The role of muscle strength & activation patterns in patellofemoral pain

BackgroundTo investigate the extent to which quadriceps muscle activation and strength are responsible for patellofemoral pain.MethodsA pain on–off switch system synchronized with a force transducer and surface electromyography was utilized on 32 volunteer patellofemoral pain patients during maximal isometric and squat exercises.FindingsThere were 26 patients out of the 32 tested who complained of pain during the squat or isometric test, of these 20 subjects presented a significant advantage for the vastus lateralis compared to the vastus medialis obliquis activation and 12 patients had decreased quadriceps strength of the symptomatic compared to the non symptomatic leg. All patients who demonstrated weak vastus medialis obliquis activation during the isometric exercise possessed the same symptoms during the squat. On the other hand, 9 patients who showed diminished vastus medialis obliquis activation during the squat displayed equal activation between the vastus medialis obliquis and the vastus lateralis during the isometric task. With regard to the timing for the onset of muscle activation, there were only 4 patients who had a difference (P = 0.03) between the symptomatic (0.042 s) and non-symptomatic legs (0.011 s).InterpretationCauses for patellofemoral pain vary and are not necessarily a result of quadriceps strength deficit or vastus medialis obliquis activation weakness. Patellofemoral pain patients who possess lower vastus medialis obliquis activation compared to the vastus lateralis do not necessarily have quadriceps weakness while patients presenting with quadriceps strength deficits do not always have an imbalance between vastus medialis obliquis and vastus lateralis activation.     

Decreased passive muscle stiffness of vastus medialis is associated with poorer quadriceps strength and knee function after anterior cruciate ligament reconstruction

BackgroundMuscle deficits of the quadriceps and hamstrings are common after anterior cruciate ligament reconstruction, and increase the risk of knee reinjury. Muscle stiffness is an important factor for dynamic joint stability. However, the changes in quadriceps and hamstring muscle stiffness and its influence after anterior cruciate ligament reconstruction remain unclear.MethodTwenty-five male subjects with anterior cruciate ligament reconstruction and twenty-one matched healthy subjects participated in this study. The passive muscle stiffness of the quadriceps and hamstrings was assessed by shear modulus using ultrasound shear wave elastography. The isokinetic muscle strengths of the quadriceps and hamstrings were tested. Knee function was evaluated by the International Knee Documentation Committee and Lysholm score. Muscle stiffness was compared between limbs via non-parametric tests. Correlation analysis was used to detect the relationship between muscle stiffness, isokinetic muscle strength and knee functional scores.FindingsThe involved limb exhibited significantly decreased shear modulus in the vastus medialis compared to the dominant limbs(z = −3.585;P = 0.001;ES = 1.13) and non-dominant limbs(z = −3.551;P = 0.002;ES = 1.24) of healthy controls. The shear modulus of ST was also significantly lower in the involved limb when compared with the contralateral limbs(z = −3.996;P < 0.001;ES = 1.33), dominant limbs(z = −4.477;P < 0.001;ES = 1.65) and non-dominant limbs(z = −4.234;P = 0.001;ES = 1.43) of healthy controls. The shear modulus of the vastus medialis was associated with quadriceps peak torque at 60°/s(r = 0.470; p < 0.001) and knee functional score(r = 0.459; p = 0.021).InterpretationThe passive muscle stiffness of the vastus medialis decreased after anterior cruciate ligament reconstruction, which is associated with poorer quadriceps strength and knee function. The effect of modulation of muscle stiffness on improving knee function warrants future investigation.     

COMPARISON OF HIP AND KNEE STRENGTH AND NEUROMUSCULAR ACTIVITY IN SUBJECTS WITH AND WITHOUT PATELLOFEMORAL PAIN SYNDROME

Purpose/Background:

Historically, patellofemoral pain syndrome (PFPS) has been viewed exclusively as a knee problem. Recent findings have suggested an association between hip muscle weakness and PFPS. Altered neuromuscular activity about the hip also may contribute to PFPS; however, more limited data exist regarding this aspect. Most prior investigations also have not concurrently examined hip and knee strength and neuromuscular activity in this patient population. Additional knowledge regarding the interaction between hip and knee muscle function may enhance the current understanding of PFPS. The purpose of this study was to compare hip and knee strength and electromyographic (EMG) activity in subjects with and without PFPS.

Methods:

Eighteen females with PFPS and 18 matched controls participated in this study. First, surface EMG electrodes were donned on the gluteus medius, vastus medialis, and vastus lateralis. Strength measures then were taken for the hip abductors, hip external rotators, and knee extensors. Subjects completed a standardized stair-stepping task to quantify muscle activation amplitudes during the loading response, single leg stance, and preswing intervals of stair descent as well as to determine muscle onset timing differences between the gluteus medius and vastii muscles and between the vastus medialis and vastus lateralis at the beginning of stair descent.

Results:

Females with PFPS demonstrated less strength of the hip muscles. They also generated greater EMG activity of the gluteus medius and vastus medialis during the loading response and single leg stance intervals of stair descent. No differences existed with respect to onset activation of the vastus medialis and vastus lateralis. All subjects had a similar delay in gluteus medius onset activation relative to the vastii muscles.

Conclusion:

Rehabilitation should focus on quadriceps and hip strengthening. Although clinicians have incorporated gluteus medius exercise in rehabilitation programs, additional attention to the external rotators may be useful.Level of Evidence: 4     

Comparison of muscle activation levels and knee valgus between individuals with medial patellofemoral ligament reconstruction and healthy individuals during fatiguing step down task

BackgroundMedial patellofemoral ligament reconstruction becomes first-choice surgical procedure for patients with a history of lateral patellar dislocations but there is limited knowledge about neuromuscular activation patterns of individuals with a history of patellar dislocation who underwent medial patellofemoral ligament reconstruction.ObjectiveThe aim of this study was to compare muscle activation levels and knee valgus during step down performance test between individuals with a history of medial patellofemoral ligament reconstruction and healthy individuals.MethodsFifteen individuals with medial patellofemoral ligament reconstruction and 15 healthy individuals were included. Vastus medialis obliquus, vastus lateralis and gluteus medius muscle activation levels and knee valgus were measured during 60-s- step down performance test. Two-way repeated-measures of analysis of covariance was used for statistical analysis.FindingsCompared to the healthy individuals, individuals with medial patellofemoral ligament reconstruction showed lower vastus medialis obliquus (p = .04) and gluteus medius (p = .005) activation levels, and higher knee valgus (p = .002) in last period of the step down performance test.InterpretationSince the significant results were only observed in the fatiguing section of the test, endurance tests may provide more information about neuromuscular control of the individuals with history of medial patellofemoral ligament reconstruction. Future studies should investigate whether endurance exercises that target to improve vastus medialis obliquus and gluteus medius activity result in better clinical outcomes than conventional programs for individuals with medial patellofemoral ligament reconstruction.     

The efficacy of Da Chaihu decoction combined with metformin tablets for type 2 diabetes mellitus: A systematic review and meta-analysis

ObjectiveTo assess the efficacy of Da Chaihu decoction combined with metformin tablets on patients with type 2 diabetes compared with metformin alone.MethodsThis systematic review and meta‐analysis is written based on 2020 PRISMA Extension for Chinese Herbal Medicines 2020 (PRISMA-CHM 2020) reporting guidelines. We reviewed all the relevant studies from a search of the following databases from inception to February 2022 without any language restriction: Excerpta Medica Database (EMBASE), Google Scholar, PubMed, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP Information, Wanfang Data, and the Chinese Biomedical Literature Database(CBM). Data were extracted and the quality was independently evaluated by two reviewers, based on the inclusion and exclusion criteria. Data were analyzed using the Cochrane software RevMan 5.3.ResultsSix randomized controlled trials comprising 516 participants were included.The meta‐analysis revealed the Da Chaihu decoction combined with metformin tablets group was significantly superior to the metformin tablets group in terms of fasting blood glucose(FPG) (−0.66 mmol/L; 95 % CI (confidence intervals) [− 1.28, − 0.04]), plasma glucose 2 h after meal (2-h PG) (−1.18 mmol/L; 95 % CI [−1.94, −0.42]) in six RCTs, body mass index (BMI) (−3.07 mmol/L; 95 % CI [−6.89, 0.75]) in three RCTs, glycosylated hemoglobin (HbAlc) (−0.36 mmol/L; 95 % CI [−1.04, 0.31]) in three RCTs, and triglycerides (TG) (−0.76 mmol/L; 95 % CI [−1.37, −0.15]) in two RCTs. In two RCTs, there were significant differences in terms of total cholesterol (TC) (−0.97 mmol/L; 95 % CI [−1.18, −0.76]).ConclusionsVery low-quality research shows that Da Chaihu decoction combined with metformin tablets exert a certain level of efficacy on patients with type 2 diabetes compared with metformin alone. However, random sequence generation methodology was reported in five studies leading to the low quality of the included studies. None of the six studies depicted the blinding method, allocation concealment, selective reporting, and assessed the purity and potency of the product. This observation requires verification through high-quality, multi-center, double-blinded randomized controlled trials, and assesses the purity and potency of the product.     

Family satisfaction in Egyptian adult intensive care units: A mixed-method study

ObjectivesTo examine family members’ satisfaction in adult intensive care units.MethodologyThis is mixed-method research. Family members of critically ill patients responded to a structured questionnaire and then were interviewed using semi-structured interviews. Quantitative and qualitative data were analyzed separately and integrated during the discussion.SettingsSix adult intensive care units in university hospitals in Egypt.Main outcome measuresFamily satisfaction was assessed using the Critical Care Family Satisfaction Survey and field notes of the interviews.ResultsThe mean total satisfaction score was 12.8 ± 3.5, and comfort has the lowest subscale mean score: 2.07 ± 0.96. Multivariate regression analysis showed that family members’ satisfaction was positively associated with their ability to communicate with patients (B [95% confidence interval]: 2.1 [1.19 to 3.02]) and negatively with daily purchasing of medications and supplies (−2.41 [−3.23 to −1.59]), low economic status (−1.57 [−2.47 to −0.67]), and perceiving patient condition to be deteriorating (−0.99 [−1.93 to −0.04]). Content analysis of qualitative data revealed four themes: aspects of family care, aspects of patient care, organizational and administrative issues and environment.ConclusionsIn Egyptian adult intensive care units, regular family meetings, flexible visiting hours, shared decision-making, increasing staff-to-patient ratio and ensuring comfortable waiting rooms are promising strategies to enhance family satisfaction.     

The influence of orthotic devices and vastus medialis strength and timing on patellofemoral loads during running

OBJECTIVE: To use a musculoskeletal model and simulation of running to examine: (1) the influence of two commonly prescribed treatments for patellofemoral pain (vastus medialis oblique strengthening and orthoses) and (2) the functional significance of timing differences between vastus medialis oblique and vastus lateralis on lateral patellofemoral joint loads. DESIGN: A three-dimensional musculoskeletal model of the lower extremity was used to simulate running at 4 m/s. BACKGROUND: Repetitive and excessive joint loading is often associated with overuse injuries that require clinical treatments to reduce pain and restore function. Affecting one in four runners, patellofemoral pain is one of the most common injuries in running. Although conservative treatments have been reported to successfully treat patellofemoral pain, the effectiveness is often based on subjective or empirical data, which have generated disagreement on the most effective treatment. METHODS: Nine subject specific running simulations were generated and experiments were performed by applying the treatments and timing differences to the nominal simulations. RESULTS: Both treatments significantly reduced the average patellofemoral joint load and the vastus medialis strengthening also significantly reduced the peak patellofemoral joint load. In addition, when the vastus medialis oblique timing was delayed and advanced relative to the vastus lateralis timing, a significant increase and decrease in the joint load was observed, respectively, during the loading response.Conclusions. Increasing vastus medialis oblique strength yielded more consistent results across subjects than the orthosis in reducing patellofemoral joint loads during running. The effect of orthoses was highly variable and sensitive to the individual subject's running mechanics. Vastus medialis oblique activation timing is an important determinant of lateral patellofemoral joint loading during the impact phase. RELEVANCE: These findings indicate that a reduction in patellofemoral pain may be achieved through techniques that selectively increase the vastus medialis oblique strength. Therefore, future studies should be directed towards identifying such techniques. Additionally, the functional significance of timing differences between the vastus medialis oblique and vastus lateralis is an important consideration in patellofemoral pain treatment and orthoses may be beneficial for some patients depending on their running mechanics.     

Gait- and Posture-Related Factors Associated With Changes in Hip Pain and Physical Function in Patients With Secondary Hip Osteoarthritis: A Prospective Cohort Study

ObjectiveTo identify gait- and posture-related factors associated with changes in hip pain and physical function in patients with hip osteoarthritis (OA).DesignProspective cohort study.SettingClinical biomechanics laboratory of a university.ParticipantsConsecutive sampling of female patients with mild-to-moderate secondary hip OA (N=30).Main Outcome MeasuresHip pain (visual analog scale) and physical function (physical component summary of the Medical Outcomes Study 36-Item Short-Form Health Survey) were measured at baseline and 12 months later. With changes in hip pain and physical function as dependent variables, linear regression analyses were performed with gait- and posture-related factors as independent variables with and without adjustment for age, joint space width, and hip pain or physical function at baseline. Posture-related factors included angles of thoracic kyphosis, lumbar lordosis, sacral inclination, spinal inclination, and spinal mobility. Gait-related factors were walking speed, steps per day, joint angles, external hip joint moment impulses, and daily cumulative hip moments.ResultsMultiple linear regression analyses showed that limited hip extension (adjusted standardized B coefficient [95% confidence interval]: −0.52 [−0.88 to −0.17]) and limited external rotation angles (−0.51 [−0.85 to −0.18]) during walking were associated with the worsening of hip pain. An increased thoracic kyphosis (−0.54 [−0.99 to −0.09]), less sacral anterior tilt (0.40 [0.01-0.79]), reduced thoracic spine mobility (0.59 [0.23-0.94]), less steps per day (0.53 [0.13-0.92]), and a slower walking speed (0.45 [0.04-0.86]) were associated with deterioration in physical function.ConclusionsGait- and posture-related factors should be considered when assessing risk and designing preventive interventions for the clinical progression of secondary hip OA.     

Temporal activity of vastus medialis obliquus and vastus lateralis in symptomatic knee osteoarthritis

OBJECTIVE: Knee osteoarthritis has a major impact on quadriceps function, yet its effect on the specific temporal recruitment of vastus medialis obliquus and vastus lateralis is unknown. The aim of this study was to determine the electromyographic onset of vastus medialis obliquus activity relative to that of vastus lateralis in individuals with symptomatic knee osteoarthritis and in an asymptomatic control group during the functional task of stair climbing. DESIGN: Cross-sectional, comprising 41 participants with symptomatic knee osteoarthritis and 33 controls matched for age, sex, and body mass. RESULTS: No significant differences were detected in the timing of onset of vastus medialis obliquus relative to that of vastus lateralis between the osteoarthritis and control groups. Radiographic osteoarthritis severity, presence of patellofemoral joint disease, and pain intensity did not seem to influence the temporal relationship of the vastii in the osteoarthritis group. CONCLUSION: The presence of symptomatic, radiographic knee osteoarthritis is not associated with deficits in the temporal recruitment of vastus medialis obliquus and vastus lateralis during stair climbing. This implies that selective retraining of the individual components of the quadriceps is not indicated in rehabilitation programs for patients with this disease.     

Neuromuscular joint function in knee osteoarthritis: A systematic review and meta-analysis

BackgroundNeuromuscular alterations are common in people with knee osteoarthritis (KOA). A comprehensive understanding of these alterations is important to enable targeted rehabilitation strategies.ObjectivesThis systematic review and meta-analysis aimed to comprehensively understand the neuromuscular alterations around the knee joint in people with KOA.MethodsModerate- and high-quality studies based on a modified version of the Downs and Black checklist, comparing neuromuscular function of peri?articular muscles between people with KOA and controls were retrieved from five databases from inception to October 2020. Outcomes included normalized isokinetic strength, muscle size, voluntary activation, cortical and spinal-reflex excitability, and torque-related outcomes. Data were pooled according to structural KOA severity with sensitivity analysis based on sex. Evidence levels are presented in evidence gap maps.ResultsA total of 7 high-quality and 22 moderate-quality studies were retained (1146 people with KOA and 1353 age- and sex-matched controls). Studies demonstrated quadriceps and hamstring strength deficits and increased hamstring-to-quadriceps strength ratios across KOA severities. Women presented lower quadriceps strength at early KOA (very limited evidence) and lower voluntary activation at end stage KOA (very limited evidence) as compared with controls, whereas men did not (moderate evidence). People with KOA also demonstrated lower quadriceps force control ability with no change in rapid force production (very limited evidence). Voluntary activation deficits for quadriceps were evident (moderate evidence), with no change in quadriceps cortical excitability (very limited evidence) or soleus spinal reflexes (very limited evidence). No muscle size change was demonstrated except for the vastus medialis (limited evidence). Evidence gaps were found for neural and torque-related measures and differences in hamstring, gastrocnemius, soleus, and popliteus.ConclusionsNeuromuscular deficits are evident across different structural KOA severities and are seen in muscle strength, voluntary activation, muscle size, and force control ability. Women may exhibit these alterations to a greater extent than men.Prospero registration numberCRD42019160845.     

Delta-tocotrienol supplementation improves biochemical markers of hepatocellular injury and steatosis in patients with nonalcoholic fatty liver disease: A randomized,placebo-controlled trial

ObjectiveThe aim of this study was to examine the effects of delta-tocotrienol (δ-tocotrienol) supplementation on biochemical markers of hepatocellular injury and steatosis in patients with nonalcoholic fatty liver disease (NAFLD).DesignThe study design was a two-group, randomized, double-blind, placebo-controlled trial. The patients with NAFLD were randomly assigned to receive δ-tocotrienol 300 mg twice daily or placebo for 24 weeks.EndpointsThe primary endpoints were change from baseline in fatty liver index (FLI) and homeostasis model of insulin resistance (HOMA-IR) after 24 weeks. Secondary endpoints included change from baseline in high sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), alanine transaminase (ALT), aspartate transaminase (AST) and grading of hepatic steatosis on ultrasound. Between-group differences were tested for significance using ANCOVA. Mean differences (MD) with 95 % CIs are reported.ResultsA total of 71 patients (tocotrienol=35, placebo=36) were randomized and included in the intention to treat analysis. Compared with placebo, δ-tocotrienol significantly reduced (MD [95 % CI]) FLI (−8.52 [−10.7, −6.3]; p < 0.001); HOMA-IR (−0.37 [−0.53, −0.21]; p < 0.001), hs-CRP (−0.61[−0.81, −0.42]; p < 0.001), MDA (−0.91 [−1.20, −0.63]; p < 0.001), ALT (−8.86 [−11.5, −6.2]; p < 0.001) and AST (−6.6 [−10.0, −3.08]; p < 0.001). Hepatic steatosis was also reduced by a significantly greater extent with tocotrienol than with placebo (p =0.047). No adverse events were reported.Conclusionδ-tocotrienol effectively improved biochemical markers of hepatocellular injury and steatosis in patients with NAFLD. δ-tocotrienol supplementation might be considered as a therapeutic option in the management of patients with NAFLD.Trial RegistrationSri Lankan Clinical Trials Registry (SLCTR/2015/023, 2015-10-03).     

髌股关节疼痛及其临床治疗的研究

概述过去十年作者在实验室进行有关髌股关节及髌股关节疼痛综合征(PFPS)的研究,研究了正常人髌股关节的几个指标及PFPS患者的康复成效。研究结果反映股内侧肌(VMO)对于控制髌股关节的压力分布所发挥的力学作用、下肢方位对促进VMO募集的影响,以及髌骨叩压、股四头肌的疲劳恢复与生物反馈辅助对PFPS康复治疗的作用。     

Changes in patellofemoral joint contact pressures caused by vastus medialis muscle weakness

Background

Patellofemoral joint pain is a common knee disorder, but its underlying causes remain unknown. One proposed mechanism is an imbalance in force in the knee extensor muscles. Specifically, the vastus medialis and vastus lateralis are thought to play a crucial role in proper patellar tracking, and weakness in vastus medialis is thought to lead to a lateral shift in the patella causing increased contact pressures and pain. The purpose of this study was to create an animal model of vastus medialis weakness and to test the effect of this weakness on patellofemoral contact pressures.

Methods

Experiments were performed using New Zealand white rabbits (mass 4.9–7.7 kg, n = 12). Loading of the patellofemoral joint was produced by femoral nerve stimulation of the knee extensor muscles. Knee extensor imbalance was produced by vastus medialis ablation. Fuji pressure sensitive film was used to record contact area, shape and pressures for maximal and sub-maximal, matched-force contractions at knee angles of 30°, 60°, and 90°.

Findings

Patellofemoral peak pressures, average pressures, contact areas and contact shapes were the same across all loading conditions for matched-force contractions before and after elimination of vastus medialis.

Interpretation

We conclude that vastus medialis weakness does not cause changes in patellofemoral contact pressures. Since the muscular and knee joint geometry in rabbits and humans is similar, we question the idea of vastus medialis weakness as a cause of patellar mal-tracking and patellofemoral joint pain.     

Do older adults present altered pelvic and trunk movement pattern during gait? A systematic review with meta-analysis and GRADE recommendations

BackgroundCognitive, sensory, and biomechanical factors may affect gait of older adults. Among biomechanical factors, reduced pelvis and trunk range of motion (ROM) were associated with slower gait speed, shorter step length, and increased susceptibility to fall in older adults.ObjectiveTo systematically review the studies that compared trunk and pelvic movement during gait among adults and older adults.MethodsElectronic search was conducted on MEDLINE, EMBASE, and Cinahl from inception until May 2020. Studies that compared trunk and/or pelvis kinematics during gait between adults and older adults were included. The following data were extracted from studies: gait speed, walking surface, and pelvis trunk ROM during gait in the three planes of motion. Meta-analyses were calculated for slow, comfortable, and fast gait speeds using random effects models. GRADE determined the strength of evidence.ResultsTwelve studies were included in this review. There was moderate-quality evidence that older adults have reduced pelvic rotation ROM at comfortable speed (SMD = −0.90 [−1.35, −0.45]) and high-quality evidence that older adults also have reduced pelvic rotation ROM at fast walking speed (SMD = −1.55 [−3.43, −0.33]). In addition, there was low-quality evidence that older adults have reduced trunk rotation at fast walking speed (SMD = −0.63 [−1.23, −0.03]). There were no differences for pelvic and trunk movement in the sagittal and frontal planes.ConclusionThere is low to high quality of evidence that older adults walk with less pelvic rotation ROM in comfortable and fast walking speeds, and less trunk rotation ROM during fast walking speed.     

Acupuncture and moxibustion for endometriosis: A systematic review and analysis

ObjectivesThis study aimed to examine the effect of acupuncture on symptoms and health-related quality of life in patients with endometriosis.MethodsNine biomedical databases were searched to April 2022 to identify randomized controlled trials of acupuncture and/or moxibustion used alone or as adjunct to guideline-recommended pharmacotherapy for the treatment of endometriosis. One reviewer extracted data and another verified the data. A random effects model was used to calculate mean differences.ResultsFifteen trials involving 1018 patients met the inclusion criteria, but diversity in comparisons and outcome measures prevented meta-analysis. Compared to sham acupuncture, manual acupuncture was more effective at reducing dysmenorrhea VAS pain score (mean difference [MD] − 2.40, 95 % CI [− 2.80, − 2.00]; moderate certainty evidence), pelvic pain VAS score (MD − 2.65, 95 % CI [− 3.40, − 1.90]; high certainty evidence) and dyspareunia VAS scores (MD − 2.88, [− 3.83, − 1.93]), lessened the size of ovarian cyst (MD − 3.88, 95 % CI [− 7.06, − 0.70]), and improved quality of life. Compared to conventional therapy, manual acupuncture plus conventional therapy and warm needle alone resulted in greater improvements in quality of life than conventional therapy. Among the six studies that reported safety, fewer adverse events were reported in participants who received acupuncture or moxibustion.ConclusionsLow to moderate certainty evidence from single studies showed that manual acupuncture may improve pain-related symptoms and quality of life; however, there is insufficient evidence on the overall effectiveness of acupuncture and moxibustion for endometriosis.     

Effects of Prophylactic Subcutaneous Fentanyl on Exercise-Induced Breakthrough Dyspnea in Cancer Patients: A Preliminary Double-Blind,Randomized, Controlled Trial

ContextDyspnea is one of the most distressing symptoms in patients with cancer, and often worsens with breakthrough episodes on exertion. We hypothesized that fentanyl given prophylactically may alleviate breakthrough dyspnea.ObjectivesTo determine the feasibility of conducting a randomized trial of subcutaneous fentanyl in patients with cancer, and examine the effects of fentanyl on dyspnea, walk distance, vital signs, and adverse events.MethodsIn this double-blind, randomized, controlled trial, we asked ambulatory patients with breakthrough dyspnea to perform a baseline six minute walk test (6MWT), and then assigned them to either subcutaneous fentanyl or placebo 15 minutes before a second 6MWT. We documented the change in dyspnea Numeric Rating Scale (NRS) score, walk distance, vital signs, and adverse events between the first and second 6MWT.ResultsA total of 20 patients were enrolled (1:1 ratio) without attrition. Comparison between baseline and second walk showed that fentanyl was associated with significant improvements in dyspnea NRS score at the end of the 6MWT (mean [95% CI] −1.8 [−3.2, −0.4]), dyspnea NRS score at rest of 15 minutes after drug administration (−0.9 [−1.8, −0.04]), Borg Scale fatigue score at the end of the 6MWT (−1.3 [−2.4, −0.2]), 6MWT distance (+37.2 m [5.8, 68.6]), and respiratory rate (−2.4 [−4.5, −0.3]). Nonstatistically significant improvements also were observed in the placebo arm, with no difference between the two study arms. No significant adverse effects were observed.ConclusionProphylactic fentanyl was safe and improved dyspnea, fatigue, walk distance, and respiratory rate. We also observed a large placebo effect. Our results justify larger randomized controlled trials with higher fentanyl doses (clinicaltrials.gov registration: NCT01515566).     

Quadriceps muscle activity in women runners with and without patellofemoral pain syndrome.

The purpose of this study was to determine whether there was a difference in the electromyographic (EMG) patterns of the quadriceps muscles in women runners diagnosed with patellofemoral pain syndrome (PFPS) compared to the quadriceps activity of women runners free of knee pain and with normal lower extremity alignment. Linear envelope EMGs from vastus medialis, vastus lateralis, and rectus femoris, together with a footswitch signal, were recorded as each subject ran on a treadmill at 80% of their normal running pace and at 12km/h. Each stride period was normalized to 100%, then the linear envelopes for ten trials were ensemble averaged to achieve a mean ensemble for each muscle from each subject. Subsequently, the ensembles for each subject were normalized by dividing by the maximum EMG per cycle; they were then averaged across subjects to obtain the grand mean ensembles of each muscle for each group. Comparisons between the experimental and control groups at both speeds showed that nowhere during the stride cycle did the mean EMG levels of the two groups differ by more than two standard deviations. It was concluded that any changes in the running pattern of the runners with patellofemoral pain syndrome could not be detected by changes in the EMG patterns.     

Vastus Lateralis Motor Unit Firing Rate Is Higher in Women With Patellofemoral Pain

Objective

To compare neural drive, determined from motor unit firing rate, in the vastus medialis and lateralis in women with and without patellofemoral pain.

Role of resveratrol supplementation in regulation of glucose hemostasis,inflammation and oxidative stress in patients with diabetes mellitus type 2: A randomized,placebo-controlled trial

ObjectiveThe objective was to determine the effects of resveratrol supplementation on glucose homeostasis, oxidative stress, inflammation and microRNAs expression in patients with diabetes mellitus type 2 on oral hypoglycemic drugs.MethodThis was a randomized, double blinded placebo-controlled parallel group trial. The diabetic patients (n = 110) were randomly assigned either to resveratrol (n = 55) and placebo (55) groups after informed consent and given once daily resveratrol 200 mg and cellulose capsules respectively for 24 weeks. Fasting glucose, insulin, HbA1c, lipid profile, TNF- α, IL-6, hs-CRP, MDA & circulatory microRNAs were measured at start and end of 24- week intervention.ResultsOut of 110 patients recruited, 94 patients completed the study comprising of 45 in resveratrol and 46 in placebo group. The resveratrol supplementation after 24 weeks was resulted in significant reduction [mean difference (95%CI)] of plasma glucose[− 0.50(−0.94 to −0.06)], insulin[− 1.31(−2.24 to −0.38)], homeostatic model assessment of insulin resistance[− 0.83(−1.37 to −0.29)], malondialdehyde[− 0.36(−0.61 to −0.11)], high sensitive-C-reactive protein[− 0.35(−0.70 to −0.01)], tumor necrosis factor-alpha[− 1.25(−1.90 to −0.61)] and interleukin-6[− 1.99(−3.29 to −0.69)]. More than two-fold down regulation in miRNA-34a, miRNA-375, miRNA-21, miRNA-192 and up regulation in miRNA-126 and miRNA-132 expression was noted in patients receiving resveratrol as compared to placebo. No side effects were reported during the trial.ConclusionResveratrol supplementation contributes in improvement of glycemic control by reducing insulin resistance. It has significant beneficial impact on chronic inflammation, oxidative stress and associated microRNA expression in diabetic patients. Thus, supplementation of resveratrol along with oral hypoglycemic agents may be useful in the reduction of diabetic associated complications.     

Intra-articular anesthesia and knee muscle response

BACKGROUND: Many receptors located within the intra-articular knee structures contribute to the neuromuscular responses of the knee. The purpose was to compare the automatic postural response induced by a perturbation at the foot before and after an intra-articular injection of a local anesthetic (bupivicaine), after a saline (sham) injection, and after no intra-articular injection (control) in the knee. METHODS: Muscle onset latencies and automatic response magnitudes for the vastus medialis, vastus lateralis, biceps femoris, medial hamstrings, tibialis anterior, and gastrocnemius were measured using electromyography (EMG) when anteriorly directed perturbations were applied to the feet of 30 subjects. All subjects then received a lidocaine skin injection followed by: an intra-articular bupivicaine injection (treatment group); an intra-articular saline injection (sham group); or no injection (control group), depending on their randomized group assignment. The perturbation tests were then repeated. FINDINGS: Muscle onset latencies and automatic response magnitudes did not change as a result of the intra-articular injections. Latencies were significantly greater for the vastus medialis and vastus lateralis when compared to the medial hamstrings, biceps femoris and tibialis anterior (P<0.001). Automatic response magnitudes for the tibialis anterior were significantly greater than those of the hamstrings, which were greater than those of the quadriceps (P<0.001). INTERPRETATION: There were no differences in muscle response when anteriorly directed perturbations were applied to the foot with or without an injection of local anesthetic in the knee. Intra-articular receptors were either unaffected by the anesthetic or the extra-articular receptors or receptors of the other joints were able to compensate for their loss.