Can a participatory organizational intervention improve social capital and organizational readiness to change? Cluster randomized controlled trial at five Danish hospitals.

AIM: This study investigates the effect of a participatory organizational intervention on social capital and organizational readiness for change. DESIGN: Cluster randomized controlled trial. METHODS: In 2016, 27 departments from five hospitals in Denmark were randomly allocated at the department level to 1 year of participatory intervention (14 clusters, 316 healthcare workers) or a control group (13 clusters, 309 healthcare workers). The participatory intervention consisted of 2 × 2 hr workshops, where managers, 2-5 healthcare workers from each department, and the hospital's health and safety staff, developed action plans for implementing solutions for improving the use of assistive devices at the department throughout the 1-year intervention period. Workplace social capital: (a) within teams (bonding); (b) between teams and nearest leaders (linking A); and (c) between teams and distant leaders (linking B) and organizational readiness for change were measured using questionnaires at baseline, 6, and 12 months. RESULTS: No group-by-time interaction occurred for any of the outcome measures. However, explorative post hoc analysis showed within-group improvements in bonding and linking B social capital and organizational readiness for change following the participatory intervention. CONCLUSION: Participatory organizational interventions may improve social capital within teams and between teams and distant leaders and organizational readiness for change. IMPACT: Implementing participatory interventions at the workplace may be a cost-effective strategy as they provide additional benefits, e.g., increased social capital and improved organizational readiness for change, that exceed the primary outcome of the intervention. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02708550) March 2016.

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.

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.

Inter-day reliability of surface electromyography recordings of the lumbar part of erector spinae longissimus and trapezius descendens during box lifting.

BACKGROUND: Low back pain and neck-shoulder pain are the most reported types of work-related musculoskeletal disorders, and performing heavy lifting at work and working with trunk rotation increase the risk of developing work-related musculoskeletal disorders. Surface electromyography (sEMG) provides information about the electrical activity of muscles. Thus it has the potential to retrieve indirect information about the physical exposure of specific muscles of workers during their actual work. This study aimed to investigate the inter-day reliability of absolute and normalized amplitude of sEMG measurements obtained during repeated standardized reference lifts. METHODS: The inter-day reliability of sEMG of the erector spinae longissimus and trapezius descendens muscles was tested during standardized box lifts. The lifts were performed with loads of 3, 15 and 30 kg from floor to table and from table to table in three conditions, i.e., forearm length (short reaching distance), ¾ arm length (long reaching distance) and forearm length with trunk rotation. Absolute and normalized root mean square (absRMS and normRMS) values were extracted. In line with the guidelines for reporting reliability and agreement studies, we reported relative and absolute reliability estimated by intra class correlation (ICC3,K), standard error of measurement (SEM) and minimal detectable change in percent (MDC). RESULTS: The ICC3,K was higher for absRMS compared with normRMS while SEM and maximal voluntary contraction (MVC) were similar. A total of 50 out of 56, i.e., 89%, and 41 out of 56, i.e., 73%, of the lifting situations were in the range from moderate to almost perfect for absRMS and normRMS, respectively. The SEM and MDC shoved more variation in the lifting situations performed from floor to table and in the trapezius descendens muscle than in the erector spinae longissimus muscle. CONCLUSION: This reliability study showed that maximum absRMS and normRMS were found to have a fair to substantial relative inter-day reliability for most lifts but were more reliable when lifting from table to table than from floor to table for both trapezius descendens and erector spinae muscles. The relative inter-day reliability was higher for absolute compared with normalized sEMG amplitudes while the absolute reliability was similar.

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.

Positive effects of 1-year football and strength training on mechanical muscle function and functional capacity in elderly men.

PURPOSE: A decline in physical capacity takes place with increasing age that negatively affects overall physical function including work ability and the ability to perform typical activities of daily living (ADL). The overall aim of the present study was to determine the neuromuscular adaptations to long-term (1 year) football and strength training in older untrained adults, and to assess the concurrent effect on functional ADL capacity. METHODS: Twenty-seven healthy elderly males (68.2 ± 3.2 years) were randomly assigned to 12 months of either recreational football training (FT: n = 10), strength training (ST: n = 9) or served as inactive controls (CON: n = 8). Recreational football training consisted of small-sided training sessions whereas strength training consisted of high intensity exercises targeting the lower extremity and upper body. Maximal thigh muscle strength and rate of force development (RFD) were assessed with isokinetic dynamometry, while postural balance and vertical jumping performance were evaluated using force plate analysis. Furthermore, functional ability was evaluated by stair-ascent and chair-rising testing. RESULTS: A total of nine, nine and seven participants from FT, ST and CON, respectively, were included in the analysis. Both exercise regimens led to substantial gains in functional ability, evidenced by 24 and 18 % reduced stair-ascent time, and 32 and 21 % increased chair-rising performance in FT and ST, respectively (all P < 0.05). Long-term strength training led to increased concentric (14 %; P < 0.01) and isometric (23 %; P < 0.001) quadriceps and isometric hamstring strength (44 %; P < 0.0001), whereas football training mainly resulted in enhanced hamstring strength (18 %, P < 0.05) and RFD (89 %, P < 0.0001). CONCLUSIONS: Long-term (1 year) strength training led to increased quadriceps and hamstring strength, whereas the adaptations to football training mainly included enhanced strength and rapid force capacity of the hamstring muscles. Gains in functional ability were observed in response to both training regimens, evidenced by reduced stair-ascent time and increased chair-rising performance. Long-term football exercise and strength training both appear to be effective interventional strategies to improve factors of importance for ADL by counteracting the age-related decline in lower limb strength and functional capacity among old male adults. This could potentially be a way to improve work ability of senior workers.

Physical exercise at the workplace reduces perceived physical exertion during healthcare work: cluster randomized controlled trial.

BACKGROUND: High physical exertion during work is a risk factor for musculoskeletal pain and long-term sickness absence. Physical exertion (RPE) reflects the balance between physical work demands and physical capacity of the individual. Thus, increasing the physical capacity through physical exercise may decrease physical exertion during work. This study investigates the effect of workplace-based versus home-based physical exercise on physical exertion during work (WRPE) among healthcare workers. METHODS: 200 female healthcare workers (age: 42.0, body mass index: 24.1, average pain intensity: 3.1 on a scale of 0 to 10, average WRPE: 3.6 on a scale of 0 to 10) from 18 departments at three participating hospitals. Participants were randomly allocated at the cluster level to 10 weeks of: (1) workplace physical exercise (WORK) performed in groups during working hours for 5×10 minutes per week and up to five group-based coaching sessions on motivation for regular physical exercise, or (2) home-based physical exercise (HOME) performed during leisure time for 5×10 minutes per week. Physical exertion was assessed at baseline and at 10-week follow-up. RESULTS: 2.2 (SD: 1.1) and 1.0 (SD: 1.2) training sessions were performed per week in WORK and HOME, respectively. Physical exertion was reduced more in WORK than HOME (p<0.01). Between-group differences in physical exertion at follow-up (WORK vs. HOME) was -0.5 points (95% CI -0.8 to -0.2). Within-group effect size (Cohen's d) in WORK and HOME was 0.43 and 0.13, respectively. CONCLUSIONS: Physical exercise performed at the workplace appears more effective than home-based exercise in reducing physical exertion during daily work tasks in healthcare workers.

Is Borg's perceived exertion scale a useful indicator of muscular and cardiovascular load in blue-collar workers with lifting tasks? A cross-sectional workplace study.

PURPOSE: To investigate associations between perceived exertion and objectively assessed muscular and cardiovascular load during a full working day among workers with manual lifting tasks. METHODS: A total of 159 men and 41 women from 14 workplaces with manual lifting tasks participated. Participants reported perceived exertion (BORG-CR10) at midday and after work. Surface electromyography of the thigh, lower back and neck muscles were normalized to isometric voluntary contractions (MVC) to express relative muscle load during the day. Cardiovascular load was measured with electrocardiography and calculated as the average percentage of the heart rate reserve capacity (((heart rate during work - resting heart rate) / (maximum heart rate - resting heart rate)) * 100) during the day. RESULTS: Using linear regression, significant but weak associations (ß < 0.23) were observed between perceived exertion and (1) high muscle activity (>60% of MVC) of the neck muscles and (2) inactivity (<1% of MVC) of the thigh muscles and (3) cardiovascular load, respectively. Using logistic regression, perceived exertion ≥4 (high exertion), referencing <4 (low-to-moderate exertion), was related to high activity of the trapezius muscle [OR 18 (95% CI 2-143)], i.e., the odds for experiencing high exertion during work increased 18-fold for each percentage increase in time above 60% MVC. CONCLUSIONS: During a full working day among blue-collar workers with lifting tasks, high neck muscle activity increases the odds for experiencing high perceived physical exertion. Perceived exertion of at least 4 on the BORG CR10 scale appears to be a good indicator that high muscular loading occurs.

EMG evaluation of hip adduction exercises for soccer players: implications for exercise selection in prevention and treatment of groin injuries.

INTRODUCTION: Exercise programmes are used in the prevention and treatment of adductor-related groin injuries in soccer; however, there is a lack of knowledge concerning the intensity of frequently used exercises. OBJECTIVE: Primarily to investigate muscle activity of adductor longus during six traditional and two new hip adduction exercises. Additionally, to analyse muscle activation of gluteals and abdominals. MATERIALS AND METHODS: 40 healthy male elite soccer players, training >5 h a week, participated in the study. Muscle activity using surface electromyography (sEMG) was measured bilaterally for the adductor longus during eight hip adduction strengthening exercises and peak EMG was normalised (nEMG) using an isometric maximal voluntary contraction (MVC) as reference. Furthermore, muscle activation of the gluteus medius, rectus abdominis and the external abdominal obliques was analysed during the exercises. RESULTS: There were large differences in peak nEMG of the adductor longus between the exercises, with values ranging from 14% to 108% nEMG (p<0.0001). There was a significant difference between legs in three of the eight exercises (35-48%, p<0.0001). The peak nEMG results for the gluteals and the abdominals showed relatively low values (5-48% nEMG, p<0.001). CONCLUSIONS: Specific hip adduction exercises can be graded by exercise intensity providing athletes and therapists with the knowledge to select appropriate exercises during different phases of prevention and treatment of groin injuries. The Copenhagen Adduction and the hip adduction with an elastic band are dynamic high-intensity exercises, which can easily be performed at any training facility and could therefore be relevant to include in future prevention and treatment programmes.

Influence of brick laying height on biomechanical load in masons: Cross-sectional field study with technical measurements.

BACKGROUND: Work-related musculoskeletal disorders (WMSDs) located in the low back and neck/shoulder regions are major concerns for both workers, workplaces, and society. Masons are prone to WMSD, because their work is characterized by repetitive work and high physical workload. However, the knowledge on the physical workload during bricklaying is primarily based on subjective measurements. OBJECTIVE: This cross-sectional field study with technical measurements aimed to quantify physical workload in terms of muscular activity and degree of forward bending during bricklaying at different working heights among masons, i.e., knee, hip, shoulder, and above shoulder height. METHODS: Twelve male (36.1±16.1 years) experienced masons participated in a cross-sectional field study with technical measurements. Surface electromyography from erector spinae longissimus and upper trapezius muscles and an inertial measurement unit-sensor placed on the upper back were used to assess the physical workload (level of muscle activation and degree of forward bending) different bricklaying heights. Manual video analysis was used to determine duration of work tasks, frequency, type, and working height. The working heights were categorized as 'knee', 'hip', 'shoulder', and 'above shoulder'. The 95 percentiles of the normalized Root Mean Square (RMSn) values were extracted assess from erector spinae and trapezius recordings to assess strenuous level muscle of muscle activation. RESULTS: The RMSn of dominant erector spinae muscle increased from hip- to shoulder height (from 26.6 to 29.6, P <  0.0001), but not from hip to above shoulder height and decreased from hip to knee height (from 26.6 to 18.9, P <  0.0001). For the dominant trapezius muscle, the RMSn increased from hip- to shoulder- and above shoulder height (from 13.9 to 19.7 and 24.0, respectively, P <  0.0001) but decreased from hip- to knee height (from 13.9 to 11.5, P <  0.0001). Compared to hip height (27.9°), an increased forward bending was detected during bricklaying at knee height (34.5°, P <  0.0001) and a decreased degree of forward bending at shoulder- and above shoulder height (17.6° and 12.5°, P <  0.0001, respectively). CONCLUSION: Based on technical measurements, bricklaying at hip height showed the best compromise between muscular load and degree of forward bending. This study contributes to the development of the work environment for masons and can help guide preventive initiatives to reduce physical workload.

Cardiovascular health effects of internet-based encouragements to do daily workplace stair-walks: randomized controlled trial.

BACKGROUND: Although the hazardous health effects of a sedentary lifestyle are well known, many adults struggle with regular physical activity. Simple and efficient encouragements for increased physical activity are needed. OBJECTIVE: To determine the effect on cardiovascular health of email-based encouragements to do daily stair-walks at work together with colleagues among adults in sedentary occupations. METHODS: A single-blind randomized controlled trial was performed at a large administrative company in Copenhagen, Denmark. Participants were 160 office workers (125 women, 35 men; mean age 42 years, SD 10; sitting 89.5% of work time). At baseline, aerobic fitness was 37 mL/min/kg (SD 9), mean blood pressure was 118/79 mmHg (SD 14/9), and mean body mass index (BMI) was 23 kg/m(2) (SD 4). Participants were randomly assigned (2:1 ratio) to an email group receiving weekly email-based encouragements to walk the stairs for 10 minutes a day or to a control group receiving weekly reminders to continue their usual physical activities. The primary outcome was the change from baseline to 10-week follow-up in aerobic fitness determined from a maximal cycle test. The examiner was blinded to group allocation. RESULTS: Adherence to the email encouragements was fairly high with 82.7% of the participants performing at least 3 sessions of 10-minute stair-walks per week (mean 3.3, SD 1.3). Mean heart rate reached 167 beats/min (SD 10) during stair-walks. In the intention-to-treat analysis, aerobic fitness increased 1.45 mL/min/kg (95% CI 0.64-2.27) at 10-week follow-up in the email group compared with the control group. In participants with low aerobic fitness at baseline (n=56), aerobic fitness increased 1.89 mL/min/kg (95% CI 0.53-3.24), and systolic and diastolic blood pressure decreased 4.81 mmHg (95% CI 0.47-9.16) and 2.67 mmHg (95% CI 0.01-5.32), respectively, in the email group compared with the control group. Body weight decreased in the email group of those with low aerobic fitness compared with the control group, but this was not statistically significant. CONCLUSIONS: Simple and inexpensive email-based encouragements to do daily stair-walks together with colleagues at work improves cardiovascular health among adults in sedentary occupations. There exists an enormous potential to prevent the hazardous health effects of a sedentary lifestyle through the use of email-based encouragements to do short bouts of physical activity at the workplace. TRIAL REGISTRATION: Clinicaltrials.gov NCT01293253; http://clinicaltrials.gov/ct2/show/NCT01293253 (Archived by WebCite at http://www.webcitation.org/6HWG2jw68).

The Importance of Lifting Height and Load Mass for Muscular Workload during Supermarket Stocking: Cross-Sectional Field Study.

High physical work demands increase the risk of musculoskeletal disorders and sickness absence. Supermarket work involves a high amount of manual material handling. Identifying specific ergonomic risk factors is an important part of occupational health and safety efforts in the supermarket sector. In this cross-sectional field study among 64 supermarket workers, we used electromyography during the workday to determine the influence of lifting height and load mass on muscular workload of the low-back and neck/shoulder muscles during un-restricted manual material handling (grocery stocking). We found a significant effect of load mass, i.e., higher loads associated with higher muscular workload in the low-back and neck/shoulder muscles. We demonstrated a significant interaction between start and end position, i.e., lifts performed from 'Low' start positions to 'High' end positions demonstrated the highest low-back muscular workload, whereas 'High' positions were associated with increased neck/shoulder workload. In conclusion, lifting higher loads and lifting goods from low to high positions (low-back) and at high positions (neck/shoulder) are associated with higher muscular workload. These results can be used to guide highly warranted preventive initiatives to reduce the physical workload during supermarket work.

Characterization of Occupational Lifting Patterns with Exposure Variation Analysis. Cross-sectional Workplace Study among Blue-Collar Workers.

OBJECTIVES: To investigate and characterize the influence of sex, age, muscle strength, and cardiovascular fitness on manual lifting patterns using exposure variation analysis (EVA) during a full working day among blue-collar workers. METHODS: Muscular activity (surface electromyography [sEMG]) of the thigh, low-back, and shoulder was measured throughout the working day in 173 employees with manual lifting tasks from 14 workplaces. Relative sEMG loading was expressed as % of maximal voluntary contraction (MVC). As an additional and more practically oriented analysis, calibration of load from standardized box lifts (5, 10, 20, and 30 kg) identified corresponding sEMG values in kg. Using an EVA 'lifting periods' of [1 to 5, >5 to 10, >10 to 20, >20 to 30, and >30] kg in time intervals [0 to 0.5, >0.5 to 1, >1 to 2, >2 to 5, >5 to 10, and >10] s were identified. Arm elevation and back inclination were measured using accelerometers. RESULTS: Females and older workers (≥50 years) primarily used the thighs for lifting and were exposed to more frequent thigh muscle 'lifting periods' of varying duration and load and performed more thigh lifts >30 kg and >60% of MVC compared with males and younger workers (P < 0.05). Females had less brief shoulder lifting periods and more work with bent back >30° than the males (P < 0.05), whereas stronger workers performed more work with elevated arm >60° and >90° than workers with low muscle strength (P < 0.05). However, besides a single difference where workers with lower cardiovascular fitness were exposed to more light (1-5 kg) and moderate duration (5-10 s) trapezius loading, the number of lifting periods was not affected by muscle strength nor cardiovascular fitness (P > 0.05). CONCLUSIONS: This EVA demonstrated sex- and age-related differences in exposure to lifting periods involving shoulder and thigh muscles.

Technical field measurements of muscular workload during stocking activities in supermarkets: cross-sectional study.

Multiple studies have reported high prevalence of musculoskeletal disorders among supermarket workers. Technical field measurements can provide important knowledge about ergonomic risk factors for musculoskeletal disorders in the physical working environment, but these measurements are lacking in the supermarket sector. Therefore, using wearable electromyography and synchronous video recording in 75 supermarket workers, this cross-sectional study measured muscular workload during stocking activities in six different types of general store departments and during the thirteen most common work tasks across five different supermarket chains. Our results showed that muscular workload varies, especially for the low-back muscles, across (1) supermarket chains, (2) departments, and (3) specific stocking activities. Highest workloads of the low-back and neck/shoulders were seen in the fruit and vegetables department and during heavy, two-handed lifts of parcels (especially without using technical aids). In conclusion, physical work demands during supermarket stocking activities differ between chains, departments, and work tasks. These results can be used by company representatives and work environment professionals to specifically address and organize the stocking procedures to reduce the muscular workload during supermarket stocking.

The effect of recreational soccer training and running on postural balance in untrained men.

The aim of this study was to examine the effect of intense intermittent exercise performed as soccer training or interval running in comparison with continuous endurance running exercise on postural balance in young healthy untrained males. Young sedentary men were randomized to soccer training (SOC, n = 10), continuous running (RUN; n = 9), high-intensity interval running (INT; n = 7) or no training (CON; n = 9). Postural balance was evaluated pre and post 12 weeks of training using a 30-s single-leg stance test on a force plate (AMTI) to yield center of pressure (CoP) sway path and 1-min beam standing (Flamingo test). CoP sway length decreased by 18.2% (p < 0.01), 14.6% (p < 0.05) and 12.8% (p < 0.05) in SOC, INT and RUN, respectively. CoP sway area decreased in SOC (-30.2%; p < 0.01) and INT (-23.4%; p < 0.01) but remained unaffected in RUN. Acceleration parameters (Mean CoP acc, SD accX, SD accY) decreased in SOC only (17-19%, p < 0.05). All training groups demonstrated fewer falls (37-41%, p < 0.01) in the Flamingo test. No changes were observed in CON. Relationships (r > 0.40) were observed between pre-training values in CoP sway area versus muscle fiber area, explosive muscle strength and countermovement jump velocity. Postural control was improved in response to 12 weeks of soccer training and high-intensity interval running, respectively, while less-marked changes were observed following continuous running. Notably, the reduced variability in CoP acceleration after soccer training indicates that this training regimen may produce superior improvements in postural sensory-motor function.

Single-item measures of stress during work- and private time in healthcare workers.

BACKGROUND: While the psychosocial work environment within the hospital sector is a topic of great debate, surveys assessing stress often do not differentiate between stress related to work- and private life. Identifying risk factors associated with these domains of daily life would help improve policies as well as target relevant treatment options. Therefore, the aim of this study was to evaluate associations between stress during to work- and private time with Cohen's Perceived Stress Scale (CPSS). METHODS: Perceived stress was assessed by the full version of CPSS (scores 0-40) as well as by two single-item questions related to stress related to work- and private life, respectively. Associations between these single-items and CPSS were modelled using general linear models controlling for lifestyle factors. RESULTS: Overall, stress due to both work- and private time was strongly associated with CPSS scores. In the full population (n = 3,600), "never experiencing stress" during both work- and private time was associated with low stress scores (6.0, 95%CI 5.1-6.9). "Never experiencing" work-related stress but experiencing private time stress "very often" was associated with high stress scores (22.4, CI 19.8-25.1). Likewise, experiencing work-related stress "very often" but "never experiencing" private time stress was also associated with high stress scores (22.2, CI 20.3-24.2). Lastly, Spearman's r between the full CPSS and the two single-item questions about work- and private time stress were 0.62 (p < 0.0001) and 0.52 (p < 0.0001), respectively, while the two items were only weakly correlated (r = 0.32). CONCLUSION: The present study shows that perceived stress due to both work and private time is strongly associated with Cohen's Perceived Stress Scale scores. The results illustrate the feasibility of using single-item questions related to work- and private time in identifying domain-specific risk factors for psychosocial stress.

Cross-sectional Study of EMG and EMG Rise During Fast and Slow Hamstring Exercises.

BACKGROUND: Hamstring injuries remain a major burden in football while the effective prevention exercise the Nordic Hamstring is poorly adopted, despite the added positive effects on performance. Better understanding of hamstring function during Nordic Hamstring compared to other exercises may provide better insight to the physiological adaptations of different types of hamstring curls. PURPOSE: This cross-sectional study therefore aimed to compare the Nordic Hamstring curl with a conventional prone Leg Curl at different loads, and novel high velocity Hamstring Catches; in terms of peak normalized electromyographical activity (nEMG) and rate of electromyographic rise (RER) of Biceps Femoris long head, and angular velocity of the knee. STUDY DESIGN: Cross-sectional study. METHODS: Out of 28 participants enrolled, the final sample included 23 recreationally active male participants who attended a session for determining RM (repetition maximum) to establish loading (8 and 16RM for Hamstring Catches, and 8, 16 and 24RM for Leg Curl) and to familiarize themselves with the three different exercises (Nordic Hamstring, Leg Curl and Hamstring Catch), and a testing session >4 days after during which EMG data were collected during 3 repetitions of each exercise performed in a random order. RESULTS: The Nordic Hamstring evoked higher RER (1091.8 nEMG/s) than Hamstring Catches (mean difference: 421 nEMG/s, p<0.0001) and Leg Curl (mean difference: 705 nEMG/s, p<0.001), and at the earliest numerical timepoint from onset of muscle contraction (the Nordic Hamstring: 6 ms; Hamstring Catches: 36-41 ms; Leg Curl: 12-14 ms). Hamstring Catches displayed high peak angular velocity (mean: 471°/s). There was no difference in peak nEMG, irrespective of load for Leg Curl (8, 16 or 24RM) or Hamstring Catches (8- or 16RM). CONCLUSION: The Nordic Hamstring displayed the highest level muscle activity and most explosive recruitment characteristics with early and high rate of electromyographic rise, compared to even high velocity exercises, thus providing a possible mechanism by which it may increase performance and reduce injuries. LEVELS OF EVIDENCE: 3. WHAT IS KNOWN ABOUT THE SUBJECT: Early phase force and muscle recruitment have been linked to both performance and hamstring-related inhibition and fatiguability. However, the potential for different hamstring exercises to elicit explosive recruitment is unknown. WHAT THIS STUDY ADDS TO EXISTING KNOWLEDGE: Early phase recruitment was higher and faster during the Nordic Hamstring exercise compared with conventional hamstring Leg Curl exercises with different loads and a high-velocity hamstring exercise. CLINICAL RELEVANCE: The surprisingly fast and explosive recruitment characteristics during the Nordic Hamstring exercise suggests the possibility that this exercise have the potential to improve the rate of force development and perhaps counter the effects of hamstring-related inhibition and fatigue.

Postural control and physiological responses to a simulated match in U-20 judo competitors.

The aim was to evaluate the effects of judo combat on the athletes' postural control (PC) and physiological loading before, during and after a simulated match. Seventeen under-20 regional and national level athletes completed one modified 7-min match. At baseline, during the combat (3rd and 7th minutes) and 2-min post-match centre of pressure (CoP) parameters were assessed. Heart rate (HR), blood lactate (BLa) and rating of perceived exertion (RPE) and local RPE (LRPE) were collected. Significant increments were observed in CoP mean positioning and velocity at 3rd and 7th minutes, but the CoP deviation in both axes was unaffected. HR and BLa were elevated at 3rd and 7th minutes, and they remained elevated 2-min post-match. However, CoP returned to baseline 2-min post-match. RPE was elevated at 3rd and 7th minutes and the greatest effort was displayed in the Deltoid and Quadriceps. Thus, one simulated judo match stimulates a significant metabolic response and balance is degraded, with the greatest effects on the anterior-posterior axis and it recovers to baseline level after 2 min of passive rest. The physiological load cannot be regarded as a potential predictor variable of CoP. Overall, a judo match predominantly affects the upper body than the other body parts.

Physical and Psychosocial Work Environmental Risk Factors for Back Injury among Healthcare Workers: Prospective Cohort Study.

The incidence of occupational back injury in the healthcare sector remains high despite decades of efforts to reduce such injuries. This prospective cohort study investigated the risk factors for back injury during patient transfer. Healthcare workers (n = 2080) from 314 departments at 17 hospitals in Denmark replied to repeated questionnaires sent every 14 days for one year. Using repeated-measures binomial logistic regression, controlling for education, work, lifestyle, and health, the odds for back injury (i.e., sudden onset episodes) were modeled. On the basis of 482 back injury events, a higher number of patient transfers was an important risk factor, with odds ratio (OR) 3.58 (95% confidence interval (CI) 2.51-5.10) for 1-4 transfers per day, OR 7.60 (5.14-11.22) for 5-8 transfers per day, and OR 8.03 (5.26-12.27) for 9 or more transfers per day (reference: less than 1 per day). The lack of necessary assistive devices was a common phenomenon during back injury events, with the top four lacking devices being sliding sheets (30%), intelligent beds (19%), walking aids (18%), and ceiling lifts (13%). For the psychosocial factors, poor collaboration between and support from colleagues increased the risk for back injury, with OR 3.16 (1.85-5.39). In conclusion, reducing the physical burden in terms of number of daily patient transfers, providing the necessary assistive devices, and cultivating good collaboration between colleagues are important factors in preventing occupational back injuries among healthcare workers.

Are Insomnia Type Sleep Problems Associated With a Less Physically Active Lifestyle? A Cross-Sectional Study Among 7,700 Adults From the General Working Population.

Background: Sleep problems are common in the general population and negatively affect both private and work life. A vicious circle may exist between poor sleep and an unhealthy lifestyle. For example, poor sleep may drain the energy to do health-promoting physical activity during leisure-time after work. The aim of the present study was to investigate the association between sleep problems and the duration of low- and high-intensity leisure-time physical activity in sedentary and physical workers. Methods: This cross-sectional study employ data from the Danish Work Environment Cohort Study in 2010, where currently employed wage-earners in Denmark on daytime schedule (N = 7,706) replied to questions about sleep quality (cf. the Bergen Insomnia Scale) and participation in low- and high-intensity leisure-time physical activity. Associations were modeled using general linear models controlling for various confounders. Results: Workers with high levels of sleep problems reported less high-intensity leisure-time physical activity. Specifically, the weekly duration of high-intensity leisure-time physical activity was 139 (95%CI 111-168), 129 (95%CI 101-158), and 122 (95%CI 92-151) min in sedentary workers with sleep problems < 1, 1-3, and ≥3 days per week, respectively. The same pattern was observed among physical workers. In sedentary workers ≥50 years, the fully adjusted model showed a weekly duration in high-intensity physical activity during leisure of 122 (95%CI 83-161), 102 (95%CI 64-141), and 90 (95%CI 51-130) among those with sleep problems < 1, 1-3, and ≥3 days per week, respectively. Conclusions: Workers, particularly sedentary older workers, having sleep problems report less high-intensity leisure-time physical activity. These data suggest that a vicious circle may indeed exist between poor sleep and reduced leisure-time physical activity.