Reliability of electromyographic amplitude values of the upper limb muscles during closed kinetic chain exercises with stable and unstable surfaces

The purpose of the present study was to evaluate the intra and interday reliability of surface electromyographic amplitude values of the scapular girdle muscles and upper limbs during 3 isometric closed kinetic chain exercises, involving upper limbs with the fixed distal segment extremity on stable base of support and on a Swiss ball (relatively unstable). Twenty healthy adults performed the exercises push-up, bench-press and wall-press with different effort levels (80% and 100% maximal load). Subjects performed three maximal voluntary contractions (MVC) in muscular testing position of each muscle to obtain a reference value for root mean square (RMS) normalization. Individuals were instructed to randomly perform three isometric contraction series, in which each exercise lasted 6 s with a 2-min resting-period between series and exercises. Intra and interday reliabilities were calculated through the intraclass correlation coefficient (ICC 2.1), standard error of the measurement (SEM). Results indicated an excellent intraday reliability of electromyographic amplitude values (ICC >= 0.75). The interday reliability of normalized RMS values ranged between good and excellent (ICC 0.52-0.98). Finally, it is suggested that the reliability of normalized electromyographic amplitude values of the analyzed muscles present better values during exercises on a stable surface. However, load levels used during the exercises do not seem to have any influence on variability levels, possibly because the loads were quite similar. (C) 2007 Elsevier Ltd. All rights reserved.

ONSET OF ELECTRICAL ACTIVITY OF PATELLAR STABILIZER MUSCLES IN SUBJECTS WITH PATELLOFEMORAL PAIN

Objective: To asses the onset (%) of patella stabilizer muscles during maximal isometric contraction exercises (MIC) in individuals with and without signs of patellofemoral pain syndrome (PFPS) in open (OKC) and closed (CKC) kinetic chain exercises, Method: Assessments were carried out on 22 women; ten with no complains of anterior knee pain, and 12 with PFPS signs during MIC in OKC and CKC with the knee flexed at 90 degrees. The onset of the electromyographic activity of the vastus mediallis obliquus (VMO), vastus lateralis obliquus (VLO) and vastus lateralis longus (VLL) was identified by means of an algorithm in the Myosystem Br 1 software. The statistical analysis used was Chi-Square test and student`s t test, which are both tests with a level of significance at 5%. Results: The VMO and VLO muscles presented a greater onset compared to the VLL during OKC exercises for both groups and for the PFPS group without CCF No differences were observed between the groups. Conclusion: CKC and OKC exercises seem to benefit the synchronism of the musculature that supposedly benefits the patella stabilizer musculature, and can be recommended in physiotherapeutic treatment programs.

Activation of the shoulder and arm muscles during axial load exercises on a stable base of support and on a medicine ball

The purpose of this study was to compare SEMG activities during axial load exercises on a stable base of support and on a medicine ball (relatively unstable). Twelve healthy male volunteers were tested (x = 23 +/- 7y). Surface EMG was recorded from the biceps brachii, anterior deltoid, clavicular portion of pectoralis major, upper trapezius and serratus anterior using surface differential electrodes. All SEMG data are reported as percentage of RMS mean values obtained in maximal voluntary contractions for each muscle studied. A 3-way within factor repeated measures analysis of variance was performed to compare RMS normalized values. The RMS normalized values of the deltoid were always greater during the exercises performed on a medicine ball in relation to those performed on a stable base of support. The trapezius showed greater mean electric activation amplitude values on the wall-press exercise on a medicine ball, and the pectoralis major on the push-up. The serratus and biceps did not show significant differences of electric activation amplitude in relation to both tested bases of support. Independent of the base of support, none of the studied muscles showed significant differences of electric activation amplitude during the bench-press exercise. The results contribute to the identification of the levels of muscular activation amplitude during exercises that are common in clinical practice of rehabilitation of the shoulder and the differences in terms of type of base of support used. (C) 2006 Elsevier Ltd. All rights reserved.

ELECTROMYOGRAPHIC AMPLITUDE RATIO OF SERRATUS ANTERIOR AND UPPER TRAPEZIUS MUSCLES DURING MODIFIED PUSH-UPS AND BENCH PRESS EXERCISES

Imbalance and weakness of the serratus anterior and upper trapezius force couple have been described in patients with shoulder dysfunction. There is interest in identifying exercises that selectively activate these muscles and including it in rehabilitation protocols. This study aims to verify the UT/SA electromyographic (EMG) amplitude ratio, performed in different upper limb exercises and on two bases of support. Twelve healthy men were tested (average age = 22.8 +/- 3.1 years), and surface EMG was recorded from the upper trapezius and serratus anterior using single differential surface electrodes. Volunteers performed isometric contractions over a stable base of support and on a Swiss ball during the wall push-up (WP), bench press (BP), and push-up (PU) exercises. All SEMG data are reported as a percentage of root mean square or integral of linear envelope from the maximal value obtained in one of three maximal voluntary contractions for each muscle studied. A linear mixed-effect model was performed to compare UT/SA ratio values. The WP, BP, and PU exercises showed UT/SA ratio mean +/- SD values of 0.69 +/- 0.72, 0.14 +/- 0.12, and 0.39 +/- 0.37 for stable surfaces, respectively, whereas for unstable surfaces, the values were 0.73 +/- 0.67, 0.43 +/- 0.39, and 0.32 +/- 0.30. The results demonstrate that UT/SA ratio was influenced by the exercises and by the upper limb base of support. The practical application is to show that BP on a stable surface is the exercise preferred over WP and PU on either surfaces for serratus anterior muscle training in patients with imbalance between the UT/SA force couple or serratus anterior weakness.

Activation of Selected Shoulder Muscles During Unilateral Wall and Bench Press Tasks Under Submaximal Isometric Effort

STUDY DESIGN: Controlled laboratory study. OBJECTIVE: To assess the activation of 7 shoulder muscles under 2 closed kinetic chain (CKC) tasks for the upper extremity using submaximal isometric effort, thus providing relative quantification of muscular isometric effort for these muscles across the CKC exercises, which may be applied to rehabilitation protocols for individuals with shoulder weakness. BACKGROUND: CKC exercises favor joint congruence, reduce shear load, and promote joint dynamic stability. Additionally, knowledge about glenohumeral and periscapular muscle activity elicited during CKC exercises may help clinicians to design protocols for shoulder rehabilitation. METHODS: Using surface electromyography, activation level was measured across 7 shoulder muscles in 20 healthy males, during the performance of a submaximal isometric wall press and bench press. Signals were normalized to the maximal voluntary isometric contraction, and, using paired t tests, data were analyzed between the exercises for each muscle. RESULTS: Compared to the wall press, the bench press elicited higher activity for most muscles, except for the upper trapezius. Levels of activity were usually low but were above 20% maximal voluntary isometric contraction for the serratus anterior on both tasks, and for the long head triceps brachii on the bench press. CONCLUSIONS: Both the bench press and wall press, as performed in this study, led to relatively low EMG activation levels for the muscles measured and may be considered for use in the early phases of rehabilitation. J Ort hop Sports Phys Ther 2011;41(7):520-525, Epub 2 February 2011. doi:10.2519/jospt.2011.3418

Electromyographic Analysis of Paravertebral Muscles in Patients with Idiopathic Scoliosis

Study Design. Prospective clinical electromyographic study in adolescents with idiopathic scoliosis and control group. Objective. To evaluate electromyographic amplitude from erector spinae muscles of patients with idiopathic scoliosis in comparison with control volunteers without spinal deformities. Summary of Background Data. Previous studies have indicated an increased electromyographic activity in paravertebral muscles in the convex side of the scoliotic curvature. However, in previous studies there is the absence or poor description of methods used, and some studies were conducted before the recording and processing recommendations for surface electromyographic signals had been described. Methods. Thirty individuals, matched by sex, age, and body mass index, were divided into two groups: scoliosis and control. The electric activity of the erector spinae muscles was determined by surface electromyography on both sides of the three levels of spine: T8, L2, and L5. Results. Normalized electromyographic amplitudes of erector spinae muscles, in the convex and concave sides of the apex region of the scoliotic curve in the thoracic and lumbar regions, were not significantly different. Also, there was no significant difference between the muscles of these regions when the scoliosis group was compared with the control group. The erector spinae muscle at the L5 level, representing the lower vertebral limit of the lumbar scoliotic curve, had significantly higher electromyographic activity on the convex side. However, the same alteration was shown in the control group homologous muscle (on the left side). Conclusion. Erector spinae muscles on the convex and concave sides at the curvature apex in patients with idiopathic scoliosis and small magnitude of curves did not show significant differences in electromyographic amplitude. Future studies should evaluate whether intragroup activation differences, at the L5 level in 80% of the maximum voluntary isometric contractions with predominance of the left side of the vertebral column, have any relation to the condition.

PHOSPHODIESTERASE-4 INHIBITION REDUCES PROTEOLYSIS AND ATROGENES EXPRESSION IN RAT SKELETAL MUSCLES

Phosphodiesterase (PDE) inhibition reduces skeletal muscle atrophy, but the underlying molecular mechanism remains unclear. We used microdialysis to investigate the effects of different PDE inhibitors on interstitial tyrosine concentration as well as proteolytic activity and atrogenes expression in isolated rat muscle. Rolipram, a PDE-4-selective inhibitor, reduced the interstitial tyrosine concentration and rates of muscle protein degradation. The rolipram-induced muscle cAMP increase was accompanied by a decrease in ubiquitin proteasome system (UPS) activity and atrogin-1 mRNA, a ubiquitin-ligase involved in muscle atrophy. This effect was not associated with Akt phosphorylation but was partially blocked by a protein kinase A inhibitor. Fasting increased atrogin-1, MuRF-1 and LC3b expression, and these effects were markedly suppressed by rolipram. Our data suggest that activation of cAMP signaling by PDE-4 blockade leads to inhibition of UPS activity and atrogenes expression independently of Akt. These findings are important for identifying novel approaches to attenuate muscle atrophy. Muscle Nerve 44: 371-381, 2011

Routine abdominal drains after Roux-en-Y gastric bypass: a prospective evaluation of the inflammatory response

Background: Despite the extensive published data regarding the use of drains in surgery, it is still controversial. Most bariatric surgeons use drains as routinely. However, drains have sometimes have been shown to be unhelpful and even to increase the anastomotic leak rates. The purpose of the present study was to evaluate the peritoneal inflammatory response in the presence of a drain left in place until the seventh postoperative day after bariatric surgery. Methods: All patients who underwent open Roux-en-Y gastric bypass from February 2007 to August 2008 were prospectively evaluated. A 24F Blake drain was left in place for 7 days. The peritoneal effluent from the drain was collected for the determination of cytokine levels and for microbiologic analysis. Results: A total of 107 obese patients were studied. A marked increase in the levels of tumor necrosis factor-alpha and interleukin-1 beta was observed by the seventh postoperative day, even in patients without any abdominal complications. Bacterial contamination of the peritoneal effluent was also demonstrated. Conclusion: The results of our study have shown that at 7 days after surgery, a marked peritoneal inflammatory response and bacterial contamination are present. These findings could have resulted from the use of the drain for 7 postoperative days. (Surg Obes Relat Dis 2010;6:648-652.) (C) 2010 American Society for Metabolic and Bariatric Surgery. All rights reserved.

Abdominal compartment syndrome in trauma resuscitation

Purpose of review Swelling is inexorably linked to shock and resuscitation in trauma. In many forms, swelling complicates and interacts with traumatic injury to raise pressures in the abdomen, resulting in intraabdominal hypertension, which may overtly manifest as abdominal compartment syndrome (ACS) driving multiple organ failure. Despite renewed clinical interest in posttraumatic intraabdominal pressure, there remains a chiasm between knowledge of the risks and clinical interventions to mitigate them. This review provides a concise overview of definitions, risk factors, diagnosis and management using an illustrative trauma case. Recent findings Intraabdominal pressure commonly increases following trauma, wherein ACS may manifest earlier than generally appreciated and complicate other insults such as shock and hemorrhage. Contemporary resuscitation strategies may exacerbate intraabdominal hypertension, particularly massive crystalloid resuscitation. Although unproven, the recent transition to crystalloid restriction and high plasma resuscitation strategies may influence the prevalence of ACS. Nonetheless, aggressive intraabdominal pressure monitoring should be mandatory in the critically ill. Despite potential nonoperative options, decompressive laparotomy remains the only definitive but often morbid treatment. Summary ACS results from many dysfunctions acting in concert with each other in self-propagating vicious cycles. Starting with greater awareness, it is imperative that the growing knowledge should be translated into clinical practice.

Combining two potential causes of metalloproteinase secretion causes abdominal aortic aneurysms in rats: a new experimental model

P>Progress in understanding the pathophysiology of abdominal aortic aneurysms (AAA) is dependent in part on the development and application of effective animal models that recapitulate key aspects of the disease. The objective was to produce an experimental model of AAA in rats by combining two potential causes of metalloproteinase (MMP) secretion: inflammation and turbulent blood flow. Male Wistar rats were randomly divided in four groups: Injury, Stenosis, Aneurysm and Control (40/group). The Injury group received a traumatic injury to the external aortic wall. The Stenosis group received an extrinsic stenosis at a corresponding location. The Aneurysm group received both the injury and stenosis simultaneously, and the Control group received a sham operation. Animals were euthanized at days 1, 3, 7 and 15. Aorta and/or aneurysms were collected and the fragments were fixed for morphologic, immunohistochemistry and morphometric analyses or frozen for MMP assays. AAAs had developed by day 3 in 60-70% of the animals, reaching an aortic dilatation ratio of more than 300%, exhibiting intense wall remodelling initiated at the adventitia and characterized by an obvious inflammatory infiltrate, mesenchymal proliferation, neoangiogenesis, elastin degradation and collagen deposition. Immunohistochemistry and zymography studies displayed significantly increased expressions of MMP-2 and MMP-9 in aneurysm walls compared to other groups. The haemo-dynamic alterations caused by the stenosis may have provided additional contribution to the MMPs liberation. This new model illustrated that AAA can be multifactorial and confirmed the key roles of MMP-2 and MMP-9 in this dynamic remodelling process.

Thiele massage as a therapeutic option for women with chronic pelvic pain caused by tenderness of pelvic floor muscles

Aims and objectives Musculoskeletal system has been found to be involved in genesis and perpetuation of chronic pelvic pain (CPP) and has strong evidences that up to 80% of women with CPP present dysfunction of the musculoskeletal system. In this study, we report a series of women with CPP caused by tenderness of pelvic floor muscles successfully treated with Thiele massage. Methods Were included in this study six women with CPP caused by tenderness of the levator ani muscle that underwent transvaginal massage using the Thiele technique, over a period of 5 minutes repeated once a week for 4 weeks. After 1 month, the women returned for follow-up. Results The median tenderness score for the six women evaluated was 3 at the first evaluation and 0 after 1 month of follow-up (P < 0.01). The mean Visual Analogue Scale and McGill Pain Index scores were 8.1 and 34, respectively, at the first evaluation, and 1.5 and 16.6 at follow-up (P < 0.01). Conclusion Thiele massage appears to be very helpful for women with CPP caused by tenderness of the levator ani muscle. However, these results are preliminary and a larger number of women are necessary to obtain more conclusive results.

Effects of eccentric and concentric training on capillarization and myosin heavy chain contents in rat skeletal muscles after hindlimb suspension

We studied the effects of different protocols of post-disuse rehabilitation on angiogenesis and myosin heavy chain (MHC) content in rat hindlimb muscles after caudal suspension. Thirty female Wistar rats were divided into five groups: (1) Control I, (2) Control II, (3) Suspended, (4) Suspended trained on declined treadmill, and (5) Suspended trained on flat treadmill. Fragments of the soleus and tibialis anterior (TA) muscles were frozen and processed by electrophoresis and immunohistochemistry (CD31 antibody). Hindlimb suspension caused reduction of capillary/fiber (C/F) ratios and contents of MHC type I (MHCI) in the soleus in parallel to increased capillary density. Flat treadmill protocols increased the content of the MHCI isoform. The C/F ratio was increased by concentric training after hypokinesis, but was not modified by eccentric training, which caused a greater reduction of capillary density compared to the other protocols. In the TA muscle, hindlimb suspension caused a non-significant increase in capillary density and C/F ratio with limited changes in MHC. The present data demonstrate that the different training protocols adopted and the functional performance of the muscles analyzed caused specific changes in capillarization and in the content of the various MHC types. (C) 2010 Published by Elsevier GmbH.

Age and gender influence on maximal bite force and masticatory muscles thickness

The present study aimed investigate the age and gender influence on maximal molar bite force and at outlining the criteria for normal masticatory muscle development in a sample of 177 Brazilian Caucasian dentate individuals aged 7-80 years divided into five age groups: I(7-12 years), II (13-20 years), III (21-40 years), IV (41-60 years), and V (61-80 years). Except for Group V, which comprised nine women and eight men, all groups were equally divided in respect to gender (20 M/20 F). Bite force was recorded with a mouth-adapted 1000 N dynamometer and the highest out of three records was regarded as the maximal bite force. The data were submitted to multivariate statistical analysis (SPSS 17.0 p < 0.05). Effects of group and gender were found, but no interactions between them. The ANOVA showed significant differences between groups bilaterally. Bonferroni`s test showed that group I had significantly lower bite force means at both sides as compared to all groups, except group V. No differences were found between the left and right sides. In all the groups, gender was found to be a significant factor associated with maximal bite force. A global comparison including all the subjects and measures showed that the means of men were approximately 30% higher than those of women, within-group comparisons yielded similar results in all groups. Muscle thickness was measured with a SonoSite Titan ultrasound tool using a high-resolution real-time 56 mm/10 MHz linear-array transducer. Three ultrasound images were obtained from the bilateral masseter and temporal muscles at rest and at maximal voluntary contraction. The means of the three measures in each clinical condition were analyzed with multivariate statistical analysis (SPSS 17.0 p < 0.05). A gradual increase in thickness of the masseter and temporal muscles was found both at rest and maximal voluntary contraction for groups I to IV, whereas a decrease in muscle thickness was observed in group V. Multivariate analysis showed that in both conditions there was an effect of group and gender. The study of the development of the stomatognathic system in relation to age and gender can provide useful data for the identification of normal and impaired functioning patterns. The results of this study indicate that age and gender are associated with structural and functional alterations in the muscles of the stomatognathic system. (C) 2010 Elsevier Ltd. All rights reserved.