Background: High-intensity resistance training plays an essential role in the prevention and rehabilitation of musculoskeletal injuries and disorders. Although resistance exercises with heavy weights yield high levels of muscle activation, the efficacy of more user-friendly forms of exercise needs to be examined.Objective: The aim of this study was to investigate muscle activation and perceived loading during upper-extremity resistance exercises with dumbbells compared with elastic tubing.Design: A single-group, repeated-measures study design was used.Setting: Exercise evaluation was conducted in a laboratory setting.Participants: Sixteen female workers (aged 26–55 years) without serious musculoskeletal diseases and with a mean neck and shoulder pain intensity of 7.8 on a 100-mm visual analog scale participated in the study.Measurements: Electromyographic (EMG) activity was measured in 5 selected muscles during the exercises of lateral raise, wrist extension, and shoulder external rotation during graded loadings with dumbbells (2–7.5 kg) and elastic tubing (Thera-Band, red to silver resistance). The order of exercises and loadings was randomized for each individual. Electromyographic amplitude was normalized to the absolute maximum EMG amplitude obtained during maximal voluntary isometric contraction and exercise testing. Immediately after each set of exercise, the Borg CR10 scale was used to rate perceived loading during the exercise.Results: Resistance exercise with dumbbells as well as elastic tubing showed increasing EMG amplitude and perceived loading with increasing resistance. At the individually maximal level of resistance for each exercise—defined as the 3 repetitions maximum—normalized EMG activity of the prime muscles was not significantly different between dumbbells (59%–87%) and elastic tubing (64%–86%). Perceived loading was moderately to very strongly related to normalized EMG activity (r=.59–.92).Limitations: The results of this study apply only for exercises performed in a controlled manner (ie, without sudden jerks or high acceleration).Conclusions: Comparably high levels of muscle activation were obtained during resistance exercises with dumbbells and elastic tubing, indicating that therapists can choose either type in clinical practice. The Borg CR10 can be a useful aid in estimating intensity of individual rehabilitation protocols.

Regular physical exercise is a cornerstone in rehabilitation programs, but adherence to comprehensive exercise remains low. This study determined the effectiveness of small daily amounts of progressive resistance training for relieving neck/shoulder pain in healthy adults with frequent symptoms; 174 women and 24 men working at least 30 h per week and with frequent neck/shoulder pain were randomly assigned to resistance training with elastic tubing for 2 or 12 minutes per day 5 times per week, or weekly information on general health (control group). Primary outcomes were changes in intensity of neck/shoulder pain (scale 0 to 10), examiner-verified tenderness of the neck/shoulder muscles (total tenderness score of 0 to 32), and isometric muscle strength at 10 weeks. Compared with the control group, neck/shoulder pain and tenderness, respectively, decreased 1.4 points (95% confidence interval -2.0 to -0.7, p<0.0001) and 4.2 points (95% confidence interval -5.7 to -2.7, p<0.0001) in the 2-minute group and 1.9 points (95% confidence interval -2.5 to -1.2, p<0.0001) and 4.4 points (95% confidence interval -5.9 to -2.9, p<0.0001) in the 12-minute group. Compared with the control group, muscle strength increased 2.0 Nm (95% confidence interval 0.5 to 3.5Nm, p=0.01) in the 2-minute group and 1.7Nm (95% confidence interval 0.2 to 3.3 Nm, p=0.02) in the 12-minute group. In conclusion, as little as 2 minutes of daily progressive resistance training for 10 weeks results in clinically relevant reductions of pain and tenderness in healthy adults with frequent neck/shoulder symptoms. www.isrctn.org/ISRCTN60264809. In generally healthy adults with frequent neck/shoulder muscle pain, as little as 2 minutes of daily progressive resistance training reduces pain and tenderness.

Objective No previous long-term prospective studies have examined if workers with low cardiorespiratory fitness have an increased risk of cardiovascular mortality due to high physical work demands. We tested this hypothesis. Method We carried out a 30-year follow-up of the Copenhagen Male Study of 5249 employed men aged 40–59 years. We excluded from follow-up 274 men with a history of myocardial infarction, prevalent symptoms of angina pectoris, or intermittent claudication. We estimated physical fitness [maximal oxygen consumption (VO 2 Max)] using the Åstrand cycling test and determined physical work demands with two self-reported questions. Results In the Copenhagen Male Study, 587 men (11.9%) died due to ischaemic heart disease (IHD). Using men with low physical work demands as the reference group, Cox analyses – adjusted for age, blood pressure, smoking, alcohol consumption, body mass index, diabetes, and hypertension – showed that high physical work demands were associated with an increased risk of IHD mortality in the least fit [VO 2 Max range 15–26, N=892, hazard ratio (HR) 2.04, 95% confidence interval (95% CI) 1.20–3.49] and moderately fit (VO 2 Max range 27–38, N=3037, HR 1.75, 95% CI 1.24–2.46), but not among the most fit men (VO 2 Max range 39–78, N=1014, HR 1.08, 95% CI 0.52–2.17). We found a similar, although slightly weaker, relationship with respect to all-cause mortality. Conclusions The hypothesis was supported. Men with low and medium physical fitness have an increased risk of cardiovascular and all-cause mortality if exposed to high physical work demands. Ours observations suggest that, among men with high physical work demands, being physically fit protects against adverse cardiovascular effects.

Although leisure-time physical activity is important for health, adherence to regular exercise is challenging for many adults. The workplace may provide an optimal setting to reach a large proportion of the adult population needing regular physical exercise. This study evaluates the effect of implementing strength training at the workplace on non-specific neck and shoulder pain among industrial workers.

Objectives Men with low physical fitness and high occupational physical activity are recently shown to have an increased risk of cardiovascular disease and all-cause mortality. The association between occupational physical activity with cardiovascular disease and all-cause mortality may also depend on leisure time physical activity. Design A prospective cohort study. Setting The Copenhagen City Heart Study. Participants 7819 men and women aged 25–66 years without a history of cardiovascular disease who attended an initial examination in the Copenhagen City Heart Study in 1976–1978. Outcome measures Myocardial infarction and all-cause mortality. Occupational physical activity was defined by combining information from baseline (1976–1978) with reassessment in 1981–1983. Conventional risk factors were controlled for in Cox analyses. Results During the follow-up from 1976 to 1978 until 2010, 2888 subjects died of all-cause mortality and 787 had a first event of myocardial infarction. Overall, occupational physical activity predicted all-cause mortality and myocardial infarction in men but not in women (test for interaction p=0.02). High occupational physical activity was associated with an increased risk of all-cause mortality among men with low (HR 1.56; 95% CI 1.11 to 2.18) and moderate (HR 1.31; 95% CI 1.05 to 1.63) leisure time physical activity but not among men with high leisure time physical activity (HR 1.00; 95% CI 0.78 to 1.26) (test for interaction p=0.04). Similar but weaker tendencies were found for myocardial infarction. Among women, occupational physical activity was not associated with subsequent all-cause mortality or myocardial infarction. Conclusions The findings suggest that high occupational physical activity imposes harmful effects particularly among men with low levels of leisure time physical activity.

Objective To estimate the impact of pain in different body regions on future long-term sickness absence (LTSA) among blue- and white-collar workers. Method Prospective cohort study in a representative sample of 5603 employees (the Danish Work Environment Cohort Study) interviewed in 2000, and followed in 2001–2002 in a national sickness absence register. Cox regression analysis was performed to assess the risk estimates of mutually adjusted severe pain in the neck/shoulder, low back, hand/wrist and knees for onset of LTSA, defined as receiving sickness absence compensation for at least 3 consecutive weeks. Age, gender, body mass index, smoking and diagnosed disease were controlled for. Results In 2000 the prevalence among blue- and white-collar workers, respectively, of severe pain was 33% and 29% (neck/shoulder), 33% and 25% (low back), 16% and 11% (hand/wrists), and 16% and 12% (knees). During 2001–2002, the prevalence of LTSA among blue- and white-collar workers was 18% and 12%, respectively. Hand/wrist pain (HR 1.49, 95% CI 1.23 to 1.81) and low back pain (HR 1.30, 95% CI 1.11 to 1.53) were significant risk factors among the total cohort. Neck/shoulder pain was a significant risk factor among white-collar workers only (HR 1.35, 95% CI 1.21 to 1.85). Knee pain was not a significant risk factor. Conclusion While hand/wrist pain and low back pain are general risk factors for LTSA, neck/shoulder pain is a specific risk factor among white-collar workers. This study suggests the potential for preventing future LTSA through interventions to manage or reduce musculoskeletal pain.