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PubMed1992

[Evaluation of physical fitness and exercise performance in patients with chronic pulmonary emphysema].

Physical fitness was studied in patients with chronic pulmonary emphysema using Kraus-Weber methods in addition to pulmonary function and exercise tolerance. In Kraus-Weber tests, explosive strength of abdominal muscles in these patients were within the normal range, but both abdominal and back muscle endurance were significantly diminished compared to age-matched controls. On the other hand, flexibility was not different between the patients and the controls, although large variation was present. Exercise performance as assessed by 6 minutes' walk distance in patients was significantly correlated with FEV1.0, DLco and maximal inspiratory mouth pressure, as well as explosive strength of abdominal muscles and abdominal and back muscle endurance capacity. Treadmill walking training for 20 minutes with a load greater than 80% VO2max, twice a week for 2 months was performed in 11 patients with mild to moderate pulmonary emphysema. Six minutes' walk distance (6MD) was significantly prolonged with improvement of back muscle endurance and flexibility. Another walking training consisting of five repetitions of two minutes' near maximal walking and a two minute interval of rest was performed in 6 patients with severe pulmonary emphysema. 6MD tended to increase with improvement of both back and abdominal muscle endurance. However, pulmonary function tests and VO2max showed no significant changes after both types of training. Improved walked distance after the training was significantly correlated with improved VO2 at AT. Furthermore VO2, VE, HR and lactate production during exercise at the same load were significantly decreased compared to pre-training. Dyspnea sensation measured by modified Borg scale during exercise was improved after the training. It is concluded that a physical training program adapted to the condition of the individual patients could improve exercise performance, and should be prescribed in addition to medication.

Aged↗
PubMed1988

Muscular hyperalgesia and hypoalgesia after stimulation of the ureter in rats.

Vocalization electric thresholds were measured bilaterally in muscles of the lower back and in the tail after electrical stimulation of the left ureter in rats implanted with electrodes. 'Painful' stimulation immediately produced a hyperalgesia lasting about half an hour in the left lower back muscles and tail, followed by a 10 min hypoalgesia limited to the back muscles. No modification or only a delayed hypoalgesia appeared in the right muscle. Strong but 'non-painful' stimulation produced no effect or gave rise to an immediate hypoalgesia in the left muscle. Weak non-painful stimulation produced a delayed hypoalgesia in the tail.

Animals↗
PubMed2006

Surface electromyography activity of trunk muscles during wheelchair propulsion.

BACKGROUND: Trunk instability due to paralysis can have adverse effects on posture and function in a wheelchair. The purpose of this study was to record trunk muscle recruitment patterns using surface electromyography from unimpaired individuals during wheelchair propulsion under various propulsion speed conditions to be able to design trunk muscle stimulation patterns for actual wheelchair users with spinal cord injury. METHODS: Fourteen unimpaired subjects propelled a test wheelchair on a dynamometer system at two steady state speeds of 0.9 m/s and 1.8 m/s and acceleration from rest to their maximum speed. Lower back/abdominal surface electromyography and upper body movements were recorded for each trial. Based on the hand movement during propulsion, the propulsive cycle was further divided into five stages to describe the activation patterns. FINDINGS: Both abdominal and back muscle groups revealed significantly higher activation at early push and pre-push stages when compared to the other three stages of the propulsion phase. With increasing propulsive speed, trunk muscles showed increased activation (P<0.0001). Back muscle activity was significantly higher than abdominal muscle activity across the three speed conditions (P<0.0005), with lower back muscles predominating. INTERPRETATION: Abdominal and back muscle groups cocontracted at late recovery phase and early push phase to provide sufficient trunk stability to meet the demands of propulsion. This study provides an indication of the amount and duration of stimulation needed for a future application of electrical stimulation of the trunk musculature for persons with spinal cord injury.

Abdominal Muscles↗
PubMed1991

Psychophysiological responses to repeated acute pain stimulation in chronic low back pain patients.

Psychophysiological recordings (electrodermal activity, heart rate, respiration rate and frontalis and back muscle tension) were taken in chronic low back pain (CLBP) patients and control subjects during baseline conditions and during the presentation of six acute pressure pain stimuli. No baseline differences in back muscle tension between CLBP patients and controls were found, but CLBP patients did have higher baseline electrodermal activity. During pain stimulation, CLBP patients showed larger skin conductance reactions than controls. Also, the CLBP patient group showed a marked increase in lumbar muscle tension during the test compared to baseline, whereas the EMG level of the control group remained unchanged. This increase in muscle tension seemed to be more related to the postural change than to the pain stimulus, and it is hypothesized that some CLBP patients react with exaggerated and non-functional back muscle contractions to slight changes in posture. Contrary to expectation, no differences were found between CLBP patients and controls in physiological habituation after repeating the pain stimulus. Comparison of subjective pain ratings and psychophysiological variables showed that for control subjects arousal and subjective pain were related. For CLBP patients there was no such clear relationship.

Adult↗
PubMedDate not supplied

Surface EMG activity of the back musculature during axial spinal unloading using an LTX 3000 Lumbar Rehabilitation System.

Electromyographic (EMG) analysis has been used successfully to identify back muscle impairment in patients with low back pain. EMG signals from normal subjects during axial spinal unloading using an LTX 3000 device were obtained and spectral parameters of the electromyographic (EMG) signal were analyzed. The purpose of the study was to determine the optimal time for effective traction using the LTX 3000 rehabilitation device. These data will serve as a baseline for future studies to help assess back muscle function in low back patients undergoing rehabilitation. Three time points during axial spinal unloading were compared to pre-unloading to detect alterations in median power frequency (MPF), root-mean-square (RMS) and rectified integrated EMG (riEMG) during axial spinal unloading. There were reductions of riRMG during 0-10 minutes of axial spinal unloading in all muscle groups, followed by an increase in riEMG value from 10 to 15 minutes. A similar trend was seen in the RMS values. The MPF did not change during the course of unloading, indicating that there was likely no change in fatigue properties of the paraspinal muscles during axial spinal unloading. The optimal time for effective axial spinal unloading on the basis of muscle activity was determined to be 10 minutes of axial spinal unloading, and a back assessment procedure was presented that uses surface EMG electrodes to objectively characterize muscle activity and relative fatigue properties. Future studies will use this methodology to assess treatment outcome in a chronic low back pain population.

Adult↗
PubMed1990

Effect of season on physical activity score, back extensor muscle strength, and lumbar bone mineral density.

Seasonal variation in physical activity, back extensor muscle strength (BES), and bone mineral density (BMD) of the lumbar spine was studied in 65 healthy postmenopausal women. Physical activity score (PAS) was assessed with an ordinal scale (0-18); this score and the BES were obtained monthly for 2 years (25 readings). BMD values were obtained semiannually (5 readings). A periodic (cosine) regression model was fit to each subject's PAS and BES data to obtain individual estimates of the annual peak day d and the average annual range due to seasonality. There was a strong (P less than 0.001) seasonal pattern in physical activity; August 3 was the average peak day, and the seasonal range was 2.0 PAS units. There was modest (P = 0.047) seasonality in BES; June 6 was the estimated peak day, and the seasonal range was 8.22 pounds (about 7% of the 0.002), and the highest monthly average BMD was in August. This seasonal range of 1.4% is larger than the average annual decline with age in BMD observed in longitudinal studies of postmenopausal women. The results of this study have important implications for the planning of longitudinal studies involving changes in physical activity or bone mass in geographic areas with diverse seasons.

Aged↗
PubMed2001

Snapping turtles (Chelydra serpentina) as monitors for mercury contamination of aquatic environments.

We assessed the distribution of mercury in snapping turtles (Chelydra serpentina) by analyzing front shoulder muscle, back leg muscle, tail muscle, blood, liver, and marginal carapacial scute (shell) of 26 adult turtles from five small lakes. Total mercury concentration in muscle ranged from 50 to 500 ng g(-1) wet weight and was highly correlated among the three tissue locations. There was no relationship between muscle mercury concentration and body size. Mercury concentration in blood was similar to muscle; the correlation with muscle mercury concentration was significant but there was some variability. Mercury concentration in shell was much higher than in muscle or blood, ranging from 500 to 3300 ng g(-1), and was highly correlated with muscle mercury concentration. Liver mercury concentration was similar to shell, but was highly variable and uncorrelated with any other tissue. We conclude that snapping turtles accumulate mercury from their environment and may be useful monitors of mercury contamination.

Animals↗
PubMed1999

Fine-scale transgenic mapping of the MyoD core enhancer: MyoD is regulated by distinct but overlapping mechanisms in myotomal and non-myotomal muscle lineages.

Skeletal muscle lineage determination is regulated by the myogenic regulatory genes, MyoD and Myf-5. Previously, we identified a 258 bp core enhancer element 20 kb 5' of the MyoD gene that regulates MyoD gene activation in mouse embryos. To elucidate the cis control mechanisms that regulate MyoD transcription, we have mutagenized the entire core enhancer using linker-scanner mutagenesis, and have tested the transcriptional activity of enhancer mutants using lacZ reporter gene expression in transgenic mouse embryos. In total, 83 stable transgenic lines representing 17 linker-scanner mutations were analyzed in midgestational mouse embryos. Eight linker-scanner mutations resulted in a partial or complete loss of enhancer activity, demonstrating that MyoD is primarily under positive transcriptional control. Six of these mutations reduced or abolished transgene expression in all skeletal muscle lineages, indicating that activation of MyoD expression in trunk, limb and head musculature is regulated, in part, by shared transcriptional mechanisms. Interestingly, however, two adjacent linker-scanner mutations (LS-14 and LS-15) resulted in a dramatic reduction in transgene expression specifically in myotomes at 11.5 days. At later stages, transgene expression was absent or greatly reduced in myotomally derived muscles including epaxial muscles (deep back muscles) and hypaxial muscles of the body wall (intercostal muscles, abdominal wall musculature). In contrast, head muscles, as well as muscles of the body derived from migrating muscle progenitor cells (e.g. limb, diaphragm), were unaffected by these mutations. In Pax-3-mutant mice, LS-14 and LS-15 transgene expression was eliminated in the body, but was unaffected in the head, yielding an identical expression pattern to the endogenous MyoD gene in mice mutant for both Myf-5 and Pax-3. These data support the hypothesis that LS-14 and LS-15 define the core enhancer targets for Myf-5-dependent activation of MyoD in myotomal muscles.

Alternative Splicing↗
PubMed1998

Distribution of actin and tropomyosin in Cryptosporidium muris.

Actin and tropomyosin of Cryptosporidium muris were localized by immunogold labeling. Two kinds of antibodies for actin labeling were used. The polyclonal antibody to skeletal muscle (chicken back muscle) actin was labeled on the pellicle and cytoplasmic vacuoles of parasites. The feeder organelle has showed a small amount of polyclonal actin antibody labeling as well. Whereas the monoclonal antibody to smooth muscle (chicken gizzard muscle) actin was chiefly labeled on the filamentous cytoplasm of parasites. The apical portion of host gastric epithelial cell cytoplasm was also labeled by smooth muscle actin together. The polyclonal antibody to tropomyosin was much more labeled at C. muris than host cells, so it could be easily identified even with low magnification (x2,000). The tropomyosin was observed along the pellicle, cytoplasmic vacuoles, and around the nucleus also. The skeletal muscle type actin seems to play a role in various cellular functions with tropomyosin in C. muris; on the other hand, the smooth muscle type actin was located mainly on the filamentous cytoplasm and supported the parasites' firm attachment to host cells. Tropomyosin on the pellicle was thought to be able to stimulate the host as a major antigen through continuous shedding out by the escape of sporozoites or merozoites from their mother cells.

Actins↗
PubMed1996

The medullary reticular formation is a site of muscle relaxant action of diazepam on deep back and neck muscles in the female rat.

We tested the hypothesis that the effect of systemic injections of diazepam (DZ, 125 mg/kg) to reduce the quality of the reproductive behavior, lordosis, and to reduce the EMG of lumbar back muscles involved in lordosis (Schwartz-Giblin et al., 1984) is exerted through a reticulospinal pathway with cells of origin in the nucleus gigantocellularis that excites lumbar motoneurons indirectly (Robbins et al., 1990, Robbins et al., 1992). In contrast, DZ facilitates lordosis behavior when infused into the midbrain central gray (McCarthy et al., 1995). Direct deposits of crystalline mixtures of DZ (20-80 ng) in dextrose were delivered to the medullary reticular formation (MRF) by diffusion from a cannula inserted through a guide to which a bipolar stimulating electrode was attached. The multiunit EMG response evoked by 20 (300 ms long) stimulus trains was recorded in back and neck muscles, lateral longissimus and splenius before and 5, 15, 30 and 60 min after local DZ deposits. There was a significant reduction in EMG response over this time period when stimulus intensities were within the range of 1.2-1.5 times threshold (Friedman two-way non-parametric test, P < 0.002). Large amplitude motor units that provide large tensions were the most sensitive to DZ-induced inhibition. Control deposits of dextrose had no significant effect. Systemic injections of progesterone (1 mg, i.p.) 60 min after DZ deposits, but not after dextrose deposits, further reduced the MRF-evoked EMG responses over the course of 1 h. As predicted, DZ infusions into the midbrain central gray did not reduce the reticulospinal-evoked axial muscle response, consistent with the facilitatory effect of midbrain central gray infusions of DZ on the lordosis quotient. The results suggest that benzodiazepine agonists (if endogenous) acting at sites in the MRF would be effective muscle relaxants during pregnancy, prior to the fall in progesterone that precedes labor.

Animals↗
PubMed2006

Postoperative change of the cross-sectional area of back musculature after 5 surgical procedures as assessed by magnetic resonance imaging.

Many investigators have reported that persistent low back pain may occur after posterior surgical intervention, and studies have investigated the histologic and histochemical changes in back muscle after posterior lumbar spine surgery. The purpose of the current study is to compare the pre- and postoperative cross-sectional area of the back musculature among 5 surgical groups including anterior lumbar interbody fusion, which has no direct invasion of the back musculature, using magnetic resonance imaging, and to correlate the clinical results with the degree of atrophy. The cross-sectional area of the back musculature was measured before and after surgery in T2-weighted axial magnetic resonance images using a computer-linked digitizer. The degree of atrophy (atrophy ratio) was calculated as a ratio of the postoperative cross-sectional area to the preoperative cross-sectional area. Clinical results were evaluated using the Japanese Orthopaedic Association's scores for the management of low back pain. Atrophy of the back musculature was confirmed in each group. However, no significant difference was seen in the atrophy ratio between the groups. Back musculature atrophy occurred even in anterior lumbar interbody fusion, which does not involve any direct surgery of the back muscle. A positive correlation was noted between the atrophy ratio and operation time only in posterior surgery, especially in nonfusion surgery. In conclusion, the current study suggests that a shorter operation time may minimize back muscle injury, and shows that factors inducing back musculature atrophy include not only direct invasion of the back muscle via a posterior approach, but also postoperative external fixation.

Adult↗
PubMed1989

Isolation of alpha-connectin, an elastic protein, from rabbit skeletal muscle.

alpha-Connectin (also called titin 1) has been isolated from rabbit back muscle. Myofibrils were well washed with 5 mM NaHCO3 and then extracted with 0.2 M sodium phosphate, pH 7.0. The extract was dialyzed against 0.1 M potassium phosphate, pH 7.0, to sediment myosin. The supernatant, adjusted to 0.18 M potassium phosphate, pH 7.0, and 4 M urea, was subjected to DEAE Toyopearl column chromatography. beta-Connectin was eluted in the flow-through fraction and alpha-connectin was eluted at around 0.1 M NaCl, when a 0 to 0.25 M NaCl gradient was applied. The separated alpha-connectin was dialyzed against 0.2 M potassium phosphate, pH 7.0. The resultant alpha-connectin showed the same mobility as that in an SDS extract of rabbit back muscle on SDS gel electrophoresis using 1.8% polyacrylamide gels. A monoclonal antibody against chicken breast muscle beta-connectin reacted with the alpha-connectin isolated from rabbit back muscle.

Animals↗
PubMed2006

The effect of increasing resistance on trunk muscle activity during extension and flexion exercises on training devices.

Although progressive resistance training of trunk muscles on devices is very common, today, the effects of increasing resistance on trunk muscle activity during dynamic extension and flexion movements on training devices have not been reported yet. Thirty healthy subjects participated in maximal isometric and submaximal dynamic (at 30%, 50% and 70% of maximum mean torque (MMT)) extension and flexion exercises on Tergumed lumbar training devices. The normalized (as a percentage of maximal voluntary isometric contractions (MVIC)) electromyographic activity of 16 abdominal and back muscles was investigated. The results of the present study indicated that in general, with increasing resistance from 30% MMT to 50% MMT and 70% MMT, the activity of all back muscles during the extension exercises and the activity of all abdominal muscles during the flexion exercises increased significantly. To train strength (>60% of MVIC), low intensities (30% and 50% MMT) appeared sufficient to affect the back muscles, but for the abdominals higher resistance (70% MMT) was required. In contrast to the other back muscles, the lumbar multifidus demonstrated high activity levels during both the extension and the flexion exercises. As the lumbar multifidus is demonstrated to be an important muscle in segmental stabilization of the lumbar spine, this finding may help in understanding the efficacy of rehabilitation programs using specific training devices.

Abdominal Muscles↗
PubMed2005

Statistical modelling of fatigue-related electromyographic median frequency characteristics of back and hip muscles during a standardized isometric back extension test.

The purpose of the present study was to evaluate which statistical model - linear, logarithmic, quadratic or exponential - best described the fatigue-related electromyographic (EMG) changes of back and hip muscles. Twenty healthy volunteers performed a modified Biering-Sorensen test. The EMG activity of the latissimus dorsi (LD), longissimus thoracis pars thoracis (LTT) and lumborum (LTL), iliocostalis lumborum pars thoracis (ILT) and lumborum (ILL), multifidus (MF), gluteus maximus (GM) and biceps femoris (BF) was measured bilaterally using surface electrodes. Higher R(2) values were found for the quadratic models (p<0.05 for all muscles), and lower R(2) values for the logarithmic models (p<0.05 for LTT, LTL, ILL, MF and GM). The exponential models generated higher R(2) values compared to the linear ones for the LTT, LTL and MF (all p<0.05). Further analyses revealed, however, that these models did not add useful additional information, and therefore would only increase the complexity. The findings of the current study validate the use of simple linear regression techniques when studying fatigue-related EMG median frequency characteristics of back and hip muscles during isometric contractions.

Adult↗
PubMed2005

Assessment of the paraspinal muscles of subjects presenting an idiopathic scoliosis: an EMG pilot study.

BACKGROUND: It is known that the back muscles of scoliotic subjects present abnormalities in their fiber type composition. Some researchers have hypothesized that abnormal fiber composition can lead to paraspinal muscle dysfunction such as poor neuromuscular efficiency and muscle fatigue. EMG parameters were used to evaluate these impairments. The purpose of the present study was to examine the clinical potential of different EMG parameters such as amplitude (RMS) and median frequency (MF) of the power spectrum in order to assess the back muscles of patients presenting idiopathic scoliosis in terms of their neuromuscular efficiency and their muscular fatigue. METHODS: L5/S1 moments during isometric efforts in extension were measured in six subjects with idiopathic scoliosis and ten healthy controls. The subjects performed three 7 s ramp contractions ranging from 0 to 100% maximum voluntary contraction (MVC) and one 30 s sustained contraction at 75% MVC. Surface EMG activity was recorded bilaterally from the paraspinal muscles at L5, L3, L1 and T10. The slope of the EMG RMS/force (neuromuscular efficiency) and MF/force (muscle composition) relationships were computed during the ramp contractions while the slope of the EMG RMS/time and MF/time relationships (muscle fatigue) were computed during the sustained contraction. Comparisons were performed between the two groups and between the left and right sides for the EMG parameters. RESULTS: No significant group or side differences between the slopes of the different measures used were found at the level of the apex (around T10) of the major curve of the spine. However, a significant side difference was seen at a lower level (L3, p = 0.01) for the MF/time parameter. CONCLUSION: The EMG parameters used in this study could not discriminate between the back muscles of scoliotic subjects and those of control subject regarding fiber type composition, neuromuscular efficiency and muscle fatigue at the level of the apex. The results of this pilot study indicate that compensatory strategies are potentially seen at lower level of the spine with these EMG parameters.

Adolescent↗
PubMed1995

Dorsal ramus irritation associated with recurrent low back pain and its relief with local anesthetic or training therapy.

Nerves leave the spinal cord as mainly motor primary rootlets and sensory rootlets. These join to nerve root before leaving the spinal canal. After the root canal, the nerve root branches into the ventral root, which contains sensory and motor fibers innervating the extremities, and the dorsal root, that is, the dorsal ramus, which innervates the posterior structures, for example, back muscles: the dorsal ramus itself may become irritated (dorsal ramus syndrome). Especially predisposed to entrapment is the medial branch of the dorsal ramus, which innervates the multifidus muscle and also contains pain fibers. Here we describe the influence of local anesthesia and back-muscle-training therapy on subjective and objective pain parameters in 21 low-back-pain patients who had similar clinical status and neurophysiologic findings and whose recurrent low back pain was most apparently associated with dorsal ramus neuropathy, without any radiologic or neurophysiologic evidence of more proximal ventral nerve root damage in the spinal cord or at the nerve root origin. After treatment, all were pain free and back muscle activity during lumbar-pelvic rhythm was normalized.

Adult↗
PubMed2004

Associations between the prion protein genotype and performance traits of meat breeds of sheep.

The prion protein (PrP) genotypes of four German meat breeds of sheep were examined in relation to their scores for muscle mass, conformation, wool quality, daily liveweight gain and ultrasonic measurements of the depth of back muscle and back fat. The dataset included 912 genotyped German texel sheep among 10,383 recorded sheep, 474 genotyped Suffolk sheep among 4079 recorded sheep, 271 genotyped German white-headed mutton sheep among 3393 recorded sheep, and 99 genotyped German black-headed mutton sheep among 1642 recorded sheep. The model included the fixed effects of PrP genotype, herd, year and season, test day, sex, rearing method, the regression coefficient of average age, and the random additive genetic effect of the animal. In all four breeds there were no statistically significant associations between these performance traits and the occurrence of ARR alleles and the ARR/ARR genotype except for the depth of back muscle and the daily liveweight gain of German black-headed mutton sheep; however, in this breed, the interpretation could be affected by the small number of animals involved. All the genotyped sheep had significantly better performance traits than the non-genotyped sheep.

Animals↗
PubMed2005

[Effect of acupuncture treatment for a patient with severe axial dystonia appearing during treatment for schizophrenia].

We performed acupuncture treatment on first consultation for a female 28-year-old patient with severe axial dystonia, causing involuntary movement and abnormal posture of the neck and body, which had developed during treatment for schizophrenia. Involuntary movement involving elevation of the right shoulder began to occur in October X-1. Drugs were prescribed by her doctor, but her involuntary movement worsened and spread to the whole body. Thereafter, she began receiving acupuncture treatment at the out patient clinic for dystonia at the Kansai Medical College Hospital in July X. Involuntary movements of her neck involved repeated left lateral bending or a rigidly straight posture while sitting and standing. Her neck also showed a left lateral bend and right rotation. Her body showed a left lateral bend and right shoulder elevation. The neck problems in this case were induced by a hypertonicity of the left sternocleidomastoid (SCM), which caused the left lateral bending and right rotation of the neck. Problems in her body involved left lateral bending due to hypotonicity of the left abdominal muscle and hypotonicity of the left back muscles, which were unable to control the left lateral bending of the body. The right shoulder elevation was caused by a hypertonicity of the right trapezius and this was another of her problems. Acupuncture treatments were given using a penetrating needle method. The treatment points were left LI4 to decrease the hypertonicity of the left SCM, left ST41 to increase the hypotonicity of the left abdominal muscles, right BL60 to increase the hypotonicity of the right back muscles and right TE5 to decrease the hypertonicity of the right trapezius. At the initial stage of acupuncture treatment, the patient was not able to attend the hospital regularly enough to obtain sufficient improvement by acupuncture. In December X+1, she started to receive acupuncture treatment weekly, and the posture of the neck and body improved. In May X+3, her neck and body postures remained erect while sitting and she did not show involuntary movement. For problems of dystonia, we perform acupuncture treatment, using meridian and acupressure points selected based on the oriental medicine system, and we achieved improvement of symptoms in this case. The patient also achieved improved stability with regard to the symptoms of schizophrenia. It is suggested that acupuncture treatment has had a positive effect on tardive dystonia including axial dystonia.

Acupuncture Therapy↗