ORCID Profile
0000-0002-7341-3426
Current Organisations
University of Oxford
,
Tung Wah College
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.APERGO.2016.08.020
Abstract: This systematic review aimed at evaluating the prevalence and risk factors for musculoskeletal complaints associated with mobile handheld device use. Pubmed, Medline, Web of Science, CINAHL and Embase were searched. The methodological quality of included studies was assessed. Strength of evidence for risk factors was determined based on study designs, methodological quality and consistency of results. Five high-quality, eight acceptable-quality and two low-quality peer-reviewed articles were included. This review demonstrates that the prevalence of musculoskeletal complaints among mobile device users ranges from 1.0% to 67.8% and neck complaints have the highest prevalence rates ranging from 17.3% to 67.8%. This study also finds some evidence for neck flexion, frequency of phone calls, texting and gaming in relation to musculoskeletal complaints among mobile device users. Inconclusive evidence is shown for other risk factors such as duration of use and human-device interaction techniques due to inconsistent results or a limited number of studies.
Publisher: Elsevier BV
Date: 07-2022
Publisher: Elsevier BV
Date: 2009
DOI: 10.1016/S0004-9514(09)70005-4
Abstract: Do symptomatic female office workers perform computing tasks with higher cervical postural muscle loads (in terms of higher litudes and less muscular rest) and more discomfort compared with asymptomatic in iduals? Are these differences in postural muscle loads consistent across bilateral (typing) and unilateral (mousing) conditions? an experimental case-control study. 18 symptomatic female office workers and 21 asymptomatic female office workers. Three conditions (typing, mousing, and type-and-mouse) were performed in random order. Muscle load was measured as median litude and gap frequency using surface EMG of bilateral cervical erector spinae and upper trapezius. Discomfort was measured using a numerical rating scale. The case group demonstrated 4.3% (95% CI 0.1 to 8.4) higher litude during typing and 3.5% (95% CI 0.1 to 6.9) higher litude during type-and-mouse in the right cervical erector spinae compared with the control group. There was a similar difference between groups in the left cervical erector spinae which also demonstrated a 1.2 gaps/min (95% CI -2.3 to 0.0) lower frequency during typing. The case group had significantly higher discomfort during all conditions compared with the control group. The case group demonstrated higher median litudes and lower gap frequencies than the control group during bilateral conditions (typing and type-and-mouse) compared with unilateral conditions (mousing) for both muscle groups. There was increased litude and decreased muscular rest in the cervical erector spinae of office workers performing typing and mousing tasks. These findings may represent a mechanism underlying computer-related musculoskeletal disorders.
Publisher: MDPI AG
Date: 30-11-2020
Abstract: This study examined the association between smart device usage and the 1-year change in refractive error among a representative s le 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 ( h per day on both smartphone and tablet usages), those who spent ≥2 h per day using a smartphone and 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.
Publisher: Elsevier BV
Date: 05-2005
Publisher: Springer Science and Business Media LLC
Date: 05-05-2018
DOI: 10.1007/S00421-018-3878-Z
Abstract: 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. 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. 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 litude and activation duration were found to be significantly correlated with severity of pain (R Significant differences in the activation patterns of multiple cervical and thoracic muscles were found in in iduals 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.
Publisher: Informa UK Limited
Date: 28-07-2015
DOI: 10.1080/00140139.2015.1056237
Abstract: 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. This study demonstrated that symptomatic in iduals had increased muscle activity in the neck–shoulder 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.
Publisher: Elsevier BV
Date: 2002
DOI: 10.1016/S0003-6870(01)00043-6
Abstract: Poor neck and shoulder postures have been suggested to be a cause of neck and shoulder pain in computer workers. The present study aimed to evaluate and compare the head, neck and shoulder postures of office workers with and without symptoms in these regions, in their actual work environments. The two all female subject groups reported significantly different discomfort scores across five trials repeated in a single working day. The results of repeated video capture and two-dimensional motion analysis showed that there were trends for increased head tilt and neck flexion postures in the symptomatic subjects (n = 8), compared to the asymptomatic subjects (n = 8). Symptomatic subjects also tended to have more protracted acromions compared with asymptomatic subjects and showed greater movement excursions in the head segment and the acromion. All subjects demonstrated an approximately 10% increase in forward head posture from their relaxed sitting postures when working with the computer display, but there were no significant changes in posture as a result of time-at-work.
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.APERGO.2017.10.018
Abstract: To advance our understanding about the association between smartphone use and chronic neck-shoulder pain, the objective of this study was to compare spinal kinematics between different text-entry methods in smartphone users with and without chronic neck-shoulder pain. Symptomatic (n = 19) and healthy participants (n = 18) were recruited and they performed three tasks: texting on a smartphone with one hand, with two hands, and typing on a desktop computer. Three-dimensional kinematics were examined in the cervical, thoracic and lumbar regions for each task. This study suggests that altered kinematics may be associated with pain since significantly increased angles of cervical right side flexion during smartphone texting and greater postural changes in cervical rotation were found during all text-entry tasks in the symptomatic group. Two-handed texting was associated with increased cervical flexion while one-handed texting was correlated with an asymmetric neck posture, indicating both text-entry methods are not favorable in terms of spinal postures.
Publisher: Elsevier BV
Date: 09-2005
Publisher: Springer Science and Business Media LLC
Date: 03-03-2009
DOI: 10.1007/S00421-009-1019-4
Abstract: Past studies on work-related musculoskeletal disorders (WMSD) have reported increased median muscle activities in terms of 50th% of litude probability distribution function (APDF), and this was thought to be a manifestation of altered motor control--an important mechanism contributing to WMSD. The present study aimed to examine whether such altered motor control was also present in other parameters of APDF--the 10th and 90th% values, which can be considered indicators of the low and high measures of muscle activity. The difference between 10th and 90th% APDF can be considered an indicator of the variation in muscle activity litude (the "APDF range"). Surface electromyography was examined in female office workers as Case (n = 21) and Control (n = 18) subjects. The APDF variables were measured in cervical erector spinae (CES) and upper trapezius (UT) muscles during typing, mousing and type-and-mouse, for 20 min each. The Case Group had significantly higher CES activity in the 10th, 90th% and APDF range compared to Controls. The UT muscles showed similar trends but the between-group differences were not statistically significant. These results have demonstrated the robustness of the APDF variables as sensitive indicators of motor control variations in symptomatic subjects with musculoskeletal disorders.
Publisher: Elsevier BV
Date: 06-2009
DOI: 10.1016/J.MATH.2008.05.001
Abstract: Past research on work-related musculoskeletal disorders (WMSD) has frequently examined the activity of neck-shoulder muscles such as upper trapezius (UT) and cervical erector spinae (CES) during typing tasks. Increased electromyographic activity in these postural stabilising muscles has been consistently found in chronic neck pain patients under different physically stressful conditions. The present study compared muscle activity when female office workers with chronic neck pain (n=39) and asymptomatic controls (n=34) adopted two resting postures: (1) with hands on laps versus and (2) hands on a keyboard. Resting hands on keyboard elicited significantly increased muscle activity in the right UT of subjects with high discomforts (n=22), similar to that observed during actual typing. In contrast, the asymptomatic controls showed no difference in muscle activity between the resting postures. This result suggested that altered muscle activation patterns were triggered by some anticipatory task demand associated with a task-specific position in some in iduals.
Publisher: Elsevier BV
Date: 11-2005
DOI: 10.1016/J.MATH.2005.01.005
Abstract: Prolonged static posture has been identified as a major risk factor for work-related neck and upper limb disorders (WRNULD) in computer users. Previous research has mainly examined working postures in healthy pain-free in iduals. The present study examined whether symptomatic subjects exhibited the same kinematic patterns as asymptomatic controls during a prolonged computer task. In a Case-Control comparison, female office workers performed the same computer task using the same adjustable computer workstation for 1h. Three-dimensional (3D) kinematics were measured in the head-neck, thorax and shoulder (upper arm) segments. Case Group subjects (n=21) displayed trends for increased head-neck flexion angles and greater ranges of movements than the Control Group (n=17). There were also small but significant differences between groups in side flexion and rotation angles of the head-neck region. The shoulder joints displayed significantly greater flexion and abduction angles on the right in both groups, although no group differences were observed. The increased neck flexion angles were associated with significantly higher activity in the upper trapezius muscle and with neck and shoulder discomfort. The in idual differences in postural habits appeared to be independent of the physical environment. These results suggest motor control changes are associated with the presence of WRNULD.
Publisher: Elsevier BV
Date: 11-2005
DOI: 10.1016/J.MATH.2005.01.004
Abstract: Work-related neck and upper limb disorders (WRNULD) are common problems among office workers who use computers intensively and maintain prolonged static postures. These disorders have often been attributed to result from sustained muscle activity in the neck-shoulder musculature. The present study examined whether symptomatic subjects exhibited the same muscle activity patterns as asymptomatic controls when they performed a prolonged computer task under the same conditions. Surface electromyography (EMG) of four major neck-shoulder muscles were compared between a Case Group (n=23) and a Control Group (n=20) of female office workers. The Case Group had higher activity in the right upper trapezius (UT) while the Control Group had more symmetrical muscle activity between left and right UT. The Case subjects could also be differentiated into "High Discomfort" and "Low Discomfort" sub-groups based on their discomfort scores. The High Discomfort Group had significantly higher right UT activity compared to the Low Discomfort and Control Groups. Results suggested that symptomatic in iduals had altered muscle recruitment patterns that persisted throughout the sustained occupational task, while discomfort increased with time-at-task. These findings indicate that altered muscle recruitment patterns observed in the symptomatic subjects preceded the onset of task discomfort, and this finding may have important implications for the etiology of WRNULD.
Publisher: Elsevier BV
Date: 12-2005
DOI: 10.1016/J.JELEKIN.2005.06.004
Abstract: The problem of work-related neck and upper limb disorders among computer users has been reported extensively in the literature, and commonly cited risk factors include static posture, speed and force of keyboard operation. The present study examined changes in median frequency (MF) of the neck-shoulder muscles in symptomatic and asymptomatic office workers when they were exposed to these three physical stressors. A quasi-experimental Case-Control design was used to examine MF changes in two groups of female office workers when they were subjected to controlled doses of computer work involving prolonged static posture, increased typing speed and increased typing force. The MF of four major neck-shoulder muscles were examined bilaterally and compared between groups. The MF changes over time-at-task did not clearly illustrate any muscle fatigue mechanism. However, Case Group consistently showed trends for higher MF than the Control Group, and this pattern was observed in response to all three physical stressors. The consistent group differences in MF suggest different muscle recruitment strategies between symptomatic and asymptomatic office workers. These results implied that symptomatic in iduals had altered motor control, which may have important implications in understanding the etiology of work-related musculoskeletal disorders.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Lidao Li.