Musculoskeletal disorders among female dental personnel--clinical examination and a 5-year follow-up study of symptoms.

OBJECTIVES: To explore the natural course of musculoskeletal disorders during a 5-year period among dental personnel, to survey findings and diagnoses according to a standardized protocol, and to compare and evaluate different methods for the detection of musculoskeletal disorders in a population. METHODS: In a 5-year follow-up study, dental personnel (n = 90) and referents (n = 30) were studied. The Nordic questionnaire (years 0 and 5), the present pain rating according to the Borg category ratio scale, and physical examination (year 5) were used. RESULTS: In year 0 the prevalence of symptoms in the shoulders, the wrists/hands, and, unexpectedly, the hips was higher in the dental personnel as compared with the referents. Furthermore, those (16%) who had left the dental profession during the observation period showed a higher prevalence of and, often, combined symptoms from several body regions in year 0 than did those who stayed. Dental personnel who remained in the profession tended to have an increased risk of developing more symptoms in the shoulders and the elbows/wrists/hands in year 5 as compared with year 0 and at year 5 were in more pain and had received more diagnoses for the neck/shoulder region relative to the referents. Furthermore, there was a considerable variation in symptoms during the follow-up period. The sensitivity of the pain rating and of the Nordic questionnaire in detecting musculoskeletal disorders was high for the neck and shoulders but was not as high for the elbow, wrists/hands, or hips. The association was better for diagnoses than for findings. The opposite patterns were observed for specificity. CONCLUSIONS: Dental personnel had an increased risk of developing musculoskeletal disorders as verified by symptoms and diagnoses and more painful or persistent conditions. This led to a selection out of work. The questionnaire and the present pain rating gave a relatively good picture of the prevalence of musculoskeletal disorders arising from the neck, shoulders, and hips and would be useful as screening tools. Their sensitivity in detecting disorders was higher for diagnoses than for findings. However, these methods were not as sensitive for disorders involving the elbows/wrists/hands. Physical examinations gave more detailed information.

The Natural Course of Musculoskeletal Symptoms and Clinical Findings in Upper Extremities of Female Milkers.

To explore milkers' state of health with regard to symptoms in the wrists and hands, a study of 80 female milkers was carried out 12 months after a Nordic questionnaire study of these subjects. Of these 80, 41 had reported pain and discomfort in the wrists and hands at the time of the questionnaire study, whereas the remaining 39 had had no such symptoms. To determine the sensitivity and specificity of the Nordic questionnaire, the follow-up study included examination by an unbiased clinician. The occurrence of symptoms in the wrists and hands during the preceding 12 months was found to have been rather stable-30 of the 41 milkers still reported pain, aching, and discomfort, and eight new cases were recorded. On clinical examination, symptoms including numbness, tingling, and coldness in the forearms and hands were reported by 51 of the 80 milkers, 14 of whom had clinical symptoms and signs indicating median nerve entrapment. Peritendinitis was diagnosed in four subjects and a ganglion cyst in one. The findings in the remaining group did not meet diagnostic criteria. All subjects with wrist and hand symptoms were still at work a year after the initial study. The sensitivity of the Nordic questionnaire when it came to identifying subjects with clinical findings was found to be unsatisfactory. The actual incidence of wrist and hand disorders may be underestimated if the Nordic questionnaire is used as the only instrument in epidemiologic screenings.

Milking is a high-risk job for young females.

The prevalence of and the impact of selected factors on self-reported musculoskeletal complaints in Swedish female milkers with special reference to symptoms in the upper extremities were investigated using data from mail-in surveys. An agricultural study group was formed of three subgroups: 161 active milkers, 108 non-milkers and 62 ex-milkers, women who had been milkers earlier but were no longer doing that kind of work. In the course of the analysis these subgroups were compared with each other and also, separately or in combinations, with a non-agricultural population consisting of 166 nursing assistants. Problems in the upper extremities were significantly more common in the agricultural group than in the non-agricultural group. Milkers ran a higher risk of developing symptoms in the wrists and hands than non-milking women. Symptoms such as numbness, coldness in the wrists and white fingers were more common in all agricultural subgroups than in the non-agricultural group. Numbness and white fingers were related to vibration exposure in the ex-milker and the non-milker groups but not in the milker group. Psychosocial factors such as occupational well-being were not related to the occurrence of symptoms. Milking in a modernized barn gave fewer problems in elbows than milking in a traditional barn. Milkers who had received ergonomic instruction on how to work in order to reduce muscle stress had fewer problems in the elbow region than those who had received no such information.

A longterm prospective study of the equipotency between deflazacort and prednisolone in the treatment of patients with polymyalgia rheumatica.

OBJECTIVE: The aim of the study was to establish the antiinflammatory equipotency between prednisolone and deflazacort. METHODS: Thirty patients with newly diagnosed polymyalgia rheumatica (PMR) were treated double blind with either prednisolone or deflazacort in a 12-month study. The initial daily dose was 20 mg prednisolone or 24 mg deflazacort. RESULTS: The clinical control of muscle pain was significantly inferior in the deflazacort group from 6 weeks to 3 months. Otherwise there was no difference in the clinical and biochemical variables. The ratio between antiinflammatory equipotent doses of deflazacort and prednisolone (mg:mg) stabilized at about 1.55 for the daily doses and about 1.40 for the cumulative doses. CONCLUSION: In PMR the antiinflammatory equipotency (mg to mg) between deflazacort and prednisolone was close to 1.40 (7:5 mg). Twenty mg prednisolone/day was fully sufficient to suppress symptoms in 94% of the patients.

Repetitive industrial work and neck and upper limb disorders in females.

A cross-sectional study was performed in which physical examinations of the neck and upper limbs were conducted on 82 currently working female industrial workers with exposure to repetitive work tasks and on 64 currently working referent subjects without exposure to repetitive work tasks. Associations between results of symptom questions and physical examination were sought with variables related to the work environment and to the individuals. In a multivariate model, there were statistically significant associations between exposure to repetitive work and diagnoses in both the neck/shoulders (prevalence odds ratio, POR = 4.6) and elbows/hands (POR = 3.5). In addition, age (POR = 1.9, 75th vs. 25th percentiles), tendencies towards subjective muscular tension (POR = 2.3), and stress/worry (POR = 1.9) were also associated with diagnoses in the neck/shoulders; however, there was not an association between these variables and the prevalence of diagnoses in elbows/hands. Standardized evaluation of videotape recordings in 74 of the industrial workers revealed significant associations between neck flexion, and elevation and abduction of the arm and the prevalence of neck/shoulder diagnoses. In the multivariate model, neck flexion was significantly associated with diagnoses in the neck/shoulders (p = 0.005). In addition, low muscle strength, lack of emotional well-being at work, and a variety of psychosomatic symptoms were associated with diagnoses in the neck/shoulders (all p < 0.001). Lack of strength was also associated with disorders of elbows/hands (p = 0.007). This study demonstrated a substantial prevalence of neck and upper limb disorders associated with repetitive work performed with a flexed neck and elevated and abducted arms, as well as a possible potentiation of these ergonomic factors by certain personal traits in some workers.

Comparison of methods for immobilization to carboxymethyl dextran sensor surfaces by analysis of the specific activity of monoclonal antibodies.

The authors have recently described the development of a carboxymethyl dextran-based sensor surface for biospecific interaction analysis by surface plasmon resonance. Ligands are immobilized via primary amine groups after activation of the carboxymethyl groups on the sensor surface with a mixture of N-hydroxysuccinimide and N-ethyl-N'-(dimethylaminopropyl) carbodiimide. Methods have now been developed for efficient immobilization via thiol/disulfide exchange, aldehyde coupling and biotin-avidin coupling. The specific activity of monoclonal antibodies immobilized by the four different methods was investigated by altering the immobilization conditions, e.g., activation time, protein concentration, ionic strength and the degree of modification, etc. Investigations have also been made concerning possible differences in the specific activity for antibodies immobilized using optimized conditions with respect to the four different chemistries. These studies show that, with the flexible carboxymethyl dextran matrix used here, the immobilization methods give rise to only minor differences in specific activity. Thus, with this solid support, a 'site directed' immobilization strategy for monoclonal antibodies has no advantage. In general the specific activity for optimized systems was approximately 75% for the binding of beta 2 mu-globulin to an immobilized monoclonal antibody directed against beta 2 mu-globulin. Reduced specific activities of immobilized antibodies induced by variation of the coupling conditions could be attributed to the deterioration of the active site of the antibody.

An assessment of neck and upper extremity disorders by questionnaire and clinical examination.

To study the usefulness of a screening questionnaire for neck/upper extremity complaints, 165 women in either repetitive industrial, or mobile and varied work, were studied by the questionnaire and by a detailed clinical physical examination. A total of 94 subjects recorded complaints in the questionnaire. In 140 subjects findings were recorded at the examination. Most subjects with findings at the clinical examination of shoulders reported complaints in the questionnaire (sensitivity 80%). For the other anatomical regions, the sensitivity was rather low (42-65%). For all regions, most subjects without findings reported no complaints (specificity 77-97%). A total of 75 subjects were given clinical diagnoses according to a set of predetermined diagnostic criteria. The capacity of the questionnaire to identify diagnoses of shoulders was higher (sensitivity 92%) than for the other regions (66-79%). Of subjects who did not qualify for diagnosis, a majority (specificity 71-81%) did not report complaints in the questionnaire. We conclude that the questionnaire approach gives a fairly good picture of the neck/upper extremity status of a working female population. However, a clear view of the size of a problem is obtained only by a detailed clinical examination, particularly as regards the neck, elbows and hands, for which the questionnaire gave an underestimate.

Real-time biospecific interaction analysis using surface plasmon resonance and a sensor chip technology.

We report here the development and application of a biosensor-based technology that employs surface plasmon resonance for label-free studies of molecular interactions in real time. The sensor chip interface, comprising a thin layer of gold deposited on a glass support, is derivatized with a flexible hydrophilic polymer to facilitate the attachment of specific ligands to the surface and to increase the dynamic range for surface concentration measurements. The sensor can be used to measure surface concentrations down to 10 pg/mm2. Typical coefficients of variation are from two to five percent. We anticipate that the ability to monitor multi-molecular complexes as they form will greatly contribute to the understanding of biorecognition and the structural basis of molecular function.

Immobilization of proteins to a carboxymethyldextran-modified gold surface for biospecific interaction analysis in surface plasmon resonance sensors.

A method for fast and simple covalent immobilization of proteins to a carboxymethyldextran-modified gold surface intended for surface plasmon resonance sensors is described. The method utilizes the formation of N-hydroxysuccinimide esters from a fraction of the carboxyl groups of the carboxymethyldextran matrix via reaction with N-hydroxysuccinimide and N-ethyl-N'-(dimethylaminopropyl) carbodiimide hydrochloride in water. In a second step the protein is passed over the surface in a solution of low ionic strength with a pH value below the isoelectric point of the protein. The protein is thereby concentrated in the matrix by electrostatic attraction forces and a simultaneous reaction with the active esters takes place. In a final step, the remaining active esters are transformed into amides via reaction with ethanolamine. This sequence is performed automatically in a system comprising an integrated microfluidic cartridge and an autosampler. Typical reaction times of less than 30 min are required for the immobilization of proteins at surface concentrations in the region of 70 fmol mm-2. Parameters such as protein concentration, protein solution ionic strength, pH, reaction times, and reagent concentration can be varied in order to control the immobilized amount of ligand. The biospecific interaction of the immobilized ligand with its biological counterpart is illustrated by the effects on the interaction of immunoglobulins with immobilized Staphylococcus aureus protein A for various amounts of protein A.

Occupational cervico-brachial disorders among dentists. Psychosocial work environment, personal harmony and life-satisfaction.

The aim of the investigation was to compare dentists with and without occupational cervico-brachial disorders with regard to some psychosocial variables (work environment, personal harmony and life-satisfaction) and professional position. The investigation is based on a questionnaire sent to 143 randomly selected official dentists in Malmöhus District and the Municipality of Malmö. Of these, 96 dentists had symptoms while 47 had not. Dentists with symptoms showed less satisfaction with their work environment than dentists without. Those with symptoms experienced their work load as being more unsatisfactory, were more burdened by anxiety, had poorer psychosomatic health and less confidence in the future than dentists without symptoms. These differences were significant between the groups. It was found that specialists, both with and without cervico-brachial symptoms, were more satisfied with their psychosocial work environment than general practitioners, especially regarding their personal control over their work and the stimulation of their work. The specialists also had more self-confidence and experienced less anxiety than general practitioners and head dentists.

Cervico-brachial disorders in dentists. A comparison between two kinds of physiotherapeutic interventions.

We have evaluated two kinds of physiotherapy treatment for dentists with occupational cervico-brachial disorders. Group A received treatment with a psychosomatic approach and individual ergonomic instruction and group B received ergonomic instruction only. A reduction of the cervico-brachial disorders after the intervention was observed in both groups. In group A there was a significant decrease of pain and discomfort in the neck (p less than 0.05), and a significant improvement was also found concerning the experience of well-being (p less than 0.05). Five weeks after the intervention the feeling of self-confidence had increased significantly in group A (p less than 0.05). Both groups of dentists experienced that their control over the work had decreased (p less than 0.01 in group A and p less than 0.05 in group B). In group B it was also found that the dentists' confidence in the future had decreased, compared with the answers given a year before.

Occupational cervico-brachial disorders among dentists. Analysis of ergonomics and locomotor functions.

The aim of the investigation was to compare dentists with and without occupational cervicobrachial disorders with regard to the mobility of the neck and shoulders and the static endurance of the shoulder muscles. Further, differences in working position and the task performance on a stimulated case were to be analysed. The investigation was carried out during a visit to the workplace of 143 dental officers in the Public Dental Service in Malmöhus District and the Municipality of Malmö. Of these dentists, 96 had signs of cervico-brachial disorders and discomfort while 47 had not. The ergonomic examination showed, that significantly more dentists without symptoms of pain applied a wedge cushion under the upper part of the back of the patient to get an optimum view (p less than 0.05). It was also found that significantly more dentists without symptoms were aware of and utilised the naturally arising pauses in their work than dentists with pain and discomfort. Further dentists with cervico-brachial disorders kept their head sidebent and rotated to a greater extent than dentists without symptoms (p less than 0.01). No significant difference was found between the two groups concerning mobility of the neck and shoulders. Significant differences were found between women with and without cervico-brachial systems.

Pain and discomfort in the musculoskeletal system among dentists. A prospective study.

The aim of this prospective study was to follow the pain and discomfort among dentists in the Public Dental Service in Malmöhus District and the Municipality of Malmö. In this investigation 311 dentists, who had answered questionnaires in 1987 and in 1990, took part. The prevalence of musculoskeletal pain and discomfort had increased, except the lower back pain and headache. However, the only significant difference was found with respect to the shoulders. As in 1987, female dentists had also in 1990 a higher prevalence of pain and discomfort in the neck and shoulders than their male colleagues. Of the 311 dentists, 262 had symptoms both in 1987 and in 1990. In 1987 forty-nine dentists were free of symptoms, while 24 of them reported symptoms in the locomotor system in 1990. Of the 262 dentists with symptoms in 1987 twenty-four were without symptoms at the follow-up in 1990. The aim of the investigation was also to study the influence of some ergonomic factors on the course of symptoms. However, these ergonomic variables showed a low predictive value for recovery or for the development of pain and discomfort in the locomotor system.

Cervical pain and discomfort among dentists. Epidemiological, clinical and therapeutic aspects. Part 1. A survey of pain and discomfort.

The aim of the investigation was to study the frequency of pain, ache and discomfort in the musculoskeletal system among dentists, above all concerning headache, cervical and shoulder pain and further, to find possible correlations between these symptoms and various working positions and different working actions. A questionnaire was answered by 359 dentists (90.8%). Of those who answered the questionnaire 72% had pain and discomfort from either the neck, shoulders or headaches. Only 60 dentists had no pain or discomfort. Concerning the male dentists, the investigation revealed that younger dentists had pain and discomfort in the neck, shoulders and headaches to a greater extent than the older dentists. Younger female dentists had a significantly higher frequency of pain and discomfort in the neck and headaches than older colleagues. The results showed that dentist who positioned the patient carefully so that a direct view gained had a significantly lower frequency of headaches. Of the 359 dentists 55% mostly used the mirror to facilitate a direct view. From the answers it was clear that those dentists who did not have discomfort in the upper locomotor system used the mirror more often than those who did suffer discomfort.