Stabilization of lumbo-pelvic region and electromyography of the abdominal muscles

It is usual to find athletes that can perform de curl up test easily, but are unable to maintain the stabilization of the low back during the double straight leg lowering (DSLL). In spite of having strong abdominal muscles, its stabilization role seems not to be effective. Thus, the purpose of this study was to verify the relation among individuals with strong abdominal muscles and the ability in perform posterior pelvic tilt (PPT); the ability to stabilize the low back during the DSLL and the eletromyographic activity of the abdominal muscles. Eighteen male subjects (aged 19.27 ± 3.5), without history of muscle skeletal dysfunction, performed both the PPT and DSLL tests. During these tests electromyographic signals of the rectus abdominis (RA), obliquus internus abdominis (01) and obliquus externus abdominis (OE) were recorded, the angle of the hip and the pressure under the low back were measured The results of analyses of variance (ANOVA) show that most volunteers accomplished the PPT test, actively flattening the low back with regular or good quality. However, none of them was able to stabilize the low back during the DSLL test. During the PPT test all abdominal muscle portions analysed were activated without significant differences. In an attempt of maintaining the lumbo-pelvic region stabilized during the DSLL, it was observed a tendency of higher bilateral activation of OE when compared to RA and 01 muscle portions between 70 and 20 degrees of hip flexion.

Lumbo-pelvic stability and electromyography of abdominal muscles in ballet dancers

Evaluating the ability to rectify and maintain lumbar adjustment can contribute toward the understanding of the behavior of abdominal muscles and their participation in the stability of pelvic muscles in dancers during the posterior pelvic tilt and double straight leg lowering tests. Nine healthy volunteers (male and female ballet dancers; age mean: 25.9 ±7.37 years) underwent maximal isometric voluntary contraction (MIVC), isometric voluntary contraction at 50% of MIVC, posterior pelvic tilt (PPT) and double straight leg lowering (DSLL) tests. The tests were carried out in a single day, with 3 repetitions each. During the tests, electromygraphic signals of the rectus abdominis, obliquus internus and obliquus externus were recorded. The signal acquisition system was made up of bipolar surface electrodes, electrogoniometer and an electromechanic device (pressure sensor), which were connected to a signal conditioner module. Root mean square values of each muscle during the DSLL and PPT were converted into percentage of activation of 50% MIVC. Lower back pressure was submitted to the same process. ANOVA with repeated measures was performed, with the level of significance set at p < 0.05. The results revealed that all dancers were able to maintain posterior pelvic tilt and there was trend toward greater activation of the bilateral obliquus internus muscle. In an attempt to keep the pelvic region stabilized during DSLL, there was a greater contribution from the obliquus externus muscle in relation to other abdominal muscles.

Postural activity of the abdominal muscles varies between regions of these muscles and between body positions

The abdominal muscles have an important role in control and movement of the lumbar spine and pelvis. Given there is new evidence of morphological and functional differences between distinct anatomical regions of the abdominal muscles, this study investigated whether there are regional differences in postural activity of these muscles and whether recruitment varies between different body positions. Eleven subjects with no history of low back pain that affected function or for which they sought treatment participated in the study. Electromyographic (EMG) activity of the upper, middle and lower regions of transversus abdominis (TrA), the middle and lower regions of obliquus internus abdominis (OI) and the middle region of obliquus externus abdominis (OE) was recorded using intramuscular electrodes. All subjects performed rapid, unilateral shoulder flexion in standing and six subjects also moved their upper limb in sitting. There were regional differences in the postural responses of TrA with limb movement. Notably, the onset of EMG of the upper region was later than that of the lower and middle regions. There were no differences in the EMG onsets of lower and middle TrA or OI. The postural responses of the abdominal muscles were also found to differ between body positions, with recruitment delayed in sitting compared to standing. This study showed that there is regional differentiation in TrA activity with challenges to postural control and that body position influences the postural responses of the abdominal muscles. These results may reflect variation in the contribution of abdominal muscle regions to stability of the trunk. (c) 2004 Elsevier B.V. All rights reserved.

Comparação entre pericárdio bovino preservado em glicerina e malha de poliéster no reparo de falhas da parede abdominal em ratos

OBJETIVO: Comparar uma malha comercial de poliéster com o pericárdio bovino preservado em glicerina na reconstituição de defeitos da parede abdominal. MÉTODOS: Foram utilizados 30 ratos, divididos em dois grupos eqüitativos. Efetuou-se uma excisão retangular de 2,5 x 2 cm, incluindo toda a musculatura abdominal e peritônio. No grupo I a parede abdominal foi reparada com malha de poliéster e no grupo II com pericárdio bovino conservado em glicerina. Os animais foram sacrificados aos 15, 60 e 90 dias de pós-operatório, sendo o local cirúrgico avaliado macroscópica e histologicamente. RESULTADOS: Os animais do grupo I apresentaram aderências mais severas e em maior número quando comparados aos do grupo II; porém, sem comprometimento funcional. A análise histológica revelou incorporação dos tecidos aos implantes, com maior resposta fibroblástica nos animais do grupo I. CONCLUSÃO: A malha de poliéster oferece maior resistência estrutural e resposta fibroblástica mais intensa; contudo, promove grande quantidade de aderências às vísceras abdominais, quando comparada ao pericárdio bovino.

Estudo comparativo entre a sutura contínua e a com pontos separados na parede abdominal de ratos

O objetivo deste experimento foi comparar a sutura contínua e a sutura com pontos separados no fechamento da parede abdominal. Foram utilizados 48 ratos machos Wistar, submetidos a laparotomia com técnica de diérese padronizada, 24 submetidos a sutura da parede abdominal por técnica contínua e 24 com pontos separados, com fio polidioxanona. No 7º e 14º dia de pós-operatório foram submetidos a eutanásia 12 animais de cada grupo e deles retirados a camada músculo-fascial abdominal envolvendo a cicatriz operatória e dividida aleatoriamente em dois segmentos (cranial e caudal), um para ser submetido a avaliação da força de rotura mediante o uso de tensiômetro e outro para exame histológico, onde foi realizada a avaliação quantitativa de colágeno na linha de sutura. Os resultados encontrados foram analisados estatisticamente. Concluiu-se que no 7º dia de pós-operatório a parede abdominal suturada com pontos separados é mais resistente, porém sem diferenças significantes na quantidade de colágeno, do que a suturada por técnica contínua, e no 14º dia, ambas se equivalem nos dois parâmetros estudados, em ratos.

Relação entre aliança terapêutica e o recrutamento muscular do Transverso Abdominal e Oblíquo Interno em pacientes com lombalgia crônica não específica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaiação da Dor e da Postura em Pacientes com Lombalgia Submetidos a Dois Protocolos de Fortalecimento Abdominal

Introduction: the lumbar spine is the main part of the body responsible for the support of the loads, where approximately half of body weight is in stable balance. This support relates to the action of abdominal muscles, of great importance in the balance of that region. The existence of abdominal muscle weakness, such won’t perform its function, may induce pathological postural attitude, that predispose the pain. Objective: to compare the effects of two abdominal strengthening protocols on pain and postural alignment in individuals with low back pain. Method: participated of the study 21 individuals of both genders, with ages between 19 and 25 years old (average 21,8±1,5) and average Body Mass Index (BMI) 21,9 (±2,48), divided randomly in isometric abdominal stimulation group (n=8), abdominal strengthening group (n=7) and control group (n=6). They realized eight sessions of strengthening, when responded Visual Analogue Scale (VAS) before and after each intervention. The control group (n=6) had no intervention. The postural data had been analyzed by photogrammetry. Results: Pain and posture data were analyzed using paired t test, with signifi cance index of 5%. Postural angles had no signifi cant differences (p>0,05) from all angles analyzed after the intervention to none of the groups. For pain values, a signifi cant decrease (p<0,05) was observed since the fi fth session in patients who were treated by the abdominal exercises protocol, and the fi rst session in patients who were treated by the isometric abdominal stimulation protocol. However, this decrease in pain was immediate, not lasting along the treatment sessions, in both protocols. Conclusion: the proposed protocols did not interfere in postural alignment. They were effective to decrease pain in a same session, once the isometric was the most effective, but they weren’t effective in preserving the improves over time.

Relationship between therapeutic alliance and deep abdominal muscle recruitment in nonspecific low back pain sufferers

Chronic low back pain is a difficult condition to be treated. As some patients respond positively to treatment and others do not present any improvements, one can think there are others conditional factors that need to be elucidated. By means of this study, we sought to investigate the association between the occurrence of the formation of a positive relationship between patient and therapist, assessed by the therapeutic alliance inventory, and the adequate recruitment of the deep abdominal muscles, as well as to verify the effect of a protocol intervention based on motor control exercises on levels of pain and disability. The recruitment of the transverse abdominal and internal oblique muscles was examined by ultrasound imaging in 12 subjects with nonspecific chronic low back pain before and after implementation of a protocol for motor control exercises, with subsequent application of the therapeutic alliance inventory questionnaire. No association was found between the level of therapist/patient alliance and muscle recruitment. The proposed protocol was effective in reducing the levels of pain and disability; however, recruitment of transverse abdominal and internal oblique muscles showed no significant changes in the end of the intervention. Based on these findings, we verified that the therapeutic alliance has no association with muscle recruitment in the short term. However, although there were no changes in muscle recruitment after the intervention program, the level of pain and disability was reduced.

Pain pressure threshold algometry of the abdominal wall in healthy women

The objective of this study was to determine the inter- and intra-examiner reliability of pain pressure threshold algometry at various points of the abdominal wall of healthy women. Twenty-one healthy women in menacme with a mean age of 28 +/- 5.4 years (range: 19-39 years) were included. All volunteers had regular menstrual cycles (27-33 days) and were right-handed and, to the best of our knowledge, none were taking medications at the time of testing. Women with a diagnosis of depression, anxiety or other mood disturbances were excluded. Women with previous abdominal surgery, any pain condition or any evidence of inflammation, hypertension, smoking, alcoholism, or inflammatory disease were also excluded. Pain perception thresholds were assessed with a pressure algometer with digital traction and compression and a measuring capacity for 5 kg. All points were localized by palpation and marked with a felt-tipped pen and each individual was evaluated over a period of 2 days in two consecutive sessions, each session consisting of a set of 14 point measurements repeated twice by two examiners in random sequence. There was no statistically significant difference in the mean pain threshold obtained by the two examiners on 2 diferent days (examiner A: P = 1.00; examiner B: P = 0.75; Wilcoxon matched pairs test). There was excellent/good agreement between examiners for all days and all points. Our results have established baseline values to which future researchers will be able to refer. They show that pressure algometry is a reliable measure for pain perception in the abdominal wall of healthy women.

Postural and respiratory activation of the trunk muscles changes with mode and speed of locomotion

Despite the importance of the deep intrinsic spinal muscles for trunk control, few studies have investigated their activity during human locomotion or how this may change with speed and mode of locomotion. Furthermore, it has not been determined whether the postural and respiratory functions, of which these muscles take part, can be coordinated when locomotor demands are increased. EMG recordings of abdominal and paraspinal muscles were made in seven healthy subjects using fine-wire and surface electrodes. Measurements were also made of respiration and gait parameters. Recordings were made for 10s as subjects walked on a treadmill at 1 and 2 ms(-1) and ran at 2, 3, 4 and 5 ms(-1). Unlike the superficial muscles, transversus abdominis was active tonically throughout the gait cycle with all tasks, except running at speeds of 3 ms(-1) and greater. All other muscles were recruited in a phasic manner. The relative duration of these bursts of activity was influenced by speed and/or mode of locomotion. Activity of all abdominal muscles, except rectus abdominis (RA), was modulated both for respiration and locomotor-related functions but this activity was affected by the speed and mode of locomotion. This study provides evidence that the deep abdominal muscles are controlled independently of the other trunk muscles. Furthermore, the pattern of recruitment of the trunk muscles and their respiratory and postural coordination is dependent on the speed and mode of locomotion. (C) 2003 Published by Elsevier B.V.

Abdominal muscle recruitment during a range of voluntary exercises

Various exercises are used to retrain the abdominal muscles in the management of low back pain and other musculoskeletal disorders. However. few studies have directly investigated the activity of all the abdominal muscles or the recruitment of regions of the abdominal muscles during these manoeuvres. This study examined the activity of different regions of transversus abdominis (TrA), obliquus internus (OI) and externus abdominis (OE), and rectus abdominis (RA), and movement of lumbar spine, pelvis and abdomen during inward movement of the lower abdominal wall, abdominal bracing, pelvic tilting, and inward movement of the lower and upper abdominal wall. Inward movement of the lower abdominal wall in supine produced greater activity of TrA compared to OI. OE and RA. During posterior pelvic tilting. middle OI was most active and with abdominal bracing. OE was predominately recruited. Regions of TrA were recruited differentially and in inverse relationship between lumbopelvic motion and TrA electromyography (EMG) was found. This study indicates that inward movement of the abdominal wall in supine produces the most independent activity of TrA relative to the other abdominal muscle, recruitment varies between regions of TrA, and observation of abdominal and lumbopelvic motion may assist in evalation of exercise performance. (c) 2004 Elsevier Ltd. All rights reserved.