[Show abstract][Hide abstract] ABSTRACT: Muscle force and functional capacity generally decrease with aging in the older population, although this effect can be reversed, attenuated, or both through strength training. Fish oil (FO), which is rich in n-3 (omega-3) PUFAs, has been shown to play a role in the plasma membrane and cell function of muscles, which may enhance the benefits of training. The effect of strength training and FO supplementation on the neuromuscular system of the elderly has not been investigated.
The objective was to investigate the chronic effect of FO supplementation and strength training on the neuromuscular system (muscle strength and functional capacity) of older women.
Forty-five women (aged 64 ± 1.4 y) were randomly assigned to 3 groups. One group performed strength training only (ST group) for 90 d, whereas the others performed the same strength-training program and received FO supplementation (2 g/d) for 90 d (ST90 group) or for 150 d (ST150 group; supplemented 60 d before training). Muscle strength and functional capacity were assessed before and after the training period.
No differences in the pretraining period were found between groups for any of the variables. The peak torque and rate of torque development for all muscles (knee flexor and extensor, plantar and dorsiflexor) increased from pre- to posttraining in all groups. However, the effect was greater in the ST90 and ST150 groups than in the ST group. The activation level and electromechanical delay of the muscles changed from pre- to posttraining only for the ST90 and ST150 groups. Chair-rising performance in the FO groups was higher than in the ST group.
Strength training increased muscle strength in elderly women. The inclusion of FO supplementation caused greater improvements in muscle strength and functional capacity.
American Journal of Clinical Nutrition 01/2012; 95(2):428-36. · 6.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Intervertebral discs are exposed to compressive forces, which produces fluid loss. This loss decreases disc height, spinal length and consequently overall stature. The loss of stature has been associated with spine loading and low back pain. Abdominal exercises increase intra-abdominal pressure and unload the spine. The purpose of this study was to identify if abdominal exercises may produce acute spinal unloading compared to a known unloading position.
Nine subjects performed a loading protocol and an unloading protocol on three experimental sessions. The loading protocol consisted of three sets of military press, while three unloading protocols were: three sets of regular abdominal exercises, three sets of abdominal exercises performed in an inclined board or an unloading resting posture.
Abdominal exercises showed a greater recovery (mean (SD)) (regular=87.8 (20.4)%; inclined=70.1 (14.5)%) in comparison to the resting position (Fowler=33.6 (14.1)%), although no significant differences were found between abdominal exercises in stature recovery (P=0.07).
Abdominal exercises may be introduced between sets of resistance training to decrease the negative effect of compressive forces imposed during such highly stressing activities. Further studies are required to confirm the proposed underlying mechanisms.
[Show abstract][Hide abstract] ABSTRACT: The aim of the present study was to quantify the kinematics of the spine and stature loss induced by the asymmetric load carriage. Six healthy males with no history of low-back disorders walked at their self-selected pace for 8,500 m with and without a standard Royal Mail bag (model MB36) containing 17.5% of the participant's body mass. The load was reduced gradually during the task. The loaded condition produced a stature loss double that observed in the unloaded condition. Increased forward leaning (up to 6 degrees ) and lateral bending of the spine (up to 12 degrees ) was observed with load. Thoracic adjustments occurred in the sagittal plane, changes in the lumbar area occurred in the frontal plane. The data provided evidence against mailbags designs in which the workers cannot alternate the side of the mailbag.
[Show abstract][Hide abstract] ABSTRACT: This study analysed the effect of handling products of different weights on trunk kinematics of supermarket cashiers. Eight participants performed a simulated task involving handling products of light (0.2 kg), intermediate (1.0 kg) and heavy (5.0 kg) weights, while 3D images of the trunk were collected. Light products required negligible changes in the trunk movements, while intermediate and heavy products caused greater amplitude of trunk flexion movements. Lateral trunk leaning increased as the weight of the product increased. Rotational movements of the trunk were not affected by the load weight, although rotation to the right (grasp) was up to four times greater than that to the left side (deposit). The data provided evidence against checkouts that require large amplitude of movement, which are repeated frequently each day. Postural problems may occur among checkout cashiers due to the strain imposed during the task. Supermarket cashiers remain at a high risk for occupational injury due to biomechanically incorrect workstations. Studies designed to quantify the impact of the workstation over the operators’ movements are required.
International Journal of Industrial Ergonomics. 02/2006;
[Show abstract][Hide abstract] ABSTRACT: This study aimed to verify and compare the mechanical behaviour of the spine after procedures of gravitational inversion and Fowler position. Eleven healthy male participants volunteered to participate in the study. A special stadiometer was used to quantify small changes in stature, which were used as a spinal stress index. Gravitational inversion caused a stature recovery of 6,68 ± 1,60 mm, while the Fowler position allowed a recovery of 4,61 ± 1,39 mm (p<0,05). Both unloading strategies proved able to reduce spinal stress. Although gravitational inversion position produced the greatest spinal recovery, it was noticed that such benefits were not sustained as much as that provided in the Fowler position.. INTRODUÇÃO A inversão gravitacional tem sido utilizada como uma estratégia para minimizar o estresse compressivo sobre a coluna vertebral antes e/ou após a realização de atividades físicas (BOOCOCK et al., 1988 e 1990; HEALEY et al., 2005). A inversão gravitacional também tem sido freqüentemente usada como um procedimento terapêutico para o tratamento e alívio de dores na coluna vertebral (GIANAKOPOULOS et al., 1985). A inversão gravitacional consiste em uma técnica de tração na qual o indivíduo permanece em uma posição invertida ou parcialmente invertida (por meio de pranchas, cadeiras ou botas especiais). A força de separação nos discos intervertebrais é imposta pela ação do peso corporal que causa uma força de tração sobre as estruturas da coluna vertebral (BORENSTEIN et al., 1995). A racionalidade deste procedimento é reduzir o estresse compressivo sobre a coluna vertebral através do tracionamento (alongamento) de alguns tecidos moles da coluna (ex: discos intervertebrais, fáscias e ligamentos) com o objetivo de recuperar a morfologia e funcionalidade mecânica (SHEFFIELD, 1964; BORENSTEIN et al., 1995). Quando uma força de alongamento é aplicada sobre a coluna vertebral, ocorre uma deformação imediata elástica dos ânulos fibrosos e reabsorção de fluido para o interior do núcleo pulposo e ânulos fibrosos, recuperando a forma inicial dos discos intervertebrais (WATKINS, 1999). Tais mecanismos ocasionam uma recuperação na altura dos discos intervertebrais e aumentam a capacidade mecânica da coluna em absorver e dissipar estresses compressivos (KANE et al., 1985). Por exemplo, DUNLOP et al. (1984) e ADAMS e DOLAN (1995) reportaram que uma recuperação na altura dos discos intervertebrais pode reduzir o estresse compressivo sobre algumas estruturas da coluna vertebral (ex: as facetas articulares, raízes nervosas e ânulo fibroso posterior) as quais são fontes de dores na coluna vertebral. Contudo, os estudos que procuraram verificar in vivo os efeitos mecânicos da inversão gravitacional são poucos e apresentam resultados contraditórios. TROUP et al. (1985) observaram que a realização de inversão gravitacional em diferentes angulações (30°, 50°, 70° e 90°) não ocasionou uma maior recuperação na altura dos discos intervertebrais que o simples repouso na posição de Fowler (ex: 0°). Em contrapartida, HAKER et al. (2002) reportaram que a inversão gravitacional (50° de inclinação com a horizontal) causou uma recuperação na altura dos discos intervertebrais maior que o repouso na posição de Fowler. Tal discrepância entre os estudos dificulta a prescrição em termos de dose-resposta para os procedimentos de inversão gravitacional. O presente estudo possui o objetivo de comparar o comportamento mecânico dos discos intervertebrais após a inversão gravitacional e posição de Fowler, utilizando pequenas variações de estatura como critério. Um melhor entendimento dos mecanismos envolvidos em diferentes posturas de redução do estresse sobre os discos intervertebrais (ex: inversão gravitacional e posição de Fowler) pode auxiliar no desenvolvimento de estratégias que diminuam o estresse sobre a coluna vertebral.
[Show abstract][Hide abstract] ABSTRACT: Back pain is a common condition which has been described as a serious public health problem. Spinal shrinkage has been used as an index of spinal loading in a range of tasks. Epidemiological evidence shows that body mass index (BMI: 30 kg/m(2)) is related to the development of low back pain however, no studies have described the stature change patterns of obese individuals. This study aimed to compare changes in stature after an exercise task in obese and non-obese individuals.
Twenty volunteers were divided into two equal groups; obese: BMI>30 kg/m(2), non-obese: BMI<25 kg/m(2). Stature was measured at 3 min intervals during a 30 min walking task and a 30 min standing recovery period. Tests were performed on two occasions, once with participants loaded during the walking task (10% body mass) and once unloaded. The influence of obesity and load condition on the magnitude and rate of stature change were compared by a two-way ANOVA:
In both groups the stature loss was greater in the loaded than unloaded condition (mean (SD)) (6.52 (1.45)mm and 3.55 (0.93)mm non-obese; 8.49 (1.75)mm and 7.02 (1.32)mm obese: P=0.016). The obese presented a greater reduction in stature in both task conditions. The obese group were unable to recover stature regardless of the task condition during the recovery period (loaded: 0.06 (0.3)mm; unloaded: 0.32 (0.6)mm; P=0.013).
It was concluded that the acute response of the spine to loading may represent a risk factor for low back pain in the obese, in addition to the chronic adaptations previously reported. A greater period of recovery may be necessary for obese individuals to re-establish intervertebral disc height. These findings may help to explain the high incidence of back disorders in obese individuals.
[Show abstract][Hide abstract] ABSTRACT: To assess the behavior of the spinal column after loading in participants with and without low back pain (LBP) using spinal shrinkage measurements as a criterion and to analyze the relations among spinal shrinkage, recovery, and LBP.
A case-control study with repeated measures.
University department with recruitment from primary care.
Convenience sample of 31 women (15 with chronic, nondisabling LBP [LBP group]; 16 with no history of low back disorders [control group]).
Changes in body length as determined by using a stadiometer.
The spinal shrinkage induced by the exercise was similar ( P >.05) in both groups (control group, mean +/- standard deviation of -3.99+/-1.13 mm; LBP group, -4.16+/-1.54 mm). Differences in spinal length were found after 20 minutes in the recovery position ( P <.05). The control group was able to recover stature to a greater extent (111.2%+/-13.6%) than the LBP group ( P <.05), which was unable to regain stature beyond baseline (57.5%+/-25.1%). A negative correlation was found between regaining stature and low back pain ( r =-.52, P <.05).
Participants with LBP were unable to recover stature to the same extent as controls. We suggest that LBP is related to the diminished ability to recover rather than to the magnitude of the spinal shrinkage imposed during the task.
Archives of Physical Medicine and Rehabilitation 03/2005; 86(3):505-11. · 2.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To assess the loss of stature and its recovery in normal and pregnant women with and without low back pain (LBP) and to examine the relations between spinal shrinkage, recovery, and LBP.
Stature changes were measured before and after physical activity in each group and differences in response compared between groups.
A laboratory environment.
Thirty-one women (7 pregnant without LBP, 8 pregnant with LBP, 16 nonpregnant with no history of low back disorders) were recruited using convenience sampling. Controls were recruited from the general community; subjects in the pregnant groups were recruited from local primary care groups.
Stature change was assessed as the main outcome measure. Changes in stature were interpreted with respect to the woman's stature at the start of the trial.
Stature loss induced by a moderate physical activity was similar (P>.05) in all groups (control, -3.99+/-1.13 mm; pregnant no back pain, -4.23+/-1.23 mm; pregnant with back pain, -4.57+/-1.53 mm). Differences were found after 20 minutes in a recovery position (P<.05): the controls were able to recover stature to a greater extent (111.2%+/-13.6%) than the other groups (P<.05). A negative correlation was found between regain in stature and LBP in pregnant subjects (r=-.81, P<.05).
The pregnant women with LBP were unable to recover stature to the same extent as the controls and pregnant women without LBP. Results suggest that LBP in pregnancy may be related to the woman's diminished ability to recover, rather than the magnitude of the spinal shrinkage imposed during the task.
Archives of Physical Medicine and Rehabilitation 04/2003; 84(4):507-12. · 2.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to determine the effect of sitting and standing postures on the repeatability of a stadiometer designed to detect small variations in spinal length. Two groups of ten healthy subjects, with no previous or known history of back problems, participated in this study. One group was measured in the standing posture, while the other group was measured in a sitting posture. All subjects gave informed consent to participate in this study. Subjects had a set of landmarks defining the spinal contour marked on their backs and then stood in the stadiometer for three series of ten measurements to be performed. At the end of each measurement, the subjects were requested to move away from and then be repositioned in the stadiometer. Subjects improved the repeatability across the measurement series. At the end of the second measurement series, all subjects presented mean standard deviations of 0.43 +/- 0.08 mm (range 0.30-0.50 mm) in the standing posture. In the sitting posture, deviations of less than 0.05 mm were obtained only at the end of the third measurement series (0.48 +/- 0.08 mm; range 0.34-0.62 mm), suggesting that this posture required three measurement series before repeatable measurements could be assured rather than two in the standing posture.