Effects of smartphone screen viewing duration and body position on head and neck posture in elementary school children

Analysis of abnormal muscle activities in patients with loss of cervical lordosis: a cross-sectional study

BACKGROUND

This study aimed to detect the differences in cervical muscle activation patterns in people with versus without cervical lordosis and explore the possible mechanism of cervical pain originating therein.

METHODS

This cross-sectional design included 39 participants without and 18 with normal cervical lordosis. Muscular activation was measured for 5 s in both groups using surface electromyography. Subsequently, the root mean square (RMS) of muscle amplitude was obtained at the bilateral splenius capitis, upper and lower parts of the splenius cervicis, upper and lower parts of the semispinalis cervicis, sternocleidomastoid, upper trapezius, and rhomboid muscles in five cervical positions: 0° (resting), 30° of flexion, 30° of extension, 60° of extension, and upon a 1-kg load on the head in a resting posture.

RESULTS

The RMS values of the upper trapezius muscle at all postures and the rhomboid muscles at 60° of extension were significantly lower in the loss of lordosis than control group. Comparing the RMS ratio of each posture to the resting position, the ratio of the upper trapezius at flexion was significantly higher and that of the rhomboids at 60° of extension and upon loading was significantly lower in the loss of lordosis than control group. Moreover, the pattern changes in the RMS values according to posture showed a similar shape in these two muscles, and lower in the loss of lordosis than the normal group.

CONCLUSIONS

The loss of normal cervical alignment may correlate with predisposed conditions such as reduced muscle activation of the trapezius and rhomboid muscle, and may also provoke over-firing of the upper trapezius muscle, possibly increasing neck musculoskeletal pain.

TRIAL REGISTRATION

CLINICALTRIALS

gov, registration number: NCT03710785.

Smartphone use affects gait performance, spinal kinematics and causes spinal musculoskeletal discomfort in young adults

BACKGROUND

Smartphone use may lead to alterations in spinal kinematics and musculoskeletal discomfort.

OBJECTIVES

The aim of this study was to evaluate the effect of smartphone use on spinal kinematics, and to examine the relationship between smartphone addiction, spinal discomfort, and gait parameters.

DESIGN

Cross-Sectional Study.

METHODS

The study included 42 healthy adults aged 18-30 years. A photographic method was used for spinal kinematic evaluation in sitting, standing and at the end of a 3-min walk. GAITRite electronic walkway was used for spatiotemporal gait parameters. Smartphone addiction was evaluated with the Smartphone Addiction Scale - Short Version (SAS-SV). The Cornell Musculoskeletal System Discomfort Questionnaire (CMDQ) was used to evaluate feelings of discomfort and pain.

RESULTS

There was an increase in head, cervical, and thoracic flexion angles while sitting, standing, and at the end of a 3-min walk. Similarly, an increase in thoracolumbar and lumbar flexion angles was observed only in the sitting position (p < 0.05). While using a smartphone during walking, cadence, walking speed, step length decreased, while step duration and double support duration increased (p < 0.05). A statistically significant correlation was determined between the SAS-SV and CMDQ scores (p < 0.05).

CONCLUSION

The study showed that smartphone use has an impact on spinal kinematics during sitting, standing and at the end of a 3 min-walk, as well as on the spatiotemporal parameters of gait. This study suggest that smartphone addiction should be taken into consideration due to its potential to cause musculoskeletal discomfort and there may be a need to raise public awareness on this matter.

Internet addiction and depression among Chinese adolescents: anxiety as a mediator and social support as a moderator

This study constructed a moderated mediation model to investigate the mediating effect of anxiety and the moderating effect of social support between Internet addiction and depression. A sample of 17 058 middle school students in one district of Chengdu were selected. The Internet Addiction Test (IAT), Generalized Anxiety Disorder (GAD-7), Patient Health Questionnaire (PHQ-9), and Social Support Scale for adolescents were used to investigate their Internet addiction, anxiety, depression and social support. The descriptive statistics and Spearman correlation analysis were performed with SPSS 25.0. An SPSS macro process was used to analyze the data from complex models that contained mediators and moderators. The results show that adolescents with Internet addiction are more likely to suffer from depression. Anxiety partially mediated the relations between Internet addiction and depression. Social support moderated both direct and indirect pathways leading from Internet addiction to depression, and these two effects were stronger for adolescents with low social support than for those with high social support. It will be possible for researchers to gain a better understanding of the conditions, pathways, and effects of Internet addiction on depression in adolescents through the results of this study.

Influence of forward head posture on muscle activation pattern of the trapezius pars descendens muscle in young adults

Forward head posture (FHP) is a serious problem causing head and neck disability, but the characteristics of muscle activity during long-term postural maintenance are unclear. This study aimed to investigate a comparison of electromyography (EMG) activation properties and subjective fatigue between young adults with and without habitual FHP. In this study, we examined the changes in the spatial and temporal distribution patterns of muscle activity using high-density surface EMG (HD-SEMG) in addition to mean frequency, a conventional measure of muscle fatigue. Nineteen male participants were included in the study (FHP group (n = 9; age = 22.3 ± 1.5 years) and normal group (n = 10; age = 22.5 ± 1.4 years)). Participants held three head positions (e.g., forward, backward, and neutral positions) for a total of 30 min each, and the EMG activity of the trapezius pars descendens muscle during posture maintenance was measured by HD-SEMG. The root mean square (RMS), the modified entropy, and the correlation coefficient were calculated. Additionally, the visual analogue scale (VAS) was evaluated to assess subjective fatigue. The RMS, VAS, modified entropy, and correlation coefficients were significantly higher in the FHP group than in the normal group (p < 0.001). With increasing postural maintenance time, the modified entropy and correlation coefficient values significantly decreased, and the mean frequency and VAS values significantly increased (p < 0.001). Furthermore, the forward position had significantly higher RMS, correlation coefficient, modified entropy, and VAS values than in the neutral position (p < 0.001). The HD-SEMG potential distribution patterns in the FHP group showed less heterogeneity and greater muscle activity in the entire muscle and subjective fatigue than those in the normal group. Excess muscle activity even in the neutral/comfortable position in the FHP group could potentially be a mechanism of neuromuscular conditions in this population.

The impact of lumbosacral alignment on lumbar mobility, functional disability and psychological wellbeing in office workers with chronic low back pain

Background/aims

The lumbosacral curvature of the spine has a special role in its mobility during weight-bearing activities. Office work is a sedentary role, which requires sitting for long durations, having a negative effect on spinal posture. Therefore, low back pain risk factors in office workers are different from other populations. The aim of this study was to examine the effect of lumbosacral joint angle on the lumbar mobility, functional disability, pain intensity and overall health in office workers with chronic low back pain.

Methods

A total of 116 male office workers with chronic low back pain (aged between 30–59 years) participated in this cross-sectional study. The lumbosacral radiography was used to divide the participants into two groups, according to the value of their lumbosacral joint angle: group A (lumbosacral joint angle <20°, n=61) and group B (lumbosacral joint angle group >20°, n=55). The lumbar mobility, functional disability, pain intensity and overall health issues of participants were measured.

Results

The functional disability and pain intensity of individuals in group A were significantly higher than group B (P<0.05). There was a significant decrease in the lumbar flexion and extension range of motion and activities of daily living of those in group A compared to group B (P<0.05). There was a significant increase in emotional health problems and impaired social activity of individuals in group A compared to group B (P<0.05). There were fair positive correlations between lumbosacral joint angle values and functional disability, pain intensity and social activity in office workers in group B (r=0.292, 0.036, 0.333 respectively).

Conclusions

A decreased lumbosacral joint angle increases functional disability and pain intensity, decreasing lumbar mobility and level of functionality. Furthermore, it reduces emotional health and social activity in participants with low back pain. Therefore, measuring the lumbosacral joint angle of patients with chronic low back pain during treatment may be useful to decrease their pain intensity and improve their functional disability and quality of life.