Changes in the range of head flexion rotation and neck muscle activity after prolonged use of a smartphone

2020 ◽  
Vol 64 (1) ◽  
pp. 930-933
Author(s):  
Donghyun Song ◽  
Eunjee Kim ◽  
Yujin Kwon ◽  
Hyorim Kim ◽  
Gwanseob Shin
Keyword(s):  
Muscle Activity ◽  
Activity Level ◽  
Flexion Angle ◽  
Health Concern ◽  
Neck Muscle ◽  
Study Results ◽  
Smartphone Use ◽  
Head Flexion ◽  
Full Head ◽  
Over Time

Text-neck has been the main health concern among smartphone users. The current study explored a potential association between the duration of static head flexion posture during smartphone use and the viscoelastic changes of the cervical spine passive tissues. Ten participants conducted a smartphone task for 30 minutes, and their full head flexion angle and the neck muscle activity during a head extension motion were quantified before, in the middle, and after the 30-min task. Participants reported higher neck discomfort ratings after smartphone use, and the neck muscle activity showed an increasing trend over time. However, no significant difference was found in the muscle activity level between the three time levels. Full head flexion angle also did not vary significantly over time (p > 0.05). Study results imply the reduction of tissue stiffness during smartphone use, but warrant further research with a more sensitive evaluation method.

Trunk Posture Influences Neck Angle When Reading A Tablet Computer

2016 ◽  
Vol 60 (1) ◽  
pp. 942-942
Author(s):  
Kaitlin M. Gallagher ◽  
Ethan C. Douglas
Keyword(s):  
Muscle Activity ◽  
Erector Spinae ◽  
Flexion Angle ◽  
Neck Flexion ◽  
Handheld Computer ◽  
Extensor Muscles ◽  
Head Flexion ◽  
The Moment ◽  
Trunk Position ◽  
Gravitational Moment

In 2013, 64% of American households owned a handheld computer device (e-reader, tablet, smartphones, etc.). The presence of these devices has grown more quickly than our understanding of their effects on musculoskeletal disorders. Their use on a tabletop or a person’s lap causes increased head and neck flexion, as well as an inreased gravitational moment produced by the weight of the head (Straker et al., 2009, Young et al., 2012, Vasavada et al., 2015). A limitation to these studies is that they keep a standard trunk position throughout all tasks; however, people can also assume a semi-reclined position when reading a tablet. The purpose of this study was to determine the influence of a semi-reclined trunk position on neck and head flexion angle, and cervical erector spinae muscle activity. Nineteen participants (10 male, 9 female) read off of a tablet in four postures: with the tablet in their lap, on a tabletop, off of a standard computer monitor, and semi-reclined to an angle of 30 degrees from the vertical. Having the tablet on the lap ( M=16%MVC, SD=8%MVC) significantly increased muscle activity of the cervical erector spinae ( p=.0023) compared to reading off of a monitor or in the semi-reclined position (approximately 10%MVC). Neck and head flexion angles significantly increased ( p<.001) when reading the tablet off the lap (neck M=56.8o, SD=17.3o; head M=53.4o, SD=12.9o) versus the computer (neck M=6.4o, SD=6.4o; head M=8.2o, SD=7.4o), however, the head angle during semi-reclined reading stayed more vertical despite having the highest increase in neck flexion angle (neck M=71.6o, SD=14.0o; head M=19.7o, SD=9.2o). In the semi-reclined position, the gravitational moment of the head is second smallest for the four reading positions. In theory, this is desired as the moment that must be produced by the musculature and surround tissues would be less. The downside to this posture is that many of the neck extensor muscles may still not be in optimal force and moment production position. Many of the neck muscles that assist with extension originate from C5 to T5 and insert on C5 and above (Vasavada et al., 1998). At 30 degrees of neck flexion, the moment generating capability of the spenius and semispinalis muscles are decreased compared to when at a neutral position and fascicle length of splenius cervicis, capitis, and semispinalis capitis muscles experience changes of more than 70% of optimal length (Vasavada et al., 1998). While many of the extensor muscles only show moment arms that vary by 1 cm or less, for some there can be about a 2-3 cm changes as one goes from a flexed to extended neck posture (Vasavada et al., 1998). These combined changes mean that the force producing capabilities of the neck extensor muscles may be compromised a semi-reclined position. Future studies should report torso angle to properly analyze biomechanical risk factors during handheld computer use and compare results between studies.

Influence of neck flexion angle on gravitational moment and neck muscle activity when using a smartphone while standing

Ergonomics ◽  
2021 ◽  
pp. 1-12
Author(s):  
Weerasak Tapanya ◽  
Rungthip Puntumetakul ◽  
Manida Swangnetr Neubert ◽  
Rose Boucaut
Keyword(s):  
Muscle Activity ◽  
Flexion Angle ◽  
Neck Muscle ◽  
Neck Flexion ◽  
Gravitational Moment

scholarly journals A Holistic Framework for Evaluating Adaptation Approaches to Coastal Hazards and Sea Level Rise: A Case Study from Imperial Beach, California

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1324
Author(s):  
David Revell ◽  
Phil King ◽  
Jeff Giliam ◽  
Juliano Calil ◽  
Sarah Jenkins ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Public Trust ◽  
Adaptation Strategy ◽  
Public Benefits ◽  
Study Results ◽  
Local Risk ◽  
Over Time

Sea level rise increases community risks from erosion, wave flooding, and tides. Current management typically protects existing development and infrastructure with coastal armoring. These practices ignore long-term impacts to public trust coastal recreation and natural ecosystems. This adaptation framework models physical responses to the public beach and private upland for each adaptation strategy over time, linking physical changes in widths to damages, economic costs, and benefits from beach recreation and nature using low-lying Imperial Beach, California, as a case study. Available coastal hazard models identified community vulnerabilities, and local risk communication engagement prioritized five adaptation approaches—armoring, nourishment, living shorelines, groins, and managed retreat. This framework innovates using replacement cost as a proxy for ecosystem services normally not valued and examines a managed retreat policy approach using a public buyout and rent-back option. Specific methods and economic values used in the analysis need more research and innovation, but the framework provides a scalable methodology to guide coastal adaptation planning everywhere. Case study results suggest that coastal armoring provides the least public benefits over time. Living shoreline approaches show greater public benefits, while managed retreat, implemented sooner, provides the best long-term adaptation strategy to protect community identity and public trust resources.

Smartphone addiction and the relationship with head and neck pain and electromiographic activity of masticatory muscles

Work ◽  
2021 ◽  
pp. 1-8
Author(s):  
Fabiana Foltran Mescollotto ◽  
Érica Brito Gonçalves ◽  
Ester Moreira de Castro Carletti ◽  
Ana Beatriz Oliveira ◽  
Elisa Bizetti Pelai ◽  
...  
Keyword(s):  
College Students ◽  
Neck Pain ◽  
Head And Neck ◽  
Muscle Activity ◽  
Neck Region ◽  
Masticatory Muscles ◽  
Smartphone Addiction ◽  
Before And After ◽  
Smartphone Use ◽  
The Right

Background: Excessive use of smartphones may be associated with behavioral and physical health changes and might cause musculoskeletal alterations in the head and neck region. Objective: To evaluate the prevalence of smartphone addiction in college students and its correlation with symptoms of head and neck pain and masticatory and trapezius muscle activity while resting, before and after smartphone use. Methods: Twenty university students participated in the study. They answered the Smartphone Addiction Scale and the Fonseca Anamnestic Index. Next, the participants were seated and prepared for electromyography through the placement of surface electrodes on the masseter, temporal, and trapezius muscles. Rest condition data were collected for 10 seconds before and after 30 minutes of smartphone use. Results: The results showed that 35% of the evaluated individuals were classified as smartphone addicted and 35% reported no head or neck pain in the previous 30 days. There was no association between smartphone use and head and neck pain. In the electromyography, there was an increase in RMS values after smartphone use in the right and left masseter muscles and the left trapezius. Conclusion: College students presented a high prevalence of smartphone addiction and head and neck pain, but these were not statistically associated. There was a change in muscle activity only in the right trapezius muscles before and after 30 minutes of smartphone use. These findings are contrary to the current belief that the use of smartphones correlates with pain in the neck region and changes in the electrical muscle activity, leading to fatigue in the cervical muscles.

‘No one ever asked us’: a feasibility study assessing the co-creation of a physical activity programme with adolescent girls

2019 ◽  
Vol 27 (3) ◽  
pp. 34-43
Author(s):  
Méabh Corr ◽  
Elaine Murtagh
Keyword(s):  
Physical Activity ◽  
Data Collection ◽  
Behaviour Change ◽  
Adolescent Girls ◽  
Retention Rate ◽  
Controlled Trial ◽  
Activity Level ◽  
Health Concern ◽  
Post Intervention ◽  
Behaviour Change Wheel

Background: Globally, the poor activity level of adolescent girls is a public health concern. Little research has involved adolescents in the design of interventions. This study assessed the feasibility of involving girls in the co-creation of an activity programme. Methods: Thirty-one students (15–17 years old) were recruited from a post-primary school. The Behaviour Change Wheel guided intervention design, providing insights into participants’ capability, opportunity and motivation for change. Step counts and self-reported physical activity levels were recorded pre- and post-intervention. Feasibility benchmarks assessed recruitment, data collection, acceptability and adherence. Results: Activity and educational sessions were delivered for six weeks during physical education class. Average attendance was 87% (benchmark = 80%). Eligibility was 61% (benchmark = 60%). There was a 100% retention rate (benchmark = 90%). All participants ( n = 31) completed baseline measures and 71% ( n = 22) completed post-measures. 54% ( n = 17) of students completed pedometer measurements, with 32% ( n = 10) having complete data. Average daily steps were 13,121 pre-intervention and 14,128 post-intervention ( p > 0.05). Data collection was feasible, receiving a mean score > 4/5 (benchmark > 3.5/5). Conclusions: The Behaviour Change Wheel can be used to co-create an activity programme with adolescent girls. Predetermined benchmarks, except for pedometer recordings, were reached or exceeded, providing evidence for the need of a randomised controlled trial to test effectiveness.

Heterogeneous activity level of jaw-closing and -opening muscles and its association with arousal levels during sleep in the guinea pig

2010 ◽  
Vol 298 (1) ◽  
pp. R34-R42 ◽  
Author(s):  
Takafumi Kato ◽  
Yuji Masuda ◽  
Hayato Kanayama ◽  
Norimasa Nakamura ◽  
Atsushi Yoshida ◽  
...  
Keyword(s):  
Heart Rate ◽  
Eye Movement ◽  
Rem Sleep ◽  
Muscle Activity ◽  
Guinea Pigs ◽  
Nrem Sleep ◽  
Activity Level ◽  
Jaw Muscles ◽  
High Activity Level ◽  
Motor Activities

Exaggerated jaw motor activities during sleep are associated with muscle symptoms in the jaw-closing rather than the jaw-opening muscles. The intrinsic activity of antagonistic jaw muscles during sleep remains unknown. This study aims to assess the balance of muscle activity between masseter (MA) and digastric (DG) muscles during sleep in guinea pigs. Electroencephalogram (EEG), electroocculogram, and electromyograms (EMGs) of dorsal neck, MA, and DG muscles were recorded with video during sleep-wake cycles. These variables were quantified for each 10-s epoch. The magnitude of muscle activity during sleep in relation to mean EMG activity of total wakefulness was up to three times higher for MA muscle than for DG muscle for nonrapid eye movement (NREM) and rapid-eye-movement (REM) sleep. Although the activity level of the two jaw muscles fluctuated during sleep, the ratio of activity level for each epoch was not proportional. Epochs with a high activity level for each muscle were associated with a decrease in δEEG power and/or an increase in heart rate in NREM sleep. However, this association with heart rate and activity levels was not observed in REM sleep. These results suggest that in guinea pigs, the magnitude of muscle activity for antagonistic jaw muscles is heterogeneously modulated during sleep, characterized by a high activity level in the jaw-closing muscle. Fluctuations in the activity are influenced by transient arousal levels in NREM sleep but, in REM sleep, the distinct controls may contribute to the fluctuation. The above intrinsic characteristics could underlie the exaggeration of jaw motor activities during sleep (e.g., sleep bruxism).

The Effect of Preference Stability and Extremity on Personalized Advertising

2018 ◽  
Vol 96 (2) ◽  
pp. 406-427 ◽  
Author(s):  
Cong Li ◽  
Jiangmeng Liu ◽  
Cheng Hong
Keyword(s):  
Preference Stability ◽  
Message Type ◽  
Study Results ◽  
Two Phases ◽  
Personalized Advertising ◽  
Over Time

Personalized advertising is widely believed to be an effective persuasion strategy. A typical personalized advertising process consists of two phases: The message sender first “learns” the message receiver’s preferences, and then “matches” the message to that person according to his or her preferences. The present study argues that this process may be problematic because it assumes that an individual’s preferences are always stable (i.e., preferences remain the same over time) and extreme (i.e., preferences are highly polarized). Through a 2 (message type: personalized vs. nonpersonalized) × 2 (preference stability: high vs. low) × 2 (preference extremity: high vs. low) between-participants experiment ( N = 227), it is shown that the effectiveness of personalized advertising is moderated by preference stability and extremity. A new conceptualization of personalization is proposed based on the study results, and how the two phases of personalized advertising may be refined is highlighted.

Coaching Teachers to Use a Simultaneous Prompting Procedure to Teach Core Content to Students With Autism

2017 ◽  
Vol 40 (3) ◽  
pp. 225-245 ◽  
Author(s):  
Elif Tekin-Iftar ◽  
Belva C. Collins ◽  
Fred Spooner ◽  
Seray Olcay-Gul
Keyword(s):  
General Education ◽  
Future Research ◽  
Simultaneous Prompting ◽  
Baseline Design ◽  
Teacher Student ◽  
Core Content ◽  
Study Results ◽  
Students With Autism ◽  
Academic Content ◽  
Over Time

The researchers in this study used a multiple baseline design across dyads to examine the effects of professional development with coaching to train general education teachers to use a simultaneous prompting procedure when teaching academic core content to students with autism and the effects of the procedure on the students’ outcomes. Three teacher–student dyads participated in the study. Results showed that (a) teachers acquired the ability to use the simultaneous prompting procedure with 100% accuracy, maintained the acquired teaching behaviors over time, and generalized them in teaching new academic content to their students; and (b) students acquired the targeted academic content, maintained it over time, and generalized it across different persons and settings. In addition, the students acquired instructive feedback stimuli added to instruction and maintained these over time as well. Last, both the opinions of the teachers and students about the social validity of the study were positive. Future research is needed to support these findings.

Upper extremity muscle activity during household floor vacuuming with upright cleaners

2018 ◽  
Vol 62 (1) ◽  
pp. 1018-1021
Author(s):  
Haerim Bak ◽  
Clive D’Souza ◽  
Gwanseob Shin
Keyword(s):  
Upper Extremity ◽  
Muscle Activity ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Activity Levels ◽  
Physical Demands ◽  
Study Results ◽  
Musculoskeletal Problems ◽  
Muscle Groups ◽  
Intensive Work

Physical demands of household carpet vacuuming and associated risks for musculoskeletal problems have received little attention although the level of muscle exertions is often assumed to be similar to that of occupational vacuuming. The aim of this study was to quantitatively assess the level of muscle activities of the upper extremity during carpeted floor vacuuming with household upright vacuum cleaners. Eighteen participants conducted four different carpet vacuuming tasks with two different cleaner models. Electromyography data from seven upper extremity muscles were collected. Median muscle activity ranged from 4.5% to 47.5% of the maximum voluntary contraction capacity for female participants and from 2.7% to 23.6% for male participants. Normalized muscle activity levels were significantly higher in women compared to men across tasks and muscle groups. Study results suggest that home vacuuming with upright vacuum cleaners is physically intensive work, especially for female users who are less physically capable.

scholarly journals Methylene blue improves hemodynamic shock but increases lipoperoxidation in severe acute pancreatitis pig model

2008 ◽  
Vol 23 (suppl 1) ◽  
pp. 8-16 ◽  
Author(s):  
Roberto Ferreira Meirelles Jr ◽  
Reginaldo Ceneviva ◽  
Fernanda Viaro ◽  
Caroline Floreoto Baldo ◽  
Paulo Roberto Barbosa Evora
Keyword(s):  
Methylene Blue ◽  
Acute Pancreatitis ◽  
Bolus Dose ◽  
Serum Amylase ◽  
Tissue Perfusion ◽  
Pancreatic Tissue ◽  
Control Group ◽  
Hemodynamic Pattern ◽  
Study Results ◽  
Over Time

PURPOSE: Study hemodynamic pattern and lipoperoxidation during methylene blue (MB) treatment on taurocholate - enterokinase induced acute pancreatitis (AP). METHODS: Thirty pigs were equally divided in control group; MB group; AP group; MB previous AP group; and MB after 90 min of induced AP group. MB was given iv in a bolus dose (2mg.kg-1) followed by maintenance dose (2 mg.kg-1.h-1). Hemodynamic parameters were recorded continuously during 180 min by Swan-Ganz catheter. Blood samples were taken every 60 min to determine arterial and venous nitrate, malondialdehyde (MDA) and amylase. Pancreatic tissue was removed for histopathologic study. RESULTS: In AP group MBP and CO decreased over time 33% (p<0.05) and 52% (p<0.05), respectively. In MB previous induced-AP group, there was 70 minutes delay (p<0.05) to decrease MBP and CO. In MB group arterial and venous nitrite decreased (p<0.05) over time. MB infusion increased (p>0.05) serum MDA when associated to AP. After induced AP, MB did not reverse MBP and CO decrease. There was no difference in serum amylase and necro-hemorrhagic findings with MB treatment. CONCLUSIONS: In this taurocholate-induced AP model MB treatment delayed hemodynamic shock and decreases serum nitrate levels but increases serum MDA levels. No volemic replacement was done and it may have been a mitigated factor to a poor tissue perfusion and impairment microcirculation. Further investigations are needed to elucidate MB treatment role during AP treatment.

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