Impact of urinary incontinence on quality of life in female CrossFit practitioners: A cross-sectional study

OBJECTIVE

Investigate the impact of urinary incontinence (UI) on quality of life (QoL) in female CrossFit practitioners and to verify the strategies used by them to minimize the occurrence of urine leakage. In addition, to verify whether anthropometric and clinical characteristics increase the UI impact on QoL of female CrossFit practitioners.

STUDY DESIGN

This was an online cross-sectional survey. The impact of UI on QoL was investigated by International Consultation on Incontinence Questionnaire - Short Form (ICIQ-SF). Associations between the impact of UI on QoL and the clinical (age, BMI, gestations, mode of delivery, practice of other physical activities) and the others pelvic floor dysfunctions (PFD) related independent variables were tested using logistic regression analysis.

RESULTS

A total of 828 female CrossFit practitioners answered the questionnaire and 36% reported UI symptoms. The women who obtained the highest score on the ICIQ-SF have high UI interference in QoL. Previous history of two or more gestations and sexual dysfunctions (dyspareunia or vaginismus) or pelvic organ prolapse increase 2.65 and 1.82 times the risk of female CrossFit practitioners with UI having a high impact of UI on their QoL, respectively (OR = 2.65 95% CI 1.30-5.40, p = 0.01; and OR = 1.82 95% CI 1.04-3.21, p = 0.04, respectively). The most strategies used by them to minimize the occurrence of urine leakage were emptying the bladder before training (77.5%) and use absorbent (17.8%).

CONCLUSIONS

Women who had higher scores on the ICIQ-SF reported greater impact on QoL, and the previous history of two or more gestations and sexual dysfunction/pelvic organ prolapse increase the risk of women with UI who practice CrossFit to have a greater impact on QoL. Multigravida and women with sexual dysfunction/pelvic organ prolapse who practice CrossFit could have more attention on the UI symptoms due to the high impact on their QoL.

Cross-cultural adaptation and psychometric properties of the short version of COPSOQ II-Brazil

OBJECTIVES

Translate and culturally adapt the short version of Copenhagen Psychosocial Questionnaire II (COPSOQ II) into Brazilian Portuguese (COPSOQ II-Br) and evaluate its psychometric properties.

METHODS

Translation and cultural adaptation followed the standardized guidelines. Structural validity was assessed using exploratory factorial analysis. Test-retest reliability was evaluated by intraclass correlation coefficient (ICC_3,1) and internal consistency by Cronbach’s alpha. Floor and ceiling effect was considered acceptable if less than 15% of participants reported the lowest or highest scores. Measurement error was assessed by standard error of measurement (SEM), while construct validity was tested by correlating the COPSOQ II-Br, the Job Content Questionnaire and the Nordic Musculoskeletal Questionnaire.

RESULTS

The study evaluated a total of 211 civil servants and service providers in the test and 157 in the retest. After cross-cultural adaptation, the COPSOQ II-Br structure comprised seven domains and 11 dimensions. Most dimensions showed acceptable floor and ceiling effects, excepting “Work family conflicts” (floor effect of 26.1%), and “Meaning and commitment” and “Job satisfaction,” with ceiling floor of 27.5% and 22.3%, respectively. Cronbach’s alpha values reached the recommended levels (varied between 0.70 and 0.87). Test-retest reliability indicated that all dimensions had ICC between 0.71 and 0.81. SEM ranged from 0.6 to 2.2 and the construct validity showed good results with the tested instruments (significant positive and negative correlations).

CONCLUSIONS

All psychometric properties of the short version COPSOQ II-Br are suitable for use in Brazil. The instrument is thus validated and can be used by occupational health and human resources professionals to evaluate psychosocial working conditions.

Musculoskeletal symptoms in formal and informal caregivers of elderly people

OBJECTIVE

to evaluate musculoskeletal symptoms in formal and informal caregivers of elderly people, and check association with personal and work-related factors.

METHODS

this is a cross-sectional study. Instruments for assessment were the International Physical Activity Questionnaire, Self-Reporting Questionnaire-20, Borg's effort perception scale and Nordic Musculoskeletal Questionnaire.

RESULTS

informal caregivers had been working for a longer time (60.2% vs. 41%), had more hours of work (37.4% >12h for day), less time off (85.4% vs. 2.5%) and lack of care guidelines (90.2%). The region with the most musculoskeletal symptoms was the spine and the greater dependence of the elderly, the greater the chances of developing musculoskeletal symptoms (OR= 1.3, 95% CI= 1.1-1.6, p <0.05).

CONCLUSION

personal and work-related factors were more prevalent in informal group and the elderly person's dependence interferes with the increase in musculoskeletal symptoms of caregivers.

Is there agreement between the preference of examiner and women for unidigital and bidigital vaginal palpation? A qualitative study

INTRODUCTION AND HYPOTHESIS

The International Continence Society recommends vaginal palpation as a method for assessing pelvic floor muscle (PFM) function. Our aim was to analyze the agreement between preferences of examiner and participants according to unidigital and bidigital vaginal palpation during PFM assessment. The second aim was to investigate qualitatively women's perception of vaginal palpation.

METHODS

Maximal voluntary contractions (MVCs) were requested during both types of vaginal palpation and were classified by the Modified Oxford Scale (MOS). Examiner and participants answered if they had preferences regarding vaginal palpation. Women answered qualitatively what they felt during the assessment. Cohen's linear kappa (κ) evaluated the agreement after allocation of the women with a weaker and stronger MVC and qualitative analysis was performed by transcription considering age range (18-35; 36-59; ≥60 years).

RESULTS

Agreement was almost zero for women with weaker and stronger MVC at unidigital (κ = 0.06 and κ = -0.12) and bidigital vaginal palpation (κ = 0.008 and κ = 0.005). Participants associated bidigital palpation with more perception and an easier way of contracting the PFMs. Women between 36 and 59 years associated unidigital palpation with a harder but comfortable way of contracting the PFMs. Subjects aged ≥60 years associated bidigital palpation with an uncomfortable, harder way of contracting PFM, with less space into the vagina.

CONCLUSIONS

Agreement between preferences was almost zero neither between women with a weaker and stronger PFM contraction, nor between the types of vaginal palpation. Bidigital palpation increased women's perception, made the contraction easier, and was associated with less space in the vaginal canal and less comfort.

Cardiovascular benefits of a home-based exercise program in patients with sickle cell disease

BACKGROUND

Physical inactivity is an important risk factor for cardiovascular disease. The benefits of exercise in patients with chronic diseases, including cardiovascular diseases, are well established. For patients with sickle cell disease, medical recommendation was to avoid physical exercise for fear of triggering painful crises or increasing the impairment of the cardiopulmonary function. Only recently, studies have shown safety in exercise programs for this population. Despite that, there is no report that assess the effects of physical exercise on cardiac parameters in patients with sickle cell disease.

OBJECTIVE

This study aimed to evaluate the impact of regular physical exercise (a home-based program) on cardiovascular function in patients with sickle cell disease.

DESIGN

A quasi-randomized prospective controlled trial.

SETTING

During the years 2015 and 2016, we started recruiting among adult patients treated at a Brazilian Center for Patients with Sickle Cell Disease to participate in a study involving a home exercise program. The experimental (exercise) and control groups were submitted to clinical evaluation and cardiovascular tests before and after the intervention. Analysis of variance was applied to compare groups, considering time and group factors.

PARTICIPANTS

Twenty-seven adult outpatients with a sickle cell disease diagnosis.

INTERVENTIONS

Exercise group (N = 14): a regular home-based aerobic exercise program, three to five times per week not exceeding give times per week, for eight weeks; no prescription for the control group (N = 13).

MAIN OUTCOME MEASURES

Echocardiographic and treadmill test parameters.

RESULTS

The exercise group showed significant improvement in cardiovascular tests, demonstrated by increased distance traveled on a treadmill (p<0.01), increased ejection fraction (p < 0.01) and improvement of diastolic function assessed by mitral tissue Doppler E' wave on echocardiography (p = 0.04). None of the patients presented a sickle cell crisis or worsening of symptoms during the exercise program.

CONCLUSION

The selected home-based exercise program is safe, feasible, and promotes a favorable impact on functional capacity and cardiovascular function in sickle cell disease patients.

Heart rate during work and heart rate variability during the following night: a day-by-day investigation on the physical activity paradox among blue-collar workers

Objectives:

Contrary to leisure-time physical activity, occupational physical activity (OPA) may have harmful health effects, called the physical activity paradox. A proposed mechanism is that OPA can elevate the heart rate (HR) for several hours per day. We aimed to investigate the association between the mean intensity of OPA and HR variability (HRV) indices the following night.

Methods:

Three cohorts (NOMAD, DPhacto, and Physical Workload and Fitness) involving blue-collar workers from different sectors were merged in this study. HR monitors (Actiheart) recorded 24-hour inter-beat intervals (IBI) for up to four consecutive days. The relative intensity of the mean HR during work was estimated by HR reserve (%HRR), and time-domain indices of HRV were analyzed during the following night. Data were analyzed using a multilevel growth model to test the association between mean %HRR during work and HRV indices at night in a day-by-day analysis adjusted for age, BMI, alcohol consumption, smoking, and occupation.

Results:

The dataset included a sample of 878 Danish blue-collar workers, with a mean %HRR during work of 31%, and 42% worked at an intensity ≥30%HRR. The multilevel model showed negative within- and between-subject associations between %HRR during work and HRV indices at night.

Conclusions:

Our results indicate a higher %HRR during work to associate with lower HRV indices the following night and a higher HR, reflecting an imbalanced autonomic cardiac modulation. This finding supports a high mean HR during work to be a potential underlying mechanism for the harmful health effect of OPA.

Inter- and intrarater reliability of unidigital and bidigital vaginal palpation to evaluation of maximal voluntary contraction of pelvic floor muscles considering risk factors and dysfunctions

AIMS

To evaluate inter- and intrarater reliability of unidigital and bidigital vaginal palpation of pelvic floor muscle (PFM) maximal voluntary contraction (MVC) according to PFM risk factors and dysfunctions.

METHODS

A total of 187 women were recruited and evaluated by two examiners. Both performed the evaluation of MVC with unidigital and bidigital palpation, graded by Modified Oxford Scale. After 7-10 days, one examiner repeated the assessment. To analyze reliability by Cohen's linear Kappa (κw), participants were allocated into different groups according to: body mass index (BMI), menopause, parity, type of delivery and PFM dysfunctions, as pelvic organ prolapse (POP), constipation, urgency, urgency urinary incontinence, pelvic pain, and stress urinary incontinence.

RESULTS

Inter-rater reliability of unidigital palpation was considered fair (κw = 0.21-0.40) to moderate (κw = 0.41-0.60) according to BMI, postmenopausal status, parity, type of delivery, and PFM dysfunctions. Inter-rater reliability of bidigital palpation varied from none (κw = 0.00-0.20) to moderate for all risk factors and PFM dysfunctions. Intra-rater reliability of unidigital palpation was considered fair only for women with POP (κw = 0.37) and moderate to substantial (κw = 0.61-0.80) to all other variables. Intra-rater reliability of bidigital palpation ranged from moderate to almost perfect (κw = 0.81-1.00).

CONCLUSIONS

When performing vaginal palpation, physiotherapists must consider the way that is performing the evaluation, as some PFM risk factors and dysfunctions could influence the inter- and intrarater reliability of unidigital and bidigital palpation.

Pelvic floor dysfunctions and associated factors in female CrossFit practitioners: a cross-sectional study

INTRODUCTION AND HYPOTHESIS

It is known that high-impact exercises can cause an increase in intra-abdominal pressure and provide overload in the pelvic floor structures. We hypothesized that female CrossFit practitioners would report symptoms of pelvic floor dysfunction (PFD) and that there will be factors associated with these dysfunctions.

METHODS

The study design is an online cross-sectional survey. Demographic and anthropometric data, the characterization of CrossFit activity, the description of PFD and previous obstetric history were collected through a structured web-based questionnaire. Associations between PFD and the clinical and CrossFit-related independent variables were tested using logistic regression analysis.

RESULTS

A total of 828 female CrossFit practitioners answered the questionnaire. The most prevalent symptom was anal incontinence (AI) (52.7%), with flatus incontinence (FI) being the most reported (93.3%). Women who reported constipation are 1.7 times more likely to have FI, and women who practice CrossFit more than five times a week are 3.0 times more likely to have FI. Urinary incontinence(UI) affected 36% of women, and 84.2% of participants reported urinary loss during CrossFit practice. The occurrence of dyspareunia was reported by 48.7% and showed an inverse association with age and body mass index. POP was reported by only 1.4% of the sample.

CONCLUSION

There is a high prevalence of PFD in female CrossFit practitioners, with AI being the most reported symptom, especially FI. In addition, constipation and weekly training frequency were significantly associated with FI. UI occurred primarily in CrossFit exercises, and dyspareunia was the most prevalent sexual symptom.

Activation of pelvic floor, lumbar and abdominal musculature during a simulated manual material handling task: a cross-sectional study

ABSTRACT Pelvic floor muscles act synergistically with the abdominal and lumbar muscles contributing to spine and pelvic control. These muscles are activated during activities that increase intra-abdominal pressure, such as manual material handling. The aim of our study was to assess the electrical activity of the lumbar, abdominal and pelvic floor muscles during manual material handling with different loads. This is a cross-sectional study with sixteen nulliparous continent women aged between 18 and 35 years. An electromyographic system was used to evaluate the activation of the multifidus, erector spinal (iliocostal) and abdominal rectus muscles bilaterally (Trigno Wireless®, DelSys®, Boston, USA) and another for the pelvic floor muscles (Thought Technology Ltd, Canadá). Electromyographic data were collected during manual handling of three loads: light (1.5 kg), medium (4.5 kg) and heavy (11.3 kg). Repeated measures ANOVA was applied to compare the activation among loads at a 5% level of significance (α = 0.05). There was a significant increase in the activation of the lumbar and abdominal musculature as the load increases. No difference among loads was found for the pelvic floor muscle activation. Pelvic floor muscles did not increase their activation in function of the load, as occur for the lumbar and abdominal muscles in nulliparous continent women. These findings need to be confirmed for incontinent woman, since it could have clinical implications for designing both occupational tasks and pelvic floor rehabilitation.

Factors associated with musculoskeletal symptoms and heart rate variability among cleaners - cross-sectional study

BACKGROUND

The professionals who perform cleaning activity constitute a major economic sector in Brazil. Cleaners may develop health problems related to the musculoskeletal and cardiovascular systems. It is necessary to understand the working and health conditions of cleaners in Brazil. Thus, the aim of this study was to identify factors associated with musculoskeletal symptoms and heart rate variability (HRV) among cleaners.

METHODS

A cross-sectional study conducted at a public higher education institution with 45 outsourced cleaners following approval from the institutional ethics committee. The participants answered a questionnaire addressing sociodemographic, occupational and health data, the Nordic Musculoskeletal Questionnaire, the Physical Activity Questionnaire (work and leisure) and the short version of the Copenhagen Psychosocial Questionnaire. Clinical data (height, body mass, waist-to-hip ratio and blood pressure) and heart rate variability (HRV) were also collected. Logistic and linear regression models were created to identify factors associated with symptoms and HRV.

RESULTS

The sample consisted of women (100%) predominantly older than 50 years of age (44%), without a conjugal life (64%), with three or more children (59%), low educational level (58%) and who worked less than 12 months at the company (87%). Systemic arterial hypertension (23%) was the most reported health problem. The highest frequency of musculoskeletal symptoms was identified in the lower limbs (ankles/feet: 31% in the previous 12 months and 24% in the previous 7 days; knees: 31% in the previous 12 months and 20% in the previous 7 days). Moreover, the workers reported not practicing physical activity during leisure time (84%). Psychosocial aspects indicated health risks for the dimensions "influence at work" (74%), "burnout" (59%) and "stress" (52%). Associations were found between ankle/foot symptoms and body mass index, shoulder symptoms and predictability, and knee symptoms and self-rated health and burnout. HRV indices were associated with age.

CONCLUSIONS

This study outlined the profile of female cleaners and identified risk factors. The workers exhibited musculoskeletal symptoms, which were associated with the body mass index and some psychosocial factors. HRV indices were associated with age. Thus, health promotion and prevention measures should be taken to benefit this population of workers.

IMPACT OF STRESS ON THE QUALITY OF LIFE OF HOSPITAL NURSING WORKERS

ABSTRACT Objective: to analyze the association between socio-occupational characteristics, stress level, and quality of life in hospital Nursing workers. Method: a cross-sectional, quantitative study, with data collected by means of a socio-occupational questionnaire to survey the profile of the workers, the Bianchi Stress Scale to assess stress, and the WHOQOL-Bref to assess quality of life. Results: 180 Nursing workers participated in the research, being 49 nurses and 131 Nursing technicians and assistants, most of them women, predominantly aged up to 35 years old, married, and with up to three years of experience in the sector. In general, the participants presented medium stress level, with a higher level among the nurses, and greater satisfaction with the quality of life level related to the physical (65.6%), psychological (64.7%), and social relationships (67.9%) domains. This study identified significant associations between stress and quality of life in hospital Nursing workers. Conclusion: it was demonstrated that there was an association between stress and quality of life, and the greater the stress, the lower the quality of life in hospital Nursing workers.

Comparison of two methods of sorting recyclable materials on posture among trash sorters in Brazil: a cross-sectional study

Objective. The aim of the present study was to compare postural exposure between two methods of sorting recyclable materials: manual sorting on a fixed work surface and the use of conveyor belts. Materials and methods. Postures and movements of the head, upper back and upper arms were recorded during 2 h among 40 workers using inclinometers. Sociodemographic variables were collected with the aid of a standardized questionnaire and musculoskeletal symptoms were evaluated using the Nordic musculoskeletal questionnaire. Results. The angular velocity of the head, upper back and upper arms was significantly higher when sorting on a fixed work surface compared to the conveyor belt method. Upper arm elevation was also higher on the fixed work surface. Conclusion. The conveyor belt method showed lower angular velocities during the manual sorting of recyclable materials compared to a fixed work surface.

Rapid office strain assessment (ROSA): Cross cultural validity, reliability and structural validity of the Brazilian-Portuguese version

Forty-three occupational health professionals (observers) and 90 workers were enrolled in this study to perform the cross-cultural adaptation of the Rapid Office Strain Assessment into Brazilian Portuguese (ROSA-Br) and evaluate its psychometric properties. After cross-cultural adaptation, the measurement properties were checked in three stages: study 1: pre-testing (27 observers rated 15 office worker videos), study 2: intra- and inter-observer reliability (26 observers rated 15 office worker videos), and study 3: validity and accuracy of ROSA-Br final scores (90 office workers). For the ROSA scores, acceptable intraclass correlation coefficients were found for 75% and 86% of the intra-observer reliability comparisons for non-trained and trained observers, respectively, and for 100% of the inter-observer reliability comparisons (0.43-0.86). For construct validity, moderate correlations were observed for 70% of the comparisons between ROSA final scores and other ergonomic instruments. Moderate accuracy was observed for a ROSA-Br final score of 6 (AUC [area under the curve] = 0.72, 0.89). Taken together, these results support the use of the ROSA-Br for ergonomic field assessments and research.

Effects of a muscular stretching and strengthening school-based exercise program on posture, trunk mobility, and musculoskeletal pain among elementary schoolchildren - a randomized controlled trial

Abstract Introduction: The exercise benefits for the most prevalent postural changes require proper investigation, with large samples, control group, and concealed allocation. Objective: To assess the effects of a muscular stretching and strengthening school-based exercise program on posture, trunk mobility, and musculoskeletal pain among elementary schoolchildren. Method: Three hundred students from three schools in Brazil were evaluated. Stretching and strengthening exercises, twice a week, for eight weeks in group sessions were provided by one physiotherapist. The control group did not undergo any intervention. Head, back and shoulder posture were qualitatively evaluated. Head and trunk alignment were evaluated using the Posture Assessment Software. Cervical, thoracic, low back and upper limb pain were assessed for the last seven days. The trunk mobility was recorded through the flexibility of the posterior chain. Posture, pain and trunk mobility were recorded at baseline and after the intervention. Groups were compared using χ2 test, two-way MANOVA, and two-way ANOVA, with α set at 5%. Results: Shoulder posture showed significant results (P = 0.04), the intervention group showed the lower worsening rate. In the quantitative evaluation, a statistically significant difference was observed between assessments (P < 0.01 for head and trunk; ES = 0.53) but not between groups. The intervention group had a higher percentage of improvement in the overall musculoskeletal pain (P = 0.04; ES = 0.54). Mobility decreased an average of 1.8° in the control group and increased 5.0° in the intervention group, without statistical significance. Conclusion: The program was effective in reducing pain level and shoulder misalignment at the intervention group.

The association between multisite musculoskeletal pain and cardiac autonomic modulation during work, leisure and sleep - a cross-sectional study

Background

The prevention and rehabilitation of multisite musculoskeletal pain would benefit from studies aiming to understand its underlying mechanism. Autonomic imbalance is a suggested mechanism for multisite pain, but hardly been studied during normal daily living. Therefore, the aim of the study is to investigate the association between multisite musculoskeletal pain and cardiac autonomic modulation during work, leisure and sleep.

Methods

This study is based on data from the “Danish Physical activity cohort with objective measurements” among 568 blue-collar workers. Pain intensity scales were dichotomized according to the median of each scale, and the number of pain sites was calculated. No site was regarded as the pain-free, one site was considered as single-site musculoskeletal pain and pain in two or more sites was regarded as multisite musculoskeletal pain. Heart rate variability (HRV) was measured by an electrocardiogram system (ActiHeart) and physical activity using accelerometers (Actigraph). Crude and adjusted linear mixed models were applied to investigate the association between groups and cardiac autonomic regulation during work, leisure and sleep.

Results

There was no significant difference between groups and no significant interaction between groups and domains in the crude or adjusted models for any HRV index. Significant differences between domains were found in the crude and adjusted model for all indices, except SDNN; sleep time showed higher values than leisure and work time, except for LF and LF/HF, which were higher during work.

Conclusion

This cross-sectional study showed that multisite musculoskeletal pain is not associated with imbalanced cardiac autonomic regulation during work, leisure and sleep time.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2312-3) contains supplementary material, which is available to authorized users.

Relationship between rearfoot, tibia and femur kinematics in runners with and without patellofemoral pain

BACKGROUND

Patellofemoral pain (PFP) is the most common running overuse injury. Excessive rearfoot eversion is commonly considered as a PFP risk factor and the relationship between ankle-foot complex movement and lower limb may be involved with this dysfunction. The purpose of this study was to evaluate the correlation between rearfoot eversion with tibia and femur kinematics in frontal and transverse planes during running in individuals with and without PFP. The secondary purpose was to compare the lower limb kinematics between runners with and without PFP.

METHODS

Fifty-four recreational runners were divided into 2 groups: healthy runners (CG, n = 27) and runners with patellofemoral pain (PFPG, n = 27). Kinematics during running were assessed using three-dimensional motion analysis system. Pearson's correlation coefficients (r) were calculated to establish the correlation of rearfoot eversion with tibial and femur movements.

FINDINGS

Greater peak rearfoot eversion was correlated with greater peak femur adduction in PFP runners. Greater peak rearfoot eversion was correlated with greater peak tibial internal rotation and tibial adduction in the PFPG and CG. Additionally, greater peak rearfoot eversion was correlated with greater tibial internal rotation range of motion in the PFPG and CG. No significant differences were found between the PFPG and CG for all kinematics variables.

INTERPRETATION

Correlation between greater rearfoot eversion and greater peak hip adduction in the PFPG might be related to PFP persistence in runners with excessive rearfoot eversion, and indicates that treatment strategies aimed at controlling the movement of the rearfoot could help modify the symptoms.

Effects of work surface and task difficulty on neck-shoulder posture and trapezius activity during a simulated mouse task

OBJECTIVES

The purpose of this study is to evaluate the influence of the work surface and task difficulty on the head, upper back and upper arm postures and activity of the descending trapezius during a simulated mouse task.

METHODS

Healthy female university students (N = 15) were evaluated. The work surface was positioned at elbow height (EH) and above elbow height (AEH) and the task difficulty was set at low (LD) and high (HD) levels. The postures were recorded by inclinometers. Trapezius activity was normalized by the maximum voluntary isometric contraction (MVIC).

RESULTS

Significantly higher head flexion was found at EH compared to the AEH condition, with an average difference of 2°-5° at the same difficulty level. The HD task significantly increased head (3°-6°) and upper back flexion (6°-7°) at the same table height. For upper arm elevation and trapezius activation, the AEH condition presented higher upper arm elevation (about 6°-8°) and trapezius activity (0.8-1.4% of MVIC), regardless of the difficulty level of the task.

CONCLUSIONS

Head posture was influenced by the table height and task difficulty; the upper back posture by high difficulty; and upper arm posture and trapezius activity were only influenced by table height.

The effects of forearm support and shoulder posture on upper trapezius and anterior deltoid activity

[Purpose] To assess the effects of forearm support and shoulder posture on upper trapezius and anterior deltoid activity. [Subjects and Methods] Twenty-three female university students were evaluated. Muscle activity was assessed by a portable surface electromyography (sEMG) system (Myomonitor IV, Delsys, USA). Upper trapezius and anterior deltoid activity were recorded in five shoulder flexion postures: 0°, 15°, 30°, 45° and 60° and in two conditions: with the forearm supported and unsupported. Descriptive data analysis was performed and statistical analysis was conducted by a multivariate analysis of variance with three repeated factors (posture, support and side). [Results] Three-way interactions were not significant. Two-way interaction was significant for support and posture for both muscles, indicating that the muscular activity depends on the forearm support and shoulder posture. The forearm support reduced upper trapezius and anterior deltoid activity for all shoulder flexion angles. The mean and standard deviation for this decrease was 7.8 (SD=4.6)% of the maximal voluntary contraction for anterior deltoid and 3.8 (SD=2.0)% of the maximal voluntary contraction for upper trapezius. In the unsupported condition, increasing the shoulder flexion angle caused an increase in the upper trapezius and anterior deltoid activation. [Conclusion] These results highlight the importance of using forearm support and to maintain neutral shoulder posture, when the upper arms are not supported, to reduce muscle activation. Thus, this study provides evidence about the effect of these recommendations to reduce muscular activity.