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Technique, muscle activity and kinematic differences in young adults texting on mobile phones
Ergonomics
Abstract
The aim of this study was to investigate whether there are differences in technique between young adults with and without musculoskeletal symptoms when using a mobile phone for texting and whether there are differences in muscle activity and kinematics between different texting techniques. A total of 56 young adults performed a standardised texting task on a mobile phone. Their texting techniques were registered using an observation protocol. The muscular activity in six muscles in the right forearm/hand and both shoulders were registered by surface electromyography and the thumb abduction/adduction and flexion/extension were registered using a biaxial electrogoniometer. Differences in texting techniques were found between the symptomatic and the asymptomatic group, with a higher proportion of sitting with back support and forearm support and with a neutral head position in the asymptomatic group. Differences in muscle activity and kinematics were also found between different texting techniques. The differences in texting technique between symptomatic and asymptomatic subjects cannot be explained by them having symptoms but may be a possible contribution to their symptoms. STATEMENT OF RELEVANCE: There has been a dramatically increased use of mobile phones for texting especially among young people during the last years. A better understanding of the physical exposure associated with the intensive use is important in order to prevent the development of musculoskeletal disorders and decreased work ability related to this use.
... Literature reveals that the primary factors influencing the prevalence of neck and shoulder pain associated with TNS can be grouped into three categories: the duration and frequency of mobile device use, the purpose of mobile device use and the angle of the neck in relation to the body while using the mobile device [21][22][23] . ...
Text Neck Syndrome (TNS), referred to as the syndrome of the 21st century, is a health problem which has
the potential to affect millions globally, particularly children and adolescents. TNS occurs as a result of
exposure to neck flexion with prolonged use of smart devices. This review aims to examine the mechanism,
assessment and physiotherapy, and rehabilitation approaches used in the treatment of TNS. There are a
limited number of studies in the literature regarding the evaluation and treatment of TNS. The evaluation of
TNS requires the assessment of several parameters, including the patient's history, pain level, range of
motion, and muscle stiffness. A variety of conservative treatment approaches are used for TNS treatment,
including physiotherapy, rehabilitation techniques, pharmacological intervention, rest, and patient
education. The findings of the studies indicate that physiotherapy and rehabilitation approaches, including
neck stabilization, low-load endurance, cervical range of motion, posture-oriented exercises, and stretching
techniques, are effective in reducing TNS symptoms. Further studies are needed to establish the optimal
treatment of TNS.
Keywords: Text neck syndrome, forward head posture, neck pain, posture, physiotherapy, smartphone
use.
... It is possible that the nature of the task and the size and distribution of visual elements on the screen could affect performance (Schedlbauer, Pastel, and Heines, 2006). Contrary to the previous research suggesting higher error rates when using thumbs for mobile interactions (Gustafsson et al., 2011;Trudeau et al., 2012), our study with Disc-O demonstrated no significant association between playing style and performance. Studies suggest an optimal finger position for performing tasks on touchscreens, where neither full flexion nor extension offers the best performance (Trudeau et al., 2012;Dennerlein, 2015). ...
We explored the relationships between expertise, in-game performance, posture, and screen interactions in mobile sports games. Twenty participants (10 experienced) played Disc-O, a turn-based air hockey game. Posture, phone holding style, play style, and screen metrics (displacement, velocity, touch size, pressure, and time to action) were compared. No significant associations were found between experience or performance and handedness, posture, holding style, or play style (p > 0.05). Experienced players performed better (p = 0.02) but showed no significant screen interaction differences compared to novices (p > 0.05). They reacted faster, with victors having smaller touch points, suggesting more precise motor control and efficient decision-making. The lack of posture and holding style differences suggests adaptability and potential for training interventions.
... Furthermore, they held the smartphone with one hand and used only one thumb, implying increased repetitive movements of the hands and fingers. This distinguished them from a group without symptoms, who were more likely to sit with a straight neck, support the forearm, hold the smartphone with two hands, and use both thumbs [22]. ...
Introduction
A cascade of biomechanical changes occurs with postural deviations. Therefore, this study aimed to determine the trunk position and spine shape during smartphone use.
Methods
Body posture was tested by the photogrammetric method in habitual standing position and while using smartphones in 39 healthy subjects of both sexes.
Results
While using smartphones, the trunk was shifted backwards (F(1.37) = 166.19, p = 0.0000), and the angle of the cervical spine increased in both sexes (p < 0.05). Furthermore, the depth of thoracic kyphosis and lumbar lordosis increased (p < 0.001), though only in the female group, but there were no differences in cervical load between groups (p > 0.05).
Conclusions
Using a smartphone caused backward displacement of the upper torso in both sexes. It was also found that using a smartphone increased the depth of thoracic kyphosis and lumbar lordosis in females, which should be interpreted as a compensatory mechanism.
Background and aims: With the increasing prevalence of smart mobile
phones, their impact on various aspects of life has become a
significant issue. This study aimed to investigate the effects of longterm use of smart mobile phones on the structural profile of the upper
body and overall quality of life.
Methods: In a causal comparative research, 90 participants, consisting
of both males and females aged 18 to 30 years from the city of
Miandoab, Iran, voluntarily took part in this research. The subjects
were divided into two groups: 45 long-term users and 45 short-term
users, as determined by the mobile phone addiction questionnaire.
The assessment included measurements of forward head posture,
rounded shoulders, cervical spine alignment, and shoulder
asymmetry through photographic analysis. Kyphotic curvature and
lordotic posture were evaluated using a flexible ruler, while quality of
life was measured using the SF-36 questionnaire.
Results: The results indicated a significant difference in forward head
posture, rounded shoulders, and kyphosis between long-term and
short-term users (p<0.05). However, there were no significant
differences in terms of wry neck, shoulder asymmetry, lordosis, or
overall quality of life between the two groups.
Conclusion: Based on the findings of this research, it is recommended
that long-term mobile phone users reduce their usage duration to
prevent musculoskeletal abnormalities such as kyphosis and forward
head and shoulder posture. Additionally, implementing considerations
for corrective exercises is advised to mitigate these issues.
Introduction
Musculoskeletal disorders (MSDs) are rapidly rising in Saudi Arabia, reaching levels similar to those in the Western world. Hence, we aimed to assess the prevalence of neck, shoulder, and lower back pains (musculoskeletal pain, MSP) among students at King Khalid University in Abha, Saudi Arabia.
Methods
This cross-sectional study was conducted at King Khalid University in Abha, Saudi Arabia, from March 2023 to August 2023. Inclusion criteria were: university students aged 18 years and older of both sexes who agreed to participate in the study. The modified Nordic questionnaire was used, which comprised three parts.
Results
Out of 536 respondents, 337 were women and 199 were men. The average body mass index (BMI) of the study population was 25.3 ± 4.01. In total, 223 (41.60%) had a history of MSDs. Only 232 (43.28%) of the population did regular exercise. According to multiple logistic regression analysis, factors associated with MSDs are mobile device use (with both hands) with a large neck tilt below the horizon line position (OR = 2.276, CI 1.178–4.397, p = 0.014), family history of trauma (OR = 5.450, 95% CI 3.371–8.811, p = 0.000), family history of MSDs (OR = 4.241, 95% CI 2.296–7.835, p = 0.000), coffee consumption (OR = 1.967, CI 1.281–3.020, p = 0.002), and time spent on electronic devices: 1–3 h (OR = 0.252, 95% CI 0.124–0.511, p = 0.0001), 4–6 h (OR = 0.455, 95% CI 0.237–0.873, p = 0.018), and 6–9 h (OR = 0.348, 95% CI 0.184–0.660, p = 0.001).
Conclusion
The present study concludes that MSP among university students is high. A history of trauma, a family history of MSDs, the hand and neck position when using electronic devices, the amount of time spent using them, and regular exercise are risk factors that are strongly associated with MSP. There is strong evidence to suggest that increasing physical activity plays a significant role in enhancing the functionality of the musculoskeletal (MSK) system and alleviating pain. It is recommended that universities implement educational programs to raise awareness and health screenings about the impact of device usage on MSK health and the benefits of regular exercise.
Background: The purpose of this study is to describe the macroscopic and radiological changes on the fifth finger related to mobile phone use and to evaluate the effect of size and weight of the device and the average time spent using the smartphone on these morphological alterations. Methods: One-hundred and one patient were included in the study. Age, weight, height, education, mobile phone data and digital photographs used in this cross-sectional study were obtained from interviews with the participants in an outpatient orthopedics clinic setting. Digital photographs of the dorsal aspects of both hands were taken with an iPhone X ® (dual 12-megapixel wide camera). The DIP joint angle of the fifth finger was measured on computer software (Image J® version 1.46, National Institute of Health, Bethesda, MD) separately for digital photographs and AP hand X-rays. Results: The proportion of smartphone usage time over 4 hours was significantly higher in patients with complaints than patients without complaints (p<0.05). The mean time of smartphone use over 4 hours was significantly higher in patients with shape discrepancy than in patients without shape discrepancy (p<0.05). Conclusion: Smartphone use of more than 4 hours per day, regardless of size and weight, can cause deformity of the fifth finger, which may disturb the patient even if it does not cause radiologically changes.
Background:
Smartphone usage has increased rapidly in the last decade due to rapid technological advancements. This extensive usage of smartphones led to physiological problems and musculoskeletal disorders (MSD) due to inappropriate postures.
Objective:
Past studies have reported the effects/discomfort of smartphone usage for short periods, ranging from 3-20 min, which does not represent the current era of smartphone dependency (approximately 7-hr/day).
Methods:
This study was performed on fifty-four participants aged 20-28 with 1-hr smartphone texting in a sitting posture. Flexion angles, both sides (dominant and non-dominant) muscle activity (maximum voluntary contraction %) at sternocleidomastoid (SCM), upper-trapezius (TRP), extensor digitorum (EDM) and abductor pollicis brevis (APB) muscles, and subjective discomfort were analyzed.
Results:
After 1-hr smartphone texting, the muscle activity at eight upper extremities: SCM (24.80%), TRP (29.45%), EDM (14.44%) and APB (19.87%) significantly (p < 0.001) increased by 1.5-1.9 times with 27.4±3.18° and 82.94±7.03° head and lower-arm flexion angles, respectively. The mechanical loads on the cervical spine increased by 4.6 times, and subjective discomfort by 3 times.
Conclusion:
Maintaining the same posture for a long duration causes postural stress, muscular imbalances, and discomfort, leading to MSD with increased cervical intervertebral disc pressure.
Background:
Internet gaming disorder (IGD) leads to social disturbances and isolation, neglect of daily responsibilities, behavioral disorders, and physical impairments.
Objective:
This study aimed to investigate the effect of IGD on spine biomechanics, range of motion in the neck and low back, and lung functions and respiratory muscle strength in children and adolescents.
Methods:
Sixty-four children and adolescents with IGD (Group I) and 41 healthy controls (Group II) were included in the study. The outcomes were assessed with the Visual Analogue Scale (VAS), Internet Addiction Scale, active range of motion (AROM) in the neck and lumbar spine, posture and spinal alignment, lung function tests, and respiratory muscle strength.
Results:
There is a significant difference in pain intensity at rest, during activity, and daily sitting time between groups (p < 0.05). Craniovertebral angle, shoulder asymmetry, thoracic kyphosis angle, cervical extension and rotation, and right lumbar rotation significantly decreased in Group I than in Group II (p < 0.05). Besides, the PEF, FEF 25-75%, and respiratory muscle strength were lower in Group I than in Group II (p < 0.05). With a multiple linear regression model, MEP, FEV1, and weekly time spent playing online games were significant predictors of internet addiction intensity (R2 = 0.28; p = 0.02, p = 0.01, and p < 0.001, respectively).
Conclusion:
Postural misalignment and increased sedentary time cause physical health deterioration and negatively affect lung functions in children and adolescents with IGD. Consequently, considering both psychological and physical health is necessary to assess the problematic nature of internet gaming. A comprehensive assessment and multidisciplinary team approach is essential to managing the IGD.
Mobil cihazlar günümüzde yaygın olarak iletişim, video izleme, e-ticaret gibi amaçlar için kullanılmaktadır. Bu cihazların kullanım sürelerinin artması hatta bağımlılık haline gelmesi günümüz çağının bir sorunu haline gelmiştir. Amerika’ da 2017 yılında hazırlanmış bir rapora göre son 8 yıl içinde gelir düzeyinin bilgisayar, mobil
cihaz, tablet ya da yüksek hızlı internet sahibi olmaya etkisi gittikçe azalmıştır ve iki kesimin mobil cihaz kullanım düzeyi eskisine oranla birbirine oldukça yaklaşmış ve artmıştır (Philanthropynewsdigest, 2017).
Mobil cihazların yüksek kullanım düzeyi bağımlılık sorunlarını ve ilişkili faktörleri bir araştırma sahası haline getirmiştir. Bağımlılık, olumsuz olarak bir madde ya da davranışı kullanmayı bırakamama veya kontrol edememe şeklinde tanımlanmaktadır
(Egger, 1996). Mobil cihazlar için bağımlılık kullanım süresi ile eşleştirilmese de ekranlı bir cihazın kullanımı için günlük iki saat ve üzeri sağlık için risk faktörü olarak değerlendirilmektedir. Konu ile ilgili sistematik bir derlemede mobil cihazların uzun süreli kullanımı fiziksel aktivite düzeyinin azalması, obesite ve uyku problemleri ile
ilişkili olarak ifade edilmiştir (Domoff et. al., 2019). Mobil cihazların fazla kullanımı ruhsal sağlık üzerinde olumsuz etkilere neden olmaktadır. Bu konu gerek uyku bozuklukları gerekse depresif belirtiler çerçevesinde incelenmiştir. Konu ile ilgili bir çalışmaya göre mobil cihazların fazla kullanımı uyku süresini azalttığı gibi sık uyanma problemine neden olarak uyku kalitesini de bozmaktadır. Yine akıllı telefon bağımlılığı ile ilgili psikolojik ve bilişsel sonuçları üzerine yapılmış çalışmalar bulunmaktadır. Bu çalışmalara göre diğer bağımlılıklarda olduğu gibi akıllı telefon bağımlılığı da depresyon, obsesif kompulsif bozukluk, dürtüsellik gibi psikolojik bozukluklar ile ilişkili sonucuna varılmıştır. Aşırı akıllı telefon kullanımı depresyon ve anksiyeteyi tetiklemekte ve bağımlılarda bu durumun uyku problemlerine zemin hazırlayabileceği ifade edilmiştir
Background
This study examined the relationship of repetitive work and other physical stressors to prevalence of upper limb discomfort, tendinitis, and carpal tunnel syndrome.Methods
Three hundred fifty-two workers from three companies participated. Job exposure levels for repetition and other physical stressors were quantified using an observational rating technique. Ergonomic exposures were rated on a 10-point scale, where 0 corresponded to no stress and 10 corresponded to maximum stress. Job selection was based on repetition (three categories: high, medium, and low) to ensure a wide range of exposures. Physical evaluations on all participating workers were performed by medical professionals and included a self-administered questionnaire, physical exam, and limited electrodiagnostic testing.ResultsRepetitiveness of work was found to be significantly associated with prevalence of reported discomfort in the wrist, hand, or fingers (odds ratio (OR) = 1.17 per unit of repetition; OR = 2.45 for high vs. low repetition), tendinitis in the distal upper extremity (OR = 1.23 per unit of repetition; OR = 3.23 for high vs. low repetition), and symptoms consistent with carpal tunnel syndrome (OR = 1.16 per unit of repetition; OR = 2.32 for high vs. low repetition). An association was also found between repetitiveness of work and carpal tunnel syndrome, indicated by the combination of positive electrodiagnostic results and symptoms consistent with carpal tunnel syndrome (OR = 1.22 per unit of repetition; OR = 3.11 for high vs. low repetition).Conclusions
These findings indicate that repetitive work is related to upper limb discomfort, tendinitis, and carpal tunnel syndrome in workers. Further research with a wider range of exposures is needed to evaluate the effects of other physical stresses alone and in combination. Am. J. Ind. Med. 36:248–259, 1999. © 1999 Wiley-Liss, Inc.
PW. Differences between work methods and gender in computer mouse use. Scand J Work Environ Health 2000;26(5):390-397. Objectives The aim of this study was to investigate whether gender or different methods of operating a computer mouse have an effect on pelfo~mance and lnusculoskeletal load in the use of a computer mouse. Methods Thirty experienced computer mouse users, 15 men and 15 women, participated in the study. Electromy-ography (right first dorsal interossei, right extensor digitorum and right and left trapezius), a force-sensing mouse, and subjective ratings were used to register muscular load. An electrogoniometer was used to register the wrist movements. The subjects worked with 3 different methods, their own, a wrist-based method and an arm-based method. Gender comnparisons were made when the subjects used their own method. Results The women worked with greater extension and range of motion and tended to work with a greater ulnar deviation of the wrist. They also applied higher forces to the mouse when expressed as a percentage of a maximum voluntary contraction and had higher muscular activity in the right extensor digitomm. When using the arm-based method, the subjects worked with greater wrist extension, had higher muscular activity in the right and left trapezius muscles, and had the highest ratings of perceived exertion in the neck and shoulder. The wrist-based method resulted in higher forces being applied to the sides of the mouse and the highest ratings of perceived exertion in the wrist and hand-fingers. C O ~ C I U S ~ O ~ S Gender differences were found for musculoskeletal load, and for most of the measured variables the women worked with higher loads than the men. The work method affected performance and musculoskeletal load. Finally, subjective measures appeared to have some utility in characterizing muscular load.
Epidemiologic and experimental studies were reviewed to assess the role of postural factors, high handgrip and pinch forces, repetitive hand and wrist movements, external pressure, and vibration in the occurrence of carpal tunnel syndrome (CTS). Forceful repetitive work, vibration, and extreme wrist postures have been associated with CTS in several epidemiologic studies. Experimental studies have shown that certain forearm, wrist, and finger postures, even moderate hand loads and external pressure on the palm, can increase carpal tunnel pressure (CTP) at least temporarily to levels at which nerve viability is threatened. It is concluded that while more research is needed, there is sufficient information to suggest that reducing the duration, frequency or intensity of exposure to forceful repetitive work, extreme wrist postures and vibration is likely to result in a reduction of the incidence or severity of CTS in working populations.
Aims
To determine the occurrence of pain conditions and disorders in the forearm and to evaluate risk factors for forearm pain in a cohort of computer workers.
Methods
A total of 6943 participants with a wide range of computer use and work tasks were studied. At baseline and at one year follow up participants completed a questionnaire. Participants with relevant forearm symptoms were offered a clinical examination. Symptom cases and clinical cases were defined on the basis of self reported pain score and palpation tenderness in the muscles of the forearm.
Results
The seven days prevalence of moderate to severe forearm pain was 4.3%. Sixteen of 296 symptom cases met criteria for being a clinical forearm case, and 12 had signs of potential nerve entrapment. One year incidence of reported symptom cases was 1.3%; no subjects developed new signs of nerve entrapment. Increased risk of new forearm pain was associated with use of a mouse device for more than 30 hours per week, and with keyboard use more than 15 hours per week. High job demands and time pressure at baseline were risk factors for onset of forearm pain; women had a twofold increased risk of developing forearm pain. Self reported ergonomic workplace factors at baseline did not predict future forearm pain.
Conclusion
Intensive use of a mouse device, and to a lesser extent keyboard usage, were the main risk factors for forearm pain. The occurrence of clinical disorders was low, suggesting that computer use is not commonly associated with any severe occupational hazard to the forearm.
De Quervain's tenosynovitis is a disorder characterized by pain on the radial (thumb) side of the wrist, impairment of thumb function, and thickening of the ligamentous structure covering the tendons in the first dorsal compartment of the wrist. It is precisely defined as stenosing tenosynovitis of the first dorsal compartment. It is a relatively common, uncomplicated, and noncontroversial musculoskeletal disorder of the distal upper extremity. The purpose of this review is to summarize information from the medical literature on aspects of De Quervain's tenosynovitis likely to be of interest and relevant to occupational medicine practitioners. The topics covered include normal anatomy and kinesiology; history; clinical observations related to diagnosis; pathology ; pathophysiology; clinical observations on etiology; descriptive epidemiology; epidemiological studies; and case management. Models for the pathogenesis of De Quervain's tenosynovitis are proposed and opportunities for future research presented.
The objectives of this study were to examine the association between work-related upper limb disorders (WRULDs) and duration of computer and mouse use, to investigate differences in these associations between men and women, and to examine whether a possible relationship between duration of computer use and WRULDs was explained by physical or psychosocial risk factors. The study population in this cross-sectional questionnaire study consisted of 5400 office employees. Participants had filled out a questionnaire on job characteristics, job content, physical workload, psychosocial workload and musculoskeletal symptoms.Working with a computer during more than 6 h/day was associated with WRULDs in all body regions. Stratified analyses showed that the strength of the associations differed between men and women. In men, only moderate associations were seen for computer use more than 6 h/day. In women, moderately increased ORs were observed for a duration of computer use of more than 4 h/day and strongly increased risks for a computer use during more than 6 h/day.Frequent computer users who often used a mouse did not report more WRULDs or neck or shoulder disorders than frequent computer users who did not use a mouse. Only for arm, elbow or wrist or hand problems a moderately increased OR among the mouse users was observed, but this was not statistically significant.Relevance to industryRecent increases in the number of employees working with computers and in the durations of computer and mouse use coincide with a huge prevalence increase of work-related disorders of neck and upper limb (WRULDs) and sick leave, which poses financial burdens on companies. Research on risk factors and preventive measures is relevant for these companies.
Supporting the forearm on the work surface during keyboard operation may increase comfort, decrease muscular load of the neck and shoulders, and decrease the time spent in ulnar deviation. Wrist rests are used widely in the workplace and are more commonly being incorporated in keyboard design. The aim of this study was to examine the effect of wrist rest use on wrist posture during forearm support. A laboratory based, experimental study was conducted (subjects n=15) to examine muscle activity and wrist postures during keyboard and mouse tasks in each of two conditions; wrist rest and no wrist rest. There were no significant differences for right wrist flexion/extension between use of a wrist rest and no wrist rest for keyboard or mouse use. Left wrist extension was significantly higher without a wrist rest than with a wrist rest during keyboard use (df=14; t=2.95; p=0.01; d=0.38). No differences with respect to use of a wrist rest were found for the left or right hand for ulnar deviation for keyboard or mouse use. There were no differences in muscle activity between the test conditions for keyboard use.Relevance to industryWrist rests are used widely in the workplace and are more commonly being incorporated in keyboard design. Use of a wrist rest in conjunction with forearm support when using a conventional desk does not appear to have any impact on wrist posture or muscle activity during keyboard use.