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At least 1,081 records · Page 60Linked to original sources
PubMed1999

Endurance training of the trunk extensor muscles in people with subacute low back pain.

BACKGROUND AND PURPOSE: Clinicians treating patients with low back pain often use exercise to reduce pain and improve function. The aim of this study was to evaluate the effectiveness of trunk extensor endurance training in reducing pain and decreasing disability in subjects with subacute low back pain (ie, onset of back pain within 7 days to 7 weeks). SUBJECTS AND METHODS: Patients were randomly assigned to either an experimental group or a control group. A visual analog scale and the pain rating index (PRI) of the McGill Pain Questionnaire (MPQ) were used to obtain baseline measurements of pain. The Roland Morris Disability Questionnaire (RMDQ) was used to measure disability, and the Sorensen Test was used to measure trunk extensor endurance. Subjects in the experimental group attended exercise sessions 3 times a week for 6 weeks. Subjects in the control group did not do exercises. Both groups were given back care advice and hot packs for 15 minutes, 3 to 5 times per week. Reassessments were carried out at 3 and 6 weeks. RESULTS: There were differences between the 2 groups at 3 weeks in regard to pain intensity during the evaluation session and pain experienced over the preceding 24 hours, the total MPQ PRI, the sensory component of the MPQ PRI, and the RMDQ. At 6 weeks, no differences were found for pain measurements, disability scores, and holding time on the Sorensen Test. CONCLUSION AND DISCUSSION: Trunk extensor endurance training reduced pain and improved function at 3 weeks but resulted in no improvement at 6 weeks when compared with the control group. Endurance exercise is considered to expedite the recovery process for patients with an acute episode of low back pain.

Adult↗
PubMed2002

Rigid spine syndrome with chronic respiratory failure.

Rigid spine syndrome (RSS) is a rare myopathic ailment characterized by mild axial and proximal muscle weakness. Muscle contraction in these patients causes limitation of neck and trunk flexion, scoliosis, and mild joint deformity. We report the case of a 30-year-old man with RSS who presented with severe restrictive ventilatory defect (forced vital capacity, 1.53 L, 39% of predicted), mild scoliosis (Cobb's angle 12), proximal muscle weakness and stiff back. Creatine phosphokinase was 986 IU/L. Muscle biopsy of the right vastus lateralis revealed increased variation in muscle fiber diameter, proliferation of endomysium, and type I fiber atrophy. Round and whorled fibers indicating myopathic change were found on sections stained with nicotinamide adenine dinucleotide dehydrogenase and succinate dehydrogenase. RSS was diagnosed based on myopathic findings and clinical presentation. Nocturnal chronic respiratory failure and fragmented sleep developed. He was treated with continuous positive airway pressure and had recovered his normal daily activity by 1-year follow-up. We suggest that patients with RSS should be assessed for possible ventilatory failure; treatment with nasal continuous positive airway pressure or bilevel continuous positive airway pressure therapy should be considered.

Adult↗
PubMed1976

[Condition of the nervous elements of skeletal muscle in Duchenne myopathy].

In order to determine the role of the nervous system in the pathogenesis of myopathy, the author examined the nervous apparatus in a bioptate of the widest muscle of the back in 8 patients with Duchenne's myopathy and in some other muscles in one post-mortem case of the same disease. The morphological changes in the nervous structures of skeletal muscles were expressed in signs of irritation, substituted by destruction which began in the terminal parts and was more expressed in the atrophized muscles. Besides there were symptoms of excessive growth of the nervous filaments especially in the initial phases of the process. The regenerating nervous filaments are subjected to destruction and do not provide an innervation of the muscles.

Adolescent↗
PubMed1997

Reliability of lumbar dynamometry measurements in patients with chronic low back pain with test-retest measurements on different days.

Lumbar dynamometry is a potentially useful method for assessing the state of trunk muscles in low back pain (LBP) patients. The purpose of this study was to assess the reliability of lumbar dynamometry measurements in chronic LBP patients by conducting test-retest measurements on different days. Thirty-one men and 14 women with chronic LBP participated in this study. The experiments consisted of three sets of lumbar dynamometry measurements (Isostation B200) carried out on three different days with a 2- to 3-day interval. A standard protocol was administered to all subjects, consisting of a range-of-motion measurement about each axis, a 5 s maximum isometric trial about each axis and five dynamic repetitions about each axis against a resistance set at 25% and at 50% of the maximum isometric torque. Correlation coefficients and regression analysis were used to detect possible learning effects. One-way anova and regression analysis were used to assess the reliability of the measurements. High coefficients were found for the correlation between the first and second lumbar dynamometry measurements. Regression analysis showed that the differences between those measurements were not significant. This means that there was no learning effect operating between the first and second lumbar dynamometry measurements. One-way anova showed a reliability higher than 0.90 for the torque and velocity parameters. Reliability for the range-of-motion parameters was somewhat lower: between 0.76 and 0.94. Regression analysis showed no significant differences between the second and third measurements for the torque and velocity parameters. For range-of-motion parameters significant differences were found. From this study it can be concluded that the Isostation B200 provides reliable measures of torque and velocity parameters, but measures of the range-of-motion parameters are unreliable. No learning effect operates between the first and second lumbar dynamometry measurements, which means that a single measurement, with prior warming up and practice, is sufficient to assess the performance of the LBP patient.

Adult↗
PubMed1979

Interstitiospinal action on forelimb, hindlimb, and back motoneurons.

Responses of motoneurons supplying muscles of the forelimbs, hindlimbs, and back to stimulation of the interstitial nucleus of Cajal (INC) were recorded intracellularly in cats under chloralose anesthesia. Stimulation of the ipsilateral and contralateral INC evoked predominantly excitatory postsynaptic potentials in these motoneurons. Response latencies and properties of responses to multiple shock stimuli indicated that the responses were evoked by a di- or polysynaptic pathway. Stimulation of the anterior MLF (P2), which should have activated the entire interstitiospinal tract, but few reticulospinal or vestibulospinal fibers, evoked only polysynaptic responses. These results indicate that the INC does not establish direct synaptic connections with limb and back motoneurons.

Animals↗
PubMed1994

Supercharged latissimus dorsi muscle flap for coverage of the problem wound in the lower back.

Described is the "supercharging" of a latissimus dorsi muscle flap for coverage of an irradiated nonhealing wound of the lumbar area of the back. Nonhealing wounds of the lower back pose difficult management problems. In the face of radiation therapy, infection, and the presence of foreign materials, they can have the potential for disastrous outcomes. Exposed bone and prosthetic materials in an irradiated bed were covered by turning a latissimus dorsi muscle flap over its lower paraspinous origin and anastomosing the thoracodorsal artery and vein to the ipsilateral superior gluteal vessels. Postoperatively, the patient's wound healed without incident, and the muscle flap and skin graft provided a stable and durable reconstruction. Subsequent duplex Doppler imaging demonstrated a significant inflow to the flap from the superior gluteal artery and vein anastomosed to the thoracodorsal artery and vein of the muscle.

Back↗
PubMed1995

[Backward fall in Alpine skiing. Case study of the effect of the back spoiler of the ski shoe on muscle activity and kinematics].

For the investigation of the boot-induced anterior cruciate ligament injury and experimental case study with a prototype ski boot was performed. The back spoiler of this boot was designed to yield by only some degrees with a certain level of backward moment. A mechanical switch allowed to activate or to block this mechanism. Ten jumps over a prepared hill with activated and ten jumps with blocked spoiler mechanism were performed in randomised order. During the jump and landing the EMG of eight lower extremity muscles were recorded and synchronised to two S-VHS cameras suitable for 2D-analysis of the angle kinematics. The aim of these experiments was to quantify the muscular and kinematic effects caused by the new spoiler characteristics and also to establish a method for their judgement. For the quantification of the muscular effects an activity quotient was defined and for the analysis of the kinematics the time history of three body angles and their variation between the trials were found to be appropriate. The results of this case study showed an increase of the activity quotient for all observed muscles and a higher accuracy of motion with the activated spoiler mechanism. These findings an be taken as an indication for better muscular joint guiding in the knee and justify a randomised field study using the proposed methods.

Adult↗
PubMed1984

Personal characteristics and back injury among hospital nursing personnel.

Since back injury is the largest workman's compensation claim in most industries, the relationship between selected personal characteristics and back injury in hospital nursing personnel were studied. The sample included 64 female nursing personnel, half back injured and half not. Demographic: Workers were more likely to be back injured if they were older, worked longer on nursing units requiring frequent lifting, had family members with back problems, and had family members whose back problems began at an early age. Physical: The back injured had less muscle flexibility, less keen proprioception, and greater unequal leg length. Life style: Back injured were more vulnerable to frustration and stress overload (overstimulation), smoked more cigarettes, spent fewer hours exercising, and rated their physical condition lower. The variables with the greatest discriminatory power to predict back injury were a sense of overload, muscle flexibility, proprioception, family history of back problems, difference in leg length, years of risk in nursing practice, and smoking.

Adult↗
PubMed1988

Calcium concentration in the myoplasm of skinned ferret ventricular muscle following changes in muscle length.

1. Ferret ventricular muscles were skinned by prolonged application of Triton X-100. Aequorin was allowed to diffuse into the myoplasmic space and the resulting light emission was used to monitor the myoplasmic [Ca2+]. The muscle was then activated with a lightly buffered Ca2+ solution and the changes in myoplasmic [Ca2+] and tension in response to length changes were investigated. 2. A sudden reduction in muscle length led to a rapid increase in myoplasmic [Ca2+] to a new level which was maintained as long as muscle length was reduced and which was reversed when the muscle was stretched back to the control length. The rate of increase of [Ca2+] when the muscle length was reduced was greater than the rate of decrease in [Ca2+] when the muscle was stretched. 3. Increasing the concentration of EGTA in the activating solution, so as to increase its Ca2+-buffering capacity, eliminated the changes in myoplasmic [Ca2+] in response to a length change but had little effect on developed tension. 4. On stretching the muscle there was a slow component of recovery of tension with a time course broadly similar to the rate of decrease of myoplasmic [Ca2+]. The time course of tension redevelopment and of the accompanying reduction in myoplasmic [Ca2+] both decreased to a similar extent when the [Ca2+] used to activate the muscle was increased. 5. Step reductions of length of increasing amplitude caused increases in myoplasmic [Ca2+] which were larger in proportion to the size of the step. 6. Step reductions of length of equal size but from different starting lengths caused changes in myoplasmic [Ca2+] the amplitude of which correlated with the change in tension rather than the change in length. 7. The increase in myoplasmic [Ca2+] when muscle length is reduced suggests that Ca2+ is released from a site in the muscle, probably troponin C. The time course and magnitude of the changes in myoplasmic [Ca2+] correlate more closely with the changes in developed tension than muscle length.

Aequorin↗
PubMed2003

Primary position and listing's law in acquired and congenital trochlear nerve palsy.

PURPOSE: In ocular kinematics, the primary position (PP) of the eye is defined by the position from which movements do not induce ocular rotations around the line of sight (Helmholtz). PP is mathematically linked to the orientation of Listing's plane. This study was conducted to determine whether PP is affected differently in patients with clinically diagnosed congenital (conTNP) and acquired (acqTNP) trochlear nerve palsy. METHODS: Patients with unilateral conTNP (n = 25) and acqTNP (n = 9) performed a modified Hess screen test. Three-dimensional eye positions were recorded with dual search coils. RESULTS: PP in eyes with acqTNP was significantly more temporal (mean: 21.2 degrees ) than in eyes with conTNP (6.8 degrees ) or healthy eyes (7.2 degrees ). In the pooled data of all patients, the horizontal location of PP significantly correlated with vertical noncomitance with the paretic eye in adduction (R = 0.59). Using a computer model, PP in acqTNP could be reproduced by a neural lesion of the superior oblique (SO) muscle. An additional simulated overaction of the inferior oblique (IO) muscle moved PP back to normal, as in conTNP. Lengthening the SO and shortening the IO muscles could also simulate PP in conTNP. CONCLUSIONS: The temporal displacement of PP in acqTNP is a direct consequence of the reduced force of the SO muscle. The reversal of this temporal displacement of PP, which occurs in some patients with conTNP, can be explained by a secondary overaction of the IO muscle. Alternatively, length changes in the SO and IO muscles, or other anatomic anomalies within the orbit, without a neural lesion, may also explain the difference in location of PP between conTNP and acqTNP.

Adaptation, Ocular↗
PubMed2001

Lumbar back and posterior pelvic pain during pregnancy: a 3-year follow-up.

This study is a prospective, consecutive, 3-year cohort study of women with back pain in an index pregnancy. The aim was to describe the physical status and disability among women with back pain 3 years after delivery. Pain was identified as lumbar back pain, posterior pelvic pain or combined lumbar as well as posterior pelvic pain. Previous studies have established that all three types of pain can be reduced by structured physiotherapy during pregnancy, and the beneficial effect may last for several years. Though it is known that some women have residual pain for a long time, the relative incidence of the three pain types and their degree of disability associated with each have never been reported. Neither has any study presented findings of a physical examination of women 3 years post partum with a focus on the type of pain. All women who were registered as having experienced back pain during an index pregnancy were interviewed by mail 3 years post partum. Women who had residual back pain filled in an additional questionnaire and were physically examined. Out of 799 pregnant women, 231 had some type of back pain during the index pregnancy, and 41 women had pain 3 years later. Women with combined lumbar and posterior pelvic pain were significantly more disabled ( P<0.05) and had significantly lower endurance in the lumbar back and hip abduction muscles ( P<0.01). Some 5% of all pregnant women, or 20% of all women with back pain during pregnancy, had pain 3 years later. The key problem may be poor muscle function in the back and pelvis.

Cohort Studies↗
PubMed2006

[The effect of an exercise program on body composition and physical fitness in obese female college students].

PURPOSE: This study was done to analyze the effects of an exercise program on body composition and physical fitness of obese female college students. METHOD: Data was collected from September 29, 2003 to December, 29, 2003. The research design was a randomized control group pretest-posttest experimental design. The subjects were college nursing students at K University. Forty four students, 20 in the experimental group and 24 ina control group, with more than 30% body fat were randomly assigned. The subjects in the experimental group participated in an exercise program for 12 weeks, sixty minutes per session, five times per week. Body composition and physical fitness was measured by a body composition analyzer, cardiovascular endurance, muscle endurance, muscle strength(grip strength, back strength), flexibility, balance, agility(whole body reaction time) and power(standing long jump). RESULT: Body weight(F=4.76, p=0.035), body fat(kg)(F=5.68, p=0.022) and body mass index(F=5.73, p=0.021) of the experimental group were significantly different from the control group, but there were no significant differences in body fat(%), lean body mass, muscle mass and WHR. Back strength(F=6.50, p=0.015), flexibility(F=14.62, p=0.000), muscle endurance(F=7.98, p=0.007), power(F=5.76, p=0.021) and balance(F=2.46, p=0.018) of the experimental group were significantly different from the control group, but there were no significant differences in cardiovascular endurance, grip strength or agility. CONCLUSION: The exercise program was effective in improving body weight, body fat(kg), body mass index, back strength, muscle endurance, flexibility, balance and power of obese female college students.

Adolescent↗
PubMed1995

A back-propagation neural network model of lumbar muscle recruitment during moderate static exertions.

A model employing artificial neural networks (ANNs) is developed for the prediction of lumbar muscle activity in response to steady-state static external moment loads. The model is constructed using standard feedforward networks and trained with available data using the standard back-propagation algorithm. Training with a limited set of exemplars allowed accurate prediction of muscle activity for novel moment loads (generalization). Sensitivity analyses during training and testing phases showed that the choice of specific network parameters was not critical except at extreme values of those parameters. Model predictions were better correlated with experimental data than predictions made using two optimization-based methods (average r2 = 0.83 using ANNs and 0.65 using optimization). The results suggest that lumbar muscle response varies smoothly and consistently with respect to the magnitude and orientation of external moments, and they also imply an upper limit on the accuracy of muscle activity prediction using only moment loads as input. ANNs present a useful alternative to EMG- and optimization-based approaches by being both 'reality-based' and predictive.

Biomechanical Phenomena↗
PubMed1978

Further observations on back-firing in the motor nerve fibres of a muscle during twitch contractions.

1. The tension developed by a muscle in response to a single supramaximal nerve volley is often the sum of two contractions, the second resulting from re-excitation of some nerve terminals during the first contraction. Re-excitation or back-firing can be prevented if the muscle nerve is stimulated twice with the second volley arriving in the muscle at a time when muscle fibres are still refractory following the first volley (Brown & Matthews, 1960). 2. Back-firing has been studied here in the medial gastrocnemius muscle of the spinal cat and responses have been recorded, either representing the summed activity of the muscle's motor supply or discharges of single functional motor axons. 3. When stimulating at a distance from the muscle, the second of two shocks is effective in suppressing back-firing over a narrower range of stimulus intervals than when stimulating close to the muscle. 4. The amount of back-firing can be reduced by stretching the muscle. At a length corresponding to the optimum for a twitch little if any back-firing remains. 5. Measurements of threshold to electrical stimulation of single functional motor axons suggests that low threshold axons are more likely to show back-firing. In the majority of cases, most or all of the motor units in the muscle have to be active before back-firing can be observed.

Animals↗
PubMed1994

Extraocular muscle surgery in a rabbit model: site of reattachment following hang-back and conventional recession.

To determine the precise site of reattachment of recessed muscles, 4-mm conventional and hang-back recessions of the inferior rectus muscle were performed in 18 albino rabbits. Six weeks later, the distance from the anterior border of the reattached muscle to the insertion was measured both grossly and microscopically. In all cases the operated muscles had advanced minimally from the site of surgical placement. Gross observation showed that the mean forward creep was significantly greater for those rabbits which underwent hang-back recession (1.81 +/- 0.67 mm) than for those that were submitted to the conventional technique (0.83 +/- 0.38 mm). Measurements done on histological sections revealed that the mean distance of the anterior border of the muscle fiber from the reference suture was larger for conventional recession (2.73 +/- 0.75 mm) than for hang-back recession (1.91 +/- 0.72 mm).

Animals↗
PubMedDate not supplied

Activation of flexor and extensor trunk muscles in hemiparesis.

OBJECTIVE: The purpose of this work was to study the bilateral activity of trunk flexor and extensor muscles in post-stroke hemiparetic patients. DESIGN: Criterion variables were degree of temporal synchronization and level of electromyographic activity in pertinent muscle pairs during two symmetrical tasks: (1) from reclined sitting, bringing the trunk forward; (2) during upright sitting, shrugging shoulders, and extending back. The recti abdomini and external oblique muscles were tested as prime movers of the first task, and the lumbar erector spinae and latissimus dorsi muscles were tested in the second task. Electromyographic recordings from these muscles during three repetitions of each exercise were used for analysis. RESULTS: Cross-correlation analysis pointed to higher temporal synchronization between the abdominal muscles than between the back extensor muscles and in axial compared with para-axial muscles. Differences between patients and controls were found only for the erector spinae muscle pair, which indicates less synchronous activity between the two sides in the patients. The average electromyographic activity level was comparable for corresponding abdominal muscles, both in the patients and in the control subjects. Regarding the back extensor, side differences were detected for the latissimus dorsi muscles in both groups, with the paretic and right side less active in the patients and controls, respectively. CONCLUSIONS: Altogether, the findings do not support the claim of unilateral deficits in the function of trunk muscles in post-stroke hemiparetic patients. They emphasize the need for further characterization of the impairment of trunk extensor and flexor muscles in post-stroke patients.

Abdominal Muscles↗