Jaqueline Martins

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.

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 > or = 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.

Assessment of the Performance of Acoustic and Mass Balance Methods for Leak Detection in Pipelines for Transporting Liquids

On-line leak detection is a main concern for the safe operation of pipelines. Acoustic and mass balance are the most important and extensively applied technologies in field problems. The objective of this work is to compare these leak detection methods with respect to a given reference situation, i.e., the same pipeline and monitoring signals acquired at the inlet and outlet ends. Experimental tests were conducted in a 749 m long laboratory pipeline transporting water as the working fluid. The instrumentation included pressure transducers and electromagnetic flowmeters. Leaks were simulated by opening solenoid valves placed at known positions and previously calibrated to produce known average leak flow rates. Results have clearly shown the limitations and advantages of each method. It is also quite clear that acoustics and mass balance technologies are, in fact, complementary. In general, an acoustic leak detection system sends out an alarm more rapidly and locates the leak more precisely, provided that the rupture of the pipeline occurs abruptly enough. On the other hand, a mass balance leak detection method is capable of quantifying the leak flow rate very accurately and of detecting progressive leaks.

Tradução e adaptação cultural do Penn Shoulder Score para a Língua Portuguesa: PSS-Brasil

INTRODUCTION/OBJECTIVE: To produce the Brazilian version of Penn Shoulder Score (PSS) designated to measure pain, satisfaction, and function of patients with shoulder painful musculoskeletal conditions. PATIENTS AND METHODS: The Brazilian version development of PSS questionnaire was based on the protocol proposed by the American Academy of Orthopaedic Surgeons (AAOS) and International Quality of Life Assessment (IQOLA). The process consists of translation, synthesis, back-translation, expert Committee review, pretest and evaluation of documents by the Committee and author of the PSS. This pre-final version was administered to a sample of 90 subjects with clinical diagnosis of painful musculoskeletal shoulder, male and females, aged over 18 years. In applications, the patients were inquired about their understanding of each item, and items not understood by 20% or more of patients were analyzed and modified by the Committee, requiring three questionnaire applications (n = 30). RESULTS: The application of pre-final versions of the PSS revealed the difficulties encountered by patients, which were resolved by transforming the self-applied questionnaire in an instrument applied through interview. CONCLUSION: The translation and cultural adaptation resulted in the final Brazilian version of the PSS questionnaire.

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.

Measurement Properties of the Brazilian Version of the Penn Shoulder Score (PSS-Brazil): Reliability, Validity, and Responsiveness

STUDY DESIGN Clinical measurement. OBJECTIVES To determine the reliability, validity, and responsiveness of the Brazilian version of the Penn Shoulder Score (PSS-Brazil) in patients with shoulder dysfunctions. BACKGROUND Several questionnaires assessing shoulder dysfunctions are available in Brazil, but the measurement properties of most of them, such as the PSS, have not yet been tested. METHODS Internal consistency, measurement error, construct validity, and floor and ceiling effects were evaluated in 62 patients, 36 of whom completed the questionnaire at baseline and after 2 to 7 days to assess test-retest reliability. Responsiveness was determined with 50 patients who completed the questionnaire at an initial visit and after 4 weeks of physical therapy. RESULTS The PSS-Brazil displayed acceptable internal consistency, with a Cronbach alpha of .92. Test-retest reliability was excellent, with an intraclass correlation coefficient of 0.95; the standard error of measurement and minimal detectable change were 12.8 and 14.4 points, respectively. A high correlation was obtained between the PSS and the Shoulder Pain and Disability Index (0.96) and the Disabilities of the Arm, Shoulder and Hand questionnaire (0.86). There was moderate correlation between the PSS and its subscales and the pain and function subscales of the Medical Outcomes Study 36-Item Short-Form Health Survey (0.40-0.68). There was high responsiveness, with an effect size of 0.95 and standardized response mean of 1.13 for patients with improvement of shoulder dysfunction, and adequate area under the curve of 0.81. No floor or ceiling effects were observed. CONCLUSION The PSS-Brazil is a reliable, valid, and responsive measure for assessing patients with shoulder dysfunction.

Intrarater and interrater reliability of three classifications for scapular dyskinesis in athletes

Clinical evaluation of scapular dyskinesis (SD) aims to identify abnormal scapulothoracic movement, underlying causal factors, and the potential relationship with shoulder symptoms. The literature proposes different methods of dynamic clinical evaluation of SD, but improved reliability and agreement values are needed. The present study aimed to evaluate the intrarater and interrater agreement and reliability of three SD classifications: 1) 4-type classification, 2) Yes/No classification, and 3) scapular dyskinesis test (SDT). Seventy-five young athletes, including 45 men and 30 women, were evaluated. Raters evaluated the SD based on the three methods during one series of 8–10 cycles (at least eight and maximum of ten) of forward flexion and abduction with an external load under the observation of two raters trained to diagnose SD. The evaluation protocol was repeated after 3 h for intrarater analysis. The agreement percentage was calculated by dividing the observed agreement by the total number of observations. Reliability was calculated using Cohen Kappa coefficient, with a 95% confidence interval (CI), defined by Kappa coefficient ±1.96 multiplied by the measurement standard error. The interrater analyses showed an agreement percentage between 80% and 95.9% and an almost perfect reliability (k>0.81) for the three classification methods in all the test conditions, except the 4-type and SDT classification methods, which had substantial reliability (k<0.80) in shoulder abduction. Intrarater analyses showed agreement percentages between 80.7% and 89.3% and substantial reliability (0.67 to 0.81) for both raters in the three classifications. CIs ranged from moderate to almost perfect categories. This indicates that the three SD classification methods investigated in this study showed high reliability values for both intrarater and interrater evaluation throughout a protocol that provided SD evaluation training of raters and included several repetitions of arm movements with external load during a live assessment.

Reliability and Validity of the Belt-Stabilized Handheld Dynamometer in Hip- and Knee-Strength Tests

CONTEXT   The belt-stabilized handheld dynamometer (HHD) has been used to assess the strength of knee- and hip-muscle groups. However, few researchers have examined its reliability and validity for assessing the strength of these muscles. OBJECTIVE   To evaluate the intra-examiner reliability of the belt-stabilized HHD and its validity and agreement with the isokinetic dynamometer for assessing the strength of knee- and hip-muscle groups. DESIGN   Cross-sectional study. SETTING   University laboratory. PATIENTS OR OTHER PARTICIPANTS   We evaluated 26 healthy participants (13 men, 13 women; age = 23.5 ± 2.8 years, height = 1.7 ± 0.1 m, mass = 68.6 ± 12.4 kg) in 2 sessions using the belt-stabilized HHD and an isokinetic dynamometer for maximum strength of the hip adductors, abductors, flexors, extensors, internal rotators, and external rotators and the knee flexors and extensors. MAIN OUTCOME MEASURE(S)   We used reliability values provided by the intraclass correlation coefficient (2,3), standard error of measurement (SEM and percentage SEM), and minimal detectable change; correlation values comparing the belt-stabilized HHD and the isokinetic instrument using the Pearson correlation coefficient (r); and the mean difference in values comparing the 2 instruments using the Bland-Altman method. RESULTS   The intrarater HHD reliability was excellent for most measurements (range = 0.80-0.96; SEM = 1.3-5.3 kilograms of force or 4.8-18.9 Nm, percentage SEM = 7.0%-22.0%, minimal detectable change = 3.6-18.8 kilograms of force or 13.2-52.4 Nm) and was moderate only for bilateral knee flexion and left hip internal rotation (intraclass correlation coefficient [2,3] = 0.62-0.66 and 0.70, respectively). Correlation with the isokinetic dynamometer was moderate to high (r = 0.60-0.90), but the absolute values did not demonstrate concordance between results using the Bland-Altman method. CONCLUSIONS   The belt-stabilized HHD measurements were reliable, and although they did not agree with those from the isokinetic dynamometer, the values were correlated for the hip- and knee-muscle groups.