Effect of two dynamic seat cushions on postural shift, trunk muscle activation and spinal discomfort in office workers.

We investigated the effect of two dynamic seat cushions on postural shift, trunk muscle activation and spinal discomfort. In this repeated-measures study, 30 healthy office workers were randomly assigned to a sequence of three conditions: sitting on a dynamic seat cushion-A, cushion-B and control (no seat cushion). The two dynamic seat cushions had different inflation levels. Participants typed a standard text for an hour and were monitored for postural shift by using a seat pressure mat, transversus abdominis/internal oblique and lumbar multifidus muscles activity by using surface EMG, spinal discomfort by using Borg's CR-10 scale. Two-way repeated ANOVAs showed no statistically significant interaction effects between condition and time on postural shift and muscle activation. Post hoc Bonferroni tests showed that postural shifts and lumbar multifidus activation during sitting on cushion-A were significantly higher (p < 0.01) than in the control and cushion-B conditions. Both cushions reduced spinal discomfort, compared to the control condition (p < 0.05).

How low back pain is managed-a mixed methods study in 32 countries. Part 2 of Low Back Pain in Low- and Middle-Income Countries Series.

BACKGROUND: The Lancet Series of Low Back Pain (LBP) highlighted the lack of LBP data from low- and middle-income countries (LMICs). The study aimed to describe (1) what LBP care is currently delivered in LMICs, and (2) how that care is delivered. METHODS: An online mixed-methods study. A Consortium for LBP in LMICs (n=65) was developed with an expert panel of leading LBP researchers (>2 publications on LBP) and multidisciplinary clinicians and patient partners with five years of clinical/lived LBP experience in LMICs. Quantitative data were analyzed using descriptive statistics. Two researchers independently analyzed qualitative data using deductive and inductive coding and developed a thematic framework. FINDINGS: Forty-seven (85%) of 55 invited panel members representing 32 LMICs completed the survey (38% women; 62% men). The panel included clinicians (34%), researchers (28%), educators (6%), and patient partners (4%). Pharmacotherapies and electrophysiological agents were the most used LBP treatments. The Thematic Framework comprised of eight themes: (1) Self-management is ubiquitous; (2) Medicines are the cornerstone; (3) Traditional therapies have a place; (4) Society plays an important role; (5) Imaging use is very common; (6) Reliance on passive approaches; (7) Social determinants influence LBP care pathway; and (8) Health systems are ill-prepared to address LBP burden. INTERPRETATION: LBP care in LMICs did not consistently align with the best available evidence. Findings will help research prioritization in LMICs and guide global LBP clinical guidelines. FUNDING: The lead author's Fellowship was supported by the International Association for the Study of Pain.

Mediators and moderators of a walking intervention to prevent neck pain among high-risk office workers: a secondary analysis of a randomized controlled trial.

OBJECTIVES: To test hypothesized mediators and moderators of the benefits of an app-provided walking intervention for preventing neck pain in high-risk office workers. METHODS: Ninety-one office workers at risk for developing neck pain participated in the primary clinical trial. Two hypothesized mediators (the total number of steps taken and the number of days that participants exceed the number of recommended steps) were tested using a smartphone application every month during a 6-month period. Four hypothesized moderators (number of working hours, level of work psychological demands, chair height adjustability, and body mass index) were assessed at baseline. Parallel mediation and moderation analyses were conducted using the Hayes PROCESS macro, model 4 and 1, respectively, with post-hoc Johnson-Neyman techniques. RESULTS: The number of days that participants exceeded the recommended steps ‒ the specific number was tailored to each participant, but averaged 7735 steps/day ‒ mediated the benefits of the walking intervention for reducing the risk for neck pain at each of six assessment points (B's range -0.63 to -0.89, all p's < 0.05) over 6-month period. None of the hypothesized moderators evidenced statistically significant moderator effects of the walking intervention. CONCLUSION: Workers should walk at rates greater than recommended levels on as many days as possible, rather than attempt to maximize walking within a limited number of days. Given that the walking program studied appeared to be similarly effective across multiple groups of workers, the findings suggest that regular walking can reduce the risk for developing neck pain among high-risk office workers.

Cross-cultural adaptation and psychometric properties of the Thai version of the patient-reported outcomes measurement information system short form- depression 8a in individuals with chronic low back pain.

BACKGROUND: The study aimed to cross-culturally adapt the Patient-Reported Outcomes Measurement Information System Short Form v1.0 - Depression 8a (PROMIS SF v1.0 - Depression 8a) into Thai and evaluate its psychometric properties in individuals with chronic low back pain (CLBP). METHODS: The PROMIS SF v1.0- Depression 8a was translated and cross-culturally adapted into Thai using the Functional Assessment of Chronic Illness Therapy translation methodology. Two hundred and sixty-nine individuals with CLBP completed the Thai version of PROMIS SF v1.0- Depression 8a (T-PROMIS-D-8a) scale and a set of measures assessing validity criterion domains. Structural validity, internal consistency, and test-retest reliability at a 7-day interval of the T-PROMIS-D-8a scale were computed and its construct validity was evaluated by computing correlations with the Thai version of Patient Health Questionnaire-9 (T-PHQ-9), Numeric Rating Scale of pain intensity (T-NRS), and Fear Avoidance Beliefs Questionnaire (T-FABQ). RESULTS: Data from 269 participants were analyzed. Most participants were women (70%), and the sample had a mean age of 42.5 (SD 16.6) years. The findings supported the unidimensionality, internal consistency (Cronbach's alpha = 0.94), and test-retest reliability (ICC [2,1] = 0.86) of the T-PROMIS-D-8a. A floor effect was observed for 16% of the sample. Associations with the T-PHQ-9, T-NRS, and T-FABQ supported the construct validity of the T-PROMIS-D-8a. CONCLUSIONS: The T-PROMIS-D-8a was successfully translated and culturally adapted. The findings indicated that the scale is reliable and valid for assessing depression in Thai individuals with CLBP.

Effects of Postural Shifting Frequency on Perceived Musculoskeletal Discomfort During 1-Hour Sitting in Office Workers.

OBJECTIVE: The purpose of this study was to evaluate the effects of postural shifting frequency on perceived musculoskeletal discomfort during 1 hour of sitting in healthy office workers. METHODS: An experimental study comparing 3 different postural shifting frequencies was conducted on 60 healthy office workers who were asked to sit for an hour. The effects of 3 postural shifts (ie, 10, 20, and 30 times/h) on discomfort, measured by Borg's CR-10 scale, were compared. A seat pressure mat was used to confirm an individual's postural shift. RESULTS: Postural shifting frequency of 10 to 30 times/h had significant effects on perceived discomfort in the neck, shoulder, and upper and lower back during 1-hour sitting. At the neck and shoulder, a postural shifting frequency of 30 times/h significantly reduced perceived discomfort compared to a postural shifting frequency of 10 times/h during 1-hour sitting. At the upper and lower back, a postural shifting frequency of 20 to 30 times/h significantly reduced perceived discomfort compared to a postural shifting frequency of 10 times/h. CONCLUSION: Postural shifts of 30 times/h provided buffering effects on perceived musculoskeletal discomfort at the neck, shoulder, and upper and lower back.

The effect of three-part breathing exercise on smoking cessation: A 6-month cluster-randomized clinical trial.

INTRODUCTION: Negative affect was identified as an important barrier to smoking cessation. Three-part breathing exercise showed a significant effect on decreasing negative affect immediately after being practiced. Thus, this study evaluated the effect of three-part breathing exercise on smoking cessation. METHODS: A 6-month cluster-randomized clinical trial was conducted. Forty-three participants recruited from 8 companies in Bangkok Metropolitan areas were randomly assigned at the cluster level into either the intervention or control groups. Control group (n = 23) received counseling for smoking cessation once a week for 12 weeks. Intervention group (n = 20) received counseling for smoking cessation plus a three-part breathing exercise program once a week for 12 weeks. The primary outcomes were 7-day point prevalence and continuous abstinence rate as validated by saliva cotinine. The secondary outcomes were cigarette cravings, nicotine withdrawal symptoms, affect and quality of life. RESULTS: The results revealed no significant difference in smoking abstinence rate between the three-part breathing exercise and control group. Participants demonstrated significant pre-post improvement in cigarette cravings, nicotine withdrawal symptoms, affect, and quality of life within each group. CONCLUSION: There were no statistically significant differences between the two groups. However, the improvement in abstinence rate from the three-part breathing exercise was deemed clinically relevant. Thus, it may be recommended to smokers interested in smoking cessation and more research is needed on this topic.

Poor neck posture and longer working duration during root canal treatment correlated with increased neck discomfort in dentists with <5-years' experience in endodontics.

OBJECTIVE: This study investigated the effects of neck posture and working duration during each step of root canal treatment (i.e. opening the canal [OC], length determination, mechanical instrumentation, try main cone, and filling the root canal) on neck discomfort (ND) in dentists with <5-years' endodontic experience. METHODS: Twenty-four dentists performed a one-visit endodontic treatment of an upper molar in a phantom head model. A video was recorded to evaluate the dentistsá¾½ neck postures using the Modified-Dental Operator Posture Assessment Instrument (M-DOPAI) and treatment duration. The M-DOPAI divides the dentistsá¾½ neck postures into three categories: acceptable, compromised, or harmful posture. The participants rated their ND using Borgá¾½s CR-10 scale every 10 min. and at the end of each treatment step. The relationships between neck posture/treatment duration and Borgá¾½s CR-10 scores were examined using partial correlation. RESULTS: The number of compromised and harmful neck postures during the endodontic procedure (r = 0.43, P = .04) and treatment duration (r = 0.58 P = .005) significantly correlated with ND at the end of treatment. The number of compromised and harmful neck postures during the OC step (r = 0.75, P < .001) and the duration of the OC step (r = .70, P < .001) significantly correlated with ND at the end of the step. CONCLUSION: Poor neck postures and long working duration during endodontic treatment correlated with ND among inexperienced dentists. Neck pain interventions should focus on neck postures and work duration during root canal treatment, particularly in the OC step.

Can the Borg CR-10 scale for neck and low back discomfort predict future neck and low back pain among high-risk office workers?

PURPOSE: Perceived discomfort could indicate an early sign of pain, for example, as a result of a biomechanical load on the musculoskeletal system. Assessing discomfort can, therefore, help to identify workers at increased risk of musculoskeletal disorders for targeted intervention development. We aimed: (1) to identify the optimal cut-off value of neck and low back discomfort among office workers and (2) to evaluate its predictive validity with future neck and low back pain, respectively. METHODS: At baseline healthy participants (n = 100) completed questionnaires, including the Borg CR-10 discomfort scale (on a 0-10 scale), and were followed for six months, during which musculoskeletal pain was assessed monthly. Logistic regression analyses were performed to assess the associations of baseline discomfort with the onset of future neck or low back pain. Sensitivity, specificity, and the area under the receiver operating characteristics curve were estimated to identify the optimal discomfort cut-off value predicting future pain. RESULTS: Borg CR-10 scores ≥ 3.5 for perceived neck and low back discomfort had acceptable sensitivity and specificity to predict future neck and low back pain, respectively. Perceived discomfort at baseline as a dichotomous measure (using the ≥ 3.5 cut-off) was a statistically significant predictor of future neck pain (OR = 10.33) and low back pain (OR = 11.81). CONCLUSION: We identified the optimal cut-off value of the Borg CR-10 discomfort scale to identify office workers at increased risk of developing neck and low back pain. These findings might benefit ergonomists, primary health care providers, and occupational health researchers in developing targeted interventions.

Responsiveness of the UW Concerns About Pain Scale and UW Pain-Related Self-Efficacy Scale in Individuals With Chronic Low Back Pain.

OBJECTIVES: The aim was to examine the responsiveness, presence of floor or ceiling effects, and minimal clinically important differences (MCIDs) for 2 new measures of pain-related catastrophizing and self-efficacy in individuals with chronic low back pain. METHODS: A total of 183 individuals with chronic low back pain recruited from physical therapy clinics in Thailand completed the Thai versions of the 6-item University of Washington Concerns About Pain scale (T-UW-CAP6) and 6-item University of Washington Pain-Related Self-Efficacy scale (T-UW-PRSE6) at baseline and at 4 weeks follow-up. Perceived change in low back symptom was assessed at 4 weeks using a 7-point measure of Global Perceived Effect (GPE). Responsiveness of the T-UW-CAP6 and the T-UW-PRSE6 scale scores were evaluated by computing the effect sizes and standardized response means for change over time, and examining these as a function of the GPE ratings. Floor and ceiling effects were examined by evaluating the score distributions. Scale core MCIDs were estimated by computing a half a SD and SE of measurement statistics for each scale. RESULTS: Responsiveness of the scales to pain treatment was supported by differences found in the mean change scores as a function of the treatment response categories. No significant floor or ceiling effects were found for either measure. Changes of 4.38 and 3.68 appeared to be the smallest change score perceived as clinical meaningful for the T-UW-CAP6 and T-UW-PRSE 6 scale scores, respectively. DISCUSSION: The T-UW-CAP6 and T-UW-PRSE6 demonstrated good ability to detect perceived changes over time in patients with chronic low back pain. The MCIDs values provide a benchmark for assessing individual improvement in this clinical context.

Characteristics of office workers who benefit most from interventions for preventing neck and low back pain: a moderation analysis.

Introduction: Neck and low back pain are significant health problem in sedentary office workers. Active break and postural shift interventions has been proved to reduce the incidence of new onset of both neck and low back pain. Objectives: To identify variables that moderate the effects of active breaks and postural shift interventions on the development of neck and low back pain in office workers. Methods: Using data from a 3-arm (active break, postural shift, and control group) cluster randomized controlled trial (N = 193), we evaluated the moderating effects of age, job position, education level, sex, perceived psychological work demands, number of working hours, and using a chair with lumbar support on the benefits of 2 interventions designed to prevent the development of neck and low back pain in office workers. Moderation analyses were conducted using the Hayes PROCESS macro, with post hoc Johnson-Neyman techniques and logistic regressions. Results: Significant interactions between intervention groups and 3 moderators assessed at baseline emerged. For the prevention of neck pain, the effect of the active break intervention was moderated by the number of working hours and the effect of the postural shift intervention was moderated by the level of perceived psychological work demands and the number of working hours. For the prevention of low back pain, the effect of postural shift intervention was moderated by having or not having a chair with lumbar support. Conclusions: The study findings can be used to help determine who might benefit the most from 2 treatments that can reduce the risk of developing neck and low back pain in sedentary workers and may also help us to understand the mechanisms underlying the benefits of these interventions.

The effects of chair intervention on lower back pain, discomfort and trunk muscle activation in office workers: a systematic review.

Objectives. The chair is a standard piece of workstation equipment in an office. Previous studies showed that a suitable chair may reduce musculoskeletal symptoms. This review investigated the effect of chair intervention on lower back pain (LBP), discomfort and trunk muscle activation among office workers. Methods. Five electronic databases from 1980 to May 2020 were searched for relevant randomized and non-randomized controlled trials. The methodological quality of the included studies was assessed using the 13-item Cochrane risk of bias tool. Quality of evidence was assessed and rated according to Grading of Recommendations, Assessment, Development and Evaluations (GRADE) guidelines. Results. Two randomized controlled trials, 10 repeated-measures studies and two prospective cohort studies were included in this review. Nine studies were rated as high quality. The results indicated very low-quality to low-quality evidence for the conflicting effect of chair intervention on pain and discomfort reduction as well as trunk muscle activation among office workers. When stratified by chair type, the level of evidence for health benefits derived from any type of chair was still of very low to low quality. Conclusion. Unless supplementary high-quality studies provide different evidence, chair interventions are not recommended to reduce LBP or discomfort and activate trunk muscles.

Work ability in aging office workers with musculoskeletal disorders and non-communicable diseases and its associated factors: a cross-sectional study.

Objectives. The prevalence of musculoskeletal disorders (MSDs) and non-communicable diseases (NCDs) increases with age. This study examined the impact of MSDs and NCDs on work ability, using the work ability index (WAI), among aging office workers (between 45 and 60 years old) and determined factors associated with WAI scores. Methods. A cross-sectional study was conducted in office workers from 27 government offices in Bangkok and nearby provinces using an online questionnaire. Analyses were conducted using the Mann-Whitney U test and a multivariable logistic regression model. Results. Of 689 workers (452 females and 237 males), 34, 13, 12 and 41% reported MSDs, NCDs, MSDs + NCDs and no MSDs/NCDs, respectively, in the past year. Median scores (interquartile range) of WAI were 37.0 (6) for MSDs, 37.0 (4) for NCDs, 34.5 (6) for MSDs + NCDs and 40.0 (4) for no MSDs/NCDs. Significant difference in WAI scores was found between the MSDs and MSDs + NCDs groups (p = 0.005); and between the NCDs and MSDs + NCDs groups (p < 0.001). Female, high work experience and low job control were significantly associated with reduced WAI scores (WAI ≤ 36). Conclusion. The presence of MSDs or NCDs reduced work ability among aging office workers compared to their healthy counterparts. Having MSDs + NCDs further reduced work ability.

The effects of active break and postural shift interventions on recovery from and recurrence of neck and low back pain in office workers: A 3-arm cluster-randomized controlled trial.

OBJECTIVES: To investigate the efficacy of active break and postural shift interventions aimed to reduce sitting discomfort on recovery duration and recurrence of neck and low back pain among high-risk office workers. METHODS: A 3-arm cluster-randomized controlled trial with 12-month follow-up was conducted in 193 healthy but high-risk office workers. Participants in the intervention groups received custom-designed apparatus to facilitate either active breaks or postural shifts to reduce sitting discomfort at work. Participants in a control group received a placebo seat pad. Incidence of neck and low back pain with pain intensity and disability level was recorded monthly. Main outcome measures were recovery time and recurrent rate of neck and low back pain. Analyses were performed using log rank test and Cox proportional hazard models. RESULTS: Median time to recovery in those receiving active break and postural shift interventions (1 month) was significantly shorter than those in the control group (2 months). Neck and low back pain recurrent rates for the active break, postural shift, and control groups were 21%, 18%, and 44%, respectively. Hazard rate (HR) ratios after adjusting for biopsychosocial factors indicated a protective effect of active break and postural shift interventions for neck and low back pain recurrence (HRadj 0.22, 95% CI 0.06-0.83 for active breaks and HRadj 0.35, 95% CI 0.16-0.77 for postural shift). CONCLUSION: Active break and postural shift interventions shortened recovery time and reduced recurrence of neck and low back pain among high-risk office workers.

Effects of an active break and postural shift intervention on preventing neck and low-back pain among high-risk office workers: a 3-arm cluster-randomized controlled trial.

OBJECTIVE: This study evaluated the effects of the promotion of active breaks and postural shifts on new onset of neck and low-back pain during a 6-month follow-up among high-risk office workers. METHODS: A 3-arm cluster-randomized controlled trial with 6-month follow-up was conducted among healthy but high-risk office workers. Participants were recruited from six organizations in Bangkok, Thailand (N=193) and randomly assigned at cluster level into active break intervention (N=47), postural shift intervention (N=46), and control (N=100) groups. Participants in the intervention groups received a custom-designed apparatus to facilitate designated active breaks and postural shifts during work. Participants in the control group received a placebo seat pad. The primary outcome measure was new onset of neck and low-back pain during 6-month follow-up. Analyses were performed using Cox proportional hazard models. RESULTS: One-hundred and eighty-six (96%) predominantly female participants were successfully followed up over six months. New onset of neck pain during the 6-month follow-up occurred in 17%, 17%, and 44% of the participants in the active break, postural shift, and control groups, respectively. For new onset of low-back pain, these percentages were 9%, 7%, and 33%, respectively. Hazard rate (HR) ratios after adjusting for biopsychosocial factors indicated a protective effect of the active break and postural shift interventions for neck pain [HRadj 0.45, 95% confidence interval (CI) 0.20-0.98 for active break and HRadj 0.41, 95% CI 0.18-0.94 for postural shift] and low-back pain (HRadj 0.34, 95% CI 0.12-0.98 for active break and HRadj 0.19, 95% CI 0.06-0.66 for postural shift). CONCLUSION: Interventions to increase either active breaks or postural shifts reduced new onset of neck and low-back pain among high-risk office workers.

Factors associated with exercise adherence to prevent or treat neck and low back pain: A systematic review.

BACKGROUND: Much attention has been paid to the evaluation of the efficacy of exercise therapy or increasing physical activity with the aim to prevent or alleviate neck and low back pain. However, exercise adherence is necessary for the effective management of neck and low back pain. OBJECTIVE: We aimed to systematically review randomized controlled trials and cohort studies to gain insights into the factors associated with adherence to exercise or physical activity programs to prevent or treat neck pain and low back pain. METHOD: Publications were systematically searched from 1980-December 2019 in several databases. The following key words were used: neck pain or low back pain paired with exercise or physical activity and adherence or compliance. Relevant studies were retrieved and assessed for methodological quality by two independent reviewers. Quality of evidence was assessed and rated according to GRADE guidelines. RESULTS: Nine randomized controlled trials and eight cohort studies were included in this review. Randomized controlled trials indicated moderate-quality evidence for the association between exercise adherence and self-efficacy. Cohort studies showed moderate-quality evidence for the association between exercise adherence and education level. CONCLUSIONS: Literature investigating factors associated with exercise adherence to prevent or treat neck and low back pain was heterogeneous. Few factors were found to be associated with exercise adherence. More studies are needed before any firm conclusions can be reached.

Responsiveness of the PROMIS-29 Scales in Individuals With Chronic Low Back Pain.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To evaluate responsiveness and estimate the minimal clinically important differences (MCIDs) for the Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29) scales in individuals with chronic low back pain. SUMMARY OF BACKGROUND DATA: The PROMIS-29 questionnaire assesses seven health-related quality-of-life domains. However, research to evaluate the responsiveness and MCIDs of the PROMS-29 scores in individuals with low back pain is limited. METHODS: The study was conducted in physical therapy clinics in Thailand, using validated Thai versions of the study measures. One hundred and eighty-three individuals with chronic low back pain completed the PROMIS-29 at baseline and at 4-weeks follow-up. Perceived change in each domain assessed by the PROMIS-29 scales was assessed at 4 weeks using a 7-point measure of Global Perceived Effect (GPE). Responsiveness of the PROMIS-29 scale scores was evaluated by examining the effect sizes, the standardized response means (SRMs) for change over time, and examining these as a function of the GPE ratings. MCIDs for the scales were estimated by computing a half a standard deviation (SD) and standard error of measurement statistic for each scale. RESULTS: The mean change scores, effect sizes, and SRMs increased as a function of the GPE ratings. Significant differences in change scores between those who reported that they were very much improved and those who did not improve were found for the PROMIS-29 Pain Intensity, Physical Function, and Anxiety scales. The correlations between changes scores and GPE ratings were mostly weak in magnitude. The MCID estimates computed as 0.50 of a SD unit and as a standard error of measurement showed similar values. CONCLUSION: The PROMIS-29 scale scores assessing pain intensity, physical function, and anxiety evidenced the most responsivity in the study sample. The results, when considered in light of the findings from other investigators, support 5.0 points as a reasonable MCID for most of the PROMIS-29 scales. Further studies are needed to determine the generalizability of the findings.Level of Evidence: 2.

Efficacy of risk factor education on pain intensity and disability in office workers with nonspecific neck or low back pain: A pilot cluster randomized clinical trial.

BACKGROUND: Musculoskeletal disorders are of multi-factorial origin, including individual, physical, and psychosocial factors. An effective education program for musculoskeletal disorders should include predisposing factors. OBJECTIVE: This study aimed to examine the effect of risk factor education on pain intensity and disability levels compared to a home-based exercise program in office workers with nonspecific neck or low back pain. METHODS: A pilot cluster randomized clinical trial was conducted in 46 workers with neck or low back pain. The education group received checklists of risk factors and handbooks providing information on how to manage them. The exercise group received a home-based exercise program to manage their neck or low back pain. The primary outcome measures were pain intensity and disability levels. RESULTS: There was no significant difference in pain intensity or disability level between groups at baseline and follow-ups. However, neck and low back pain intensity, but not disability level, at the 3-month and 6-month follow-ups was significantly lower than those at baseline in both groups. CONCLUSION: Risk factor education was not more effective than the home-based exercise program in terms of pain intensity or disability reduction in workers with nonspecific neck or low back pain.

The Effect of Breathing Exercise on Nicotine Withdrawal Symptoms, Cigarette Cravings, and Affect.

The aim of this study was to evaluate the effects of a single bout of controlled deep breathing and a "three-part breathing" exercise on nicotine withdrawal symptoms, cigarette cravings, and affect. A secondary aim was to determine whether autonomic nervous system activity mediates these effects. Twenty-four participants attended one practical session followed by three intervention sessions on 3 separate days: control condition, controlled deep breathing, and three-part breathing. Participants were asked to abstain from smoking for 15 hours before intervention. Nicotine withdrawal symptoms, cigarette cravings, affect, and heart rate variability were assessed preintervention and again on four occasions postintervention: immediately postintervention and every 10 minutes on three more occasions. Results revealed that the three-part breathing exercise resulted in lower negative affect scores relative to control condition and controlled deep breathing immediately after postintervention (p < .05). In addition, high-frequency heart rate variability score was significantly reduced throughout the 30-minute session.

Perceived musculoskeletal discomfort and its association with postural shifts during 4-h prolonged sitting in office workers.

This study examined the characteristics of perceived discomfort and postural shifts at different magnitudes during a 4-h sitting period and the association between perceived discomfort and number of postural shifts. Forty healthy participants continuously typed a standardized text passage at a computer work station for 4 h. Subjects rated perceived body discomfort using Borg's CR-10 scale in 10 body regions (i.e. neck, shoulder, elbow, wrist/hand, upper back, lower back, buttock, thigh, knee, and ankle/foot). A seat pressure mat device was used to gather seat pressure data during sitting. Postural shifts were determined by analysis of the dispersion index of both ischial tuberosities from seat pressure data. The threshold for a postural shift was set at ±10% and ±20%. Perceived discomfort in all body regions increased continuously during a 4-h sitting period. The body regions with the highest perceived discomfort were the low back, buttocks, upper back, thigh, and neck. The average (±SD) numbers of postural shifts during the 1st, 2nd, 3rd, and 4th hour of sitting were 14.8 ± 9.5, 17.8 ± 9.4, 18.2 ± 11.1, and 18.1 ± 9.8 shifts per hour for the 10% threshold, and were 4.8 ± 4.4, 6.0 ± 5.6, 7.4 ± 6.7, and 7.7 ± 6.6 shifts per hour for the 20% threshold, respectively. Prolonged sitting led to an increase in perceived musculoskeletal discomfort over time. The number of postural shifts at both magnitudes increased in the first 2 h of sitting and, in the second 2-h period of sitting, only the number of larger postural shifts (with 20% threshold) increased. The findings extend our understanding of sitting behaviors.