Gudrun E. Hedberg

Determinants of Self-Reported Neck-Shoulder and Low Back Symptoms in a General Population

Study Design. A combined cross‐sectional and longitudinal design. Objectives. To investigate relation between, on one hand, self‐reported neck‐shoulder symptoms and, on the other hand, low back symptoms and self‐reported work‐related physical load, psychosocial factors, and individual characteristics and to study the influence of physical capacity in adolescence on neck‐shoulder and low back symptoms in adulthood. Summary of Background Data. Heavy physical work and exposure to vibration constitute risk factors for low back problems, and repetitive and static work are risk factors for neck‐shoulder symptoms in many jobs. The interplay between individual factors and work‐related psychosocial and physical exposure, however, is not well documented. This study addresses effects of adolescent capacity on this interplay in a general population. Methods. A random sample of 425 Swedish students was investigated when the students were 16 years and 34 years of age. Sixty‐five percent participated in both examinations; only those who worked ≥ 6 hours/week at the follow‐up period, 148 men and 90 women, were included in these analyses. Data about musculoskeletal symptoms, work, and sociodemographic and individual characteristics were collected at the age of 34 years; physical performance data were collected at the ages of 16 years and 34 years. Results. Among the men, self‐employment and worry were associated with neck‐shoulder symptoms; among the women, monotonous work and high decision latitude were associated with neck‐shoulder symptoms. Low back problems were related to monotonous work among men and women and to exposure to vibration among men. Performance in certain fitness tests at the ages of 16 years and 34 years was negatively associated with musculoskeletal symptoms. Conclusions. The inverse relationships between performance at the age of 16 years and adult musculoskeletal symptoms may imply benefits of early fitness training.

Secular trends in body dimensions and physical fitness among adolescents in Sweden from 1974 to 1995

Aim: To investigate changes over time in body dimensions, and muscular and aerobic fitness in a representative sample of 16‐year‐old‐girls and boys in secondary schools in Sweden from 1974 to 1995 (n = 855).Method: Height and weight were measured and five tests were performed: run–walk, two‐hand‐lift, Sargent jump, sit‐ups, and bench‐press.Results: In 1995, girls and boys had higher body mass index (BMI) than in 1974. Girls and boys performed less well in bench‐press, sit‐ups, and run–walk‐tests in 1995. Boys, but not girls, performed better in Sargent jump in 1995 than in 1974. Girls and boys performed better in two‐hand‐lift in 1995 than in 1974. However, after adjustment for body dimensions, there were no differences in performance in two‐hand‐lift or run–walk‐tests between 1974 and 1995.Conclusion: There was a decreased aerobic fitness and an increased maximal static strength among adolescents in Sweden between 1974 and 1995. These changes were partly due to increased BMI. However, decreased daily physical activity level cannot be excluded as a contributing factor to the decreased aerobic fitness. The reduced performance in muscular endurance in 1995 was not related to increased BMI. Instead, it is suggested that it is to be related to a specific decrease in hip flexion and arm muscle endurance.

Physical activity pattern in men and women at the ages of 16 and 34 and development of physical activity from adolescence to adulthood.

The aim of this study was to investigate gender‐related differences in physical activity patterns at the ages of 16 and 34 and to analyse those factors that might contribute to an explanation of physical activity habits in adulthood. A randomly selected group, consisting of 220 boys and 205 girls, was tested in 1974 and reinvestigated in 1992 by means of a questionnaire. Eighty‐eight percent participated in the reinvestigation. At the age of 16 more boys (69%) than girls (51%) participated in some sports activity in their leisure time. The results showed an overall decrease in participation in vigorous physical activity, although participation in light physical activity remained relatively constant. At the age of 34, there was no difference in overall physical activity between men and women, but the men exercised more vigorously (44% vs. 29%). Early experience of physical activity at the age of 16 decreased the risk of becoming inactive in adulthood. At the age of 34 cohabiting for the men, and having children and high socio‐economic class for the women, increased the risk of being physically inactive in adulthood, whereas positive beliefs about health effects of exercise decreased the risk for both men and women.

Prediction of physical fitness and physical activity level in adulthood by physical performance and physical activity in adolescence--an 18-year follow-up study.

Barnekow‐Bergkvist M, Hedberg G, Janlert U, Jansson E. Prediction of physical fitness and physical activity level in adulthood by physical performance and physical activity in adolescence ‐ An 18‐year follow‐up study.

Adolescent determinants of cardiovascular risk factors in adult men and women

Aims: To investigate how physical activity, physical performance and sociodemographic characteristics at the age of 16 are related to adult health habits (physical activity, dietary intake, smoking) and biological risk factors for cardiovascular diseases (being overweight, low aerobic fitness, unfavorable levels of serum lipids, high blood pressure). Methods: A randomly selected group of 220 male and 205 female students at 16 years of age was tested in 1974, and reinvestigated 18 years later. Results: The predictive health profiles for adult lifestyle and biological risk factors were different in men and women. Leisure sports activity along with high performance in the nine-minute run among the boys and in the two-hand lift test among the girls were significant predictors of adult physical activity. A positive attitude to aerobic exercise and high performance in the nine-minute run test among the boys and high marks in physical education among the girls decreased the risk of smoking. Leisure sports activities together with body mass index at young ages were the most powerful predictors of adult biological risk factors, but attitudes to sports and educational level were also significant determinants. Conclusion: These results contribute to the knowledge of which factors at young ages may promote adult healthy habits in particular physical activities.

Secular trends in sports: participation and attitudes among adolescents in Sweden from 1974 to 1995

Aim: To study the secular trend (time changes) in participation in leisure‐time sports activities and in attitudes towards sports activities and physical education in a representative sample of Swedish adolescents between 1974 and 1995. Methods: A questionnaire was distributed to 16‐y‐old girls and boys (n= 395 in 1974, n= 542 in 1995) to assess participation in leisure‐time sports activity, attitudes towards sports activities and attitudes towards physical education at school. Height and weight were measured and body mass index (BMI) was calculated. Results: Compared with 1974, more subjects in 1995 answered that they were engaged in leisure‐time sports activities, and that they were members of sports clubs. BMI increased from 1974 to 1995. By 1995, adolescents participated in and had become more interested in individual sports activities, including keep‐fit activities (e.g. strength training and aerobics) compared with 1974. A gender difference in the feeling of anxiety towards physical education, with more girls experiencing it, appeared in 1995, but not in 1974.

Relationships between physical activity and physical capacity in adolescent females and bone mass in adulthood

This study investigates whether physical activity and physical performance in adolescence are positively related to adult bone mineral density (BMD). In 1974, physical activity, endurance, and muscular strength were measured in 204 randomly selected female students, age 16.1 ± 0.3 year (range 15–17 years). Twenty years later, 36 of the women volunteered to undergo a measurement of their BMD. Women who were members in a sports club in adolescence had significantly higher adult BMD (mean differences of 5% to 17% depending on site) compared with subjects who were not engaged in a sports club. Furthermore, women with persistent weight‐bearing activity in adulthood had significantly higher BMD compared with women who had stopped being active or had never been active. The differences ranged between 5% and 19% with the highest difference found in trochanter BMD. Stepwise regression analyses showed that membership in a sports club at baseline was a significant independent predictor of BMD in the total body, lumbar spine, legs, trochanter, and femoral neck, explaining 17–26% of the variation in BMD. Change in body weight was a strong independent predictor of BMD of the total body and arms, explaining 8% of the variation in both sites. In addition, running performance at baseline was an independent predictor of total body BMD, whereas the two‐hand lift performance significantly predicted BMD of the total body, legs and trochanter. The hanging leg‐lift and handgrip were both significant predictors of arm BMD. In conclusion, membership in a sports club and site‐specific physical performance in adolescence together with the change in body weight were significantly associated with adult BMD in premenopausal women.

High Thigh Muscle Strength but Not Bone Mass in Young Horseback-Riding Females

Abstract. To evaluate whether the type of weight-bearing loading subjected to the skeleton during horseback-riding was associated with differences in bone mass and muscle strength of the thigh, we investigated bone mass and isokinetic muscle strength in 20 female horse riders (age 17.9 ± 0.6 years) who were riding 7.0 ± 3.4 hours/week, and 20 nonactive females (age 17.8 ± 1.1 years). The groups were matched according to age, weight, and height. Areal bone mineral density was measured in total body, head, lumbar spine, right femoral neck, Wards triangle, and trochanter, the whole dominant and nondominant humerus, and in specific sites in the right femur diaphysis, distal femur, proximal tibia, and tibia diaphysis using dual X-ray absorptiometry. Isokinetic concentric and eccentric peak torque of the quadricep and hamstring muscles were measured using an isokinetic dynamometer. There were no significant differences in bone mass between the horseback riders and nonactives at any site measured. The horse riders were significantly (P < 0.05–0.01) stronger in concentric hamstrings strength at 90°/second and 225°/second and in eccentric quadricep and hamstring strength at 90°/second. Horseback riding in young females is associated with a high muscle strength of the thigh, but not with a high bone mass.

Physical and muscular strain in Swedish tanker truck drivers

The aim of the investigation was to measure the physical and muscular strain in Swedish tanker truck drivers. Twenty-two drivers were studied in the laboratory and at their work. Heart rate recordings showed that the work was moderately strenuous. Dragging the hose from the tanker truck to the filler pipe was most strenuous. There was a significant increase in serum creatine kinase (S-CK) at the end of the week, which may be indicative of high local muscular strain. Measurements of tractive force showed that the average length which the hose was dragged horizontally over grass from the tanker truck to the filler pipe required between 38 and 61 % of maximum tractive force depending on the dimensions of the hose. The effects of uphill slopes and obstacles are also considered together with improvements aimed at reducing exertion.

ANTHROPOMETRIC STUDY OF SWEDISH ENGINE DRIVERS

The main purpose of the investigation was to obtain a representative sample of anthropometric measurements of Swedish engine drivers. The selection of measurements was made with respect to their ergonomic relevance for the design of the cab in the Swedish Rapid type c (Re) engine. Anthropometric measurements were obtained from 150 engine drivers and 91 driver trainees. The results indicated that, on average, the future engine driver was taller than the present population of engine drivers. The results also showed that engine drivers and driver trainees do not notably differ in stature from other groups of men in Sweden. There were marked differences between the body size of engine drivers and the corresponding dimensions of the cab in the Re engine. The compartment seemed to be best suited to taller drivers and was too large for smaller drivers.