Post-mortem changes in the colour of pig longissimus dorsi muscle.
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Animals↗
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Correlation of back pain, compression fracture and quadriceps muscle strength with bone mineral density in renal insufficiency patients.
AIM: The purpose of this study was to evaluate bone mineral density (BMD), bone parameters, complete blood count, erythrocyte sedimentation rate, electrolyte values, back pain, compression fracture and quadriceps muscle strength in mild and moderate renal insufficiency patients. METHODS: Thirty-six female, 3 male, patients with the diagnosis of osteoporosis in addition to mild or moderate chronic renal insufficiency who were followed in Istanbul University, Cerrahpasa Faculty of Medicine, Physical Therapy and Rehabilitation Department, Osteoporosis and Nephrology Outpatient Clinics between March 2003 and March 2004, were included in the study. In the control group there were 17 female, 5 male patients with osteoporosis but without renal insufficiency. The inclusion criteria were to have osteoporosis, be aged between 40-70 with a creatinine clearance between 30-70 mL/min in the case group, >70 mL/min in the control group. The patients whose creatinine clearance was <30 mL/min, and whose BMD was normal or osteopenic even though creatinine clearance was >30 mL/min were excluded from the study. RESULTS: There was no significant difference with respect to back pain, compression fracture and quadriceps muscle strength between the 2 groups. The mean value of neck BMD, T and Z score were significantly lower in the case group (P<0.05). CONCLUSIONS: As a conclusion, PTH related bone disease had an important effect on BMD, although, the risk factors for osteoporosis were equally important. In various researches, the relationship between BMD values and history of fracture in renal osteodystrophy patients could not be shown. In our study, the history of prior fracture or fracture in the family were important risk factors for osteoporosis. Renal osteodystrophy patients had low BMD values in mild and moderate stages of the disease. Prior fracture as well as osteoporotic fractures in the family should be part of a comprehensive evaluation of the patient.
Adult↗
Pain-related factors contributing to muscle inhibition in patients with chronic low back pain: an experimental investigation based on superimposed electrical stimulation.
OBJECTIVE: To evaluate muscle strength, as a component of physical deconditioning, and central activation ratio, representing the performance level during testing, in patients with chronic low back pain as compared to healthy controls, and to evaluate the contribution of cognitive-behavioral and pain-related factors to the central activation ration of patients with chronic low back pain. METHODS: Twenty-five patients with chronic low back pain and 25 age and gender-matched controls participated. Muscle strength, that is, peak torque of the quadriceps muscle, was measured on a Cybex dynamometer. During peak torque, the quadriceps muscle was percutaneously stimulated using superimposed electrical stimulation, generating an additional twitch torque in case of submaximal performance. The central activation ratio was calculated as peak torque/(peak torque + additional twitch torque). To evaluate cognitive-behavioral and pain-related factors influencing the central activation ratio, measures of fear of injury, pain catastrophizing, psychologic distress, and pain intensity were used. Differences between groups were tested using either T tests or Mann-Whitney U tests. Associations were tested by partial correlation coefficients controlling for gender. RESULTS: The male:female ratio was 15:10. Mean age and chronic low back pain duration were 42.7 (+/-9.5) and 9.9 (+/-8.3) years, respectively. Mean muscle torque (per kg lean body mass) in patients (1.95 Nm/kg +/-0.8) was less than in controls (3.16 Nm/kg +/-0.7) (P < 0.01). Median central activation ratio was lower in patients (P < 0.05). Patients experiencing increased psychologic distress and patients with a higher current pain level showed a lower central activation ratio (P < 0.05). CONCLUSIONS: When interpreting decreased muscle strength in terms of physical deconditioning in patients with chronic low back pain, submaximal performance has to be taken into account. The results suggest that patients with chronic low back pain who report increased psychologic distress and a higher level of current pain tend to show increased inhibition of muscle activity, leading to submaximal performance.
Adolescent↗
[Preventive back care. The right chair can prevent muscle aches].
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Back Pain↗
Effect of lumbar extensor fatigue on paraspinal muscle reflexes.
Low back disorders are a frequent medical problem. Altered neuromuscular control of the spine has been associated with low back pain, and may contribute to its occurrence. The purpose of this study was to investigate the effect of lumbar extensor fatigue on reflex delay and amplitude in the paraspinal muscles. Ten healthy males (20-22 years of age) were subjected to an anteriorly-directed perturbation applied at the inferior margin of the scapulae while standing quietly before and after a lumbar extensor fatiguing protocol. The fatiguing protocol consisted of multiple sets of back extensions and intermittent isometric maximum voluntary contraction on a Roman chair for 14 min until 60% of unfatigued lumbar extensor MVC was reached. Reflexes were recorded from the paraspinal muscles at the level of L4. Results indicated the mean reflex delay was 60+/-18 ms and was not affected by fatigue (p=0.278). Reflex amplitude increased 36+/-32% with fatigue (p=0.017). The increase in reflex amplitude may reflect an attempt to compensate for losses in muscle force capacity with fatigue in order to maintain sufficient spinal stability. However, additional studies are necessary to investigate the mechanisms of this fatigue-related change in paraspinal reflex.
Adult↗
Intra-abdominal pressure and trunk muscle activity during lifting. II. Chronic low-back patients.
The aim of this study was to compare trunk muscle strength and intra-abdominal pressure during lifting in low-back patients and in healthy controls. Twenty male workers with 2-18 year history (median 5.5 years) of low-back pain went through strength tests of trunk flexion and extension and a series of standardized lifts. The intra-abdominal pressure (IAP) and the EMG activity of the oblique abdominal muscles and of the erector spinae muscles were recorded. The results were compared with those in 20 healthy men exposed to similar loads at work and at leisure. The low-back patients had reduced abdominal muscle strength (-25%) compared with the healthy controls. The IAP during lifting was the same in the two groups despite the difference in abdominal muscle strength. The trunk extension strength was the same in the two groups. The oblique abdominal muscles were only moderately activated during lifting (5-15% of maximum activity with 25 kg) both in low-back patients and in healthy controls. The erector spinae muscle was strongly activated during lifting (40-60% of maximum activity with 25 kg) both in low-back patients and in healthy controls. During backlifting the duration of erector spinae activity varied. Back patients had extended activity compared with the healthy controls. Stiffness seemed to affect the duration of activity in both groups. The oblique abdominal muscles seem to be of no decisive importance to the IAP.
Abdomen↗
Retroperitoneal transposition of rectus abdominis myocutaneous flaps to the perineum and back.
Rectus abdominis myocutaneous flaps may be transposed through the retroperitoneum to reconstruct defects of the back and perineum. Cadaver dissections and clinical cases are presented to demonstrate the surgical technique and reconstructive possibilities of this flap.
Abdominal Muscles↗
Fat content of lumbar paraspinal muscles in patients with chronic low back pain and in asymptomatic volunteers: quantification with MR spectroscopy.
PURPOSE: To prospectively evaluate the fat content of paraspinal muscles by using proton magnetic resonance (MR) spectroscopy in patients with chronic low back pain (LBP) and in asymptomatic volunteers matched with regard to age, sex, and body mass index. MATERIALS AND METHODS: The study was approved by the responsible institutional review board. Informed consent was obtained from each patient and each volunteer. Single-voxel proton MR spectroscopy was used to measure the fat content of the lumbar multifidus and longissimus muscles in 25 patients (13 women, 12 men; mean age, 40.5 years) with chronic LBP and in 25 matched asymptomatic volunteers (13 women, 12 men; mean age, 39.8 years). The fat content was also graded semiquantitatively (grades 0-4). The relationship between fat content and LBP duration, LBP intensity, and self-rated disability was assessed (Pearson correlation). RESULTS: The mean percentage fat content of the multifidus muscle was 23.6% (95% confidence interval [CI]: 17.5%, 29.7%) in patients with chronic LBP and 14.5% (95% CI: 10.8%, 18.3%) in the volunteers (P = .014). The corresponding values for the longissimus muscle were 29.3% (95% CI: 23.4%, 35.3%) in patients with LBP and 26.0% (95% CI: 21.9%, 30.0%) in the volunteers (P = .66). The semiquantitative grading of the fat content of the multifidus muscle was 0 in 12 (48%) of 25 patients and in 14 (56%) of 25 volunteers, 1 in 11 (44%) patients and in eight (32%) volunteers, and 2 in two (8%) patients and three (12%) volunteers. The semiquantitative grading of the fat content of the longissimus muscle was 0 in nine (36%) of 25 patients and 15 (60%) of 25 volunteers, 1 in 13 (52%) patients and nine (36%) volunteers, and 2 in three (12%) patients and one (4%) volunteer. Neither grade 3 nor grade 4 was assigned to any muscle. The grading differences were not significant between patients and volunteers. No significant correlation was found between fat content and pain intensity, pain duration, or self-rated disability. CONCLUSION: Proton MR spectroscopy demonstrates a significantly higher fat content in the multifidus muscle in patients with chronic LBP than in asymptomatic volunteers. No difference was detected with a semiquantitative grading system.
Adipose Tissue↗
Spinal cord-muscle relations: their role in neuro-muscular development in birds.
In the present study we focused our attention on the role of spinal cord-muscle interactions in the development of muscle and spinal cord cells. Four experimental approaches were used: 1) muscle fiber-spinal cord co-culture; 2) chronic spinal cord stimulation in chick embryos; 3) direct electrical stimulation of the denervated chick muscle; 4) skeletal muscle transplantation in close apposition to the spinal cord in chick embryos. The characteristics of mATPase and energetic metabolism enzyme activities and of myosin isoform expression were used as markers for fiber types in two peculiar muscles, the fast-twitch PLD and the slow-tonic ALD. In vitro, in the absence of neurons, myoblasts can express some characteristics of either slow or fast muscle types according to their origin, while in the presence of neurons, muscle fiber differentiation seems to be related to the spontaneous rhythm delivered by the neurons. The in ovo experiments of chronic spinal cord stimulation demonstrate that the differentiation of the fast and slow muscle features appears to be rhythm dependent. In the chick, direct stimulation of denervated muscles shows that the rhythm of the muscle activity is also involved in the control of muscle properties. In chick embryos developing ALD, the changes induced by modifications of muscle tension demonstrate that this factor also influences muscle development. Other experiments show that muscle back-transplantation can alter the early spinal cord development.
Aging↗
Lean body mass and body fat distribution in participants with chronic low back pain.
BACKGROUND: Loss of muscle mass and central obesity progress with aging, but the effect of muscle loss on chronic low back pain has not been precisely evaluated. METHODS: Three hundred thirty Japanese persons aged 45 to 69 years, with a complaint of low back pain for longer than 3 months (n = 203) and age- and sex-matched healthy control subjects (n = 127), were enrolled in this study. Participants with chronic low back pain were classified into the following groups: (1) women with a positive straight leg raise test result, (2) women with a negative straight leg raise test result, (3) men with a positive straight leg raise test result, and (4) men with a negative straight leg raise test result. Controls were classified by sex into a female and a male group. Anthropometric data, consisting of body mass index, percentage body fat, waist-hip ratio, and lean body mass of the upper extremities, trunk, and lower extremities divided by body weight, were measured in participants with low back pain, and the results were compared with those of controls. RESULTS: The waist-hip ratio in women with a negative straight leg raise test result was significantly higher than those in the female control group (P<.001) and in the women with a positive straight leg raise test result (P =.04). The lean body mass of the trunk and lower extremities divided by body weight of women with a negative straight leg raise test result was significantly lower than that of female controls (P =.03 for the trunk and P<.001 for the lower extremities). However, no significant differences were detected between the female negative straight leg raise test result group and the female control group for lean body mass of the upper extremities divided by body weight or body mass index. There were no significant differences in anthropometric data between the male test and control groups or between the female positive straight leg raise test result group and the female control group. CONCLUSION: Trunk and lower extremity loss of muscle mass and central obesity may be risk factors for chronic low back pain without a positive straight leg raise test result in women aged 45 to 69 years. Arch Intern Med. 2000;160:3265-3269.
Adipose Tissue↗
Clinical holistic medicine: chronic pain in the locomotor system.
Most pains from the locomotor system arise due to involuntary, chronic tensions in the muscles or other tissues. When the patient is motivated, the pain is easily cured in most of the cases by using the tools of consciousness-based medicine, primarily therapeutic touch, conversation, and coaching the patient in a positive philosophy of life. The pains are often caused by "blockages" that may cause problems other than just pain. Often it turns out that the blocked areas develop actual physical damage over time: a slipped disk in the back, articular degeneration, or osteoarthritis when the cartilage is affected, can often be explained in this way. Apparently, the exact areas where the blockage is situated cause cellular problems, disrupting cellular order. The holistic process theory of healing and the related quality of life theories state that return to the natural state of being is possible, whenever the person gets the resources needed for existential healing. The resources needed are "holding" in the dimensions of awareness, respect, care, acknowledgment, and acceptance with support and processing in the dimensions of feeling, understanding, and letting go of negative attitudes and beliefs. The preconditions for holistic healing are trust and the intention for the healing to take place. Case stories of holistic treatment of patients with chronic back pain, low back pain, muscle problems, knee pain, and symptoms of rheumatoid arthritis are discussed with exercises relevant for patients with these conditions in the holistic clinic.
Adult↗
Altered abdominal muscle recruitment in patients with chronic back pain following a specific exercise intervention.
The efficacy of specific exercise interventions that advocate training the co-contraction of the deep abdominal muscles with lumbar multifidus for treating chronic back pain conditions has not been tested. A randomized controlled trial involving 42 subjects with a specific chronic back pain condition investigated whether this form of intervention results in changes to the ratio of activation of the internal oblique relative to the rectus abdominis. Data were collected before and after the intervention, using surface electromyography, while subjects performed different abdominal maneuvers. Subjects were randomly allocated to either a specific exercise group or control group. Following intervention, the specific exercise group showed a significant (p < 0.05) increase in the ratio of activation of the internal oblique relative to the rectus abdominis. The control group showed no significant change. The study findings provide evidence that the conscious and automatic patterns of abdominal muscle activation can be altered by specific exercise interventions.
Abdominal Muscles↗
[Ball or chair as seating arrangement in the classroom. A prospective study].
False posture is believed to be connected with sitting habits in school: the child who used to play and run now has to sit in one place. The aim of our study was to determine the value of a new type of seating accommodation--a large plastic ball. During one school year a group of 162 children (ages 8 and 12) used this ball as the only seating accommodation, while another similar group of 148 used normal chairs. At the beginning and the end of the study both groups were examined (muscle testing, modified Matthiass test and balance test). The results suggest a possible effect of the new seating accommodation on the back and abdominal muscles, but on the whole we found little improvement due to the ball alone. When incorporating movement into the classroom context the ball may be helpful. We recommend basic training and supervision of the teachers involved.
Abdominal Muscles↗
Neuronal pathways from group-I and -II muscle afferents innervating hindlimb muscles to motoneurons innervating trunk muscles in low-spinal cats.
Synaptic inputs to motoneurons innervating the back and abdominal muscles in the lumbar part of the body from low-threshold hindlimb muscle afferents were studied in unanesthetized low-spinal cats. At a stimulus intensity of 1.2-1.5x threshold (T), which was sufficient to activate only group-I afferents, the incidence of post-synaptic potentials (PSPs) was higher when stimulating proximal muscle nerves than when stimulating distal muscle nerves (e.g., 52% versus 22% for motoneurons innervating m. iliocostalis lumborum: Ilio MNs; 38% versus 18% for motoneurons innervating m. obliquus externus: OEA MNs). At 2-5 T, at which group-II as well as group-I muscle afferents were presumably stimulated, the PSP incidence increased irrespective of nerves stimulated (e.g., 76% for Ilio MNs; 60% for OEA MNs). The minimal central latencies of EPSPs evoked at 1.2-1.5 T ranged 0.8-16.7 ms for Ilio motoneurons and 1.4 -14.2 ms for OEA motoneurons, indicating that the connection between back and abdominal motoneurons and low-threshold afferents from the hindlimb muscle include a monosynaptic one. The latencies of IPSPs were longer and ranged 1.9-18.8 ms for Ilio motoneurons and 2.4-15.8 ms for OEA motoneurons. Input patterns from various hindlimb muscles varied among individual motoneurons, even though they were within the same motoneuron pool. Such synaptic organization seems to differ from that for the leg motoneuron pool. The overall projection pattern of low-threshold afferents from leg muscles to lumbar back and abdominal motoneurons nevertheless suggests that group-I afferent inputs are related to lateral and vertical movements, and that group-II afferent inputs control the stiffness of the trunk.
Afferent Pathways↗
Analysis of factors that influence rates of carbon monoxide uptake, distribution, and washout from blood and extravascular tissues using a multicompartment model.
To better understand factors that influence carbon monoxide (CO) washout rates, we utilized a multicompartment mathematical model to predict rates of CO uptake, distribution in vascular and extravascular (muscle vs. other soft tissue) compartments, and washout over a range of exposure and washout conditions with varied subject-specific parameters. We fitted this model to experimental data from 15 human subjects, for whom subject-specific parameters were known, multiple washout carboxyhemoglobin (COHb) levels were available, and CO exposure conditions were identical, to investigate the contributions of exposure conditions and individual variability to CO washout from blood. We found that CO washout from venous blood was biphasic and that postexposure times at which COHb samples were obtained significantly influenced the calculated CO half times (P < 0.0001). The first, more rapid, phase of CO washout from the blood reflected the loss of CO to the expired air and to a slow uptake by the muscle compartment, whereas the second, slower washout phase was attributable to CO flow from the muscle compartment back to the blood and removal from blood via the expired air. When the model was used to predict the effects of varying exposure conditions for these subjects, the CO exposure duration, concentration, peak COHb levels, and subject-specific parameters each influenced washout half times. Blood volume divided by ventilation correlated better with half-time predictions than did cardiac output, muscle mass, or ventilation, but it explained only approximately 50% of half-time variability. Thus exposure conditions, COHb sampling times, and individual parameters should be considered when estimating CO washout rates for poisoning victims.
Carbon Monoxide↗
Body composition and the evolution of the Macropodidae (Potorous, Dendrolagus, and Macropus).
The segmental distribution of body weight and the proportions of skin, muscle, and bone are compared for three genera of the Macropodidae (Potorous, Dendrolagus, and Macropus) and one genus of the Petauridae (Pseudocheirus). Potorous and Macropus possess high proportions of muscle mass to total body weight, high concentrations of musculature in the lumbar extensors, thigh, and tail, and disproportionate ratios of forelimb: hindlimb bone and forelimb: hindlimb muscle which correspond to disproportions of intermembral length. These species converge with high-speed terrestrial runners in some traits and remain distinctive in others. Macropus, larger, more muscular, and faster than Potorous, appears to store and return energy to the hopping cycle more efficiently. Dendrolagus has less than three-fourths the musculature of the other macropod genera, low proportions of the back extensor muscles compared to the other macropods, and relatively more equal ratios of forelimb:hindlimb bone and forelimb:hindlimb muscle. This species converges with slow-moving arboreal climbers such as Pseudocheirus. These data on body mass and tissue proportions translate directly into center of gravity, strength-to-weight ratio, and muscular (kinetic) chains, key elements of macropod evolution. The geometric similarity of muscle between smaller potoroids and larger macropodids, and assumption critical to allometric comparison, is not confirmed.
Adaptation, Biological↗
Trunk muscle responses to demands of an exercise progression to improve dynamic spinal stability.
OBJECTIVES: To compare relative activation amplitudes among abdominal and trunk extensor muscle sites of healthy people performing a leg-loading exercise protocol aimed at progressively challenging spinal stability. DESIGN: A prospective, comparative, repeated-measures design. SETTING: Motion analysis research laboratory. PARTICIPANTS: Eighteen healthy male and female volunteers (mean age +/- standard deviation, 23.8+/-3.4y). INTERVENTIONS: Subjects performed 5 progression levels in random order, while surface electromyograms were recorded from 5 abdominal and 2 back extensor muscle sites. Levels 2 through 5 were of interest because they included a leg-extension phase. The root mean square (RMS) amplitude during the leg-extension phase was calculated and normalized to maximal voluntary isometric contractions (MVICs) for each muscle. A 2-factor repeated-measures analysis of variance tested the muscle-by-level interactions and the 2 main effects for the abdominal and trunk extensor sites separately. Bonferroni adjustments were performed on significant results. MAIN OUTCOME MEASURE: Normalized RMS (NRMS) amplitude for each muscle during the leg-extension phase. RESULTS: There were statistically significant muscle-by-level interactions (P<.05) for both abdominal and trunk extensor sites. The relative amplitudes increased for the abdominal muscles and erector spinae muscles among levels, except between levels 3 and 4. Significant differences were found among the abdominal muscle sites for the lower-level exercises (levels 2-4), but not for level 5. The highest NRMS amplitude was at level 5, that is, 40% of MVIC. CONCLUSIONS: The patterns of activation amplitudes differed among levels; therefore, this was not a simple progressive loading protocol because muscles responded in a nonuniform manner to the demands associated with the various levels of progression. Based on the results, the protocol met some of the objectives of dynamic stability protocols.
Adult↗
Isokinetic testing of flexor and extensor muscles in athletes suffering from low back pain.
BACKGROUND: The aim of the study was to verify the usefulness of isokinetic testing in athletes with chronic low back pain (LBP) to obtain quantitative information for rehabilitation purposes. METHODS EXPERIMENTAL DESIGN: a comparative study. SETTING: Physiotherapy Department--Institute of Sports Medicine in Italy. PARTICIPANTS: 50 men, aged 25-65, practising running, cycling, triathlon, tennis, soccer, basketball, volleyball, skiing and golf. The patients were divided into two groups. Group A was treated for 3 months with postural exercises 2 or 3 times a week. Group B was treated for the same period of time with resistive exercises performed by resorting to specific machines. MEASUREMENTS: Before and after treatment, trunk muscle strength was evaluated by means of an isokinetic test carried out in a seated position. The isokinetic measurements used were peak torque (PT), work, power-in the best repetition and total work (TW) in four repetitions. Both the pain and the functional impairment during physical activity was evaluated by subjective visual analogic scale. RESULTS: The PT showed a parallel increase in flexor and extensor muscles in Group A. In Group B it increased by 32.2% at 60 degrees/s and 44.1% at 120 degrees/s as for the extensor muscles while the flexion-to-extension ratio decreased significantly. The TW registered a bigger percentage increase in both groups (+21% at 60 degrees/s and +20.4% at 120 degrees/s in Group A; +36.5% at 60 degrees/s and +50.3% at 120 degrees/s in Group B). CONCLUSIONS: The two rehabilitation programmes had the same effect on the course of LBP, but in Group B we observed a bigger increase in strength which could be potentially useful during a sports activity.
Abdominal Muscles↗