Quadriceps Strengthening Research Articles

Quadriceps strengthening with and without blood-flow restriction in the treatment of patellofemoral pain – A double blind randomised trial

Background Quadriceps strengthening exercises are part of the treatment of patellofemoral pain (PFP), but the heavy resistance exercises may aggravate knee pain. Blood flow restriction (BFR) training may provide a low-load quadriceps strengthening method to treat PFP. Methods Seventy-nine participants were randomly allocated to a standardised quadriceps strengthening (standard) or low-load BFR. Both groups performed 8 weeks of leg press and leg extension, the standard group at 70% of 1 repetition maximum (1RM) and the BFR group at 30% of 1RM. Interventions were compared using repeated-measures analysis of variance for Kujala Patellofemoral Score, Visual Analogue Scale for ‘worst pain’ and ‘pain with daily activity’, isometric knee extensor torque (Newton metre) and quadriceps muscle thickness (cm). Subgroup analyses were performed on those participants with painful resisted knee extension at 60°. Results Sixty-nine participants (87%) completed the study (standard, n=34; BFR, n=35). The BFR group had a 93% greater reduction in pain with activities of daily living (p=0.02) than the standard group. Participants with painful resisted knee extension (n=39) had greater increases in knee extensor torque with BFR than standard (p Conclusion Compared with standard quadriceps strengthening, low load with BFR produced greater reduction in pain with daily living at 8 weeks in people with PFP. Improvements were similar between groups in worst pain and Kujala score. The subgroup with painful resisted knee extension had larger improvements in quadriceps strength from BFR. Trial registration number 12614001164684.

Terapia de ondas de choque focal para osteoartrose de joelho: um ensaio clínico randomizado duplo-cego

Objective: To assess the efficacy of focused extracorporeal shockwave therapy (f-ESWT) when compared to placebo for pain and disability in patients with knee osteoarthritis (OA). Methods: Randomized, parallel, double-blind, placebo-controlled clinical trial. Patients with primary knee OA were given a set of exercises (hamstring stretching and quadriceps strengthening) and randomized into f-ESWT or placebo (sham probe). All patients were submitted to 4 weekly sessions of 7,000 pulses, and in the f-ESWT group energy was up to 0.15mJ/mm2. Primary outcome was visual analog scale (VAS) for pain at 1 month. Secondary outcomes were WOMAC, TUG, Lequesne's index and OMERACT-OARSI responder index at 1 and 3 months; as well as VAS at 3 months and adverse events (AEs). Both patients and outcome assessors were blinded. Mann-Whitney U test and Fisher's exact test were used with alpha=5% and power=80% in an intention-to-treat analysis. Continuous outcomes were reported as mean± standard deviation. Results: 18 patients were included (9 in each group), aging 60.6±8.7, with 33.3% males. There was no significant difference at baseline across groups in any variables. f-ESWT was not superior to placebo at 1 month: VAS=-2.97±3.18 and -2.68±2.33cm, respectively, p=0.96. TUG at 1 month had significant differences: 9.09±2.30 and 11.01±2.85sec, p=0.01. No serious AEs were observed. Conclusions: f-ESWT was not superior to placebo for knee OA. This RCT was underpowered to detect differences in this study. New RCTs should use WOMAC A (pain subscale) as primary outcome and recruit at least 92 patients.

EMG Asymetricity of Selected Knee Extensor Muscles in Sustained Squat Posture (A Yogic Posture) of Athletes in Relation to their Gender and Performance

Squat is a popular yogic exercise or posture, most frequently used for quadriceps strengthening and rehabilitation. It is used for evaluation process or test by physiotherapists/clinicians/others associated with rehabilitation of athletes to strengthen their lower-body muscles and connective tissues after joint-related injury. It has been used extensively for therapeutic treatment of ligament lesions, patellofemoral dysfunctions, patellar subluxation and patellar dislocation etc. The purpose of this study was to compare the effect of sustained squat posture (a yogic posture) of athletes among male (n1=32) and female (n2=18) with high and low performance (based upon median split method) on EMG activity of Vastus Medialis (VM) and Vastus Lateralis (VL) muscles for 120 seconds. Squatting was performed at an angle of 135o-150o because strength of knee extensor (muscles) varies between these angles and is an important consideration for the performance of numerous physical daily routine activities such as walking, running, cycling, stepping and driving including development of fundamental skills for different sports across all ages and sex. VM and VL from the Quadriceps muscle group were chosen for recording the physiological signal simultaneously from right and left leg of the subjects, as these muscles determines stress on the patellofemoral joint and stabilizes the patellar bone during squatting. Frequency and time domain variables were selected to extract meaningful information from the EMG signal using the algorithm developed in MATLAB. The selected variables were Median Frequency (MDF), Mean Frequency (MNF), Root Mean Square (RMS) and Integrated EMG (IEMG). Statistical analysis showed significant differences among gender and performance level along with significant bilateral asymmetry in these athletes. Understanding from the findings is pivotal for achieving optimal muscular strength, for the development of strength endurance and reducing the prospect of training-related injuries

Association of Quadriceps Strength and Psychosocial Factors With Single-Leg Hop Performance in Patients With Meniscectomy.

Background:Clinicians use the single-leg hop test to assess readiness for return to sports after knee injury. Few studies have reported the results of single-leg hop testing after meniscectomy. Additionally, the contributions of impairments in quadriceps strength and psychosocial factors to single-leg hop performance are unknown.Purpose:To compare single-leg hop performance (distance and landing mechanics) between limbs and to examine the association of single-leg hop performance with quadriceps strength and psychosocial factors in patients with meniscectomy.Study Design:Descriptive laboratory study.Methods:A total of 22 subjects who underwent meniscectomy for traumatic meniscal tears received either standard rehabilitation alone or with additional quadriceps strengthening. Testing was conducted immediately postrehabilitation and at 1 year postsurgery. A single-leg hop test was performed bilaterally, and hop distance was used to create a hop symmetry index. Landing mechanics (peak knee flexion angle, knee extension moment, and peak vertical ground-reaction force) were analyzed with a motion-capture system and a force plate. An isokinetic dynamometer (60 deg/s) assessed knee extensor peak torque and rate of torque development (RTD0-200ms and RTD0–peak torque). Questionnaires assessed fear of reinjury (Tampa Scale for Kinesiophobia [TSK-11]) and self-efficacy (Knee Activity Self-Efficacy [KASE]).Results:Rehabilitation groups did not significantly differ in single-leg hop performance; therefore, groups were combined for further analyses. The mean hop symmetry index was 88.6% and 98.9% at postrehabilitation and 1 year postsurgery, respectively. Compared with the nonsurgical limb, the surgical limb showed decreased peak knee flexion angle at postrehabilitation and decreased knee extension moment at 1 year postsurgery. The hop symmetry index was positively associated with peak torque, RTD0-200ms, and the KASE score at postrehabilitation. Moreover, at postrehabilitation, the peak knee flexion angle was positively associated with peak torque and RTD0-200ms, and the knee extension moment was positively associated with RTD0-200ms. At 1 year postsurgery, peak knee flexion angle and knee extension moment were both positively associated with peak torque, RTD0-200ms, and RTD0–peak torque.Conclusion:Although the hop symmetry index could be considered satisfactory for returning to sports, asymmetries in landing mechanics still exist in the first year postmeniscectomy. Greater quadriceps strength was associated with greater single-leg hop distance and better landing mechanics at both postrehabilitation and 1 year postsurgery. Knee activity self-efficacy was the only psychosocial factor associated with single-leg hop performance and isolated to a positive association with single-leg hop distance at postrehabilitation.Clinical Relevance:Rate of development is not typically measured in the clinic but can be an additional quadriceps measure to monitor for single-leg hop performance. Quadriceps strength and psychosocial factors appear to have separate influence on single-leg hop performance after meniscectomy, which has implications for developing appropriate interventions for optimal single-leg hop performance.

Efficacy of live feedback to improve objectively monitored compliance to prescribed, home-based, exercise therapy-dosage in 15 to 19year old adolescents with patellofemoral pain- a study protocol of a randomized controlled superiority trial (The XRCISE-AS-INSTRUcted-1 trial).

BackgroundPatellofemoral pain is one of the most frequent knee conditions among adolescents with a prevalence of 7 %. Evidence-based treatment consists of patient education combined with hip and quadriceps strengthening. Recent evidence suggests that a large proportion of adolescents does not follow their exercise prescription, performing too few repetitions or too fast below the prescribed time under tension. Live feedback, such as a metronome or exercise games, has previously shown promising results in improving the quality of exercises. The aim of this study is to investigate if live feedback from a sensor (BandCizer™) and an iPad will improve the ability of adolescents with PFP to perform exercises as prescribed.MethodsThis study is a randomized, controlled, participant-blinded, superiority trial with a 2-group parallel design. Forty 15 to 19 year old adolescents with patellofemoral pain will be randomized to receive either live visual and auditory feedback on time under tension or no feedback on time under tension during a 6-week intervention period. Adolescents will be instructed to perform three elastic band exercises. Feedback will be provided by BandCizer™ and an iPad. The adolescents perform the exercises twice a week unsupervised and once a week during a supervised group training session. The primary outcome will be the mean deviation of the prescribed time under tension per repetition in seconds during the course of the intervention.DiscussionLow compliance is a major problem among adolescents with patellofemoral pain. Providing the adolescents with real time feedback on time under tension from a sensor and an iPad could potentially help the adolescents perform the exercises as prescribed. This may increase the total exercise dosage they receive during treatment which may help improve patient outcomes.Trial registrationRegistered at ClinicalTrials.gov (identifier: NCT02674841) on February 4th 2016.

Three-Year Outcome After a 1-Month Physiotherapy Program of Local and Individualized Global Treatment for Patellofemoral Pain Followed by Self-Management.

The main aim of this study was to assess whether improvements after a 1-month patellofemoral pain (PFP) program addressing local and global deficits were maintained for 3 years. This prospective cohort study comprised 4 treatment phases including a randomized trial during week 1. The study was conducted in a private physiotherapy practice. Thirty-seven patients (55 knees) from an original cohort of 41 patients (60 knees) with PFP were followed for 3 years after referral by doctors to participate in this study. Patients received 4 treatments: local treatment focusing on quadriceps strengthening, quadriceps stretching, and taping for fortnight 1, supplemented with individualized global treatment focusing on lower limb posture and movement patterns for fortnight 2, followed by ongoing self-management. Seven outcome measures, assessed at 4 time points, were quadriceps strength, quadriceps length, eccentric knee control, and 4 pain measures. Long-term measures included return to sporting activity, pain recurrence, exercise compliance, and Kujala score. Improvements after fortnight 1 (P < 0.001) and fortnight 2 (P < 0.05) were maintained over 3 years for 6 of 7 measures. On testing, 73% were pain free and the remaining 27% had less pain than pretreatment. Kujala scores improved 27%. Eighty-two percent resumed any sport stopped and 54% of patients started new sports/activities. Patellofemoral pain recurred in 7% and 89% of patients was still exercising 3 years posttreatment. Significant improvements after physiotherapy, incorporating local and individually targeted treatment, were maintained for 3 years in a compliant cohort.

Knee Injury – Recreational Runner

HISTORY: Case of a 41 year-old army soldier who had an acute bilateral knee giveaway weakness while jogging. After running for a mile, his left knee gaveway and he fell to the floor. He stood up without difficulties and ambulated for a short distance when he fell again due to right knee weakness. He had difficulty ambulating, although he felt no pain. During his ER visit, he had a third fall resulting in a right lateral malleolus fracture. Orthopedics was consulted and performed bilateral patellar tendon repair and right lateral malleolus ORIF. He was discharged home with bilateral hinged knee braces locked at full extension and weight-bearing precautions. Two months post-op, he was admitted to the acute inpatient rehabilitation ward of the VA Caribbean Healthcare. No past medical history of systemic conditions or regular medications. PHYSICAL EXAMINATION: Examination revealed bilateral knee valgus deformity, mild soft tissue swelling and bilateral pes planus. He had full knee extension and limited knee flexion to 90 degrees. Knee special tests were negative for meniscal, cruciate ligament or collateral ligament injury. Neurovascular exam was unremarkable. DIFFERENTIAL DIAGNOSIS: 1. Patellar tendon rupture 2. Quadriceps tendon rupture 3. Anterior cruciate ligament sprain 4. Meniscal injury 5. Collateral ligament sprain TEST AND RESULTS: 1. Bilateral knee MRI: Bilateral full-thickness tear of proximal patellar tendon with cephalad patellar displacement, medial and lateral patellar retinacula tears, and extensive soft tissue edema. Right high-grade partial versus full-thickness anterior cruciate ligament tear and anterior horn lateral meniscus tear. Left posterior horn medial meniscus tear. 2. Bilateral Knee X-ray: Bilateral patella alta. 3. Labs: Essentially normal except for low vitamin D and positive qualitative ANA test. FINAL/WORKING DIAGNOSIS: Atraumatic bilateral patellar tendon rupture TREATMENT AND OUTCOMES: 1. Outpatient-based physical therapy was provided with emphasis on ROM completion, progression of quadriceps strengthening and neuromuscular retraining. 2. He achieved full ROM in both knees and independence in ADL’s and ambulation. 3. Return to recreational sports recommendations included to avoid high impact activities, such as running, until 9-12 months post-op follow up.

Can the Use of Neuromuscular Electrical Stimulation Be Improved to Optimize Quadriceps Strengthening?

Context:Neuromuscular electrical stimulation (NMES) is a common modality used to retrain muscles and improve muscular strength after injury or surgery, particularly for the quadriceps muscle. There are parameter adjustments that can be made to maximize the effectiveness of NMES. While NMES is often used in clinical practice, there are some limitations that clinicians should be aware of, including patient discomfort, muscle fatigue, and muscle damage.Evidence Acquisition:PubMed was searched through August 2014 and all articles cross-referenced.Study Design:Clinical review.Level of Evidence:Level 3.Results:Clinicians can optimize torque production and decrease discomfort by altering parameter selection (pulse duration, pulse frequency, duty cycle, and amplitude). Pulse duration of 400 to 600 µs and a pulse frequency of 30 to 50 Hz appear to be the most effective parameters to optimize torque output while minimizing discomfort, muscle fatigue, or muscle damage. Optimal electrode placement, conditioning programs, and stimulus pattern modulation during long-term NMES use may improve results.Conclusion:Torque production can be enhanced while decreasing patient discomfort and minimizing fatigue.

Outcomes following Hip and Quadriceps Strengthening Exercises for Patellofemoral Syndrome: A Systematic Review and Meta-Analysis

There is growing evidence to support change in the rehabilitation strategy of patellofemoral pain syndrome (PFPS) from traditional quadriceps strengthening exercises to inclusion of hip musculature strengthening in individuals with PFPS. Several studies have evaluated effects of quadriceps and hip musculature strengthening on PFPS with varying outcomes on pain and function. This systematic review and meta-analysis aims to synthesize outcomes of pain and function post-intervention and at follow-up to determine whether outcomes vary depending on the exercise strategy in both the short and long term. Electronic databases including MEDLINE, EMBASE, CINAHL, Web of Science, PubMed, Pedro database, Proquest, Science direct, and EBscoHost databases were searched for randomized control trials published between 1st of January 2005 and 31st of June 2015, comparing the outcomes of pain and function following quadriceps strengthening and hip musculature strengthening exercises in patients with PFPS. Two independent reviewers assessed each paper for inclusion and quality. Means and SDs were extracted from each included study to allow effect size calculations and comparison of results. Six randomized control trials met the inclusion criteria. Limited to moderate evidence indicates that hip abductor strengthening was associated with significantly lower pain post-intervention (SMD −0.88, −1.28 to −0.47 95% CI), and at 12 months (SMD −3.10, −3.71 to −2.50 95% CI) with large effect sizes (greater than 0.80) compared to quadriceps strengthening. Our findings suggest that incorporating hip musculature strengthening in management of PFPS tailored to individual ability will improve short-term and long-term outcomes of rehabilitation. Further research evaluating the effects of quadriceps and hip abductors strengthening focusing on reduction in anterior knee pain and improvement in function in management of PFPS is needed.

Influence of step rate and quadriceps load distribution on patellofemoral cartilage contact pressures during running

Interventions used to treat patellofemoral pain in runners are often designed to alter patellofemoral mechanics. This study used a computational model to investigate the influence of two interventions, step rate manipulation and quadriceps strengthening, on patellofemoral contact pressures during running. Running mechanics were analyzed using a lower extremity musculoskeletal model that included a knee with six degree-of-freedom tibiofemoral and patellofemoral joints. An elastic foundation model was used to compute articular contact pressures. The lower extremity model was scaled to anthropometric dimensions of 22 healthy adults, who ran on an instrumented treadmill at 90%, 100% and 110% of their preferred step rate. Numerical optimization was then used to predict the muscle forces, secondary tibiofemoral kinematics and all patellofemoral kinematics that would generate the measured primary hip, knee and ankle joint accelerations. Mean and peak patella contact pressures reached 5.0 and 9.7MPa during the midstance phase of running. Increasing step rate by 10% significantly reduced mean contact pressures by 10.4% and contact area by 7.4%, but had small effects on lateral patellar translation and tilt. Enhancing vastus medialis strength did not substantially affect pressure magnitudes or lateral patellar translation, but did shift contact pressure medially toward the patellar median ridge. Thus, the model suggests that step rate tends to primarily modulate the magnitude of contact pressure and contact area, while vastus medialis strengthening has the potential to alter mediolateral pressure locations. These results are relevant to consider in the design of interventions used to prevent or treat patellofemoral pain in runners.

Impact of a 2 Week Quadriceps Strengthening Program on Response to Fatigue following ACL Reconstruction

Impact of a 2 Week Quadriceps Strengthening Program on Response to Fatigue following ACL Reconstruction

Efficacy of Blood Flow-Restricted Low-Load Resistance Training For Quadriceps Strengthening in Men at Risk of Symptomatic Knee Osteoarthritis

Background:Greater quadriceps strength has been associated with lower risk of symptomatic knee osteoarthritis (OA) in older adults. However, factors that confer elevated risk of knee OA (eg, sedentary lifestyle, obesity, and knee injury) also contribute to a reduced tolerance of resistance training programs at ≥60% 1-repetition maximum (1RM). Therefore, the current study assessed whether concurrent application of blood flow restriction (BFR) to low-load resistance training is an efficacious and tolerable means of improving quadriceps strength in men at risk of symptomatic knee OA.Methods:Men older than age 45, with a history of knee injury or elevated body mass index (BMI), were randomized to low-load resistance training (30% 1RM) either with or without concurrent BFR. Isotonic double-leg press strength and isokinetic knee extensor strength were assessed before and after 4 weeks of training 3 times/wk. Knee pain (Knee Osteoarthritis Outcome Score) was assessed for tolerance.Results:Of the 42 men (mean age 56.1 ± 7.7 years) who were randomized, 41 completed the program. There were no significant intergroup differences in age, BMI, knee pathology, or muscle strength at baseline. Although leg press 1RM improved in both control and BFR groups, there were no significant intergroup differences in primary or secondary measures of muscle strength. The BFR was not associated with worsening of knee pain, but there was a significant improvement in knee pain in the control group.Conclusions:In comparison with training without BFR, addition of BFR to 30% 1RM resistance training for 4 weeks did not confer significantly greater increases in leg press or quadriceps strength in older men with risk factors for symptomatic knee OA.

Evaluating Eccentric Hip Torque and Trunk Endurance as Mediators of Changes in Lower Limb and Trunk Kinematics in Response to Functional Stabilization Training in Women With Patellofemoral Pain

Background: Altered movement patterns of the trunk and lower limbs have been associated with patellofemoral pain (PFP). It has been assumed that increasing the strength of the hip and trunk muscles would improve lower limb and trunk kinematics in these patients. However, evidence in support of that assumption is limited. Purpose: To determine whether increases in the strength of hip muscles and endurance of trunk muscles in response to functional stabilization training will mediate changes in frontal plane lower limb kinematics in patients with PFP. Study Design: Controlled laboratory study. Methods: Thirty-one female athletes were randomized to either a functional stabilization training group that emphasized strengthening of the trunk and hip muscles or a standard training group that emphasized stretching and quadriceps strengthening. Patients attended a baseline assessment session, followed by 8 weeks of intervention, and were then reassessed at the end of the intervention period. The potential mediators that were evaluated included eccentric torque of hip muscles and endurance of the trunk muscles. The outcome variables were the lower limb and trunk kinematics in the frontal plane assessed during a single-legged squat task. Results: The eccentric strength of the gluteus muscles showed a mediation effect ranging from 18% to 32% on changes to frontal plane kinematics (decreased ipsilateral trunk inclination, pelvis contralateral depression, and hip adduction excursions) observed in the functional stabilization training group after intervention. Conclusion: Although the mediation effects were small, the results suggest that improvements in the strength of the gluteus muscles can influence the frontal plane movement patterns of the lower limb and trunk in women with PFP. Clinical Relevance: Patients with PFP might benefit from strengthening of the hip muscles to improve frontal plane lower limb and trunk kinematics during functional tasks.

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

ImportancePatellofemoral pain (PFP) is both chronic and prevalent; it has complex aetiology and many conservative treatment options.ObjectiveDevelop a comprehensive contemporary guide to conservative management of PFP outlining key considerations for...

Wearable sensor-based rehabilitation exercise assessment for knee osteoarthritis.

Since the knee joint bears the full weight load of the human body and the highest pressure loads while providing flexible movement, it is the body part most vulnerable and susceptible to osteoarthritis. In exercise therapy, the early rehabilitation stages last for approximately six weeks, during which the patient works with the physical therapist several times each week. The patient is afterwards given instructions for continuing rehabilitation exercise by him/herself at home. This study develops a rehabilitation exercise assessment mechanism using three wearable sensors mounted on the chest, thigh and shank of the working leg in order to enable the patients with knee osteoarthritis to manage their own rehabilitation progress. In this work, time-domain, frequency-domain features and angle information of the motion sensor signals are used to classify the exercise type and identify whether their postures are proper or not. Three types of rehabilitation exercise commonly prescribed to knee osteoarthritis patients are: Short-Arc Exercise, Straight Leg Raise, and Quadriceps Strengthening Mini-squats. After ten subjects performed the three kinds of rehabilitation activities, three validation techniques including 10-fold cross-validation, within subject cross validation, and leave-one-subject cross validation are utilized to confirm the proposed mechanism. The overall recognition accuracy for exercise type classification is 97.29% and for exercise posture identification it is 88.26%. The experimental results demonstrate the feasibility of the proposed mechanism which can help patients perform rehabilitation movements and progress effectively. Moreover, the proposed mechanism is able to detect multiple errors at once, fulfilling the requirements for rehabilitation assessment.

Hip Strengthening Compared With Quadriceps Strengthening in Conservative Treatment of Patients With Patellofemoral Pain: A Critically Appraised Topic

Clinical Scenario:Patellofemoral pain is a common injury that affects both athletic and sedentary populations. Clinicians may treat patellofemoral pain more effectively through a comprehensive understanding of the most effective exercise protocols.Clinical Question:In patients with patellofemoral pain, are hip abductor and external rotator muscle strengthening exercises more effective in reducing pain and improving patient-reported function compared with isolated quadriceps strengthening?Summary of Key Findings:A comprehensive and systematic database search was conducted for studies of level 2 evidence or higher. The search yielded 253 studies; of these studies, four randomized control trials and one comparative control trial fit the inclusion and exclusion criteria. A combination of quadriceps and hip strengthening exercises or hip strengthening exercises alone reduced pain and improved patient-reported function compared with quadriceps strengthening alone.Clinical Bottom Line:There is strong evidence to support the use of hip strengthening or hip strengthening combined with quadriceps strengthening in the treatment of patellofem-oral pain to decrease pain and improve patient reported function.Strength of Recommendation:The Strength of Recommendation Taxonomy recommends a grade of A for level 1 evidence with consistent patient-oriented findings.

Predictors of treatment response to strengthening and stretching exercises for patellofemoral pain: An examination of patellar alignment

BackgroundClosed kinetic chain and quadriceps strengthening, combined with flexibility exercises of the lower limb musculature, is a common treatment for patellofemoral pain syndrome (PFPS). The effectiveness has been well documented; however, very little is known about which factors predict treatment success. MethodsA total of 43 female subjects with PFPS participated in an eight-week progressive leg press (LP) strengthening and stretching exercise program. A decrease of 1.5cm on a 10cm visual analog scale (VAS) score was used as an indicator for treatment success. The baseline patellar tilt angle difference (PTA-d) due to quadriceps contraction prior to treatment was evaluated as a predictor of treatment success. The logistic regression and receiver operating characteristics (ROC) curve analysis were performed to investigate the predictive value of PTA-d. ResultsPTA-d could significantly predict the treatment success of LP strengthening and stretching exercises. The odds ratio (OR) for having an unsuccessful outcome was 1.19 (95% confidence interval (CI), 1.03−1.39, P<0.021) per degree increment of PTA-d. The most optimal cut-off value for the clinical discrimination of treatment success after LP strengthening and stretching exercise was −1.5° of PTA-d (sensitivity=0.74, specificity=0.71). The area under the ROC curve was 0.73 (standard error=0.08). ConclusionsFemale patients with PFPS whose quadriceps contraction reduced the lateral patellar tilt prior to LP strengthening and stretching exercise treatment are more likely to experience pain relief. It seems clinically important to check dynamic patellar tilt characteristics before treatment to aid in clinical decision making. Level of evidenceCohort, II

Does the Addition of Hip Strengthening to a Knee-Focused Exercise Program Improve Outcomes in Patients With Patellofemoral Pain Syndrome?

Patellofemoral pain syndrome (PFPS) is one of the most common disorders affecting the lower extremities. To improve function and decrease pain, affected individuals often undergo a guided rehabilitation program. Traditional programs have concentrated on quadriceps strengthening and other knee-focused exercises, but recent literature suggests that adding hip-muscle strengthening may improve outcomes. This review was conducted to determine the extent to which current evidence supports the addition of hip-muscle strengthening to a knee-focused strengthening and stretching program in the treatment of PFPS. Focused Clinical Question: Does the addition of hip-muscle strengthening to a knee-focused strengthening and stretching program improve outcomes in patients with PFPS?

Whole Body and Local Muscle Vibration Reduce Artificially Induced Quadriceps Arthrogenic Inhibition

ObjectiveTo evaluate the effects of whole body vibration (WBV) and local muscle vibration (LMV) on quadriceps function after experimental knee effusion (ie, simulated pathology). DesignRandomized controlled trial. SettingResearch laboratory. ParticipantsHealthy volunteers (N=43) were randomized to WBV (n=14), LMV (n=16), or control (n=13) groups. InterventionsSaline was injected into the knee to induce quadriceps arthrogenic muscle inhibition (AMI). All groups then performed isometric squats while being exposed to WBV, LMV, or no vibration (control). Main Outcome MeasuresQuadriceps function was assessed at baseline, immediately after effusion, and immediately and 5 minutes after each intervention (WBV, LMV, control) via voluntary peak torque (VPT) and the central activation ratio (CAR) during maximal isometric knee extension on a multifunction dynamometer. ResultsThe CAR improved in the WBV (11.4%, P=.021) and LMV (7.3%, P<.001) groups immediately postintervention, but they did not improve in the control group. Similarly, VPT increased by 16.5% (P=.021) in the WBV group and 23% (P=.078) in the LMV group immediately postintervention, but it did not increase in the control group. The magnitudes of improvements in the CAR and VPT did not differ between the WBV and LMV groups. ConclusionsQuadriceps AMI is a common complication following knee pathology that produces quadriceps dysfunction and increases the risk of posttraumatic osteoarthritis. Quadriceps strengthening after knee pathology is often ineffective because of AMI. WBV and LMV improve quadriceps function equivocally after simulated knee pathology, effectively minimizing quadriceps AMI. Therefore, these stimuli may be used to enhance quadriceps strengthening, therefore improving the efficacy of rehabilitation and reducing the risk of osteoarthritis.

Individualized physiotherapy in the treatment of patellofemoral pain.

Patellofemoral pain (PFP) is associated with a wide range of local and global physical factors possibly contributing to pain and thus requires detailed assessment and individualized treatment. Yet, no cohort study was found that assessed the value of individualized physiotherapy, probably because this approach lends itself to clinical practice but not to scientific research. Most studies focus on a 'knee' or 'hip' treatment approach irrespective of individual global differences in lower limb alignment, movement patterns and muscle tightness. Therefore, this study aimed to determine the effectiveness of supplementing local treatment of PFP with individualized treatment targeting global contributing factors. Secondarily it aimed to subgroup the patients according to variations in lower limb alignment/laxity, movement patterns, biarticular muscle tightness and joint degeneration. Forty-one patients (60 knees) with PFP who had followed a programme of local quadriceps strengthening, quadriceps stretching and taping for one fortnight were prescribed an individualized programme based on assessment. This global assessment included lower limb postural alignment, movement patterns, muscle tightness and range of motion. Another fortnight's treatment was prescribed accordingly and included specific, individualized postural and movement retraining, stretching and functional weight-bearing, strengthening exercises. Seven outcome measures, namely four pain measures, isokinetic quadriceps strength, quadriceps length and eccentric knee control, assessed improvement. All outcome measures showed further significant improvement following individualized treatment (p < 0.03). Patients fell into four broad physical subgroups: hypermobility (often with malalignment), hypomobility (with three of four tight muscle groups), faulty movement patterns (mostly dynamic knee valgus) and patellofemoral osteoarthritis. Individualized treatment supplementing local standard physiotherapy for PFP leads to further significant improvement over 2 weeks. This study highlights the importance of assessing patients globally in order to optimize treatment and ongoing improvement. Recognition of different subgroups may guide treatment that should include both local and deficit-targeted global treatment.