Work-limiting musculoskeletal pain and its association with loss of paid employment among senior workers: prospective cohort study with register follow-up.

BACKGROUND: A growing population of elderly necessitates a sharpened focus on sustainable employment through aging. Physically demanding work can be challenging, especially for senior workers. Establishing determinants of labor market participation could guide policy development and preventive efforts at the workplaces aiming at keeping senior workers longer in the labor market. METHODS: We used data from SeniorWorkingLife, a comprehensive questionnaire survey among a representative sample of Danish +50-year workers, and investigated the prospective association between self-reported work limitations due to musculoskeletal pain ('work-limiting pain') in 2018 and register-based loss of paid employment before state pension age at 2-year follow-up among +50-year Danish workers with physically demanding work (n = 3050). RESULTS: Results showed that work-limiting pain increased the risk of loss of paid employment before the state pension age in a progressive manner, i.e. the higher degree of work-limiting pain, the higher risk of loss of paid employment (P < 0.001). Experiencing a low degree of work-limiting pain was associated with an 18% increased risk of loss of paid employment [risk ratio (RR): 1.18, 95% confidence interval (CI): 1.14-1.21], whereas experiencing a very high degree of work-limiting pain increased the risk of loss of paid employment by 155% (RR: 2.55, 95% CI: 2.43-2.69) compared to no work-limiting pain. CONCLUSION: In conclusion, work-limiting pain constitutes an important risk factor for loss of paid employment among senior workers with physically demanding work, and effective preventive efforts at both policy and workplace levels should be documented and implemented.

Analgesics and ASH medications in workers increase the risk of disability pension and mortality: prospective cohort.

BACKGROUND: Relying on medication for musculoskeletal and mental disorders are common, but may have long-term consequences. This study investigates whether use of analgesics and anxiolytic/sedative/hypnotic (ASH) medication increases the risk of disability pension and mortality. METHODS: After completing a survey in 2005, 7773 female eldercare workers were followed for 11 years in a national register. We estimated hazard ratios (HRs) for disability pension and mortality from using analgesics and ASH. RESULTS: During follow-up, 10.3% obtained disability pension and 2.4% died. For use of analgesics, a frequency-response association for the risk of disability pension existed with HR's (95% confidence interval) of 1.30 (1.07-1.57), 2.00 (1.62-2.46) and 3.47 (2.69-4.47) for monthly, weekly and daily use, respectively. For ASH, an increased risk of disability pension also existed (HR's between 1.51 and 1.64). For mortality risk, only daily use of analgesics and ASH remained significant. Population attributable fractions of analgesics and ASH, respectively, were 30% and 3% for disability pension and 5% and 3% for mortality. CONCLUSIONS: Frequent use of analgesics and ASH medication in workers increase the risk of disability pension and early death. Better management of musculoskeletal and mental health conditions, without excessive medication use, is necessary.

Self-reported sickness absence and presenteeism as predictors of future disability pension: Cohort study with 11-year register follow-up.

Many healthcare workers in eldercare are pushed out of the labor market before the official retirement age due to poor health. Identification of early warnings signs is important to avoid complete loss of work ability. The aim of this study was to investigate to what degree sickness absence and presenteeism increase future risk for disability pension among eldercare workers. A total of 8952 Danish female eldercare workers responded to a survey about work environment and health. They were followed for 11 years in the Danish Register for Evaluation of Marginalization, with time-to-event analyses estimating the hazard ratios (HRs) for disability pension from sickness absence and presenteeism at baseline. Analyses were adjusted for age, education, body mass index, leisure-time physical activity, smoking, physical exertion at work, and psychosocial factors related to the work environment. During the 11-year follow-up, 11.9% participants received disability pension. For the whole cohort, the highest risk for disability pension was observed for the category of >30 days of combined sickness absence and presenteeism at baseline in the fully adjusted model (HR = 7.93 [95%CI 5.20-12.09]). Eldercare workers aged >45 years were at a higher risk for disability pension in all included categories. Sickness absence and presenteeism increased the risk of disability pension among female eldercare workers. These results suggest that organizations would benefit from identifying early warning signs among workers in the prevention of involuntary early retirement.

Musculoskeletal pain intensity in different body regions and risk of disability pension among female eldercare workers: prospective cohort study with 11-year register follow-up.

BACKGROUND: Musculoskeletal pain is a risk factor for leaving the labour market temporarily and permanently. While the presence of multi-site pain increases the risk of disability pension, we lack detailed knowledge about pain intensity as a risk factor. This study investigated the association between musculoskeletal pain intensity in different body regions and risk of future disability pension among eldercare workers. METHODS: Eight thousand seven hundred thirty-one female eldercare workers replied to a questionnaire on work and health in 2005 and were followed for 11 years in the Danish Register for Evaluation of Marginalization. Time-to-event analyses estimated hazard ratios (HR) for disability pension from pain intensities (0-9 numeric rating scale (NRS)) in the low-back, neck/shoulders, and knees during the previous 3 months. Analyses were mutually adjusted for pain regions, age, education, lifestyle, psychosocial work factors, and physical exertion at work. RESULTS: During 11-year follow-up, 1035 (11.9%) of the eldercare workers received disability pension. For all body regions among all eldercare workers, dose-response associations were observed between higher pain intensity and risk of disability pension (p < 0.001). The risk for disability pension was increased when reporting "very high" pain levels (≥7 points on the 0-9 NRS) in the low-back (HR 2.19, 95% CI 1.70-2.82), neck/shoulders (HR 2.34, 95% CI 1.88-2.92), and knees (HR 1.89, 95% CI 1.44-2.47). Population attributable risks (PAR) were 15.5, 23.2, and 9.6% for pain > 2 on NRS in the low-back, neck/shoulders, and knees, respectively, indicating that 15.5, 23.2, and 9.6% fewer eldercare workers would likely receive disability pension if the pain intensity was reduced to 2 or less. For workers ≤45 years and > 45 years, PAR was highest for neck/shoulder pain (27.6%) and low-back pain (18.8%), respectively. CONCLUSIONS: The present study found positive dose-response associations between pain intensity in the low-back, neck/shoulders, and knees, and risk of disability pension during 11-year follow-up. Moderate to very high levels of musculoskeletal pain in eldercare workers should, therefore, be considered an early warning sign of involuntary premature exit from the labour market. These findings underscore the importance of preventing, managing, and reducing musculoskeletal pain to ensure a long and healthy working life.

High leisure-time physical activity reduces the risk of long-term sickness absence.

OBJECTIVES: This study examined the association of leisure-time physical activity (LTPA) with the risk of long-term sickness absence (LTSA). METHODS: A total of 10 427 subjects from the general working population in Denmark answered questions about physical activity habits, health and work environment in the 2010 Danish Work Environment Cohort Study (DWECS). Data on LTSA (≥6 consecutive weeks during 2-year follow-up) were obtained from the Danish Register for Evaluation of Marginalization (DREAM). Cox regression analysis censored for competing events and adjusted for potential confounders (age, sex, BMI, smoking habits, depression, cancer, back diseases, previous LTSA, occupational social class, and psychosocial work environment) estimated the association between the predictor (LTPA) and the outcome variable (LTSA). During the 2-year follow-up period, 9.2% of the studied population experienced LTSA. RESULTS: In the general working population, moderate LTPA was not associated with LTSA (HR = 0.89, 95% CI: 0.72-1.09), while high LTPA showed a tendency (HR = 0.77, 95% CI: 0.59-1.01). In subgroup analyses, women below the age of 45 years with high LTPA showed a significantly lower risk of LTSA when compared with their low LTPA counterparts (HR = 0.44, 95% CI: 0.25-0.78). CONCLUSION: The results suggest that high levels of physical activity during leisure are associated with a lowered risk of LTSA, especially among younger women.

Dose-response association between multi-site musculoskeletal pain and work ability in physical therapists: a cross-sectional study.

PURPOSE: Multi-site musculoskeletal pain (MP) is common among health care professionals and is considered a threat to work ability and thereby a long and healthy working life. However, literature is scarce regarding these associations among physical therapists (PTs). This study aims to quantify the prevalence of local and multi-site MP among PTs, to investigate the associations between pain intensity and number of pain sites, respectively, with the level of work ability. METHODS: We conducted a survey among 1006 PTs about pain the previous month in different body areas and work ability. Work ability was measured using the Work Ability Index (WAI) including its seven categories. The odds of having lower level of work ability as a function of pain intensity (0-10) and multi-site pain were determined using binary logistic regression controlled for relevant confounders. RESULTS: The neck (36.3%) and the low back (32.3%) were the most commonly affected body areas. Furthermore, a dose-response relationship was observed between the number of pain sites and lower work ability (trend test, p < 0.001). With low pain intensity as reference, a moderate to strong association existed for lower levels of work ability in PTs who reported pain intensity of > 5 in one to two body regions (OR 2.14, 95% CI 1.27-3.60). This association was stronger when participants reported pain in three to four sites (OR 4.02, 95% CI 2.36-6.82) and even stronger when pain was experienced in five or more sites (OR 6.13, 95% CI 3.31-11.38). CONCLUSIONS: Multi-site MP is strongly associated-in a dose-response fashion-with lower levels of work ability among PTs.

Physical exposure during patient transfer and risk of back injury & low-back pain: prospective cohort study.

BACKGROUND: Work-related musculoskeletal disorders (MSDs) are common among healthcare workers. Because frequent patient transfer has been associated with increased risk of MSDs, we aim to quantify the physical load associated with commonly-used assistive devices and to investigate associations between accumulated physical exposure and risk of MSDs. METHODS: By applying an exposure matrix based on objective measurements of electromyography and trunk flexion on a large (n = 1285) prospective cohort, intensity of low-back pain (LBP) and odds of back injury at 1-year follow-up were modelled using linear models and logistic regressions, respectively. The cohort was divided into groups according to physical exposure; i.e. low (1st quartile), moderate (2nd and 3rd quartiles) and high (4th quartile) exposure. RESULTS: Exposure profiles are provided for 9 groups of assistive devices, with ceiling lifts and intelligent beds eliciting the lowest physical exposure. In the fully-adjusted model, we report differences in LBP intensity at follow-up between the low and moderate exposure groups (p = 0.0085). No difference was found between the moderate and high exposure groups (p = 0.2967). Likewise, we find no associations between physical exposure and odds of back injury at 1-year follow-up, with a prevalence of 11, 13 and 11% for the three groups, respectively. CONCLUSIONS: Low physical exposure during patient transfer was prospectively associated with lower intensity of LBP. Consistent use of assistive devices associated with low physical exposure, namely ceiling-lifts and intelligent beds, may play a role in reducing the incidence of MSDs among healthcare workers.

Biomechanical load during patient transfer with assistive devices: Cross-sectional study.

This study utilised a cross-sectional design to perform measurements of muscle activity as well as forward - and lateral trunk inclination angle during a full workday among 52 female healthcare workers from 16 different departments at five Danish hospitals. Using linear mixed models, the 95th percentile ranks of the normalised root mean square (nRMS) values were analysed for the different types of assistive devices. Compared to no assistive device (mean nRMS 27.9%, 95% CI 24.8%-31.0%), the use of intelligent beds (23.9%, CI 20.2%-27.6%) and ceiling-lifts (24.0%, CI 20.3%-27.7%) led to lower erector spinae nRMS values across all types of patient transfers. Conversely, the use of bedsheets (30.6%, CI 27.1%-34.2%), sliding-sheets (30.3%, CI 26.8%-33.9%) and sliding-boards (33.5%, CI 29.5%-37.6%) were associated with higher levels of erector spinae muscle activity.Consistent use of ceiling-lifts and intelligent beds reduces the physical workload and may thereby decrease the risk of musculoskeletal disorders among healthcare workers. Practioner Summary: Frequent patient transfer is associated with an increased risk of back pain and injury among healthcare workers. This analysis compares the level of physical load during patient transfer with commonly used assistive devices. The results show that use of the ceiling-lift and intelligent bed is associated with relatively low physical load during patient transfer. Abbreviations: RMS: root mean square; nRMS: normalized root mean square; EMG: electromyography; MSD: musculoskeletal disorder; LBP: low-back pain; VAS: visual analogue scale; MVC: maximal voluntary contraction.

Preoperative high-intensity strength training improves postural control after TKA: randomized-controlled trial.

PURPOSE: This study investigates the effectiveness of preoperative high-intensity strength training (with a special emphasis on lower limb muscle strength and secondarily on balance training) on postural control after TKA. METHODS: Forty-four subjects (7 men, 37 women, and mean age 66.7 ± 3.9 years) scheduled for unilateral TKA for osteoarthritis (OA) participated in this randomized-controlled trial. Each patient performed two postural control tests: Romberg test with eyes open and closed. These tests were assessed at 8 weeks before surgery (T1), after 8 weeks of training (T2), 1 month after TKA (T3), and finally 3 months after TKA (T4). The intervention group completed an 8-week training program 3 days per week prior to surgery, while the control group received no intervention. RESULTS: The Center of Pressure area (COP) was lower (i.e., better score) for the intervention group at T2, T3, and T4. The anteroposterior range of COP with eyes open was lower in the intervention group at T2, T3, and T4 and with eyes closed at T2. The medial-lateral standard deviation of COP with eyes open was lower in the intervention group at T2 and T4 and with eyes closed at T2 and T3. The anteroposterior standard deviation of COP with eyes open did not change, while that with eyes closed the intervention group showed lower score at T2. CONCLUSION: Preoperative high-intensity strength training is effective for improving postural control before and early after TKA. Recommendations should include preoperative strength training, and not only balance training, to speed-up recovery of postural control after TKA. LEVEL OF EVIDENCE: 1.

Influence of different attentional focus on EMG amplitude and contraction duration during the bench press at different speeds.

The purpose of this study was to investigate whether using different focus affects electromyographic (EMG) amplitude and contraction duration during bench press performed at explosive and controlled speeds. Eighteen young male individuals were familiarized with the procedure and performed the one-maximum repetition (1RM) test in the first session. In the second session, participants performed the bench press exercise at 50% of the 1RM with 3 different attentional focuses (regular focus on moving the load vs contracting the pectoralis vs contracting the triceps) at 2 speed conditions (controlled vs maximal speed). During the controlled speed condition, focusing on using either the pectoralis or the triceps muscles increased pectoralis normalized EMG (nEMG) by 6% (95% CI 3-8%; p = 0.0001) and 4% nEMG (95% CI 1-7%; p = 0.0096), respectively, compared with the regular focus condition. Triceps activity was increased by 4% nEMG (95% CI 0-7%; p = 0.0308) at the controlled speed condition during the triceps focus. During the explosive speed condition, the use of different focuses had no effect. The different attentional focus resulted in comparable contraction duration for the measured muscles when the exercise was performed explosively. Using internal focus to increase EMG amplitude seems to function only during conditions of controlled speed.

Hand strengthening exercises in chronic stroke patients: Dose-response evaluation using electromyography.

STUDY DESIGN: Cross-sectional. PURPOSE OF THE STUDY: This study evaluates finger flexion and extension strengthening exercises using elastic resistance in chronic stroke patients. METHODS: Eighteen stroke patients (mean age: 56.8 ± 7.6 years) with hemiparesis performed 3 consecutive repetitions of finger flexion and extension, using 3 different elastic resistance levels (easy, moderate, and hard). Surface electromyography was recorded from the flexor digitorum superficialis (FDS) and extensor digitorum (ED) muscles and normalized to the maximal electromyography of the non-paretic arm. RESULTS: Maximal grip strength was 39.2 (standard deviation: 12.5) and 7.8 kg (standard deviation: 9.4) in the nonparetic and paretic hand, respectively. For the paretic hand, muscle activity was higher during finger flexion exercise than during finger extension exercise for both ED (30% [95% confidence interval {CI}: 19-40] vs 15% [95% CI: 5-25] and FDS (37% [95% CI: 27-48] vs 24% [95% CI: 13-35]). For the musculature of both the FDS and ED, no dose-response association was observed for resistance and muscle activity during the flexion exercise (P > .05). CONCLUSION: The finger flexion exercise showed higher muscle activity in both the flexor and extensor musculature of the forearm than the finger extension exercise. Furthermore, greater resistance did not result in higher muscle activity during the finger flexion exercise. The present results suggest that the finger flexion exercise should be the preferred strengthening exercise to achieve high levels of muscle activity in both flexor and extensor forearm muscles in chronic stroke patients. The finger extension exercise may be performed with emphasis on improving neuromuscular control. LEVEL OF EVIDENCE: 4b.

Accuracy of identification of low or high risk lifting during standardised lifting situations.

The aim was to classify lifting activities into low and high risk categories (according to The Danish Working Environment Authority guidelines) based on surface electromyography (sEMG) and trunk inclination (tri-axial accelerometer) measurements. Lifting tasks with different weights, horizontal distance and technique were performed. The lifting tasks were characterised by a feature vector composed of either the 90th, 95th or 99th percentile of sEMG activity level and trunk inclinations during the task. Linear Discriminant Analysis and a subject-specific threshold scheme were applied and lifting tasks were classified with an accuracy of 65.1-65.5%. When lifts were classified based on the subject-specific threshold scheme from low and upper back accelerometers, the accuracy reached 52.1-58.1% and 72.7-78.1%, respectively. In conclusion, the use of subject-specific thresholds from sEMG from upper trapezius and erector spinae as well as inclination of the upper trunk enabled us to identify low and high risk lifts with an acceptable accuracy. Practitioner Summary: This study contributes to the development of a method enabling the automatic detection of high risk lifting tasks, i.e. exposure to high biomechanical loads, based on individual sEMG and kinematics from an entire working day. These methods may be more cost-effective and may complement observations commonly used by practitioners.

Mind-muscle connection training principle: influence of muscle strength and training experience during a pushing movement.

PURPOSE: To investigate the effect of different attentional focus conditions on muscle activity during the push-up exercise and to assess the possible influence of muscle strength and training experience. METHODS: Eighteen resistance-trained men performed 1RM bench press testing and were familiarized with the procedure during the first session. In the second session, three different conditions were randomly performed: regular push-up and push-up focusing on using the pectoralis major and triceps brachii muscles, respectively. Surface electromyography (EMG) was recorded and analyzed (EMG normalized to max; nEMG) for the triceps brachii and pectoralis major muscles. RESULTS: Participants had on average 8 (SD 6) years of training experience and 1RM of 1.25 (SD 0.28) kg per kg bodyweight. Focusing on using pectoralis major increased activity in this muscle by 9% nEMG (95% CI 5-13; Cohen's d 0.60) compared with the regular condition. Triceps activity was not significantly influenced by triceps focus although borderline significant, with a mean difference of 5% nEMG (95% CI 0-10; Cohen's d 0.30). However, years of training experience was positively associated with the ability to selectively activate the triceps (ß = 0.41, P = 0.04), but not the pectoralis. Bench press 1RM was not significantly associated with the ability to selectively activate the muscles. CONCLUSION: Pectoralis activity can be increased when focusing on using this muscle during push-ups, whereas the ability to do this for the triceps is dependent on years of training experience. Maximal muscle strength does not appear to be a decisive factor for the ability to selectively activate these muscles.

Electromyographic evaluation of high-intensity elastic resistance exercises for lower extremity muscles during bed rest.

PURPOSE: Prolonged hospital bed rest after severe injury or disease leads to rapid muscle atrophy and strength loss. Therefore, the main aim of this study was to evaluate the efficacy of lower extremity strengthening exercises using elastic resistance that can be performed while lying in a hospital bed. METHODS: Using a cross-sectional design, 22 healthy individuals performed three consecutive repetitions of 14 different lower extremity exercises using elastic resistance, with a perceived intensity corresponding to 8 on the Borg CR-10 scale. Surface electromyography was measured on 13 lower extremity muscles and normalized to the maximal EMG (nEMG). Likewise, exercise satisfaction was evaluated by a questionnaire. RESULTS: All participants were able to perform all exercises without discomfort and generally rated them satisfactory. High levels of muscle activity were observed for all prime movers. For example, the "femoris muscle setting" exercise showed high levels of muscle activity for rectus femoris, vastus lateralis, and vastus medialis (79, 75, and 79% nEMG, respectively), while biceps femoris and semitendinosus were highly active during the prone knee flexion exercise with (72 and 71% nEMG, respectively) and without Kinesiology Tape (73 and 77% nEMG, respectively). CONCLUSION: High levels of muscle activity in the lower extremities can be achieved using elastic resistance exercises performed when lying in a hospital bed. Even though performed on healthy individuals, the present study has the potential to provide a reference table of exercises to select from when individualizing and progressing strengthening exercises during the early rehabilitation of bedridden individuals.

Electromyographic Comparison of Elastic Resistance and Machine Exercises for High-Intensity Strength Training in Patients With Chronic Stroke.

OBJECTIVE: To investigate whether elastic resistance training can induce comparable levels of muscle activity as conventional machine training in patients with chronic stroke. DESIGN: Comparative study. SETTING: Outpatient rehabilitation facility. PARTICIPANTS: Stroke patients (N=18) with hemiparesis (mean age, 57 ± 8y). INTERVENTIONS: Patients performed 3 consecutive repetitions at 10 repetition maximum of unilateral knee extension and flexion using elastic resistance and conventional machine training. MAIN OUTCOME MEASURES: Surface electromyography was measured in vastus lateralis, vastus medialis, biceps femoris, and semitendinosus and was normalized to maximal electromyography (% of max) of the nonparetic leg. RESULTS: In the paretic leg, agonist muscle activity ranged from 18% to 24% normalized electromyography (% of max) (nEMG) during knee flexion and from 32% to 40% nEMG during knee extension. For knee extension, vastus lateralis nEMG was higher during machine exercise than during elastic resistance exercise (40% [95% confidence interval {CI}, 33-47] vs 32% [95% CI, 25-39]; P=.003). In the nonparetic leg, agonist muscle activity ranged from 54% to 61% during knee flexion and from 52% to 68% during knee extension. For knee flexion semitendinosus nEMG was higher (61% [95% CI, 50-71] vs 54% [95% CI, 44-64]; P=.016) and for knee extension vastus medialis nEMG was higher (68% [95% CI, 60-76] vs 56% [95% CI, 48-64]; P<.001) during machine exercise than during elastic resistance exercise. By contrast, antagonist coactivation was significantly higher during knee flexion when performed using elastic resistance compared with the machine. Lastly, there were no differences in perceived exertion between exercise modalities. CONCLUSIONS: Machine training appears to induce slightly higher levels of muscle activity in some of the investigated muscles compared to elastic resistance during lower limb strength training in patients with chronic stroke. The higher level of coactivation during knee flexion when performed using elastic resistance suggests that elastic resistance exercises are more difficult to perform. This is likely due to a higher level of movement instability.

Importance of mind-muscle connection during progressive resistance training.

PURPOSE: This study evaluates whether focusing on using specific muscles during bench press can selectively activate these muscles. METHODS: Altogether 18 resistance-trained men participated. Subjects were familiarized with the procedure and performed one-maximum repetition (1RM) test during the first session. In the second session, 3 different bench press conditions were performed with intensities of 20, 40, 50, 60 and 80 % of the pre-determined 1RM: regular bench press, and bench press focusing on selectively using the pectoralis major and triceps brachii, respectively. Surface electromyography (EMG) signals were recorded for the triceps brachii and pectoralis major muscles. Subsequently, peak EMG of the filtered signals were normalized to maximum maximorum EMG of each muscle. RESULTS: In both muscles, focusing on using the respective muscles increased muscle activity at relative loads between 20 and 60 %, but not at 80 % of 1RM. Overall, a threshold between 60 and 80 % rather than a linear decrease in selective activation with increasing intensity appeared to exist. The increased activity did not occur at the expense of decreased activity of the other muscle, e.g. when focusing on activating the triceps muscle the activity of the pectoralis muscle did not decrease. On the contrary, focusing on using the triceps muscle also increased pectoralis EMG at 50 and 60 % of 1RM. CONCLUSION: Resistance-trained individuals can increase triceps brachii or pectarilis major muscle activity during the bench press when focusing on using the specific muscle at intensities up to 60 % of 1RM. A threshold between 60 and 80 % appeared to exist.

Multimodal sensorimotor assessment of hand and forearm asymmetries: a reliability and correlational study.

Background: Effective rehabilitation of upper limb musculoskeletal disorders requires multimodal assessment to guide clinicians' decision-making. Furthermore, a comprehensive assessment must include reliable tests. Nevertheless, the interrelationship among various upper limb tests remains unclear. This study aimed to evaluate the reliability of easily applicable upper extremity assessments, including absolute values and asymmetries of muscle mechanical properties, pressure pain threshold, active range of motion, maximal isometric strength, and manual dexterity. A secondary aim was to explore correlations between different assessment procedures to determine their interrelationship. Methods: Thirty healthy subjects participated in two experimental sessions with 1 week between sessions. Measurements involved using a digital myotonometer, algometer, inclinometer, dynamometer, and the Nine-Hole Peg test. Intraclass correlation coefficients, standard error of the mean, and minimum detectable change were calculated as reliability indicators. Pearson's correlation was used to assess the interrelationship between tests. Results: For the absolute values of the dominant and nondominant sides, reliability was 'good' to 'excellent' for muscle mechanical properties, pressure pain thresholds, active range of motion, maximal isometric strength, and manual dexterity. Similarly, the reliability for asymmetries ranged from 'moderate' to 'excellent' across the same parameters. Faster performance in the second session was consistently found for the Nine-Hole Peg test. No systematic inter-session errors were identified for the values of the asymmetries. No significant correlations were found between tests, indicating test independence. Conclusion: These findings indicate that the sensorimotor battery of tests is reliable, while monitoring asymmetry changes may offer a more conservative approach to effectively tracking recovery of upper extremity injuries.

Identification of physically demanding work tasks among cleaners: field study using electromyography.

While chronic forearm pain is a common and debilitating condition among cleaners, the most physically demanding tasks remain unidentified. The present field study examines forearm muscle activity during 9 common cleaning tasks in a real working environment. Seven healthy cleaners participated in this study (age: 35.17 ± 9.62 yr; height: 168.17 ± 8.06 cm; weight: 77.14 ± 13.78 kg; experience: 5.60 ± 3.29 yr). Surface wireless electromyography (EMG) was recorded from 2 muscles on both sides of the upper limb, flexor carpi ulnaris (FCU), and extensor carpi radialis (ECR), and normalized to maximal voluntary isometric contractions (MVIC). Top-3 demanding high-force tasks (90th percentile EMG) were the rough floor, dirty rough floor, and office floor mopping for the FCU, and mopping high walls, ceiling mopping, and baize cleaning for the ECR. Top-3 static work tasks (10th percentile EMG) were mopping low walls, ceiling mopping, and dirty rough floors mopping for the FCU and mopping of high walls, low walls, and ceiling for the ECR. The study identified the forearm muscles' most physically demanding work tasks during cleaning tasks. The development of better working tools is recommended to avoid high-force overload as well as prolonged static overload of these muscles in cleaners.

Pain Control Beliefs Predict Premature Withdrawal From the Labor Market in Workers With Persistent Pain: Prospective Cohort Study With 11-Year Register Follow-up.

While a range of work-related psychosocial factors has been associated with various pain disorders and early retirement, less is known about pain cognitions and their influence on premature exit from the labor market. Therefore, as a primary objective, this study investigates associations between pain control beliefs and risk of disability pension among Danish eldercare workers. In 2005, 2257 female eldercare workers with low-back and/or neck/shoulder pain>90 days within the previous 12 months, replied to a survey and were followed for 11 years in a national register of social transfer payments. Using Cox regression, we estimated the risk of disability pension during follow-up from experiencing different levels of "pain control" and "pain influence," controlling for pain intensity and other relevant confounders. In the fully adjusted model for pain control with "high" as reference, hazard ratios of 1.30 (95% CI 1.03-1.64) and 2.09 (95% CI 1.45-3.01) are observed for "moderate" and "low," respectively, while the metric of pain influence shows hazard ratios of 1.43 (95% CI 1.11-1.87) and 2.10 (1.53-2.89), respectively. Pain control beliefs are associated with disability pension among eldercare workers with persistent pain. These results highlight the importance of evaluating not only bodily manifestations of pain, but also individual pain-related cognitions that may influence the experience of pain. PERSPECTIVE: This article addresses the complex experience of pain within an organizational context. We introduce the metrics of "pain control" and "pain influence" among workers with persistent pain, showing that the psychometric properties of these measures are prospectively associated with premature exit from the labor market.

Can Vitality and Mental Health Influence Upper Extremity Pain? A Prospective Cohort Study of 1185 Female Hospital Nurses.

Musculoskeletal disorders of the upper extremity are among the most common occupational problems affecting nurses. The aim of this study was to analyze the prospective association between vitality and mental health and increased upper extremity pain intensity in female hospital nurses during a 1-year follow-up. A prospective cohort of 1185 female nurses from 19 hospitals in Denmark was conducted using baseline and 12-month follow-up questionnaires to identify potential associations between levels of vitality and mental health (SF-36 subscales) with pain intensity (0-10 scale) in the shoulder, elbow and hand/wrist regions. Associations were modeled using cumulative logistic regression. The fully adjusted model included the variables of age, baseline pain, body mass index, smoking status, years of occupation, leisure time physical activity level, number of daily patient transfers/handlings, as well as recognition and influence at work. The mean age was 48.3 (SD: 10.4) years. In the fully adjusted model, significant associations between low vitality levels and the odds of shoulder pain (OR = 1.96; 95%CI: 1.43-2.68) and hand/wrist pain (OR = 2.32; 95%CI: 1.58-3.42) were observed. Likewise, moderate levels of mental health was associated with increased odds of shoulder pain at follow-up (OR = 1.50; 95%CI: 1.16-1.93). These results provide an important incentive for nursing managers to assess vitality and mental health among hospital nurses and to consider this factor in prevention strategies to ensure good worker health and, by extension, high-quality care.