Grace Szeto - Academia.edu (original) (raw)

Papers by Grace Szeto

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

Environmental Science and Pollution Research

Prolonged electronic screen use can cause digital eye strain. It can be difficult to rectify due ... more 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. Linea...

Research paper thumbnail of A service learning project on inter-professional collaboration to promote health and wellness in community organisations

Research paper thumbnail of 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

PLOS ONE, 2021

This study aims to investigate the dysfunction and recovery of the lumbopelvic movement and motor... more 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 an...

Research paper thumbnail of P140 A study of sleep quality, smartphone use and chronic neck pain among male and female university students

SLEEP Advances, 2021

Purpose Intensive smartphone use may contribute to chronic neck and shoulder pain and sleep distu... more Purpose Intensive smartphone use may contribute to chronic neck and shoulder pain and sleep disturbance. This study aimed to examine the relationship of sleep quality with daytime smartphone use and self-reported neck-shoulder symptoms among university students in Hong Kong. Methods Nineteen university students participated (11 males, 9 females, mean age=21.7±3.9). The actigraphy device Actiwatch 2 (Philips Ltd) was used to record 7 nights of sleep data. Daytime smartphone use and neck and shoulder pain scores (on a Pain scale 0–10) were recorded. Results Total sleep time (TST) was significantly longer in females (410.2min) than males (359.6min) (p=0.012), as was the sleep efficiency (females: 87.8%, males: 79.8%, p=0.003). Their sleep onset latency was similar at around 18min. The mean weekly Screen time and pre-bed Screen time were 430.1min and 37.9min for females, and 427.2min and 26.7min for males respectively. All the participants reported mild neck-shoulder symptoms (mean pain...

Research paper thumbnail of Development of the Prevent for Work questionnaire (P4Wq) for assessment of musculoskeletal risk in the workplace: part 1—literature review and domains selection

BMJ Open, 2021

ObjectiveThis study aims to define appropriate domains and items for the development of a self-ad... more ObjectiveThis 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.DesignLiterature review and survey study.Setting and participantsA 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 outcomeTo 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.ResultsNine 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...

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

International Journal of Environmental Research and Public Health, 2020

This study examined the association between smart device usage and the 1-year change in refractiv... more 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 shif...

Research paper thumbnail of Bedtime smart device usage and accelerometer-measured sleep outcomes in children and adolescents

Sleep and Breathing, 2021

Purpose We analyzed the association between bedtime smart device usage habits and accelerometer-m... more 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 ...

Research paper thumbnail of The biomechanical evaluation of patient transfer tasks by female nursing students: With and without a transfer belt

Applied Ergonomics, 2020

This study was to examine the kinematics, muscle activities, and perceived physical exertion in d... more This study was to examine the kinematics, muscle activities, and perceived physical exertion in different regions of the spine during patient transfers by nursing students between a bed and a wheelchair, with or without a transfer belt in a laboratory setting. Results showed that with the effect of the belt, the % maximum voluntary contraction of the lumbar erector spinae was reduced significantly by nearly 10%. Muscle activity was significantly increased in thoracic erector and multifidus spinae during wheelchair-to-bed transfer, compared to bed-to-wheelchair transfers. There was no significant effect of belt or task on the spinal angular displacement in different spinal regions. Using the transfer belt was associated with a significantly decreased score for perceived exertion. In conclusion, this study supports the use of a transfer belt contributing to lower muscle activity and lower perceived physical exertion in the low back.

Research paper thumbnail of Association of electromyographic activation patterns with pain and functional disability in people with chronic neck pain

European Journal of Applied Physiology, 2018

This study examined the activation patterns of the cervical and thoracic muscles in people with a... more 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 (UTr), cervical erector spinae (CES), sternocleidomastoid (SCM), and thoracic erector spinae (TES) 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 (R 2 = 0.716) and functional disability (R 2 = 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.

Research paper thumbnail of Cumulative IT Use Is Associated with Psychosocial Stress Factors and Musculoskeletal Symptoms

International journal of environmental research and public health, Dec 8, 2017

This study aimed to examine the relationship between cumulative use of electronic devices and mus... more 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 ...

Research paper thumbnail of Psychometric Evaluation of the Workstyle Short Form among Nursing Assistants with Work-Related Musculoskeletal Symptoms

International journal of environmental research and public health, Apr 22, 2018

The Workstyle Short Form (24 items) (WSF-24) has been tested for its psychometric properties on w... more The Workstyle Short Form (24 items) (WSF-24) has been tested for its psychometric properties on work-related upper-extremity musculoskeletal symptoms (WRUEMSs) among office workers. However, the impact of workstyle should not only be limited to WRUEMSs and the sedentary workforce. The purpose of this study was to test the psychometric properties of the modified 24-item Chinese WSF (C-WSF-24) to identify work-related musculoskeletal symptoms (WRMSs) in various body parts among nursing assistants (NAs) working in nursing homes. Four hundred and thirty-nine NAs participated in the study. The results of the factor analysis were that a four-factor solution (working through pain, social reactivity at work, demands at work and breaks) accounted for 56.45% of the total variance. Furthermore, validation against known groups showed that the total score and subscale scores of the C-WSF-24 had the ability to discriminate between NAs with and without WRMSs in various body parts (such as low back...

Research paper thumbnail of Cervical kinematic and muscle activity during electronic game playing and their association with musculoskeletal discomforts

Research paper thumbnail of Low-Cost Ergonomic Intervention for Mitigating Physical and Subjective Discomfort during Manual Rebar Tying

Journal of Construction Engineering and Management, 2017

The construction industry around the globe is facing a massive predicament of work-related muscul... more The construction industry around the globe is facing a massive predicament of work-related musculoskeletal disorders (MSDs), largely attributed to the excessive physical exertion at worksites. While ergonomic interventions are suggested to be an effective approach to mitigate such routine exertion, these ergonomic interventions should be task specific given the unique characteristics of each trade (such as rebar work; a construction trade with a high prevalence rate of MSDs). Despite numerous potential interventions available for rebar workers, none of them have been widely adopted, especially in the Asian market. After considering various reasons impeding their broad usage, the authors coined a simple ergonomic solution by attaching a low height domestic stool to the pants of rebar workers. This would allow them to sit and work instead of squatting, which is the most preferred posture in Asian cultures for working at ground level. The novel intervention was tested against squatting for various physical outcomes (i.e. muscle activity, neuromuscular fatigue, trunk kinematics and lower extremity blood circulation) and self-perceived discomfort, using a simulated rebar tying task in a laboratory. These findings demonstrate that the intervention has beneficial effects on both physical and subjective outcomes, and has a great potential in reducing work-related MSDs among Asian rebar workers. Additionally, the current study highlights that ergonomic interventions in the construction industry should be derived based on both the characteristics of specific construction trades and culture of workers.

Research paper thumbnail of Exploring the Synergic Effects of Nursing Home Work on Work-Related Musculoskeletal Disorders Among Nursing Assistants

Workplace health & safety, 2017

Little is known about how nursing assistants (NAs) perceive the nature of their work and how thei... more Little is known about how nursing assistants (NAs) perceive the nature of their work and how their work contributes to work-related musculoskeletal disorders (WMSDs). This qualitative study addressed these gaps. Twenty-four NAs with WMSDs working in four nursing homes participated in semistructured focus group interviews. Their WMSDs were not limited to the lower back but involved several body parts. The risk factors for WMSDs included physical, psychosocial, organizational, and personal factors as well as coworkers and clients. However, it is the synergistic effects of long work hours without sufficient rest, work even with musculoskeletal pain because of staff shortages, ineffective management with insufficient prework training and inadequate equipment maintenance, and an aging workforce with strong commitment to resident care that play a crucial role in WMSDs among NAs working in nursing homes. The study found that multidimensional intervention strategies using engineering, admin...

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

BMC musculoskeletal disorders, Apr 17, 2017

Impaired lumbo-pelvic movement in people with low back pain during bending task has been reported... more 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. 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. Signific...

Research paper thumbnail of Identification of Biomechanical Risk Factors for the Development of Lower-Back Disorders during Manual Rebar Tying

Journal of Construction Engineering and Management, 2017

High prevalence of musculoskeletal disorders among construction workers pose challenges to the pr... more High prevalence of musculoskeletal disorders among construction workers pose challenges to the productivity and occupational health of the construction industry. To mitigate the risk of musculoskeletal disorders, construction managers need to deepen their understanding of the physical and biomechanical demands of various construction tasks so that appropriate policies and preventive measures can be implemented. Among various construction trades, rebar workers are highly susceptible to lower-back disorders (LBDs) given the physically demanding nature of their work tasks. In particular, rebar tying is considered to be closely related to LBDs because it exposes workers to multiple ergonomic risk factors (repetitive works in prolonged static and awkward postures). The objective of the current study was to compare the differences in lumbar biomechanics during three typical rebar tying postures: stooping, one-legged kneeling, and squatting. Biomechanical variables including trunk muscle activity and trunk kinematics were measured by surface electromyography and motion sensors, respectively. Ten healthy male participants performed a simulated rebar tying task in each of the three postures in a laboratory setting. Repeated measures analysis of variance showed that while each posture has its unique trunk kinematic characteristics, all these postures involved excessive trunk inclination that exceeded the internationally recommended trunk inclination angle of 60°for static working postures. Of the three postures, stooping posture demonstrated a significant reduction in electromyographic activity of lumbar muscles (a reduction in 60-80% of muscle activity as compared to the other two postures). The reduced muscle activity may shift the loading to passive spinal structures (e.g., spinal ligaments and joint capsules), which is known to be a risk factor for LBD development. Collectively, the results from this study may help explain the high prevalence of LBDs in rebar workers. Future studies are warranted to confirm the findings at construction sites and to develop appropriate ergonomic approaches for rebar workers.

Research paper thumbnail of Injured workers’ perception of loss and gain in the return to work process

Risk Management and Healthcare Policy, 2017

When a worker is injured at work, he has to face a tough decision-making process about when and h... more When a worker is injured at work, he has to face a tough decision-making process about when and how to return to work (RTW). This study tests how the prospect theory can be applied to influence the injured workers' perceptions about this important choice. One hundred forty-one injured workers were presented with wage-and pain-related information in four different message framing (negatively or positively) and precision (smaller or larger number) conditions. After exposure to the specific combination of this wage and pain information, the participants were asked to express intentions to RTW in terms of perceived chance, confidence, and anticipated sick leave duration. When asked to predict their RTW outcome, 101 participants (72.3%) responded favorably, whereas only 40 (27.7%) indicated an expectation for staying on sick leave. The present results did not show significant differences in the participants' responses to the positively and negatively framed information about wage and pain. However, it was noted that the control group that was presented with positive framing for both "wage" and "pain" information showed higher scores in expectation and confidence for RTW, whereas the Ambivalent Group that had both negative messages showed lower scores. Seventy-nine participants who had ≥60% perceived improvement in condition were selected for further analysis, and those who were presented with "wage loss" information rated significantly higher perceived chance of RTW than those in the "pain gain" group. More in-depth investigation is warranted on this topic, with a larger sample of injured workers to investigate the effects of message framing on the decision-making process about RTW.

Research paper thumbnail of Integrating ergonomics intervention and motor control training: an innovative approach in managing work-related musculoskeletal disorders

Research paper thumbnail of The Effect of Training Intensity on Voluntary Isometric Strength Improvement

Australian Journal of Physiotherapy, 1989

The effect of different training intensities on maximum voluntalfYisometric contraction (MVIC) st... more The effect of different training intensities on maximum voluntalfYisometric contraction (MVIC) strength was examined in a three week voluntary isometric exercise programme. Eighteen healthy university students were randomly assigned to one of three training groups: Low Intensity (LI), High Intensity (HI) and Maximal Effort (ME) groups. The LI and HI groups trained by producing voluntary isometric knee extension torques equivalent to 25% and 50% of MVIC strength, respectively. The ME group produced maximal effort contractions during training ..

Research paper thumbnail of Chinese Translation and Cross Cultural Adaptation of the Workstyle Short Form

Journal of Occupational Rehabilitation, 2013

Introduction Workstyle as it is related to symptoms of musculoskeletal symptoms of the upper limb... more Introduction Workstyle as it is related to symptoms of musculoskeletal symptoms of the upper limbs is the behavioural, cognitive and physical responses that occur in individuals to increases in work demands. A self report measure of this construct was developed that was both associated with and predictive of work related upper extremity symptoms. The aim of this study was to translate, culturally adapt, and validate a Chinese version of the Workstyle Short Form (C-WSF). Methods The C-WSF was translated following a forward and backward translation approach. Content validity was examined by item-and scale-level content validity indices. The intra-class correlation coefficient (ICC) was used to analyze test-retest reliability. Exploratory factor analysis was used to identify factor structures and the internal consistency of these factors was assessed by calculating Cronbach's alpha reliability coefficients. The construct validity of the C-WSF was first determined by convergence in relation to the Cumulative Symptoms Score for Upper Extremity symptoms and then by comparison of those with and without upper extremity pain in Chinese cooks, a work with a high level of exposures to varying levels of work demands coupled with exposure to workplace psychosocial and biomechanical stressors. Results The C-WSF demonstrated excellent item-and scale-level content validity index ([0.9). The factor structure of C-WSF was similar to its original English version. The internal consistency of different subscales of C-WSF ranged from 0.65 to 0.91. The ICC was between 0.79 and 0.93 indicating good test-retest reliability. C-WSF was significantly correlated with upper extremity symptoms (r = 0.34, p \ 0.001). Conclusions C-WSF is a reliable and valid version of the Workstyle measures for use in Chinese population.

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

Environmental Science and Pollution Research

Prolonged electronic screen use can cause digital eye strain. It can be difficult to rectify due ... more 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. Linea...

Research paper thumbnail of A service learning project on inter-professional collaboration to promote health and wellness in community organisations

Research paper thumbnail of 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

PLOS ONE, 2021

This study aims to investigate the dysfunction and recovery of the lumbopelvic movement and motor... more 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 an...

Research paper thumbnail of P140 A study of sleep quality, smartphone use and chronic neck pain among male and female university students

SLEEP Advances, 2021

Purpose Intensive smartphone use may contribute to chronic neck and shoulder pain and sleep distu... more Purpose Intensive smartphone use may contribute to chronic neck and shoulder pain and sleep disturbance. This study aimed to examine the relationship of sleep quality with daytime smartphone use and self-reported neck-shoulder symptoms among university students in Hong Kong. Methods Nineteen university students participated (11 males, 9 females, mean age=21.7±3.9). The actigraphy device Actiwatch 2 (Philips Ltd) was used to record 7 nights of sleep data. Daytime smartphone use and neck and shoulder pain scores (on a Pain scale 0–10) were recorded. Results Total sleep time (TST) was significantly longer in females (410.2min) than males (359.6min) (p=0.012), as was the sleep efficiency (females: 87.8%, males: 79.8%, p=0.003). Their sleep onset latency was similar at around 18min. The mean weekly Screen time and pre-bed Screen time were 430.1min and 37.9min for females, and 427.2min and 26.7min for males respectively. All the participants reported mild neck-shoulder symptoms (mean pain...

Research paper thumbnail of Development of the Prevent for Work questionnaire (P4Wq) for assessment of musculoskeletal risk in the workplace: part 1—literature review and domains selection

BMJ Open, 2021

ObjectiveThis study aims to define appropriate domains and items for the development of a self-ad... more ObjectiveThis 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.DesignLiterature review and survey study.Setting and participantsA 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 outcomeTo 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.ResultsNine 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...

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

International Journal of Environmental Research and Public Health, 2020

This study examined the association between smart device usage and the 1-year change in refractiv... more 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 shif...

Research paper thumbnail of Bedtime smart device usage and accelerometer-measured sleep outcomes in children and adolescents

Sleep and Breathing, 2021

Purpose We analyzed the association between bedtime smart device usage habits and accelerometer-m... more 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 ...

Research paper thumbnail of The biomechanical evaluation of patient transfer tasks by female nursing students: With and without a transfer belt

Applied Ergonomics, 2020

This study was to examine the kinematics, muscle activities, and perceived physical exertion in d... more This study was to examine the kinematics, muscle activities, and perceived physical exertion in different regions of the spine during patient transfers by nursing students between a bed and a wheelchair, with or without a transfer belt in a laboratory setting. Results showed that with the effect of the belt, the % maximum voluntary contraction of the lumbar erector spinae was reduced significantly by nearly 10%. Muscle activity was significantly increased in thoracic erector and multifidus spinae during wheelchair-to-bed transfer, compared to bed-to-wheelchair transfers. There was no significant effect of belt or task on the spinal angular displacement in different spinal regions. Using the transfer belt was associated with a significantly decreased score for perceived exertion. In conclusion, this study supports the use of a transfer belt contributing to lower muscle activity and lower perceived physical exertion in the low back.

Research paper thumbnail of Association of electromyographic activation patterns with pain and functional disability in people with chronic neck pain

European Journal of Applied Physiology, 2018

This study examined the activation patterns of the cervical and thoracic muscles in people with a... more 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 (UTr), cervical erector spinae (CES), sternocleidomastoid (SCM), and thoracic erector spinae (TES) 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 (R 2 = 0.716) and functional disability (R 2 = 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.

Research paper thumbnail of Cumulative IT Use Is Associated with Psychosocial Stress Factors and Musculoskeletal Symptoms

International journal of environmental research and public health, Dec 8, 2017

This study aimed to examine the relationship between cumulative use of electronic devices and mus... more 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 ...

Research paper thumbnail of Psychometric Evaluation of the Workstyle Short Form among Nursing Assistants with Work-Related Musculoskeletal Symptoms

International journal of environmental research and public health, Apr 22, 2018

The Workstyle Short Form (24 items) (WSF-24) has been tested for its psychometric properties on w... more The Workstyle Short Form (24 items) (WSF-24) has been tested for its psychometric properties on work-related upper-extremity musculoskeletal symptoms (WRUEMSs) among office workers. However, the impact of workstyle should not only be limited to WRUEMSs and the sedentary workforce. The purpose of this study was to test the psychometric properties of the modified 24-item Chinese WSF (C-WSF-24) to identify work-related musculoskeletal symptoms (WRMSs) in various body parts among nursing assistants (NAs) working in nursing homes. Four hundred and thirty-nine NAs participated in the study. The results of the factor analysis were that a four-factor solution (working through pain, social reactivity at work, demands at work and breaks) accounted for 56.45% of the total variance. Furthermore, validation against known groups showed that the total score and subscale scores of the C-WSF-24 had the ability to discriminate between NAs with and without WRMSs in various body parts (such as low back...

Research paper thumbnail of Cervical kinematic and muscle activity during electronic game playing and their association with musculoskeletal discomforts

Research paper thumbnail of Low-Cost Ergonomic Intervention for Mitigating Physical and Subjective Discomfort during Manual Rebar Tying

Journal of Construction Engineering and Management, 2017

The construction industry around the globe is facing a massive predicament of work-related muscul... more The construction industry around the globe is facing a massive predicament of work-related musculoskeletal disorders (MSDs), largely attributed to the excessive physical exertion at worksites. While ergonomic interventions are suggested to be an effective approach to mitigate such routine exertion, these ergonomic interventions should be task specific given the unique characteristics of each trade (such as rebar work; a construction trade with a high prevalence rate of MSDs). Despite numerous potential interventions available for rebar workers, none of them have been widely adopted, especially in the Asian market. After considering various reasons impeding their broad usage, the authors coined a simple ergonomic solution by attaching a low height domestic stool to the pants of rebar workers. This would allow them to sit and work instead of squatting, which is the most preferred posture in Asian cultures for working at ground level. The novel intervention was tested against squatting for various physical outcomes (i.e. muscle activity, neuromuscular fatigue, trunk kinematics and lower extremity blood circulation) and self-perceived discomfort, using a simulated rebar tying task in a laboratory. These findings demonstrate that the intervention has beneficial effects on both physical and subjective outcomes, and has a great potential in reducing work-related MSDs among Asian rebar workers. Additionally, the current study highlights that ergonomic interventions in the construction industry should be derived based on both the characteristics of specific construction trades and culture of workers.

Research paper thumbnail of Exploring the Synergic Effects of Nursing Home Work on Work-Related Musculoskeletal Disorders Among Nursing Assistants

Workplace health & safety, 2017

Little is known about how nursing assistants (NAs) perceive the nature of their work and how thei... more Little is known about how nursing assistants (NAs) perceive the nature of their work and how their work contributes to work-related musculoskeletal disorders (WMSDs). This qualitative study addressed these gaps. Twenty-four NAs with WMSDs working in four nursing homes participated in semistructured focus group interviews. Their WMSDs were not limited to the lower back but involved several body parts. The risk factors for WMSDs included physical, psychosocial, organizational, and personal factors as well as coworkers and clients. However, it is the synergistic effects of long work hours without sufficient rest, work even with musculoskeletal pain because of staff shortages, ineffective management with insufficient prework training and inadequate equipment maintenance, and an aging workforce with strong commitment to resident care that play a crucial role in WMSDs among NAs working in nursing homes. The study found that multidimensional intervention strategies using engineering, admin...

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

BMC musculoskeletal disorders, Apr 17, 2017

Impaired lumbo-pelvic movement in people with low back pain during bending task has been reported... more 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. 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. Signific...

Research paper thumbnail of Identification of Biomechanical Risk Factors for the Development of Lower-Back Disorders during Manual Rebar Tying

Journal of Construction Engineering and Management, 2017

High prevalence of musculoskeletal disorders among construction workers pose challenges to the pr... more High prevalence of musculoskeletal disorders among construction workers pose challenges to the productivity and occupational health of the construction industry. To mitigate the risk of musculoskeletal disorders, construction managers need to deepen their understanding of the physical and biomechanical demands of various construction tasks so that appropriate policies and preventive measures can be implemented. Among various construction trades, rebar workers are highly susceptible to lower-back disorders (LBDs) given the physically demanding nature of their work tasks. In particular, rebar tying is considered to be closely related to LBDs because it exposes workers to multiple ergonomic risk factors (repetitive works in prolonged static and awkward postures). The objective of the current study was to compare the differences in lumbar biomechanics during three typical rebar tying postures: stooping, one-legged kneeling, and squatting. Biomechanical variables including trunk muscle activity and trunk kinematics were measured by surface electromyography and motion sensors, respectively. Ten healthy male participants performed a simulated rebar tying task in each of the three postures in a laboratory setting. Repeated measures analysis of variance showed that while each posture has its unique trunk kinematic characteristics, all these postures involved excessive trunk inclination that exceeded the internationally recommended trunk inclination angle of 60°for static working postures. Of the three postures, stooping posture demonstrated a significant reduction in electromyographic activity of lumbar muscles (a reduction in 60-80% of muscle activity as compared to the other two postures). The reduced muscle activity may shift the loading to passive spinal structures (e.g., spinal ligaments and joint capsules), which is known to be a risk factor for LBD development. Collectively, the results from this study may help explain the high prevalence of LBDs in rebar workers. Future studies are warranted to confirm the findings at construction sites and to develop appropriate ergonomic approaches for rebar workers.

Research paper thumbnail of Injured workers’ perception of loss and gain in the return to work process

Risk Management and Healthcare Policy, 2017

When a worker is injured at work, he has to face a tough decision-making process about when and h... more When a worker is injured at work, he has to face a tough decision-making process about when and how to return to work (RTW). This study tests how the prospect theory can be applied to influence the injured workers' perceptions about this important choice. One hundred forty-one injured workers were presented with wage-and pain-related information in four different message framing (negatively or positively) and precision (smaller or larger number) conditions. After exposure to the specific combination of this wage and pain information, the participants were asked to express intentions to RTW in terms of perceived chance, confidence, and anticipated sick leave duration. When asked to predict their RTW outcome, 101 participants (72.3%) responded favorably, whereas only 40 (27.7%) indicated an expectation for staying on sick leave. The present results did not show significant differences in the participants' responses to the positively and negatively framed information about wage and pain. However, it was noted that the control group that was presented with positive framing for both "wage" and "pain" information showed higher scores in expectation and confidence for RTW, whereas the Ambivalent Group that had both negative messages showed lower scores. Seventy-nine participants who had ≥60% perceived improvement in condition were selected for further analysis, and those who were presented with "wage loss" information rated significantly higher perceived chance of RTW than those in the "pain gain" group. More in-depth investigation is warranted on this topic, with a larger sample of injured workers to investigate the effects of message framing on the decision-making process about RTW.

Research paper thumbnail of Integrating ergonomics intervention and motor control training: an innovative approach in managing work-related musculoskeletal disorders

Research paper thumbnail of The Effect of Training Intensity on Voluntary Isometric Strength Improvement

Australian Journal of Physiotherapy, 1989

The effect of different training intensities on maximum voluntalfYisometric contraction (MVIC) st... more The effect of different training intensities on maximum voluntalfYisometric contraction (MVIC) strength was examined in a three week voluntary isometric exercise programme. Eighteen healthy university students were randomly assigned to one of three training groups: Low Intensity (LI), High Intensity (HI) and Maximal Effort (ME) groups. The LI and HI groups trained by producing voluntary isometric knee extension torques equivalent to 25% and 50% of MVIC strength, respectively. The ME group produced maximal effort contractions during training ..

Research paper thumbnail of Chinese Translation and Cross Cultural Adaptation of the Workstyle Short Form

Journal of Occupational Rehabilitation, 2013

Introduction Workstyle as it is related to symptoms of musculoskeletal symptoms of the upper limb... more Introduction Workstyle as it is related to symptoms of musculoskeletal symptoms of the upper limbs is the behavioural, cognitive and physical responses that occur in individuals to increases in work demands. A self report measure of this construct was developed that was both associated with and predictive of work related upper extremity symptoms. The aim of this study was to translate, culturally adapt, and validate a Chinese version of the Workstyle Short Form (C-WSF). Methods The C-WSF was translated following a forward and backward translation approach. Content validity was examined by item-and scale-level content validity indices. The intra-class correlation coefficient (ICC) was used to analyze test-retest reliability. Exploratory factor analysis was used to identify factor structures and the internal consistency of these factors was assessed by calculating Cronbach's alpha reliability coefficients. The construct validity of the C-WSF was first determined by convergence in relation to the Cumulative Symptoms Score for Upper Extremity symptoms and then by comparison of those with and without upper extremity pain in Chinese cooks, a work with a high level of exposures to varying levels of work demands coupled with exposure to workplace psychosocial and biomechanical stressors. Results The C-WSF demonstrated excellent item-and scale-level content validity index ([0.9). The factor structure of C-WSF was similar to its original English version. The internal consistency of different subscales of C-WSF ranged from 0.65 to 0.91. The ICC was between 0.79 and 0.93 indicating good test-retest reliability. C-WSF was significantly correlated with upper extremity symptoms (r = 0.34, p \ 0.001). Conclusions C-WSF is a reliable and valid version of the Workstyle measures for use in Chinese population.