Taping® (KT) has been studied as adjunctive therapy, evidence on its effectiveness is limited and conflicting.

OBJECTIVE

To determine the feasibility of performing a double-blind randomized controlled trial (RCT) using KT® for PFPS treatment and to determine an ideal sample size.

DESIGN

Double-blind, randomized, controlled pilot study.

METHOD

Forty-three women (aged 18-45 years) with at least a 3-month history of PFPS were randomized based on the mechanical correction techniques: using KT® for patellar medialization (KT-PM), using KT® for lateral rotation of the femur and tibia (KT-LRFT), and the control group (CG). All groups underwent the same muscle strengthening and motor control procedures for 12 weeks. Knee pain and function were evaluated at baseline, at 6 weeks, at treatment completion (12 weeks), and during the 12-week follow-up using the numerical pain rating scale (NPRS) at rest and during effort, Anterior Knee Pain Scale (AKPS), and single jump hop test.

RESULTS

There were clinically significant differences between the KT-LRFT and the CG in terms of AKPS and NPRS scores during effort at the 6-week and 12-week follow-ups. All groups (within group) showed a significant improvement in pain and function.

CONCLUSIONS

A complete RCT using KT® for the treatment of PFPS is feasible with some changes regarding outcome measures and treatment protocols.

Patellofemoral pain: One year results of a randomized trial comparing hip exercise, knee exercise, or free activity

OBJECTIVE

Extended follow-up of a randomized trial comparing hip-focused exercise, knee-focused exercise, and free physical activity in patellofemoral pain (PFP).

METHODS

A single-blind randomized controlled trial included 112 patients aged 16-40 years (mean 27.6 years) with a clinical diagnosis of PFP ≥3 months (mean 39 months) and pain ≥3/10 on a Visual Analog Scale. Patients were randomized to a 6-week exercise-based intervention consisting of either isolated hip-focused exercises (n = 39), traditional knee-focused exercise (n = 37), or free physical activity (n = 36). All patients received the same patient education. The primary outcome measure was the Anterior Knee Pain Scale (AKPS, 0-100). Secondary outcomes were usual and worst pain, Tampa Scale of Kinesiophobia, Knee Self-Efficacy Score, Euro-Qol (EQ-5D-5L), step-down test, and isometric strength. Blinded observers assessed outcomes at baseline, 3, and 12 months. The study was designed to detect a difference in AKPS >10 at 12 months.

RESULTS

After 1 year, there were no significant between-group differences in any primary or secondary outcomes. Between-group differences for AKPS were as follows: knee versus free physical activity -4.3 (95% CI -12.3 to 3.7); hip versus free physical activity -1.1 (95% CI -8.9 to 6.7); and hip versus Knee 3.2 (95% CI -4.6 to 11.0). The cohort as a whole improved significantly at 3 and 12 months compared to baseline for all measures except for knee extension strength.

CONCLUSION

After 1 year, there was no difference in effectiveness of knee exercise, hip exercise, or free physical activity, when combined with patient education in PFP.

Influence of body mass index on patellofemoral pain

Abstract Introduction: Patellofemoral Pain Syndrome is characterized by retro-patellar and peripatellar pain during squatting, kneeling and running whose intensity can be related to Body Mass Index (BMI). Objective: To evaluate the relationship between overweight, pain and function in women with Patellofemoral Pain Syndrome (PFPS). Method: Cross-sectional observational study of fifty-four women with PFPS assessed in the period between January and December 2015, in the physiotherapy outpatient clinic of a tertiary hospital in the city of São Paulo. To verify the variables of pain at rest, at effort and function, the Numerical Pain Rating Scale (NPRS) and the Kujala Anterior Knee Pain Scale (AKPS) were used. The participants were divided into two groups, according to the BMI categories defined by the World Health Organization (WHO): Group 1, composed of women with normal BMI (18-24.9 kg/m²), with 36 patients, and group 2 composed of overweight women (25-29.9 k/m²), with 18 patients. Comparison between groups of pain at rest and effort and AKPS were performed using Student's t-test and Mann-Witney with statistical significance p < 0,05. Results: There was no statistically significant difference between groups for the pain at rest and effort and for AKPS. Conclusion: BMI does not impact pain intensity and function in women with PFPS.

Development of the University of Wisconsin Running Injury and Recovery Index

BACKGROUND

Runners experience a high proportion of overuse injuries, with extended recovery periods involving a gradual, progressive return to preinjury status. A running-specific patient-reported outcome (PRO) measure does not exist, and a questionnaire assessing critical elements of runners' recovery processes may have excellent psychometric properties.

OBJECTIVES

To develop a valid, reliable, and responsive evaluative PRO measure to assess longitudinal change in running ability after running-related injury (RRI) for clinical practice and research applications.

METHODS

Self-identified runners and selected experts participated in an iterative, 6-step development process of the University of Wisconsin Running Injury and Recovery Index (UWRI) in this longitudinal clinical measurement study. Content-related validity was assessed using open comments. Reproducibility was assessed using Cronbach's alpha, the intraclass correlation coefficient (ICC), and standard error of measurement (SEM). An anchor-based construct validity assessment measured the association between the change in UWRI score and global rating of change (GROC). Responsiveness assessments included floor and ceiling effects.

RESULTS

The 9-item UWRI assesses running ability following an RRI, with the maximum score of 36 indicating a return to preinjury running ability. The UWRI demonstrated acceptable internal consistency (α = .82), test-retest reliability (ICC = 0.93), and SEM (1.47 points). Change in UWRI score was moderately correlated with the GROC (r = 0.61; 95% confidence interval: 0.4, 0.76). Floor and ceiling effects were absent. Completion required 3 minutes 15 seconds.

CONCLUSION

The UWRI is a reliable PRO measure and is responsive to changes in running function following an RRI, with minimal administrative burden.

LEVEL OF EVIDENCE

Therapy, level 2c. J Orthop Sports Phys Ther 2019;49(10):751-760. Epub 3 Aug 2019. doi:10.2519/jospt.2019.8868.

Patellofemoral Pain

Patellofemoral pain (PFP) is a common musculoskeletal-related condition that is characterized by insidious onset of poorly defined pain, localized to the anterior retropatellar and/or peripatellar region of the knee. The onset of symptoms can be slow or acutely develop with a worsening of pain accompanying lower-limb loading activities (eg, squatting, prolonged sitting, ascending/descending stairs, jumping, or running). Symptoms can restrict participation in physical activity, sports, and work, as well as recur and persist for years. This clinical practice guideline will allow physical therapists and other rehabilitation specialists to stay up to date with evolving PFP knowledge and practices, and help them to make evidence-based treatment decisions. J Orthop Sports Phys Ther. 2019;49(9):CPG1-CPG95. doi:10.2519/jospt.2019.0302.

Effectiveness of Isolated Hip Exercise, Knee Exercise, or Free Physical Activity for Patellofemoral Pain: A Randomized Controlled Trial

BACKGROUND

Exercise for patellofemoral pain (PFP) is traditionally knee focused, targeting quadriceps muscles. In recent years, hip-focused exercise has gained popularity. Patient education is likely an important factor but is underresearched.

PURPOSE

To compare 3 treatment methods for PFP, each combined with patient education: hip-focused exercise, knee-focused exercise, or free physical activity.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A single-blind randomized controlled trial was performed with 112 patients who were 16 to 40 years old (mean, 27.6 years) and had a symptom duration >3 months (mean, 39 months) with a clinical diagnosis of PFP and no radiograph or magnetic resonance evidence of other pathology. Patients were randomized to a 6-week intervention consisting of patient education combined with isolated hip-focused exercise (n = 39), traditional knee-focused exercise (n = 37), or free physical activity (n = 36). The primary outcome was Anterior Knee Pain Scale (0-100) at 3 months. Secondary outcomes were visual analog scale for pain, Tampa Scale for Kinesiophobia, Knee Self-efficacy Scale, EuroQol, step-down, and isometric strength.

RESULTS

There were no between-group differences in any primary or secondary outcomes at 3 months except for hip abduction strength and knee extension strength. Between-group differences at 3 months for Anterior Knee Pain Scale were as follows: knee versus control, 0.2 (95% CI, -5.5 to 6.0); hip versus control, 1.0 (95% CI, -4.6 to 6.6); and hip versus knee, 0.8 (95% CI, -4.8 to 6.4). The whole cohort of patients improved for all outcomes at 3 months except for knee extension strength.

CONCLUSION

The authors found no difference in short-term effectiveness in combining patient education with knee-focused exercise, hip-focused exercise, or free training for patients with PFP.

REGISTRATION

NCT02114294 (ClinicalTrials.gov identifier).

The Effect of Valgus Control Instruction Exercises on Pain, Strength, and Functionality in Active Females With Patellofemoral Pain Syndrome

BACKGROUND

Patellofemoral pain syndrome (PFPS) is sometimes related to excessive hip adduction and internal rotation, as well as knee valgus during weightbearing activities in females. Research on injury prevention and rehabilitation strategies has shown the positive effects of valgus control instruction (VCI) exercise programs in training.

HYPOTHESIS

A VCI program would result in a positive change in pain, eccentric hip muscle torque, and performance in females with PFPS.

STUDY DESIGN

Controlled laboratory study.

LEVEL OF EVIDENCE

Level 1.

METHODS

Sixty-four amateur female volleyball players from our university (age, 18-25 years) with PFPS and equal years of exercise experience were randomly divided into VCI (n = 32; age, 22.1 ± 5.88 years) and control (n = 32; age, 23.1 ± 6.49 years) groups. Function (single, triple, and crossover hops), strength (hip abductor and external rotators), pain (visual analog scale), and knee valgus angle (single-leg squat) were assessed at baseline and after intervention.

RESULTS

There was a significant difference before and after implementation of the VCI program with regard to pain (49.18% ↓, P = 0.000), single-leg hop test (24.62% ↑, P = 0.000), triple-hop test (23.75% ↑, P = 0.000), crossover hop test (12.88% ↑, P = 0.000), single-leg 6-m timed hop test (7.43% ↓, P = 0.000), knee dynamic valgus angle (59.48% ↓, P = 0.000), peak abductor to adductor eccentric torque ratio (14.60% ↑, P = 0.000), peak external (59.73% ↑, P = 0.023) and internal rotator (15.45% ↑, P = 0.028) eccentric torques, and the ratio of peak external to internal rotator eccentric torque (40.90% ↑, P = 0.000) ( P < 0.05).

CONCLUSION

PFPS rehabilitation and prevention programs should consider VCI exercises to decrease pain, improve strength, and increase athletes' functional performance.

CLINICAL RELEVANCE

This study investigated the effect of VCI exercises on knee valgus angle, pain, and functionality of individuals with PFPS. The VCI program improves performance, knee dynamic valgus angle, and strength in participants with PFPS. A controlled and optimal knee valgus angle during a functional task is the most important factor for injury prevention specialists. VCI training can be used as a supplemental method to prevent and treat lower extremity injury in patients with PFPS.

Effects of Core Neuromuscular Training on Pain, Balance, and Functional Performance in Women With Patellofemoral Pain Syndrome: A Clinical Trial

Objective

The purpose of this study was to determine the effects of core neuromuscular training on pain, balance, and performance in women with patellofemoral pain syndrome (PFPS).

Methods

This randomized single-blind trial was based on a convenience sample of 28 women with unilateral PFPS. All participants were assigned randomly to the intervention or control group with a block randomization method. The control group received routine physical therapy exercise for PFPS. The intervention group received core neuromuscular training in addition to routine physical therapy exercise. The outcome measures evaluated were pain intensity (Visual Analog Scale), function (Kujala patellofemoral questionnaire and step-down performance test), and balance (Y balance test).

Results

In both groups the pain score was significantly lower after treatment (P = .001). The slope of this trend was greater in the intervention group. The Kujala and step-down scores improved significantly after treatment in both groups, although the improvements were greater in the intervention group. The Y balance score improved in all 3 directions after therapy in both groups (P < .05); improvement was significantly greater in the intervention group only in the posteromedial direction (P = .016).

Conclusion

For the group of participants studied, a 4-week core neuromuscular training plus routine physiotherapy exercise was more effective than routine physiotherapy exercise alone for improving pain, balance, and functional performance in individuals with PFPS.

Impairment-Based Rehabilitation With Patterned Electrical Neuromuscular Stimulation and Lower Extremity Function in Individuals With Patellofemoral Pain: A Preliminary Study

CONTEXT

Patellofemoral pain (PFP) is a chronic condition that presents with lower extremity muscle weakness, decreased flexibility, subjective functional limitations, pain, and decreased physical activity. Patterned electrical neuromuscular stimulation (PENS) has been shown to affect muscle activation and pain after a single treatment, but its use has not been studied in a rehabilitation trial.

OBJECTIVE

To determine the effects of a 4-week impairment-based rehabilitation program using PENS on subjective function, pain, strength, range of motion, and physical activity in individuals with PFP.

DESIGN

Randomized controlled trial.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 21 patients with PFP (5 males, 16 females; age = 23.4 ± 7.6 years, height = 168.0 ± 7.5 cm, mass = 69.0 ± 19.5 kg).

INTERVENTION(S)

Participants completed a 4-week supervised rehabilitation program in conjunction with random assignment to receive PENS or sham treatments.

MAIN OUTCOME MEASURE(S)

Subjective function, pain, strength, range of motion, and physical activity levels were assessed prerehabilitation and postrehabilitation. Subjective function and pain were also assessed at 6 and 12 months postrehabilitation. Repeated-measures analyses of variance and Tukey post hoc testing were conducted with α ≤ .05. We calculated Cohen d effect sizes with 95% confidence intervals.

RESULTS

Both groups had statistically and clinically meaningful differences in subjective function, pain, strength, range of motion, and activity level after 4 weeks of impairment-based rehabilitation. Improved subjective function was observed in both groups at 6 and 12 months after the interventions. The PENS group had improvements in current pain for all 3 postrehabilitation times compared with baseline measures.

CONCLUSIONS

An impairment-based intervention effectively improved subjective function, pain, strength, range of motion, and physical activity levels in individuals with PFP. Participants who received PENS in addition to the rehabilitation program had improved current pain at 6 and 12 months postrehabilitation compared with baseline scores.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02441712.

Hip abductor muscle volumes are smaller in individuals affected by patellofemoral joint osteoarthritis

OBJECTIVE

The aims of this study were twofold: firstly, to compare hip abductor muscle volumes in individuals with patellofemoral joint (PFJ) osteoarthritis (PFJ OA) against those of healthy controls; and secondly, to determine whether hip muscle volumes and hip kinematics during walking are related in individuals with PFJ OA and healthy controls.

METHODS

Fifty-one individuals with PFJ OA and thirteen asymptomatic, age-matched healthy controls ≥40 years were recruited. Volumes of the gluteus medius, gluteus minimus and tensor fasciae latae were obtained from magnetic resonance (MR) images. Video motion capture was used to measure three-dimensional hip joint kinematics during overground walking.

RESULTS

Significantly smaller gluteus medius (P = 0.017), gluteus minimus (P = 0.001) and tensor fasciae latae (P = 0.027) muscle volumes were observed in PFJ OA participants compared to controls. Weak correlations were observed between smaller gluteus minimus volume and larger hip flexion angle at contralateral heel strike (CHS) (r = -0.279, P = 0.038) as well as between smaller gluteus minimus volume and increased hip adduction angle at CHS (r = -0.286, P = 0.046).

CONCLUSION

Reduced hip abductor muscle volume is a feature of PFJ OA and is associated with increased hip flexion and adduction angles during the late stance phase of walking for PFJ OA participants and healthy controls.

Trunk postural control during unstable sitting differs between patients with patellofemoral pain syndrome and healthy people: A cross-sectional study

BACKGROUND

Patellofemoral pain syndrome (PFPS) is a common orthopedic problem with a high prevalence among young women. Patients with PFPS have altered trunk muscle activity, impaired postural control and greater displacement of the center of pressure (COP) while standing. Training in unstable sitting, by putting more emphasis on trunk sensory receptors, may improve trunk proprioception by minimizing the role of the lower extremities. The aim of this study was to compare trunk postural control in healthy persons and in patients with PFPS.

METHODS

Twenty-one women diagnosed with PFPS and 21 healthy women volunteered to participate in this cross-sectional study. The participants were asked to maintain trunk postural balance on an unstable sitting device, and COP indices of trunk postural control were compared between groups.

RESULTS

All COP indices (e.g., mean anterior-posterior and lateral COP displacement, mean COP velocity and mean area of COP displacement) were significantly increased in participants with PFPS in comparison to healthy controls (P < 0.001). The effect sizes of all the indices were greater than 0.80.

CONCLUSIONS

Trunk postural control is impaired in patients with PFPS, and this finding has clinical implications for rehabilitation in patients with PFPS. Adding seated postural control training to conventional physical therapy management in patients with PFPS may have beneficial effects by emphasizing trunk proprioception while minimizing the role of the lower extremities.

National Athletic Trainers' Association Position Statement: Management of Individuals With Patellofemoral Pain

OBJECTIVE: 

To present recommendations for athletic trainers and other health care providers regarding the identification of risk factors for and management of individuals with patellofemoral pain (PFP).

BACKGROUND: 

Patellofemoral pain is one of the most common knee diagnoses; however, this condition continues to be one of the most challenging to manage. Recent evidence has suggested that certain risk factors may contribute to the development of PFP. Early identification of risk factors may allow clinicians to develop and implement programs aimed at reducing the incidence of this condition. To date, clinicians have used various treatment strategies that have not necessarily benefitted all patients. Suboptimal outcomes may reflect the need to integrate clinical practice with scientific evidence to facilitate clinical decision making.

RECOMMENDATIONS: 

The recommendations are based on the best available evidence. They are intended to give athletic trainers and other health care professionals a framework for identifying risk factors for and managing patients with PFP.

Added Value of Isolated Core Postural Control Training on Knee Pain and Function in Women With Patellofemoral Pain Syndrome: A Randomized Controlled Trial

OBJECTIVES

To evaluate the added value of isolated core postural control training on knee pain and function in women with patellofemoral pain syndrome (PFPS).

DESIGN

Randomized controlled trial.

SETTING

Rehabilitation sciences research center.

PARTICIPANTS

Women (N=33) between 18 and 30 years of age with PFPS were randomly assigned to a control group (n=16) or the experimental group (n=17).

INTERVENTIONS

Participants in both groups received the same stretching and strengthening exercises during 4 weeks (12 sessions 3 days per week). The experimental group also received isolated core postural training with an unstable seat apparatus.

MAIN OUTCOME MEASURES

Center of pressure (CoP) trajectories in sitting postural control, pain intensity, and function were recorded before and after the 4-week intervention period. Functional capacity and pain intensity were reassessed 3 months after the intervention.

RESULTS

After treatment, both groups had significant improvements in pain, function (P<.001), and CoP trajectories in sitting postural control (control group P<.05, experimental group P<.001). Between-group comparisons demonstrated greater improvements in pain, function, and CoP trajectories in the experimental group (P<.001). This group also had significantly greater improvements in pain and Kujala Anterior Knee Pain Scale score at 3-month follow-up compared to the control group (P<.001).

CONCLUSIONS

Adding isolated core postural control training to physiotherapy exercises was associated with significantly greater improvements in pain, function, and CoP trajectories than physiotherapy exercises alone. Therefore, unstable sitting postural control training is potentially useful to enhance rehabilitation management in patients with PFPS.

The Consensus on Exercise Reporting Template (CERT) applied to exercise interventions in musculoskeletal trials demonstrated good rater agreement and incomplete reporting

OBJECTIVE

To determine inter-rater agreement and utility of the Consensus on Exercise Reporting Template (CERT) for evaluating reporting of musculoskeletal exercise trials.

STUDY DESIGN AND SETTING

Two independent reviewers applied the CERT to a random sample of 20 exercise trials published 2010 to 2015 identified from searches of PEDro, CENTRAL, and PubMed. Reviewers recorded whether each item criterion was met and detailed missing data, and appraisal time percent agreement and the Prevalence and Bias Adjusted Kappa (PABAK) statistic were used to measure inter-rater agreement.

RESULTS

The trials included a range of musculoskeletal conditions (back/neck pain, hip/knee osteoarthritis, tendinopathies). For percent agreement, inter-rater agreement was high (13 items ≥80%) and for PABAK substantial (nine items: 0.61-0.80) and excellent (three items: 0.81-1.0). Agreement was lower for starting level decision rule (percent agreement: 55%, PABAK 0.30); tailoring of exercise (%A: 65%, PABAK 0.40 [95% CI: 0.00 to 0.80]); exercise equipment (percent agreement: 70%, PABAK 0.30); and motivation strategies (percent agreement: 70%, PABAK 0.40). Sixty percent of descriptions were missing information for ≥50% of CERT items. Mean appraisal time was 30 minutes, and the majority of interventions required access to other published papers.

CONCLUSIONS

The CERT has good inter-rater agreement and can comprehensively evaluate reporting of exercise interventions. Most trials do not adequately report intervention details, and information can be difficult to obtain. Incomplete reporting of effective exercise programs may be remedied by using the CERT when constructing, submitting, reviewing, and publishing articles.