[Influence of sports mechanic demands in competitive tennis on the thoracolumbar spinal profile]

The aim of this study was to evaluate the influence of the sports mechanic demands of competitive tennis on the thoracolumbar spinal profile. For that reason the spinal curvature (C7 - S2) of 123 male active gymnasts aged 23,8 +/- 4,5 years with a sporting exposure of 14,4 +/- 3,8 years and of 1347 age and gender matched non- and recreational sportsmen was recorded by means of the non-invasive ultrasonic-controlled contact rod. In the sagittal projection no differences between both groups were found. However, in control and sports group the dominant side of the arms induced statistically significant differences for all parameters describing spinal curvature in the frontal and transversal plane, data evaluated showed a relevant increase in the tennis group. Furthermore, the criterion both-handed hitting technique in fore and backhand caused an additional extension of lateral inclination, pelvic and pelvic-shoulder tilt as well as pelvic-shoulder rotation to the hitting side of the arms. After examining the sports-specific mechanic strain the measuring values are to interpret as a functional adaptation to the tennis-specific demands. But there is only a reduced correlation with the results of epidemiologic studies taking the incidence and prevalence of spinal injuries in competitive tennis into special account. So the tennis-specific modifications of spinal profile are not to characterise a priori as pathogen.

[Effects of elastic lumbar belts on the effect of a muscle training program for patients with chronic back pain]

QUESTION

Aim of the study was to evaluate the influence of elastic lumbar belts on the effect of muscle training for patients with low back pain.

METHODS

97 male subjects aged from 23 to 42 years with and without low back pain participated in the investigation. The low back pain patients (n = 63) were randomized into a training group without and a training group with elastic lumbar belts and a control group. The subjects with healthy backs (n = 34) were divided age-matched into a training group with elastic lumbar belts and a control group. The three training groups took part in a muscle strenghtening program over 8 weeks. The control groups did not receive any alternative physiotherapeutic treatment. All groups were tested at the beginning, after 8 weeks and further 6 months later.

RESULTS

The data obtained for the control groups remained virtually unchanged over the period of investigation. However, a significant increase of the muscle flexibility of the lower limbs could be proved for the training groups. Furthermore the coordination between the lumbar spine and pelvis when flexing the trunk deeply forward was more leveled out for the training groups with patients suffered low back pain. The results confirmed a reduction for pain severity and for limitations in activities of daily living as well. The modifications for the criteria investigated were significant stronger for the training group with patients using the elastic lumbar belt.

CONCLUSIONS

The effectiveness of the muscle strengthening program for patients with low back pain could be improved significantly by means of the elastic lumbar belt as an applicable therapy instrument in the functional rehabilitation of spinal injuries.

Hints of a functional connection between the neuropeptidergic innervation of arteriovenous anastomoses and the appearance of epithelioid cells in the rabbit ear

Peripheral blood flow can be regulated by specialized vessel segments, the arteriovenous anastomoses. Their wall consists of a relatively thick layer of smooth muscle cells and so-called epithelioid cells. The epithelioid cell is a specialized myogenic cell phenotype expressing nitric oxide synthase. We studied the innervation of the different segments of arteriovenous anastomoses in the rabbit ear using antisera against neuropeptide Y, tyrosine hydroxylase, calcitonin gene-related peptide and substance P, as well as neuron-specific enolase, calbindin D and neurotubulin. The participation was especially examined of neuropeptidergic innervation and a possible morphological connection to the occurrence of epithelioid cells and a paracrine function. The NADPH diaphorase reaction and alpha-smooth muscle actin immunoelectron microscopy served to distinguish epithelioid cells from smooth muscle cells. Using conventional fluorescence microscopy and confocal laser scanning microscopy, we found the most dense innervation pattern of pan-neuronal markers (neurotubulin, neuron-specific enolase), tyrosine hydroxylase-immunoreactive nerve fibres and neuropeptidergic nerve fibres (neuropeptide Y, calcitonin gene-related peptide, substance P) around the intermediate segment in arteriovenous anastomoses, whereas the venous segment was barely marked. Single nerve fibres penetrated into the medial layer and reached the epithelioid cells. Using immunoelectron microscopy, we found intercellular contacts between epithelioid cells, but not the gap junction protein connexin 43. Here, we report for the first time a correlation of the innervation pattern with epithelioid cell type in arteriovenous anastomoses. Our findings suggest that epithelioid cells of the arteriovenous anastomoses are controlled by a dense network of neuropeptidergic nerve fibres in functional connection to their paracrine role as a nitric oxide producer.

[Organic fitness and capacity for motor performance of handicapped adolescents in vocational training]

In our modern working world, young adults with disabilities not only face problems in securing employment, but, also, in finding adequate vocational training places. This had in the 1970s lead to the establishment of vocational training institutions. Local employment offices and employers however, again and again complain about poor organic capacity and endurance in young people trained in these centres. It consequently is very difficult for these young people to be placed in the open labour market. A study of the various principal demands on motor functioning and of pulmonary capacity was to clarify the extent to which deficits in motor and cardiopulmonary fitness exist. A total of 328 subjects (mean age 18:5 years), among them 17 wheelchair users, were examined relative to their motor and organic capacity. Significant deficits were found in nearly all component functions compared to nonhandicapped peers, with arm and trunk muscle strength the only exception to this negative performance picture. The motor deficits found were greatest in respect of dexterity and balance. Possible reasons for these motor deficits are discussed, and measures concerning disability-specific sports classes are discussed.

Metabolic adaptation to prolonged exercise

A study was undertaken to evaluate and to examine the role of substrate supply in 50 healthy subjects after long distance events, such as 10 km, 25 km, and marathon races. The metabolic, variables of carbohydrate metabolism were greatest in 10-km runners, with the highest increase in glucose, lactate, and pyruvate, while in marathon runners only moderate changes were observed. Marathon competitors gave the greatest decrease in insulin concentration whereas glucagon and cortisol showed a contrary tendency. As for lipid concentrations, the most remarkable point was that after the marathon competition the best runners had the highest increase in free fatty acids; the longer the race, the higher were the beta-hydroxybutyrate and acetoacetate levels after the competition. It is important to emphasize that the limiting factor up to 90 min duration is the competitor's ability to deplete the stores of glycogen. Beyond 90 min (or 25 km) the decrease in insulin, the rise in cortisol and the higher concentration of ketnne bodies found indicate a change in metabnlic response.

Cardiopulmonary adjustment and metabolic response to maximal and submaximal physical exercise of boys and girls at different stages of maturity

Cardiopulmonary and metabolic variables were investigated at maximal and submaximal bicycle ergometer exercises in 41 swimmers of both sexes, 8--18 years old. VO2 max and VO2 max . HR-1 were higher in boys than in girls and increased with maturity, while VO2 max. kg-1 and HVE were not influenced by this. The HV increased clearly during this growth period, the pubertal and postpubertal subjects showing 16 and 17% higher values for HV and HV . kg-1 than those reported in normal schoolchildren populations. During the submaximal exercise at 70% VO2 max the highest HR values were found in the prepubertal group, whilst the lowest were observed in the postpubertal subjects. These findings suggest that a given percentage of VO2 max as a reference unit, is more reliable than a certain HR to obtain comparable results in subjects with different ages. Blood samples were collected before, during, and after the submaximal exercise. Blood glucose and FFA did not differ in relation to the stages of maturity. During exercise, insulin decreased in prepubertal children, did not alter in pubertal adolescents, and increased in postpubertal subjects. The lactate concentration, during exercise, increased in relation to maturity. The same results were found for HGH, but no differences were found with regard to sex. Since the pattern of HGH secretion during exercise is similar to that found after arginine and insulin administration it is assumed that the same mechanism (i.e., sex hormones) triggers the HGH release.

[Platelet morphology and physical stress (author's transl)]

The morphology of thrombocytes of 45 volunteers in varying conditions of training was analysed under physical stress. The probands were divided in three groups of 15 each. Group X (aged 20-26 years) had occasional gymnastics training. Group Y (aged 44-52 years) was without any physical training, and Group Z consisted of athletes (aged 22-25 years) in good training condition. By means of the platelet aggregation test (PAT), thrombocyte changes were classified in 5 stages: solitary stage (I), accumulation stage (II), degranulation stage (III), fibrin forming stage (IV), irreversible aggregation stage (V). The probands were subjected to ergometer stress in exact dosage. With the exception of the athletes, all blood smears showed a decrease in stage I (solitary), and considerable increase in stages II-V. 5, 30, or 60 min after stress, the return of irreversible aggregates (PAT V), of platelet changes in the fibrin-forming stage (PAT IV), and in the degranulation stage (PAT III), was markedly delayed in Group Y (untrained older persons) when compared with the group of well-trained athletes. The observation may offer an explanation for some cases of acute thrombotic cardiac death among trained athletes. On the other hand, it may prove the better adaptation of the thrombocytic system during physical stress when athletes are in good physical condition.