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Biomedical subjects

U Moritz

Publications and source records attributed to U Moritz.

At least 73 records · Page 4Linked to original sources

L-carnitine and haemodialysis: double blind study on muscle function and metabolism and peripheral nerve function.

Twenty-eight haemodialysis patients were randomized to L-carnitine, 2 g i.v. three times a week, and saline over a 6-week period. No obvious deficiency of carnitine was found in vastus lateralis with a median value of 12.9 mmol/kg dry weight; range 6.2-21.4. Female patients had lower total plasma carnitine compared to female controls, p less than 0.002, whereas no decrease was found in males. No relationship was found between muscle and total plasma carnitine. After carnitine administration the muscle carnitine level increased about 60%, p less than 0.01, and the total plasma carnitine level more than tenfold, whereas the initially high degree of acylation decreased, p less than 0.02. Maximum dynamic muscular strength was reduced with a mean value of 44% compared with healthy controls. Total metabolic activity of isolated skeletal muscle fibres, measured as heat production with a new technique using a perfusion microcalorimeter, showed a median value of 0.40 mW/g, 25% lower than normal, p less than 0.02. Carnitine administration had no effect on several different tests of muscular function. Neurophysiologically, discrete improvements in the temperature responses were recorded, but no changes in sensory and motor nerve conduction velocities or in vibration thresholds were noted. No symptomatic improvement was observed even in patients with the lowest carnitine levels prior to treatment. Our data do not support the hypothesis that carnitine deficiency contributes to muscle and nerve dysfunction in patients on chronic haemodialysis.

Adult↗

Intra-abdominal pressure and trunk muscle activity during lifting. III. Effect of abdominal muscle training in chronic low-back patients.

Isometric training of the abdominal muscles is often recommended in programs of primary or secondary prevention for low-back pain. In this study 20 male workers with 2-18 years' history (average 5 1/2 years) of low-back pain without sciatica went through intense isometric abdominal muscle training for 5 weeks. Before and after training the subjects had trunk flexion and extension strength tests and a series of standardized lifts. The intraabdominal pressure (IAP) and the EMG activity of the oblique abdominal muscles, and of the erector spinae muscle were recorded. It was found that: the strength of the abdominal muscles increased; the increased strength was correlated to an improved recruitment of motor units in the oblique abdominal muscles; the EMG activity of the oblique abdominal muscles when lifting decreased after training, i.e. the acquired ability to recruit more motor units was not made use of; the IAP at lifting was generally not affected. A better knowledge of the mechanisms responsible for the IAP in different situations is needed to support advice on training or other prevention.

Abdomen↗

Intra-abdominal pressure and trunk muscle activity during lifting. IV. The causal factors of the intra-abdominal pressure rise.

The intra-abdominal pressure (IAP) has been regarded as important for stabilization and relief of the lumbar spine when exposed to heavy loads, such as when lifting. Previous trials, however, have failed to increase the IAP by abdominal muscle training. Twenty healthy subjects, 20 low-back patients and 10 weight-lifters, were tested with various breathing techniques in order to elucidate the causal factors of the IAP rise during lifting and the effects respiration. Those with high IAP and low IAP as well as those with great variations in IAP underwent an extended program. The intra-abdominal and intrathoracic pressures and the EMG of the oblique abdominal, the erector spinae and--in some cases--the puborectalis muscles, were recorded. The transdiaphragmatic pressure was calculated both during lifting and during the Mueller manoeuvre. The IAP rise during lifting seems to be correlated to a good coordination between the muscles surrounding the abdominal cavity. Of these, the diaphragm seems to be the most important for the IAP level. Closure of the glottis seems to help the diaphragm to maintain the IAP rise, otherwise the respiration type seems to be less important for the IAP during lifting.

Abdomen↗

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↗

Intraabdominal pressure and trunk muscle activity during lifting--effect of abdominal muscle training in healthy subjects.

Isometric training of the abdominal muscles is recommended as a preventive measure against low back complaints in the hope that the increased strength of the abdominal muscles should result in an increased intraabdominal pressure when lifting. There is, however, neither experimental nor clinical proof of this hypothesis. Twenty healthy young men went through intense isometric training of the abdominal muscles for five weeks. Before and after training the subjects were put through a standardized test programme, measuring the strength of abdominal and back muscles, and a series of lifts, 10, 25, and 40 kg, leg lifts and back lifts. The intraabdominal pressure (IAP), and the EMG activity of the oblique abdominal muscles, and of the erector spinae muscle were recorded. It was found that: The strength of the trunk flexors increased markedly after training. The activity of the oblique abdominal muscles when lifting decreased after training, i.e. motor unit recruitment was not improved. The IAP at lifting was not affected by training. The activity of the oblique abdominal muscles was of no decisive importance to the IAP. The strength of the back muscles increased, but the activity of the back muscles at lifts was not affected by training. In back lifts there was no detectable activity of the back muscles during the beginning of the lifting and during a great part of the lowering. In back lifts the maximum activity of the abdominal muscles appeared long before the peak of the IAP which may be of importance with regard to the pathogenesis of inguinal hernia. Further investigation is needed, both to study the effect of training on patients with back complaints, and to study the factors determining the IAP.

Abdomen↗

Physical therapy and rehabilitation.

The literature on physical therapy and rehabilitation in osteoarthrosis of the hip and knee joint has been reviewed. The number of controlled clinical studies is rather limited and the clinical material is generally not clearly defined. It may be concluded, however, that the effect of short-wave, micro-wave and ultrasound on joint pain is not superior to that of sham treatment. Ice therapy and transcutaneous nerve stimulation appear to be of definite value, but the effect is transient. Controlled trials indicate that mobilization of joint and muscle contractures is facilitated by diathermy and ultrasound. Training of muscle function should include training of endurance and balance reaction. Technical aids and training of activities of daily living are an important part of the rehabilitation program, that has to be based on the functional problems experienced by the patient.

Bone Diseases↗

Evaluation of manipulation and other manual therapy. Criteria for measuring the effect of treatment.

In order to evaluate manipulation and other methods of manual therapy, the literature was reviewed. It was found that the number of publications based on scientific criteria is rather limited. However, with certain reservations it can be concluded that manipulation of the lumbar spine might have an immediate, short-time effect on low back pain in a limited number of patients. The criteria for selection, however, cannot be defined on the basis of the available material. Manipulation has no superior long-term effect as compared to other methods of treatment. The effect of specific, non-manipulative mobilization of the cervical and lumbar spine needs further elucidation. Manual therapy in decreased mobility of the extremity joints has received support from control studies.

Back Pain↗