Marcelo La Torre

Validity and Reproducibility of the Measurements Obtained Using the Flexicurve Instrument to Evaluate the Angles of Thoracic and Lumbar Curvatures of the Spine in the Sagittal Plane

Objective. to verify the validity and reproducibility of using the flexicurve to measure the angles of the thoracic and lumbar curvatures. Method. 47 subjects were evaluated by: (1) palpation and marking of the spinous processes using lead markers, (2) using X-rays in the sagittal plane to measure the Cobb angles, (3) molding the flexicurve to the spine, and (4) drawing the contour of the flexicurve onto graph paper. The angle of curvature was determined with the flexicurve based on a 3rd order polynomial. Results. No differences were found between the Cobb angles and the angles obtained using the flexicurve in thoracic and lumbar curvatures (P > 0.05). Correlations were strong and significant for the thoracic (r = 0.72, P < 0.01) and lumbar (r = 0.60, P < 0.01) curvatures. Excellent and significant correlations were found for both the intraevaluator and interevaluator measurements. Conclusion. The results show that there is no significant difference between the values obtained using the flexicurve and those obtained using the X-ray procedure and that there is a strong correlation between the two methods. This, together with the excellent level of inter- and intraevaluator reproducibility justifies its recommendation for use in clinical practice.

Electromyography for Assessment of Pain in Low Back Muscles

Background and Purpose: Pain is currently evaluated with “subjective” methods (eg, patient self-report). This study aimed to test whether fatigue indexes are able to accurately discriminate between subjects with and subjects without low back pain. Subjects: Sixty subjects separated into 2 groups—a group with low back pain (n=30) and a group without low back pain (n=30)—participated in this study. Methods: Electromyographic (EMG) and force data were obtained during a muscle fatigue test. The same test was repeated to monitor recovery. Linear regression analysis was used to obtain fatigue indexes. Results: Subjects with pain produced significantly lower force values than those without pain. The use of fatigue indexes and force values permitted accurate classification in 89.5% of cases. Discussion and Conclusion: The results confirm that subjects with pain show early myoelectrical manifestations of muscle fatigue and that EMG can be a useful tool in the evaluation of low back pain.

Validation, repeatability and reproducibility of a noninvasive instrument for measuring thoracic and lumbar curvature of the spine in the sagittal plane.

BACKGROUND The need for early identification of postural abnormalities without exposing patients to constant radiation has stimulated the development of instruments aiming to measure the spinal curvatures. OBJECTIVE To verify the validity, repeatability and reproducibility of angular measures of sagittal curvatures of the spine obtained using an adapted arcometer, by comparing them with Cobb angles of the respective curvatures obtained by using X-rays. METHODS 52 participants were submitted to two procedures designed to evaluate the thoracic and lumbar curvatures: (1) X-ray examination from which the Cobb angles (CA) of both curvatures were obtained, and (2) measuring the angles with the arcometer (AA). Two evaluators collected the data using the arcometer, with the rods placed at T1, T12, L1 and L5 spinous processes levels in a way as to permit linear measurements which, with aid of trigonometry, supplied the AA. RESULTS There was a very strong and significant correlation between AA and CA (r=0.94; p<0.01), with no-significant difference (p=0.32), for the thoracic curvature. There was a strong and significant correlation for the lumbar curvature (r=0.71; p<0.01) between AA and CA, with no-significant difference (p=0.30). There is a very strong correlation between intra-evaluator and inter-evaluator AA. CONCLUSION It was possible to quantify reliably the thoracic and lumbar curvatures with the arcometer and it can thus be considered valid and reliable and for use in evaluating spinal curvatures in the sagittal plane.

Ativação e co-contração dos músculos gastrocnêmio e tibial anterior na marcha de mulheres utilizando diferentes alturas de saltos

O objetivo deste estudo foi verificar a ativacao e a co-contracao muscular dos musculos tibial anterior (TA) e gastrocnemio lateral (GL) durante a marcha, utilizando diferentes calcados. Nove mulheres caminharam sobre uma esteira eletrica com velocidade de 3,5 Km/h em tres situacoes: sem calcado, com salto baixo (6 cm) e com salto alto (9 cm), sendo simultaneamente registrados sinais eletromiograficos do TA e GL. Os principais resultados encontrados no presente estudo demonstraram que: (1) independente da altura do salto houve maior ativacao do GL ( p <0,05), em comparacao com o TA; (2) o musculo GL apresentou maior ativacao ( p <0,05) com o calcado de salto alto, em comparacao a situacao com os pes descalcos; e (3) quanto maior a altura do salto, maiores percentuais de co-contracao muscular foram encontrados ( p <0,05).El objetivo de este estudio fue investigar la activacion muscular y la co-contraccion de los musculos tibial anterior (TA) y gastrocnemio lateral (GL) durante la marcha, utilizando zapatos diferentes. Nueve mujeres caminaron en una cinta de velocidad de 3,5km/h en tres situaciones: sin zapatos, con zapatos de tacon bajo (6 cm) y con zapatos de tacon alto (9 cm), siendo al mismo tiempo registrado senales eletromiograficos de TA y GL. Los resultados mostraron que en las tres situaciones de prueba habia una mayor activacion de GL en comparacion con TA (p<0,05). Tambien se encuentran diferencia (p<0,05) en la activacion muscular entre las condiciones sin zapatos x tacon alto solo por el musculo GL. Por ultimo, se encontro que, cuanto mayor es la altura del tacon, mayor sea el porcentaje de co-contraccion.

Effects of added elastic tubes on open-chain knee extensor strength training

Attaching elastic tubes (ETs) to resistance training machines can affect the exercise load profile. The purpose of this study was to assess the training effects of added ETs, which were strategically attached to provide additional loads only during the deceleration phase of the knee extension exercise. Twenty-two healthy participants, assigned to either an experimental group (with ETs) or a control group (without ETs), participated in a 12-week strength-training program using a knee extension exercise machine. The acceleration effects were quantified and a method of attaching the ETs to the knee extension machine was developed. The effects of the added ETs were analysed by testing dynamic and isometric maximum contractions at four knee flexion angles (10°, 30°, 50°, and 80°). Analyses of covariance with the initial values as the covariate were used to examine the ET effects. A greater increase in isometric maximum strength was found in the experimental group than in the control group at knee flexion angles of 10° [effect size (ES) = 2.25] and 30° (ES = 1.18). No significant difference in the dynamic maximum strength was found between the groups. The use of ETs increased strength at smaller knee flexion angles with quadriceps that were relatively short.

Evaluating the Electromyographical Signal During Symmetrical Load Lifting

Muscular problems account for almost half the cases of work absence, with the back being the region most involved (Kumar, 2011). Bending the trunk forward while performing domestic work or sports related activities is the cause of most back injuries (Fathallah et al., 1998). Small degrees of flexion of the trunk can be considered a medium to high risk factor of injury, mainly when the angle of the forward inclination is greater than 15 degrees and is combined with lifting activities. As the task of lifting objects from the ground exposes spinal structures to muscular-skeletal overload it has been consistently investigated (Simon, 1997). In addition, epidemiological research associates lifting to the risk of developing lumbar back pain (Ferguson & Marras, 1997; Dolan & Adams, 1998; Jager & Luttmann, 1999; Nachemson, 1999; Wilke et al., 1999; Burdorf, 2000; Kingma et al., 2001; Wilke et al., 2001; Ferguson et al., 2004). In the early 20th century, the scientific community was already studying back injuries, in particular low back pain (Ghormley, 1933), and its relation with the loads that affect the spine. Due to the invasive nature of measuring these internal loads, models employing indirect means of estimating the loads that act on the lumbar region of the spine during lifting activities began to appear in the 1940s (Wilke et al., 2001). The models found in the literature continue to be primarily concerned with the forces between the muscles, joints and ligaments in only one cross section of the lumbar region (Strait et al., 1947; Cheng, 1998; Gagnon, 2001). While considering the spine as a single rigid structure, these simplified models attempt to provide estimates of what occurs in the spine in situations such as lifting a weight. However, these models are far from representative of the functional anatomical reality of the spine, which consists of several articulated segments and a complex muscle anatomy. The growing interest in producing a more realistic model of the trunk and, consequently, the spine, may have inspired some anthropometric studies (De Leva, 1996; Erdmann, 1997; Zatsiorsky, 2002) to divide the trunk into two or more connected segments. Some models that split the spine into more than one segment are conceived using biomechanical techniques, such as the link segment model (LSM), surface electromyography (EMG) and inverse dynamics (Lariviere, 1999; Marras, 1997; La Torre, 2005). The EMG of the trunk muscles has been used as input for biomechanical models that attempt to indirectly estimate the forces acting on the spine (Granata, 1995; Arjmand, 2006).

Effect of kinesio taping in myoelectric activity in patients with shoulder impingement

Introduction: The complex shoulder joint is equipped with the greater joint mobility of the body, however, is commonly injured in repetitive, sport or occupational activities. Shoulder Impact Syndrome (SIS) is one of the most common injuries affecting the shoulder, thus causing limitations in its functionality. Several strategies have been used by physiotherapy for prevention and rehabilitation of SIS, one of them is the Kinesio Taping (KT). However, even with its abundant use there is still no clear evidence of its benefits. Objective: The aim of the study was to examine the effect of KT on myoelectric activity and the level of pain in patients with SIS. Method: Seven women with SIS participated, which performed the flexion and shoulder abduction up to 90° with and without KT. During the gestures, the pain level and surface electromyography data of the upper trapezoid, middle deltoid and anterior serratus were acquired. The treatment of the electromyography data was performed in the BIOMEC-SAS software and presented as percentage values of the maximum voluntary contraction. To compare the myoelectric activity and pain levels, it was performed, respectively, one way ANOVA and the Wilcoxon test (α <0.05). Results: Pain reductions were observed and myoelectric activity of upper trapezius (46.0±34.4% MVIC to 35.6 ± 19.5% MVIC) and middle deltoid (39.0±11.5% MVIC to 35.2±12.5% MVIC) in motion abduction use of KT. No changes were observed in the signs during flexion movement. Conclusion: Finally, the KT generated a reduction in the level of pain and myoelectric activity of the middle deltoid and upper trapezius in the movement of abduction in patients with SIS.

Development and administration of a postural and ergonomic assessment tool: a pilot study

Introduction Prevention of occupational diseases depends on the identification of risk factors, which can be complemented by the functional assessment of workers.Objective The aim of this study was to develop a postural and ergonomic assessment tool for the analysis of subjects’ sitting posture at the computer workstation.Materials and methods This is a quantitative, descriptive, observational, cross-sectional study. Eighty-two employees in the administrative sector of FIERGS were invited to participate in the study. The mean age was 32.8 ± 7.7 years. The IAPE (Instrumento de Avaliacao Postural Ergonomica [Postural and Ergonomic Assessment Tool]) development and administration process was performed in four stages: 1) observation of the most commonly adopted postures by employees in the workplace; 2) development of the first version of the IAPE; 3) content validation by two ergonomics experts and content validity index (CVI) calculation; 4) inter-evaluator reproducibility assessment. Reproducibility was assessed by Wilcoxon test and intraclass correlation coefficient (ICC) (p < 0.05).Results The results obtained from the calculation of the CVI showed that the IAPE possesses a high degree of content validity (CVI = 1). Inter-evaluator reproducibility assessment showed no differences between evaluators (p < 0.05) and ICC values above 0.80 (p < 0.05). This shows an adequate inter-evaluator reproducibility of the tool.Conclusion Based on the results of the IAPE development process, it can be concluded that the tool has content validity and adequate inter-evaluator reproducibility. This tool can aid in the development of occupational disease prevention and health promotion strategies.