Abdominal muscle strength is related to the quality of life among older adults with lumbar osteoarthritis

The aim of the present study was to determine the association between abdominal muscle strength and quality of life among older adults with lumbar osteoarthritis. A blind, cross-sectional study was conducted involving 40 older adults: 20 with lumbar osteoarthritis (12 women and 8 men, mean age of 65.90 ± 4.80 years) and 20 controls (14 women and 6 men, mean age of 67.90 ± 4.60 years). The volunteers were submitted to an abdominal muscle strength test. Quality of life was evaluated using the SF-36 questionnaire. Both abdominal muscle strength and quality of life scores were significantly lower in the group with lumbar osteoarthritis in comparison to the controls (p < 0.05). Moreover, significant and positive associations were found between abdominal muscle strength and the subscales of the SF-36 questionnaire (p < 0.05, 0.421 ≥ rs ≤ 0.694). Based on the present findings, older adults with lumbar osteoarthritis with greater abdominal muscle strength have a better quality of life.

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.

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.

An MRI investigation into the function of the transversus abdominis muscle during "drawing-in" of the abdominal wall

Study Design. An operator blinded dual modality trial of measurement of the abdominal muscles during drawing-in of the abdominal wall. Objectives. 1) To investigate, using magnetic resonance imaging (MRI), the function of the transversus abdominis muscle bilaterally during a drawing-in of the abdominal wall. 2) To validate the use of real-time ultrasound imaging as a measure of the deep abdominal muscle during a drawing-in of the abdominal wall. Summary of Background Data. Previous research has implicated the deep abdominal muscle, transversus abdominis, in the support and protection of the spine and provided evidence that training this muscle is important in the rehabilitation of low back pain. One of the most important actions of the transversus abdominis is to draw-in the abdominal wall, and this action has been shown to stiffen the sacroiliac joints. It is hypothesized that in response to a draw in, the transversus abdominis muscle forms a deep musculofascial corset and that MRI could be used to view this corset and verify its mechanism of action on the lumbopelvic region. Methods. Thirteen healthy asymptomatic male elite cricket players aged 21.3 +/- 2.1 years were imaged using MRI and ultrasound imaging as they drew in their abdominal walls. Measurements of the thickness of the transversus abdominis and internal oblique muscles and the slide of the anterior abdominal fascia were measured using both MRI and ultrasound. Measurement of the whole abdominal cross-sectional area (CSA) was conducted using MRI. Results. Results of the MRI demonstrated that, as a result of draw-in, there was a significant increase in thickness of the transversus abdominis (P < 0.001) and the internal oblique muscles (P < 0.001). There was a significant decrease in the CSA of the trunk (P < 0.001). The mean slide ( +/- SD) of the anterior abdominal fascia was 1.54 +/- 0.38 cm for the left side and 1.48 +/- 0.35 cm for the right side. Ultrasound measurements of muscle thickness of both transversus abdominis and the internal oblique, as well as fascial slide, correlated with measures obtained using MRI (interclass correlations from 0.78 to 0.95). Conclusions. The MRI results demonstrated that during a drawing-in action, the transversus abdominis contracts bilaterally to form a musculofascial band that appears to tighten (like a corset) and most likely improves the stabilization of the lumbopelvic region. Real-time ultrasound imaging can also be used to measure changes in the transversus abdominis during the draw-in maneuver.

Analise eletromiografica dos musculos reto abdominal e obliquo externo, em crianças na faixa etaria de 08 a 10 anos

Universidade Estadual de Campinas . Faculdade de Educação Física

Contraction of the pelvic floor muscles during abdominal maneuvers

Objective: To determine whether voluntary abdominal muscle contraction is associated with pelvic floor muscle activity. Design: Pelvic floor muscle activity was recorded during contractions of the abdominal muscles at 3 different intensities in supine and standing positions. Setting: Research laboratory. Participants: Six women and 1 man with no histories of lower back pain. Interventions: Not applicable. Main Outcome Measures: Electromyographic activity of the pelvic floor muscles was recorded with surface electrodes inserted into the anus and vagina. These recordings were corroborated by measurements of anal and vaginal pressures. Gastric pressure was recorded in 2 subjects. Results: Pelvic floor muscle electromyography increased with contraction of the abdominal muscles. With strong abdominal contraction, pelvic floor muscle activity did not differ from that recorded during a maximal pelvic floor muscle effort. The pressure recordings confirmed these data. The increase in pressure recorded in the anus and vagina preceded the pressure in the abdomen. Conclusions: In healthy subjects, voluntary activity in the abdominal muscles results in increased pelvic floor muscle activity. The increase in pelvic floor pressure before the increase in the abdomen pressure indicates that this response is preprogrammed. Dysfunction of the pelvic floor muscles can result in urinary and fecal incontinence. Abdominal muscle training to rehabilitate those muscles may be useful in treating these conditions.

Co-activation of the abdominal and pelvic floor muscles during voluntary exercises

The response of the abdominal muscles to voluntary contraction of the pelvic floor (PF) muscles was investigated in women with no history of symptoms of stress urinary incontinence to determine whether there is co-activation of the muscles surrounding the abdominal cavity during exercises for the PF muscles. Electromyographic (EMG) activity of each of the abdominal muscles was recorded with fine-wire electrodes in seven parous females. Subjects contracted the PF muscles maximally in three lumbar spine positions while lying supine. In all subjects. the EMG activity of the abdominal muscles was increased above the baseline level during contractions of the PF muscles in at least one of the spinal positions. The amplitude of the increase in EMG activity of obliquus externus abdominis was greatest when the spine was positioned in flexion and the increase in activity of transversus abdominis was greater than that of rectus abdominis and obliquus externus abdominis when the spine was positioned in extension. In an additional pilot experiment. EMG recordings were made from the pubococcygeus and the abdominal muscles with fine-wire electrodes in two subjects during the performance of three different sub-maximal isometric abdominal muscle maneuvers. Both subjects showed an increase in EMG activity of the pubococcygeus with each abdominal muscle contraction. The results of these experiments indicate that abdominal muscle activity is a normal response to PF exercise in subjects with no symptoms of PF muscle dysfunction and provide preliminary evidence that specific abdominal exercises activate the PF muscles. Neurourol. Urodynam. 20:31-42, 2001. (C) 2001 Wiley-Liss, Inc.

Measurement of muscle contraction with ultrasound imaging

To investigate the ability of ultrasonography to estimate musactivity, we measured architectural parameters (pennation angles, fascicle lengths, and muscle thickness) of several human muscles (tibialis anterior, biceps brachii, brachialis, transversus abdominis, obliquus internus abdominis, and obliquus externus abdominis) during isometric contractions of from 0 to 100% maximal voluntary contraction (MVC). Concurrently, electromyographic (EMG) activity was measured with surface (tibialis anterior only) or fine-wire electrodes. Most architectural parameters changed markedly with contractions up to 30% MVC but changed little at higher levels of contraction. Thus, ultrasound imaging can be used to detect low levels of muscle activity but cannot discriminate between moderate and strong contractions. Ultrasound measures could reliably detect changes in EMG of as little as 4% MVC (biceps muscle thickness), 5% MVC (brachialis muscle thickness), or 9% MVC (tibialis anterior pennation angle). They were generally less sensitive to changes in abdominal muscle activity, but it was possible to reliably detect contractions of 12% MVC in transversus abdominis (muscle length) and 22% MVC in obliquus internus (muscle thickness). Obliquus externus abdominis thickness did not change consistently with muscle contraction, so ultrasound measures of thickness cannot be used to detect activity of this muscle. Ultrasound imaging can thus provide a non-invasive method of detecting isometric muscle contractions of certain individual muscles.

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.

Electromyographic analysis of the rectus abdominis muscle in pelvic retroversion and the decrease of the lower limbs

We often face Patients searching for rehabilitation for lower back disorders during the physiotherapeutic routine, and it is known that the abdominal muscle, specially the rectus abdominis muscle, aid the stabilization of the pelvis. Therefore, this paper analyzes the electrical activity of the rectus abdominis muscle in the pelvic retroversion in dorsal decubitus and in orthostatic position and in the lowering of the lower limbs. 30 healthy students, male and female, 17-40 yr, divided into two groups - Group 1: 15 volunteers (pelvic balance); Group 2 (pelvic unbalance) took part in this study. The electrical activity of the right and left supra-umbilical and infra-umbilical portions of the rectus abdominis muscle was detected. The mean RMS values from three attempts ftom the electromyographic traces were usedfor the analysis of the electrical activity. The RMS value was submitted to the normalization process. The data were submitted to statistic treatment by the Friedman test, and the analyses of the means and standard deviation towards a level of significance of 95%. The results demonstrated that the portions of the rectus abdominis muscle presented low electrical activity for the groups studiedfor pelvic retroversion either in dorsal decubitus or and orthostatic position. However, the decreasing movement of the lower limbs towards the portions of the rectus abdominis muscle presented more significant electrical activity whereas the lower portions presented higher activity than the higher ones for Group 2.

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.

Vagal afferent control of abdominal expiratory activity in response to hypoxia and hypercapnia in rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Experimental muscle pain changes feedforward postural responses of the trunk muscles

Many studies have identified changes in trunk muscle recruitment in clinical low back pain (LBP). However, due to the heterogeneity of the LBP population these changes have been variable and it has been impossible to identify a cause-effect relationship. Several studies have identified a consistent change in the feed-forward postural response of transversus abdominis (TrA), the deepest abdominal muscle, in association with arm movements in chronic LBP. This study aimed to determine whether the feedforward recruitment of the trunk muscles in a postural task could be altered by acute experimentally induced LBP. Electromyographic (EMG) recordings of the abdominal and paraspinal muscles were made during arm movements in a control trial, following the injection of isotonic (non-painful) and hypertonic (painful) saline into the longissimus muscle at L4, and during a 1-h follow-up. Movements included rapid arm flexion in response to a light and repetitive arm flexion-extension. Temporal and spatial EMG parameters were measured. The onset and amplitude of EMG of most muscles was changed in a variable manner during the period of experimentally induced pain. However, across movement trials and subjects the activation of TrA was consistently reduced in amplitude or delayed. Analyses in the time and frequency domain were used to confirm these findings. The results suggest that acute experimentally induced pain may affect feedforward postural activity of the trunk muscles. Although the response was variable, pain produced differential changes in the motor control of the trunk muscles, with consistent impairment of TrA activity.

Intra-abdominal pressure increases stiffness of the lumbar spine

Intra-abdominal pressure (IAP) increases during many tasks and has been argued to increase stability and stiffness of the spine. Although several studies have shown a relationship between the IAP increase and spinal stability, it has been impossible to determine whether this augmentation of mechanical support for the spine is due to the increase in IAP or the abdominal muscle activity which contributes to it. The present study determined whether spinal stiffness increased when IAP increased without concurrent activity of the abdominal and back extensor muscles. A sustained increase in IAP was evoked by tetanic stimulation of the phrenic nerves either. unilaterally or bilaterally at 20 Hz (for 5 s) via percutaneous electrodes in three subjects. Spinal stiffness was measured as the force required to displace an indentor over the L4 or L2 spinous process with the subjects lying prone. Stiffness was measured as the slope of the regression line fitted to the linear region of the force-displacement curve. Tetanic stimulation of the diaphragm increased IAP by 27-61% of a maximal voluntary pressure increase and increased the stiffness of the spine by 8-31% of resting levels. The increase in spinal stiffness was positively correlated with the size of the IAP increase. IAP increased stiffness at L2 and L4 level. The results of this:study provide evidence that the stiffness of the lumbar spine is increased when IAP is elevated. (C) 2004 Elsevier Ltd. All rights reserved.

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.