Association between time spent on smartphones and digital eye strain: A 1-year prospective observational study among Hong Kong children and adolescents.

Prolonged electronic screen use can cause digital eye strain. It can be difficult to rectify due to increasing smartphone reliance, potentially leading to serious public health problems. To investigate the association between time spent on smartphones and digital eye strain (DES) among Hong Kong Chinese school-aged children. Of a total of 1,508 students (748 males, 49.6%) from 8 to 14 years old (mean age = 10.91 years, SD = 2.01) who provided valid data on DES, the 1,298 (86%) who completed the DES questionnaire at 1-year follow-up were included in the analysis. DES was measured using a 10-item scale, and the sum of the 10 dichotomised scores was used as the DES total score. The most commonly reported symptoms were eye fatigue (n = 804, 53.3%), blurred vision (changing from reading to distance viewing) (n = 586, 38.9%), and irritated or burning eyes (n = 516, 34.2%). The DES total scores at baseline and 1-year follow-up were 2.91 (SD = 2.90) and 3.20 (SD = 3.19), respectively. Linear regression controlling for demographic and socio-economic confounders showed that participants with baseline smartphone usage of 241 + min/d had a significantly higher baseline total DES score than those with baseline smartphone usage of 0-60 min/d (2.44 vs 3.21, P < 0.001), and participants with baseline smartphone usage of 181-240 min/d had a significantly higher 1-year follow-up total DES score than those with baseline smartphone usage of 0-60 min/d (2.80 vs 3.50, P = 0.003).

The Concerns and Experiences of Patients With Lumbar Spinal Stenosis Regarding Prehabilitation and Recovery After Spine Surgery: A Qualitative Study.

Objectives: To improve our understanding of patients' perspectives regarding: (1) the decision-making and prehabilitation before lumbar spinal stenosis (LSS) surgery and (2) their postoperative experiences. Design: Qualitative research with semi-structured interviews. Setting: General community. Participants: Individuals who received (N=10) and who did not receive (N=15) prehabilitation before LSS surgery were recruited at the 6-month postoperative follow-up (8 females; average age: 67.7±6.7 years) by purposive sampling. Additionally, 1 participant invited her daughter to accompany her in an interview. Interventions: Not applicable. Main Outcome Measures: Concerns and experiences of patients with LSS regarding prehabilitation and recovery after spine surgery. Results: Thematic analysis was conducted to identify 4 themes inductively: (1) sources of information about LSS surgery; (2) factors affecting the surgical decision-making; (3) attitudes toward prehabilitation; and (4) postoperative recovery. All participants desired to have more preoperative education to inform their surgical decision-making. There were mixed opinions regarding the perceived benefits of prehabilitation because some individuals hesitated to participate in prehabilitation because of their symptoms, or the cost or time of traveling. Many participants expected some or even complete relief of LSS-related symptoms after surgery. However, not all participants experienced the expected postoperative improvements. Some participants only experienced temporary symptomatic relief, while others experienced new postoperative symptoms. Patients generally found that postoperative exercises taught by physiotherapists were useful although their compliance decreased over time. Conclusions: Our study highlights the need for better preoperative LSS education. Because face-to-face prehabilitation or postoperative rehabilitation may not be feasible for all patients, future studies should explore whether online-based prehabilitation or postoperative rehabilitation may benefit certain patient subgroups.

Using cervical movement velocity to assist the prediction of pain and functional recovery for people with chronic mechanical neck pain.

BACKGROUND: Impaired cervical kinematics particularly the movement velocity had been consistently found in people with neck pain. The recovery and potential of cervical movement velocity in assisting the prediction of recovery in individuals with chronic neck pain remained unknown. This study investigated the application of cervical movement velocity to predict the outcomes of pain intensity and functional disability for a cohort of participants with chronic mechanical pain after completion of a 12-week intervention program. METHODS: Cervical movement velocity when performing neck motions in the anatomical planes, pain intensity and functional disability score were assessed before and after the physiotherapy program. Correlations between kinematic and clinical outcomes, and validity of applying the peak velocity values of the cervical spine measured at baseline for prediction of recovery of pain and function after the physiotherapy program were examined (n = 68). FINDINGS: Significant improvements were found in the peak values of cervical velocity in all movement planes, pain intensity and functional disability score at post-program reassessment (p < 0.001). Significant negative correlations between peak values of cervical movement velocity and pain intensity (for specific directions, r = -0.163 to -0.191), and functional disability were found (for all directions, r = -0.158 to -0.282). Area under the Receiver Operating Characteristics curve was >0.6 for cervical extension, flexion and right rotation velocity for predicting functional recovery post-program. INTERPRETATION: These findings suggest that cervical velocity of selected planes measured at baseline may inform the prediction of recovery of functional disability but not pain intensity in people with chronic mechanical neck pain.

Bedtime smart device usage and accelerometer-measured sleep outcomes in children and adolescents.

PURPOSE: We analyzed the association between bedtime smart device usage habits and accelerometer-measured sleep outcomes (total sleeping time, sleep efficiency, and wake after sleep onset) in Hong Kong children and adolescents aged 8-14. METHODS: A total of 467 students in Hong Kong participated in this study from 2016 to 2017. They self-reported their bedtime smart device usage habits. The primary caregiver of each participant was also invited to complete a self-administered questionnaire about the family's social-economic status and bedtime smart device usage habits. An ActiGraph GT3X accelerometer was used to assess participants' 7-day sleep outcomes. RESULTS: The mean age of the participants was 10.3 (SD 1.9), and 54% were girls. Among the participants, 27% (n = 139) used a smart device before sleep, and 33% (n = 170) kept the smart device on before sleep. In total, 27% (n = 128) placed the smart device within reach before sleep, 23% (n = 107) would wake up when notifications were received, and 25% (n = 117) immediately checked the device after being awakened by a notification. Multiple regression controlling for age, sex, socio-economic status, and other confounders showed that those who woke up after receiving a notification had a statistically longer sleeping time (19.7 min, 95% CI: 0.3, 39.1, p = 0.046), lower sleep efficiency (- 0.71%, 95% CI - 1.40, - 0.02, p = 0.04), and a longer wake after sleep onset (2.6 min, 95% CI: 0.1, 5.1, p = 0.045) than those who did not. Nonetheless, all primary caregivers' bedtime smart device habits were insignificantly associated with all sleep outcomes of their children. CONCLUSION: Those who woke up after receiving smart device notifications had lower sleep efficiency and longer wake after sleep onset than those who did not, and they compensated for their sleep loss by lengthening their total sleep time.

Recovery of the lumbopelvic movement and muscle recruitment patterns using motor control exercise program in people with chronic nonspecific low back pain: A prospective study.

This study aims to investigate the dysfunction and recovery of the lumbopelvic movement and motor control of people with chronic nonspecific low back pain after a structured rehabilitation which emphasizes on re-education and training of movement and motor control. The lumbopelvic movement and motor control pattern of 30 adults (15 with chronic low back pain, 15 healthy controls) were assessed using 3D motion and electromyographic analysis during the repeated forward bending test, in additional to the clinical outcome measures. Regional kinematics and muscle recruitment pattern of the symptomatic group was analysed before and after the 6-week rehabilitation, and compared to healthy controls. Significant improvement in back pain, functional capacity and self-efficacy of the symptomatic group was found after the rehabilitation. Patients with chronic nonspecific low back pain were capable to recover to a comparable level of the healthy controls in terms of their lumbopelvic movement and motor control pattern upon completion of a 6-week rehabilitation program, despite their dysfunction displayed at baseline. Phase specific motor control reorganization in which more profound and positive changes shown during the flexion phase. Our findings indicate that the recovery of the movement and motor control pattern in patients with chronic low back pain achieved to a comparable level of the healthy able-bodies. The improvement of both the physical outcome measures suggest that specific rehabilitation program which emphasizes on optimizing motor control during movements would help promoting the functional recovery of this specific low back pain subgroup.

Development of the Prevent for Work questionnaire (P4Wq) for assessment of musculoskeletal risk in the workplace: part 1-literature review and domains selection.

OBJECTIVE: This study aims to define appropriate domains and items for the development of a self-administered questionnaire to assess the risk of developing work-related musculoskeletal disorder (WMSD) and the risk of its progression to chronicity. DESIGN: Literature review and survey study. SETTING AND PARTICIPANTS: A literature review and a two-round interview with 15 experts in musculoskeletal pain were performed to identify the available domains for WMSD assessment. INTERVENTIONS AND OUTCOME: To ensure quality, only validated questionnaires were included for the Delphi process. A three-round Delphi method, with three round steps, was used to select the most pertinent and relevant domains and items. RESULTS: Nine questionnaires were identified through the expert discussion and literature review, comprising 38 candidate domains and 504 items. In the first round of the Delphi group, 17 domains reached more than 70% agreement and were selected. In the second round, 10 domains were rejected, while 11 were selected to complete the pool of domains. In the third and final round, 89 items belonging to 28 domains were defined as significant to develop a WMSDs risk assessment questionnaire. CONCLUSIONS: No specific risk assessment questionnaires for WMSDs were identified from the literature. WMSD risk of presence and chronicity can be defined by an assessment tool based on the biopsychosocial model and the fear-avoidance components of chronic pain. The present study provides the formulation and operationalisation of the constructs in domains and items needed for developing and validating the questionnaire.

Association between Time Spent on Smart Devices and Change in Refractive Error: A 1-Year Prospective Observational Study among Hong Kong Children and Adolescents.

This study examined the association between smart device usage and the 1-year change in refractive error among a representative sample of Hong Kong children and adolescents aged 8-14 years. A total of 1597 participants (49.9% male, mean age 10.9, SD 2.0) who completed both baseline (2017-2018) and 1-year follow-up (2018-2019) eye examinations were included in the present study. The non-cycloplegic auto-refractive error was measured and the average spherical equivalent refraction (SER) was analyzed. The participants also self-reported their smart device usage at baseline. Multivariate regression adjusted for age, sex, baseline SER, parents' short-sightedness, BMI, time spent on moderate-to-vigorous physical activity (MVPA), and caregiver-reported socio-economic status showed that, compared with the reference group (<2 h per day on both smartphone and tablet usages), those who spent ≥2 h per day using a smartphone and <2 h per day using a tablet had a significantly negative shift in refractive error (1-year change in SER -0.25 vs. -0.09 D, p = 0.01) for the right eye, while the level of significance was marginal (1-year change -0.28 vs. -0.15 D, p = 0.055) for the left eye. To conclude, our data suggested spending at most 2 h per day on both smartphones and tablets.

A field study on spinal postures and postural variations during smartphone use among university students.

This field study compared the real-time spinal movements and postural variations during smartphone-use versus non-use in university students. Ten males and eight females (mean age of 21.5 ± 2.6 years) participated, with similar daily phone use time between the two sexes. Five inertial motion sensors were attached to the cervical, thoracic and lumbar spinal regions, and kinematics was recorded for 3 h while participants went about their usual academic activities within the university campus. Significantly greater degrees of cervical and upper thoracic flexion were adopted during phone use versus non-use time (p < 0.01). There were also significantly greater frequency of postural variations (zero crossing per min) in all spinal regions in the sagittal plane (all p < 0.05), and in some of the movements in transverse and frontal planes comparing phone use vs non-use. The postural variables also showed some significant correlations with self-reported pre-existing neck and upper back pain scores.

Effects of Ergomotor Intervention on Improving Occupational Health in Workers with Work-Related Neck-Shoulder Pain.

(1) Background: Work-related neck and shoulder pain (WRNSP) are common problems, and past occupational research has focused on ergonomic interventions such as adjusting workstations while physiotherapists have traditionally focused on teaching exercises to improve posture and movement control in the clinical setting. The current study aimed to integrate these two approaches and evaluate the immediate and long-term effects of such interventions on occupational exposure outcomes. (2) Methods: A total of 101 patients diagnosed with WRNSP were randomized into 2 groups: Control (CO) group (n = 50) and ergomotor (EM) group (n = 51). Participants in the control group had 12 weeks of usual care (conventional physiotherapy) while participants in the EM group received an integrated program with tailor-made motor control training and ergonomic advice for 12 weeks. (3) Results: Both groups achieved significant improvement in pain and functional outcomes at post-intervention. The EM group also reported significantly improved scores in terms of perceived exertion in the job-related physical demands (JRPD) and the short form workstyle questionnaires compared to the control group. (4) Conclusions: The results suggest that ergomotor intervention may be more effective in producing favorable occupational health outcomes compared to conventional physiotherapy.

Psychometric Properties and Demographic Correlates of the Smartphone Addiction Scale-Short Version Among Chinese Children and Adolescents in Hong Kong.

Nearly all children and teens in Hong Kong own a smartphone. There is currently no validated instrument that measures whether they use their phone too much. This study tested the psychometric properties of a translated Chinese version of the Smartphone Addiction Scale-Short Version (SAS-SV) and examined the demographic correlates of smartphone addiction among Hong Kong children and adolescents. A total of 1,901 primary school children and secondary school pupils were recruited from 15 Hong Kong schools. Furthermore, 1,797 primary caregivers were asked to complete a self-administered questionnaire on their socioeconomic status and educational attainment. The study used exploratory factor analysis (EFA) to identify the factor structure of SAS-SV for half the participants (n = 951), while confirmatory factor analysis (CFA) was used to assess the goodness-of-fit of EFA models for the remaining half (n = 951). Spearman correlations were used to assess the convergent validity of the SAS-SV, taking account of time spent by subjects on phones per day, the Smart Device Addiction Screening Tool (SDAST), the Pittsburgh Sleep Quality Index (PSQI), the Multidimensional Scale of Perceived Social Support (MSPSS), and the Center for Epidemiological Studies Depression Scale for Children (CES-DC). EFA generated a three-factor model (with factors labeled "dependency," the incidence of a "problem," and "time spent"). CFA confirmed this model yielded an acceptable goodness-of-fit (Comparative Fit Index = 0.96, Tucker Lewis Index = 0.95, and root-mean-square error of approximation = 0.06). SAS-SV was positively correlated with SDAST (ρ = 0.59), PSQI (ρ = 0.29), and CES-D (ρ = 0.35), and negatively correlated with MSPSS (ρ = -0.10). A linear regression model showed that female adolescents, those with highly educated caregivers and those who spent more time using smartphones on their holidays, had on average higher SAS-SV scores, meaning they showed greater vulnerability to becoming addicted. The study found that SAS-SV is a valid scale for estimating excessive smartphone use among Hong Kong children and adolescents.

Comparing the effectiveness of integrating ergonomics and motor control to conventional treatment for pain and functional recovery of work-related neck-shoulder pain: A randomized trial.

BACKGROUND: Work-related neck and shoulder pain (WRNSP) is highly prevalent among patients who seek physiotherapy treatment. Clinicians may tend to focus on teaching home exercises and provide general advice about workplace improvement. The present study investigates the short- and long-term impact of an intervention approach that emphasizes on integrating the motor control re-education with ergonomic advice. METHODS: Participants diagnosed with WRNSP (n = 101) were randomly assigned into two groups in this randomized controlled trial. The Ergo-motor Group (EM, n = 51) received an integrated intervention with ergonomic advice/modifications and motor control training individualized for each participant based on their specific work demands. Control Group (CO, n = 50) received treatment for pain relief and general exercises of their necks at a designated physiotherapy clinic. Neck pain intensity and functional outcome measures were assessed before, immediately and 1-year after the 12-week intervention programmes. Global Rating of Change Score was used to evaluate the perceived recovery at 1-year follow-up. RESULTS: Both groups reported significant reductions in pain and functional disability scores at post-intervention (EM, n = 44; CO, n = 42) and 1-year follow-up (EM, n = 40; CO, n = 38); however, no significant between-group differences were found (p > 0.05). Significantly higher rating in global recovery score was reported in EM group at 1-year follow-up (p < 0.05). CONCLUSIONS: Intervention integrating ergonomic advice/modification with motor control exercise was found to be equally effective as pain relief and general exercise for pain and functional recovery. However, at 1-year follow-up, such integrated approach resulted in significantly better global recovery perceived by people with WRNSP. SIGNIFICANCE: Integrating ergonomic intervention and motor control training achieved similar reduction in pain and functional outcomes compared to conventional physiotherapy at post-intervention and at 1-year follow-up, for patients with moderate level of work-related neck-shoulder pain and mild degree of functional disability. The Ergo-motor Group reported significantly better perceived overall recovery at 1-year follow-up.

Association of electromyographic activation patterns with pain and functional disability in people with chronic neck pain.

PURPOSE: This study examined the activation patterns of the cervical and thoracic muscles in people with and without chronic neck pain during functional activities and their associations with pain intensity and functional disability. METHODS: Thirty-four adults with chronic neck pain and 34 asymptomatic adults were recruited. They were requested to perform active cervical movements and an upper limb lifting task. Electromyographic activation patterns (EMG) of bilateral upper trapezius, cervical erector spinae, sternocleidomastoid, and thoracic erector spinae were recorded during these tasks. Correlation and multiple regression analysis were used to examine the associations between EMG variables and severity of pain and functional disability. RESULTS: When performing the cervical movements, the neck pain group displayed lower EMG activity levels, especially in the cervical and thoracic extensors. In addition, significantly prolonged activation was observed in seven of the ten muscles during the upper limb lifting task. The changes in EMG amplitude and activation duration were found to be significantly correlated with severity of pain (R2 = 0.716) and functional disability (R2 = 0.623). CONCLUSIONS: Significant differences in the activation patterns of multiple cervical and thoracic muscles were found in individuals with neck pain compared with those without neck pain. These were significantly associated with their degree of pain and functional limitation. The findings of this study highlight the importance of assessing and optimising the neuromuscular activation of these muscles in the rehabilitation of those suffering from chronic neck pain.

Effects of combining ergonomic interventions and motor control exercises on muscle activity and kinematics in people with work-related neck-shoulder pain.

PURPOSE: This study compared the effects of "Ergomotor" intervention and conventional physiotherapy, on influencing the motor control in the neck-shoulder region in people with work-related neck-shoulder pain (WRNSP). METHODS: 101 patients (age range 20-54 years) diagnosed with chronic WRNSP were randomized into control (CO) group (n = 50) and Ergomotor (EM) group (n = 51). Each group received a 12-week intervention. Participants in CO group received treatment for pain relief and general exercises. EM group received individualized motor control training and advice of ergonomic modifications at their workplaces. RESULTS: At post-intervention, EM group showed significant reduction of bilateral upper trapezius muscle activity during active neck movements (left: 40-35%, right: 35-27%) and functional tasks such as lifting a weight forward-backward (left: 31-21%, right: 22-14%) and upward-downward (left: 26-23%, right: 20-13%). Cervical erector spinae also showed significant decrease in muscle activity during some phases of the functional tasks (left: 13-6%, right: 10-2%). In contrast, CO group did not show such changes in muscle activity at post-intervention. EM group also showed significant increase in movement velocity and acceleration during active neck movements in all directions (from 18 to 31%), while CO group only showed significant increase in movement velocity in some directions. Both groups reported significant but similar reduction in pain scores, at post-intervention and 1-year follow-up. CONCLUSIONS: The present results provided some evidence to support the positive and sustainable benefits of integrating motor control training into the workplace postures and motions.

The prevalence of musculoskeletal symptoms in the construction industry: a systematic review and meta-analysis.

PURPOSE: Although individual studies have reported high prevalence of musculoskeletal symptoms (MSS) among construction workers, no systematic review has summarized their prevalence rates. Accordingly, this systematic review/meta-analysis aimed to synthesize MSS prevalence in different construction trades, gender and age groups, which may help develop specific ergonomic interventions. METHODS: Nine databases were searched for articles related to the research objective. Two reviewers independently screened citations, extracted information and conducted quality assessment of the included studies. Meta-analyses were conducted on clinical and statistical homogenous data. RESULTS: Thirty-five out of 1130 potential citations were included reporting diverse types of period prevalence and case definitions. Only the 1-year prevalence rates of MSS (defined as at least one episode of pain/MSS in the last year) at nine anatomical regions had sufficient homogeneous data for meta-analysis. Specifically, the 1-year prevalence of MSS was 51.1% for lower back, 37.2% for knee, 32.4% for shoulder, 30.4% for wrist, 24.4% for neck, 24.0% for ankle/foot, 20.3% for elbow, 19.8% for upper back, and 15.1% for hip/thigh. Female workers demonstrated a higher prevalence of MSS while there was insufficient information on the prevalence of trade-specific or age-related MSS. The quality assessments revealed that many included studies estimated prevalence solely based on self-reported data, and did not report non-respondents' characteristics. CONCLUSIONS: Lumbar, knee, shoulder, and wrist MSS are the most common symptoms among construction workers. Future studies should standardize the reporting of period prevalence of MSS in different construction trades to allow meta-analyses and to develop relevant MSS prevention program.

The effects of bending speed on the lumbo-pelvic kinematics and movement pattern during forward bending in people with and without low back pain.

BACKGROUND: Impaired lumbo-pelvic movement in people with low back pain during bending task has been reported previously. However, the regional mobility and the pattern of the lumbo-pelvic movement were found to vary across studies. The inconsistency of the findings may partly be related to variations in the speed at which the task was executed. This study examined the effects of bending speeds on the kinematics and the coordination lumbo-pelvic movement during forward bending, and to compare the performance of individuals with and without low back pain. METHODS: The angular displacement, velocity and acceleration of the lumbo-pelvic movement during the repeated forward bending executed at five selected speeds were acquired using the three dimensional motion tracking system in seventeen males with low back pain and eighteen males who were asymptomatic. The regional kinematics and the degree of coordination of the lumbo-pelvic movement during bending was compared and analysed between two groups. RESULTS: Significantly compromised performance in velocity and acceleration of the lumbar spine and hip joint during bending task at various speed levels was shown in back pain group (p < 0.01). Both groups displayed a high degree of coordination of the lumbo-pelvic displacement during forward bending executed across the five levels of speed examined. Significant between-group difference was revealed in the coordination of the lumbo-pelvic velocity and acceleration (p < 0.01). Asymptomatic group moved with a progressively higher degree of lumbo-pelvic coordination for velocity and acceleration while the back pain group adopted a uniform lumbo-pelvic pattern across all the speed levels examined. CONCLUSIONS: The present findings show that bending speed imposes different levels of demand on the kinematics and pattern of the lumbo-pelvic movement. The ability to regulate the lumbo-pelvic movement pattern during the bending task that executed at various speed levels was shown only in pain-free individuals but not in those with low back pain. Individuals with low back pain moved with a stereotyped strategy at their lumbar spine and hip joints. This specific aberrant lumbo-pelvic movement pattern may have a crucial role in the maintenance of the chronicity in back pain.

Cumulative IT Use Is Associated with Psychosocial Stress Factors and Musculoskeletal Symptoms.

This study aimed to examine the relationship between cumulative use of electronic devices and musculoskeletal symptoms. Smartphones and tablet computers are very popular and people may own or operate several devices at the same time. High prevalence rates of musculoskeletal symptoms associated with intensive computer use have been reported. However, research focusing on mobile devices is only just emerging in recent years. In this study, 285 persons participated including 140 males and 145 females (age range 18-50). The survey consisted of self-reported estimation of daily information technology (IT) exposure hours, tasks performed, psychosocial stress factors and relationship to musculoskeletal discomfort in the past 12 months. Total IT exposure time was an average of 7.38 h (±5.2) per day. The psychosocial factor of "working through pain" showed the most significant association with odds ratio (OR) ranging from 1.078 (95% CI = 1.021-1.138) for elbow discomfort, to 1.111 (95% CI = 1.046-1.180) for shoulder discomfort. Desktop time was also significantly associated with wrist/hand discomfort (OR = 1.103). These findings indicate only a modest relationship but one that is statistically significant with accounting for confounders. It is anticipated that prevalence rates of musculoskeletal disorders would rise in the future with increasing contribution due to psychosocial stress factors.

Effects of chronic neck-shoulder pain on normalized mutual information analysis of surface electromyography during functional tasks.

OBJECTIVE: To investigate the effects neck-shoulder pain on the connectivity of surface electromyography (SEMG) signals during functional tasks. METHODS: Twenty adults suffering from chronic neck-shoulder pain and 20 healthy controls were recruited. The SEMG signals from the left and right proximal cervical erector spinae, upper trapezius, lower trapezius and distal extensor carpi radialis, extensor digitorum, flexor digitorum superficialis and, abductor pollicis brevis were recorded during three functional tasks: unilateral and bilateral texting on a smart-phone and computer typing. Normalized mutual information (NMI) values were computed between homonymous proximal and distal muscle pairs as an index of the functional connectivity between muscles pairs. RESULTS: NMI among homonymous muscles pairs as well as among proximal and distal muscles pairs were lower among cases compared with controls. Moreover, NMI values in homonymous proximal muscles were higher during texting compared with computer typing with both hands. CONCLUSIONS: Our results show for the first time that chronic neck-shoulder pain affects the functional connectivity of muscle pairs. SIGNIFICANCE: The study furnishes novel information about the effects of chronic neck-shoulder pain on the interplay of muscle pairs during functional tasks.

Relationship between neck acceleration and muscle activation in people with chronic neck pain: Implications for functional disability.

BACKGROUND: Previous study has found that people with chronic neck pain moved with a consistently compromised acceleration/deceleration at their cervical and thoracic spines. This study examined the strength of the association between the electromyographic activities and the acceleration/deceleration of the cervical and thoracic spine, and its correlation with the functional disabilities in individuals with neck pain. METHODS: Time history of the cervical and thoracic acceleration/deceleration and EMG activity was acquired in thirty-four subjects with chronic neck pain and thirty-four age- and gender-matched asymptomatic subjects during active neck movements. The strength of the association between the electromyographic activity of spinal muscles and the cervical and thoracic acceleration/deceleration was determined using cross-correlation method. Relationship between the strength of this association and the severity of the functional disabilities in neck pain group was examined using correlation analysis. FINDINGS: The strength of the association between cervical and thoracic acceleration/deceleration and electromyographic activities was significantly lower in neck pain group. Significant negative correlations were found between the functional disability level and the strength of this defined association in the symptomatic group. INTERPRETATION: The compromised capability of the spinal muscles to produce acceleration/deceleration in the neck pain group may imply an impaired electromechanical coupling of these spinal muscles when performing neck movements. Significant negative correlation of the degree of functional disabilities suggests that the present approach can be used as an objective and specific evaluation of the dynamic performance of the spinal muscles and its relationship with the functional disabilities in neck pain subjects.

A comparison of muscle activity in using touchscreen smartphone among young people with and without chronic neck-shoulder pain.

This study aimed to examine differences in muscle activity between young people with and without neck-shoulder pain (n = 20 in each group), when they performed texting on a smartphone. Texting was compared between using both hands ('bilateral texting') and with only one hand ('unilateral texting'). Texting tasks were also compared with computer typing. Surface electromyography from three proximal postural muscles and four distal hand/thumb muscles on the right side was recorded. Compared with healthy controls, young people with neck-shoulder pain showed altered motor control consisting of higher muscle activity in the cervical erector spinae and upper trapezius when performing texting and typing tasks. Generally, unilateral texting was associated with higher muscle loading compared with bilateral texting especially in the forearm muscles. Compared with computer typing, smartphone texting was associated with higher activity in neck extensor and thumb muscles but lower activity in upper and lower trapezius as well as wrist extensors. PRACTITIONER SUMMARY: This study demonstrated that symptomatic individuals had increased muscle activity in the neck­shoulder region when texting on a smartphone. Contemporary ergonomic guidelines should include advice on how to interact with handheld electronic devices to achieve a relaxed posture and reduced muscle load in order to reduce the risk of musculoskeletal disorders.

The application of participatory ergonomics in a healthcare setting in Hong Kong.

BACKGROUND: Work-related musculoskeletal disorders (WRMDs) are recognized as a major source of significant pain and disability in the healthcare sector. However, they are preventable if appropriate surveillance and intervention programs are implemented. OBJECTIVE: The purpose of this paper is to describe the holistic ergonomic approach that was used to address the multifactorial problems encountered by healthcare workers in their daily work. METHODS: Using participatory ergonomics, healthcare workers in this study teamed up with management and staff with expertise in ergonomic analysis, design, and implementation of remedies. Selected participatory ergonomic intervention programs targeted at an organizational level are elaborated. Interventions included pre-work stretching, workplace surveillance at a psychiatric department, on-site ergonomic teaching for community nurses, and display screen equipment consultancy. DISCUSSIONS: Changes in workplace design, equipment re-arrangement, awareness of proper posture, and adoption of good work practices all play important roles in reducing musculoskeletal disorders among healthcare workers. Prompt occupational medicine and rehabilitation services were also provided to complement the work disability prevention process. The impact of the various intervention programs on staff health, costs and productivity of the organization are simultaneously discussed.