Cláudia Tarragô Candotti

Prevalência de alterações posturais em escolares do ensino médio em uma cidade no Sul do Brasil

OBJETIVOS: Estimar a prevalencia de alteracoes posturais laterais e ântero-posteriores em adolescentes do sexo feminino e verificar se determinados fatores socioeconomicos, demograficos, antropometricos e comportamentais estao associados a essas alteracoes posturais. METODOS: Inquerito epidemiologico com amostra representativa de 495 estudantes do ensino medio regular diurno, com idade de 14 a 18 anos na Cidade de Sao Leopoldo, Brasil. As estudantes foram avaliadas nos meses de outubro e novembro de 2004. As alteracoes posturais foram definidas como alteracoes nas curvas fisiologicas da coluna vertebral, identificadas atraves de avaliacao postural nao-invasiva. RESULTADOS: Observou-se uma prevalencia de 66% (IC95%: 61,5 a 70,0) para as alteracoes laterais e de 70% (IC95%: 65,2 a 73,5) para as alteracoes ântero-posteriores. As alteracoes laterais foram mais prevalentes nas alunas com indice de massa corporal normal (razao de prevalencia, ou RP = 1,32; IC95%: 1,09 a 1,59) e nas que assistiam a televisao por mais de 10 horas semanais (RP = 1,16; IC95%: 1,02 a 1,32). A prevalencia de alteracoes ântero-posteriores foi maior nas alunas cujos responsaveis estudaram ate o nivel fundamental (responsaveis femininos, RP = 1,30; IC95%: 1,09 a 1,55; e responsaveis masculinos, RP = 1,20; IC95%: 1,02 a 1,40) e nas alunas com sobrepeso ou obesidade (RP = 1,33; IC95%: 1,19 a 1,48). CONCLUSOES: Preocupa a alta prevalencia de alteracoes na postura das adolescentes, uma vez que essas alteracoes podem gerar problemas na coluna vertebral a medio e longo prazo. E importante que profissionais da area da saude, inclusive professores de educacao fisica, estejam aptos a realizar avaliacoes posturais, e que esse procedimento seja realizado rotineiramente nas escolas.

Effective force and economy of triathletes and cyclists.

The effective force applied on the crank, the index of pedalling effectiveness, and the economy of movement at 60, 75, 90, and 105 rev/min cadences were examined in nine cyclists and eight triathletes. Tests were performed on two days. Maximal oxygen uptake was measured and the second ventilatory threshold was estimated on day 1 using a stationary bicycle. On day 2, the four different cadences were tested at about 5% below the second ventilatory threshold. A strain gauge instrumented clip-less pedal mounted on the bicycle enabled us to measure the normal and tangential forces exerted on the pedal, while the pedal and crank angles were monitored with the aid of a video system. Based on this information, the effective force and the index of pedalling effectiveness were calculated. Cyclists produced significantly more effective force and a higher index of pedalling effectiveness at 60 and 75 rev/min and were significantly more economic at all cadences than triathletes. The significant and positive correlation between effective force and economy at all cadences suggests that improvement of the effective force would reflect on economy.

Cocontraction and economy of triathletes and cyclists at different cadences during cycling motion

The purpose of this study was to compare the cycling technique of triathletes and cyclists on the basis of the cocontraction of selected muscles of the lower limbs and economy at different cadences. The economy (EC) and percent cocontraction from nine triathletes and eight cyclists were compared at 60, 75, 90 and 105 rpm cadences. Tests were performed on two separate days. The maximal oxygen uptake was measured and the second ventilatory threshold (VO(2VT)) was estimated on the first day using a stationary bicycle. On the second day the four different cadences were tested at approximately 5% below the VO(2VT). The EMG activity of the rectus femoris (RF), biceps femoris (BF) and vastus lateralis (VL) was recorded and the EMG signal was normalized using the 60 rpm dynamic contraction. The percent cocontractions were calculated from RF/BF and VL/BF muscles. The EC was also calculated. The results showed that cyclists were significantly more economic, indicating that they exerted more power with less VO(2), and presented significantly lower percent cocontraction than triathletes (p<0.05). Thus, the results suggest that the cyclists had a better technique than the triathletes. The simultaneous use of the percent cocontraction and economy seems to be a good performance indicator for cyclists and triathletes.

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.

Avaliação da ativação neuromuscular em indivíduos com escoliose através da eletromiografia de superfície

OBJECTIVE: The aim of this study was to investigate the potential of surface electromyography (EMG) for assessing neuromuscular efficiency and localized muscle fatigue in the lumbar extensors, in individuals with scoliosis. METHODS: Twenty individuals participated in this study, divided equally into two groups: (1) Scoliosis Group and (2) Control Group. These subjects underwent a fatigue induction test on their lumbar extensor muscles, consisting of one maximum voluntary isometric contraction (MVIC) followed by a test at 80% of the MVIC effort. Force and EMG signals were collected simultaneously. The EMG signal was processed in the frequency domain by means of fast Fourier transforms using the median frequency; and in the time domain by calculating the root mean square value. The data were analyzed by means of one-way analysis of variance to investigate the differences between the two groups. Paired t test was used to investigate the symmetry between the right and left sides. The significance level adopted was 0.05. RESULTS: The results showed that the individuals with scoliosis presented: (1) symmetrical neuromuscular activation between the sides; (2) lower neuromuscular efficiency; (3) greater capacity to resist fatigue; and (4) force values 42.6% lower than those of the individuals in the Control Group. CONCLUSIONS: The results suggest that surface EMG is an effective tool for functional assessments of scoliosis, although the protocol established limited the participation of individuals with scoliosis, from the perspective of neuromuscular efficiency.

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.

A incidência de desvios posturais em meninas de 6 a 17 anos da cidade de Novo Hamburgo

O objetivo deste estudo foi verificar a incidencia de desvios posturais em escolares. Foram realizadas avaliacoes posturais estaticas, goniometricas e medicoes das distancias escapulares em meninas entre 6 e 17 anos de idade (n=154). Os resultados indicaram que e comum a ocorrencia de desvios posturais, principalmente a partir dos 10 anos, quando passa a ocorrer tambem um percentual maior de assimetrias entre as medidas do lado direito e esquerdo da cintura escapular e pelvica. Analisando as faixas etarias como um todo, os desvios mais observados foram: anteriorizacao da coluna cervical (66,23%), protusao de ombros (47,40%), abducao escapular (80,52%), nipercifose dorsal (10,39%), hiperlordose lombar (31,17%) e cifolordose (29,22%). The objective of this study was to identify the incidence of postural deformity in students. Assessments of static posture, goniometrics and scapular measurements were mada in girls from 6 to 17 years old (n=154). The results indicate that the occurrence of postural deviation is common, specially from 10years old, when also starts to occur i righer percentage of asymmetry between the left and right sides of both the scapular and pelvic girths. The deformities most frequently observed were: anteriorization of the cervical spine

Avaliação do peso e do modo de transporte do material escolar em alunos do ensino fundamental

Objectives: To identify the way school material is carried and the weight of the material carried, and to compare these findings for 2 nd , 5 th and 9 th graders. Methods: This study evaluated 58 students from a randomly selected school in Dois Irmaos, a city in southern Brazil, using anthropometric variables and a questionnaire to identify what schoolchildren used to carry school material and the way it was carried. School material was weighed over a five-day period. Descriptive statistics was used to analyze the responses to the questionnaires. Mean weight of the school material, normalized by body weight, was analyzed using one-way ANOVA and the Bonferroni post hoc test (a=0.05). Results: Second, 5 th and 9 th graders carried their own material using a backpack with two straps (60.0%, 77.3%, and 85.5%, p<0.05) over their shoulders (60.0%, 77.3%, and 81.0%, p<0.05), and mean rate of schoolbag weight to body weight was 7.2%±2.3, 8.8%±3.0, and 5.9%±1.7. The only significant difference ( p<0.05) was between 5 th and 9 th graders. Conclusion: Students in the 2 nd , 5 th and 9 th grades prefer to carry their school material using a backpack with two straps symmetrically placed over the shoulders. Regardless of school grade, the backpack weight was less than 10% of body weight, and 5 th graders carried the heaviest relative loads.

Validating a postural evaluation method developed using a Digital Image-based Postural Assessment (DIPA) software

OBJECTIVE To investigate (1) the accuracy of the palpatory method to identify anatomical points by comparison with the X-ray exams, (2) the validity of classifying spinal posture in the frontal plane using Digital Image-Based Postural Assessment (DIPA) software by comparison with the X-ray exams and (3) the intra and inter-evaluator reproducibility of the DIPA software. MATERIALS AND METHODS The postural assessment and X-ray examination of the spine, both in the frontal plane and standing position, were performed consecutively in 24 subjects. The postural assessment protocol consisted of: (1) palpation and the use of reflective markers containing lead to mark the spinous processes (SP) of the C7, T2, T4, T6, T8, T10, T12, L2, L4 and S2 vertebrae and; (2) acquisition of photographic records. First, the X-ray examinations were used to check the correlation between the palpated and marked SP and the true location of the SP of the vertebra in question, by assessing the distance between them. The spinal posture was classified based on the calculation of the scoliosis arrows in the DIPA (DIPA-SA). The X-ray examinations provided the scoliosis arrows (X-SA), the Cobb angles and the classification of spinal posture based on the Cobb angle. The results from the DIPA protocol were compared to those from the X-ray examination-based protocol. The statistical tests used were: (1) Kruskal-Wallis--differences in terms of the numerical distance between the markers and the anatomical landmarks, (2) Pearsons Correlation--DIPA-SA and Cobb angles, (3) Pearsons Correlation--X-SA and DIPA-SA; (4) Bland and Altmans graphic representation--X-SA and DIPA-SA, (5) Spearmans Correlation--classification of spinal posture obtained using the X-ray and DIPA protocols, (6) the intraclass correlation test (ICC) for the relationship between the DIPA-SA made by each evaluator (inter-evaluator), and (7) independent t-test to compare the data from the two evaluation days (intra-evaluator), α=0.05. RESULTS There were no significant differences between the location of the anatomical points located using palpation and identified with reflective markers and the respective location of the SP as identified using X-ray exams (χ²=9.366, p=0.404). Significant correlations were found between the DIPA-SA and the Cobb angles in the dorsal (r=0.75, p<0.001) and lumbar (r=0.76, p=0.007) regions; between the DIPA-SA and the X-SA in the dorsal (r=0.79, p<0.001) and lumbar (r=0.92, p<0.001) regions and; between the classifications of posture obtained with the DIPA and X-ray protocols (r=0.804, p<0.001). Bland and Altmans representation showed agreement between DIPA-SA and X-SA for both curvatures. Significant correlations were found for the intra-evaluator test in the thoracic (r=0.99, p<0.001) and lumbar (r=0.98, p<0.001) regions; for the inter-evaluator test in the thoracic (r=0.99, p<0.001) and lumbar (r=0.88, p<0.001) regions. CONCLUSION The results suggest that the DIPA protocol constitutes a valid simple, practical and low-cost non-invasive tool for the evaluation of the spine in the frontal plane which can be used to obtain reproducible measurements (inter and intra-evaluators).