Biomedical subjects

B Stenlund

Publications and source records attributed to B Stenlund.

7 recordsLinked to original sources

PubMed2002

Significance of house painters' work techniques on shoulder muscle strain during overhead work.

House painters represent a group of construction workers with a high frequency of neck and shoulder complaints and concomitant high risks for early retirements. Shoulder tendinitis, especially supraspinatus tendinitis, occurs frequently among house painters. The tasks of sanding and painting of ceilings with extension handles are particularly strenuous for these body regions. The purpose of this study was to identify work techniques that would be less strenuous to the arms and shoulders during sanding work. A biomechanical model was applied to quantify the shoulder loads during sanding and to determine the likely muscle force distribution. The necessary input data were measured experimentally for the model by means of a load cell and strain gauges on an extension handle, a Kistler force plate, and a MacReflex motion analysis system. Forty experienced male painters participated in the study. Three different work techniques were identified: the normal technique, the reversed grip and the pushing technique. The pushing technique was characterized by shorter stroke length and lower speed of the grinding block than the other techniques. The painters among the group of subjects who used the pushing technique were found to report fewer shoulder disorders during sanding than the others. The most common shoulder tendinitis is the supraspinatus tendinitis, also among house painters, and using the Pushing technique could possibly prevent from this disorder. However, further research in larger groups of house painters is needed to be able to recommend this technique for a wider use.

Adult↗

PubMed1993

Shoulder tendinitis and osteoarthrosis of the acromioclavicular joint and their relation to sports.

A sample of 207 men from the construction industry was studied using an epidemiological technique of cross-sectional design to investigate if sport activities involving the arms increase the risk of developing shoulder tendinitis or osteoarthrosis of the acromioclavicular joint. The relative risk for shoulder tendinitis was estimated to be 9.5 on the right side, and 4.9 on the left side for a lifetime of sport activity exceeding 8399 h. Subjects who reported both extremely high physical load from work and from sports had an estimated relative risk for signs of shoulder tendinitis of 5.9 on the right side and 10.4 on the left side. High sport activity yielded relative risks of 4.6 on the right side and 2.8 on the left side for osteoarthrosis of the acromioclavicular joint. The combination of high activity in sports and high exposure to load lifted during work yielded relative risks for osteoarthrosis of the acromioclavicular joint of 12.5 on the right side and 6.7 on the left side. There seems to be an increased risk for shoulder tendinitis and acromioclavicular osteoarthrosis for subjects who have been extremely active in sports, and an even higher risk for those who have been extremely active in sports and also report a high exposure to load lifted during work.

Acromioclavicular Joint↗

PubMed1993

Shoulder tendinitis and its relation to heavy manual work and exposure to vibration.

Three categories of construction industry workers (54 bricklayers, 55 rockblasters, and 98 foremen) were compared in a cross-sectional study. In a structured interview they reported exposure to loads lifted, vibration, and years of manual work. They were also subjected to a clinical investigation including medical history and a detailed shoulder examination. Among the rockblasters 33% had signs of tendinitis in the left and 40% in the right shoulder. Among the bricklayers and foremen 8-17% had signs of shoulder tendinitis. In a multiple logistic regression being a rockblaster compared with being a foreman showed an odds ratio (OR) of 3.33 for left-sided and 1.71 for right-sided shoulder tendinitis. Vibration exposure yielded an OR of 1.84 and 1.66 for the left and right sides, respectively. Vibration exposure or work as a rockblaster seemed to be risk indicators for tendinitis of the shoulders.

Adult↗

PubMed1992

Diminished space in the acromioclavicular joint in forced arm adduction as a radiographic sign of degeneration and osteoarthrosis.

The purpose of this study was to examine the acromioclavicular joint by radiography under forced arm adduction to demonstrate diminished joint space as a sign of cartilage degeneration and osteoarthrosis. A total of 192 right and left joints were investigated in 96 healthy working men. There were three main results from the manoeuvre: in 135 of the 192 joints the space was reduced, in 33 joints it was unchanged, and in 24 joints the joint space was increased. In 43 joints (22% of the total) a marked reduction of the joint space to 1 mm or less occurred during the manoeuvre; in the remaining 92 joints with space reduction the reduction was less pronounced. A narrow acromioclavicular joint space during forced adduction of the arm indicates cartilage thinning and may be interpreted as a sign of osteoarthrosis.

Acromioclavicular Joint↗

PubMed1992

Radiographic osteoarthrosis in the acromioclavicular joint resulting from manual work or exposure to vibration.

The hypothesis that manual work and exposure to vibration are antecedents to the development of osteoarthrosis was assessed employing a cross sectional study design. The frequency of osteoarthrosis in the acromioclavicular joint was studied in three groups of workers in the construction industry. Two groups were manual workers (54 bricklayers and 55 rock blasters); the third group consisted of 98 foremen. The radiographic appearance of the right and left acromioclavicular joints was classified into one of five grades of osteoarthrosis. A protocol was developed to assess exposure on the basis of job title, years of manual work, total weight lifted during working life, and total hours of exposure to vibrating tools. Odds ratios for job titles (manual worker v foreman) and for years of manual work as indicators of exposure were of similar magnitude of around 2.5. Construction workers who had lifted more than 709 tonnes had an increased risk of developing severe osteoarthrosis of the right acromioclavicular joint, odds ratio: 2.62 (95% confidence interval (95% CI), 1.13-6.06). The odds ratio for the left side was 7.67 (95% CI, 2.76-21.34). In the analysis of vibration exposure, workers who had been highly exposed to vibration had an odds ratio of 1.99 (95% CI, 1.00-3.92) on the right side and 2.20 (95% CI, 1.07-4.56) on the left. This effect almost disappeared after simultaneous adjustment for manual work. Occupational and ergonomic factors, such as the sum of lifted tonnes during working life, job title, and the sum of years of manual work seem to be risk factors for osteoarthrosis of the acromioclavicular joint, whereas vibration alone was a weaker risk factor.

Acromioclavicular Joint↗

PubMed1976

Polyelectrolyte effects in gel chromatography.

When polyelectrolytes (i.e., lignosulfonates) are eluted from Sepfected by steric exclusion, polyelectrolyte expansion, ion exclusion, and ion inclusion effects. The last-mentioned effect arises from the interaction of charged sites in the high-MW macroions, which are more or less excluded from the gel phase with charged sites in more permeable macroions. The ion inclusion effect depends on the counterion in such a way that the fractionation of polyelectrolytes with a univalent counterion is affected to a greater extent than is the fractionation of polyelectrolytes with a divalent counterion. This is attributable to the existence of a higher density of free charges in the former case, since univalent counterions have a lesser tendency to form ion pairs with the charged sites of the macroion than have divalent counter-ions. The ion inclusion effect may have a favorable influence on the resolution of components of relatively equal molar volume, but of different charge densities. Polyelectrolyte effects are suppressed if the elution is carried oe polyelectrolyte behaves as a nonionic polymer. However, since the separation effected by differences in charge densities is eliminated (swamped out), resolution may deteriorate; nevertheless, the fractionation order is independent of the composition of the sample, the concentration of sample solution, and other fractionation variables. If one wishes to acquire a general picture of the composition of a certain polyelectrolyte, a solution of a simple electrolyte may be the most appropriate eluent. However, if polyelectrolyte components with small differences in hydrodynamic volume are to be separated, an eluent comprising a solution of a high-MW polyelectrolyte, completely excluded by the gel (e.g., dextran sulfate), can be used.

Chemical Fractionation↗

PubMedDate not supplied

Correlation of macroscopic osteoarthrotic changes and radiographic findings in the acromioclavicular joint.

In a total of 108 acromioclavicular articulations from cadavers the osteoarthrotic changes were studied. The articulations were macroscopically and radiographically ranked according to their grade of osteoarthrosis. The two ranking lines were correlated statistically and showed a rank correlation of 0.741. In 38 articulations tomography was also carried out. These articulations were classified into five grades of osteoarthrosis and the macroscopic, conventional radiographic and tomographic gradings were compared. The correlation coefficient for tomography versus macroscopy was 0.714. Tomography versus standard radiography showed a correlation of 0.767 and standard radiography versus macroscopy a correlation of 0.841. The standard radiographic investigation reveals moderate and severe osteoarthrotic changes in the acromioclavicular joint but cannot depict smaller changes. Tomography does not seem to improve the specificity. There is a need for a better radiologic technique in the examination of the acromioclavicular joint. Radiography during some kind of loading might be a practical way of improving the specificity and make it possible to show early osteoarthrosis in the acromioclavicular articulation.

Acromioclavicular Joint↗