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Biomedical subjects

P Helin

Publications and source records attributed to P Helin.

At least 37 records · Page 2Linked to original sources
PubMed1988

Shoulder strain in keyboard workers and its alleviation by arm supports.

Keyboard work consists mostly of dynamic contractions of the small muscles of the forearms and hands. This is accompanied by continuous activity in the arm, shoulder and neck muscles keeping the head and hand in the correct position. Eliminating the weight from the arm by means of support and the position of the arms influences the electrical activity of shoulder muscles when working at a keyboard. We studied the influence of elbow angle; as well as that of different arm supports, on electrical activity of upper trapezius muscle during keyboard work in healthy workers and persons suffering from shoulder pains. The measurements were carried out in the laboratory. EMG activities, which where measured as mean square root (RMS)-values at every 100-millisecond period in trapezius muscle when working, were lower, the greater the elbow angle. Furthermore electrical activity decreased when subjects used arm supports while working. It is evident that the static load to shoulder muscles can be lowered significantly in keyboard work, when the forearms are at an angle of at least 100 degrees and by using arm supports. The most convienient and ergonomic working position can also be found individually be the method used here.

Adult↗
PubMed1988

Activation in professional ballet dancers.

The purpose of the study was to examine professional ballet dancers' psychophysiological activation in different types of rehearsal and performance. Electrical activity of the trapezius muscle (EMG), blood pressure, heart rate, and skin conductance level were measured. Self-estimated mental tension was evaluated, as was success in the performance. The effect of sex, age, professional experience, artistic status, role, and type of rehearsal and performance was studied. Principals had lower EMG at rest than soloists or corps de ballet dancers. The principals' psychophysiological activation during performance was increased more than that of soloists or corps de ballet dancers as compared to the values at rest. The type of performance had an effect on self-estimated mental tension and psychophysiological responses. During the last general rehearsals (with an audience) physiological activation was higher than on first nights or in other performances or rehearsals.

Adult↗
PubMed1988

Human urinary biogenic amines and some physiological responses during situation stress.

Using a shooting competition as a model, the effect of situation stress on self-assessed mental tension, urinary metanephrine, normetanephrine, 3-methoxy-4-hydroxymandelic acid, 4-hydroxy-3-methoxyphenyl acetic acid and 5-hydroxyindole acetic acid (5-HIAA), as well as heart rate (HR), systolic and diastolic blood pressure (SBP, DBP), skin conductance level (SCL) and electromyographic (EMG) parameters were studied in 7 male and 2 female champion rifle and (rapid-fire and air-)pistol shooters. The sample collection and recordings were carried out first in the training (baseline) circumstances and then during the competition. Self-assessed mental tension was higher than suitable during the competition but good performance was the expectation. During the competition, HR, SBP, DBP, SCL and EMG were increased significantly as compared with the baseline levels. No significant correlations between the variables and between the biogenic amine metabolite excretions were observed. The competition-induced changes in self-assessed mental tension correlated positively with the corresponding changes in SCL (r = 0.63), but negatively with changes in SBP (r = -0.74). The HR of male rapid-fire pistol shooters was higher than that of male rifle shooters (P less than 0.05). All the urinary biogenic amine metabolite excretion levels were increased significantly as compared with the baseline values. Higher metabolite excretion was observed in rifle shooters than in rapid-fire shooters (P less than 0.05). The correlation between catecholamine metabolites was significant (r = 0.67-0.93), but surprisingly the correlation between 5-HIAA and catecholamine metabolites was highly significant (r = 0.80-0.91). This study indicates a marked divergence in the behaviour of various stress-responsive variables during shooting competitions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Leucopenia in adult Still's disease during treatment with azathioprine and sulphasalazine.

The experience is reported concerning treatment of adult Still's disease with a combination of azathioprine and sulphasalazine. In three patients a favourable effect on the symptoms was noted. In one of these patients a year-long prednisone treatment was withdrawn and replaced by sulphasalazine. In all these cases, however, a decrease was seen in leucocyte counts to subnormal levels after the addition of sulphasalazine to a basis therapy with azathioprine 150-200 mg/d (2.1-3.3 mg/kg). The effect was only transitory in two patients, while it lasted several months in the third. In a fourth patient agranulocytosis developed after four days following the combined treatment with azathioprine 150 mg/d (2.3 mg/kg) and 250-1000 mg/d (4-15 mg/kg) of sulphasalazine, lasting four days before recovery. A later resumption of the combination therapy with these same drugs, but in a lower dosage, did not induce any acute changes in leucocyte counts. The skin rash provoked by sulphasalazine in two of the patients did not recur after desensitization. It is concluded, that this combination therapy is valuable in adult Still's disease, but that caution should be exerted during the initiation of sulphasalazine therapy. This should be monitored by daily measurements of leucocyte counts in the first weeks and preferably started by the use of a desensitising kit.

Adult↗
PubMed1987

Relaxation training affects success and activation on a teaching test.

We studied the effects of an audiocassette-relaxation training period (ART) and its timing on success at a teaching test (lecture type), on observed tension and on a number of physiological responses. The electrical activity of the upper trapezius muscle (EMG), heart rate (HR) and blood pressure (BP), of female and male instructor candidates, were examined before, during and after the teaching test as well as during its critique. The relaxation period (18 min) was presented either on the preceding night (ARTnt) or immediately before the teaching test (ARTimm). The influence of personality (types A-B and extrovert-introvert) was also studied. ART improved success at the teaching test in both sexes. In males (but not in females), ARTimm decreased EMG level during the test, but ARTnt increased EMG at the test period as compared to the control group. In females, both ARTnt and ARTimm lowered HR more than in the control group. ARTimm lowered systolic BP in both sexes. Personality types affected the ART responses; ART was more beneficial for type A than B subjects.

Achievement↗
PubMed1987

Timing of the triggering action of shooting in relation to the cardiac cycle.

The purpose of this study was to verify the timing of triggering in relation to the cardiac cycle in shooting. The test subjects were six Finnish rifle and pistol champions as well as three beginners at shooting. The electrical activity of the trigger finger muscle (m. flexor digitorum superficialis; surface electrodes) and the heart cycle were fed into a two-channel x-t recorder. The movements of the gun were recorded using a laser technique and, at the same time, cardiac cycles were also monitored. Results showed that the champion shooters triggered during diastole whereas the beginners triggered both during diastole and systole. The results of those beginners triggering during diastole were better than those triggering during systole.

Adult↗
PubMed1986

The effect of l-thyroxine treatment on skin accumulation of acid glycosaminoglycans in primary myxoedema.

We assessed skin accumulation of acid glycosaminoglycans in ten patients with primary myxoedema (median age 70 years) before and during l-thyroxine treatment (median 7 months). Eight subjects matched for sex and age served as controls. Acid glycosaminoglycans were determined biochemically on small skin biopsies. Hyaluronic acid was elevated in untreated myxoedema, median 0.60, range 0.39-0.90 microgram hexosamine/mg dried defatted tissue compared to a median control value of 0.52, range 0.43-0.65 microgram hexosamine/mg dried defatted tissue, P less than 0.02. Chondroitin-4,6-sulphate and dermatan sulphate showed no elevation, while heparan sulphate was actually reduced in myxoedema, P less than 0.01. l-thyroxine treatment induced a significant reduction in hyaluronic acid, median 0.41, range 0.24-0.71 microgram hexosamine/mg dried defatted tissue, while no consistent changes occurred in the remaining three acid glycosamine glycans. The accumulation of hyaluronic acid might contribute to the peculiar non-pitting oedema of the skin in myxoedema, due to the strong water-binding capacity of the substance.

Adult↗
PubMed1985

Shuttle case records: link between general practice and the specialist unit.

General practitioners have participated in the long term follow up of 367 patients who have undergone treatment with potent antirheumatic drugs at this hospital. Over the past two and a half years we have used the "shuttle case record" system, whereby patients' records are mailed back and forth between our department and general practitioners. This seems to work well. It is safe for the patients, and they save time and money in travel. The general practitioners like it, it improves communication between them and the specialist unit, and it enables the specialist unit to use its resources and manpower more effectively. The system may also be used to monitor patients with other chronic disorders, and it may be a valuable tool for doing research in general practice.

Denmark↗
PubMed1985

Physiotherapy and electromyography in muscle cramp.

Four cases of muscle cramps, at a sports institute, are presented. Electric activity was increased in cramp due to overload. The influence of stretching, electro- and compression therapies on these increased Electromyographic (EMG) activities was studied. The registration was performed with an EMG-analyser combined with a recorder, using surface electrodes.

Adult↗
PubMed1985

Vascular injury compared to ageing of normal rabbit aorta. Biochemical and histochemical studies on time-dependent alterations of vascular connective tissue.

Male albino rabbits of the Danish country strain, 5 months of age, were divided into two groups. One group of animals was killed 180 days after a single mechanical dilatation injury of the thoracic aorta. A second group of untreated controls was killed at ages of 150, 165, 180, 210, 330, and 450 days. Glycosaminoglycans, uptake of 35S-sulphate, collagen, uptake of 125I-albumin, and vascular histochemistry and morphology were analyzed in the thoracic aorta. In the injured aortae the dry weight and the total amounts of hexosamine, hyaluronic acid, chondroitin-4,6-sulphate, dermatan sulphate, heparan sulphate, and hydroxyproline were increased. The concentration of hyaluronic acid decreased, whereas the concentration of dermatan sulphate increased. The concentrations of chondroitin-4,6-sulphate and heparan sulphate were unchanged. The total uptake of 35S-sulphate into the sulphated proteoglycans as well as the uptake of 125I-albumin were increased. The light microscopical examination showed thickening of the intima, medial changes with fibrosis, accumulations of proteoglycans, calcifications, formation of cartilage, and ossified tissue with haematopoiesis. In the uninjured thoracic aorta the only significant change during ageing was an increase in the total amount of hyaluronic acid and a decrease of the 35S-sulphate incorporation into the chondroitin-4,6-sulphate in the aorta. No morphological or histochemical alterations were observed during ageing. Spontaneous lesions were observed in 2 out of 55 aortas. It may be concluded that injury and ageing are reflected quite differently in the thoracic aorta of the rabbits. The observations may be of relevance to the interpretation of the alterations in human arterial diseases involving processes of injury and repair as well as ageing.

Aging↗