An investigation of an ergonomics intervention to affect neck biomechanics and pain associated with smartphone use

Work ◽  
2021 ◽  
pp. 1-13
Author(s):  
Minghao Tang ◽  
Carolyn M. Sommerich ◽  
Steven A. Lavender
Keyword(s):  
Muscle Activity ◽  
Head Tilt ◽  
Trapezius Muscle ◽  
Erector Spinae ◽  
Neck Flexion ◽  
Head Posture ◽  
Subjective Perceptions ◽  
Upper Trapezius ◽  
Direct View ◽  
Smartphone Use

BACKGROUND: Neck discomfort and pronounced neck flexion have been associated with smartphone use. OBJECTIVE: Eye glasses with a 90 deg prism in each lens were investigated as a potential intervention to reduce awkward head and neck postures during activities involving viewing the device. METHODS: Sixteen smartphone users with neck pain and 9 asymptomatic users performed a texting task on a smartphone with and without the prism glasses, in sitting and standing postures in a laboratory setting. RESULTS: Cervical erector spinae and upper trapezius muscle activity, head posture and motion, performance, discomfort and other subjective perceptions were assessed. Prism glasses reduced neck extensor muscle activity, neck flexion, and head tilt compared to the direct view. In the symptomatic group, the intervention produced less neck and shoulder discomfort compared to the direct view. CONCLUSIONS: This intervention could offer an alternative way of interacting with a smartphone while texting in stationary postures, by reducing exposure to pronounced flexed neck and head posture commonly seen in users, and thereby could reduce neck discomfort associated with smartphone use.

Analysis of neck and back muscle activity during the application of various pillow designs in patients with forward head posture

2021 ◽  
pp. 1-9
Author(s):  
Sirirat Kiatkulanusorn ◽  
Bhornluck Paepetch Suato ◽  
Phurichaya Werasirirat
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Trapezius Muscle ◽  
Back Muscle ◽  
Forward Head Posture ◽  
Sleeping Position ◽  
Head Posture ◽  
Upper Trapezius ◽  
Activation Response ◽  
Lower Trapezius

BACKGROUND: There are currently no reports of biomechanical changes in patients with forward head posture (FHP) that result in altered muscle activation throughout various functions with muscle activation response during diverse sleep postures. OBJECTIVE: This study investigated neck and back muscle activity in individuals with and without FHP during a maintained side-sleeping position by incorporating various pillow designs. METHODS: Thirty-four participants (i.e. 17 in each group) were enrolled. The muscle activity was investigated via surface electromyography during the use of three trial pillows: orthopedic pillow, hollow pillow, and Thai neck support pillow. RESULTS: With the application of all three trial pillows the FHP group demonstrated significantly greater lower trapezius muscle activity than the normal head posture group (p< 0.05). Sternocleidomastoid and upper trapezius (UT) muscle activity were similar between the two groups (p> 0.05). Only UT muscle activity was affected by variations in pillow design. In the normal group no difference was observed in the muscle activity between all three pillows (p> 0.05). CONCLUSIONS: Feasibly, the ability to appropriately modify a pillow configuration without creating undesired muscle activation was limited to those exhibiting FHP. Therefore, specially designed pillows or mattresses should be investigated in terms of their relevance to muscle fatigue and potential musculoskeletal pain in FHP patients.

scholarly journals Musculoskeletal disorder and pain associated with smartphone use: A systematic review of biomechanical evidence

2018 ◽  
Vol 38 (02) ◽  
pp. 77-90 ◽  
Author(s):  
Aitthanatt Chachris Eitivipart ◽  
Sirinya Viriyarojanakul ◽  
Lucy Redhead
Keyword(s):  
Systematic Review ◽  
Musculoskeletal Disorders ◽  
Head Tilt ◽  
Standing Position ◽  
Erector Spinae ◽  
Assessment Scores ◽  
Upper Trapezius ◽  
Increased Risk ◽  
Smartphone Use ◽  
Head Flexion

The number of smartphone users is growing dramatically. Using the smartphone frequently forces the users to adopt an awkward posture leading to an increased risk of musculoskeletal disorders and pain. The objective of this study is to conduct a systematic review of studies that assess the effect of smartphone use on musculoskeletal disorders and pain. A systematic literature search of AMED, CINAHL, PubMed, Proquest, ScienceDirect using specific keywords relating to smartphone, musculoskeletal disorders and pain was conducted. Reference lists of related papers were searched for additional studies. Methodological quality was assessed by two independent reviewers using the modified Downs and Black checklist. From 639 reports identified from electronic databases, 11 were eligible to include in the review. One paper was found from the list of references and added to the review. The quality scores were rated as moderate. The results show that muscle activity of upper trapezius, erector spinae and the neck extensor muscles are increased as well as head flexion angle, head tilt angle and forward head shifting which increased during the smartphone use. Also, smartphone use in a sitting position seems to cause more shift in head–neck angle than in a standing position. Smartphone usage may contribute to musculoskeletal disorders. The findings of the included papers should be interpreted carefully in light of the issues highlighted by the moderate-quality assessment scores.

scholarly journals Motion Analytics of Trapezius Muscle Activity in an 18-Year-Old Female with Extended Upper Brachial Plexus Birth Palsy

2021 ◽  
Vol 16 (01) ◽  
pp. e51-e55
Author(s):  
Jasmine J. Lin ◽  
Gromit Y.Y. Chan ◽  
Cláudio T. Silva ◽  
Luis G. Nonato ◽  
Preeti Raghavan ◽  
...  
Keyword(s):  
Brachial Plexus ◽  
Upper Extremity ◽  
Muscle Activity ◽  
Visual Analytics ◽  
Three Dimensional ◽  
Trapezius Muscle ◽  
Shoulder Abduction ◽  
Upper Trapezius ◽  
Brachial Plexus Birth Palsy ◽  
Birth Palsy

Abstract Background The trapezius muscle is often utilized as a muscle or nerve donor for repairing shoulder function in those with brachial plexus birth palsy (BPBP). To evaluate the native role of the trapezius in the affected limb, we demonstrate use of the Motion Browser, a novel visual analytics system to assess an adolescent with BPBP. Method An 18-year-old female with extended upper trunk (C5–6–7) BPBP underwent bilateral upper extremity three-dimensional motion analysis with Motion Browser. Surface electromyography (EMG) from eight muscles in each limb which was recorded during six upper extremity movements, distinguishing between upper trapezius (UT) and lower trapezius (LT). The Motion Browser calculated active range of motion (AROM), compiled the EMG data into measures of muscle activity, and displayed the results in charts. Results All movements, excluding shoulder abduction, had similar AROM in affected and unaffected limbs. In the unaffected limb, LT was more active in proximal movements of shoulder abduction, and shoulder external and internal rotations. In the affected limb, LT was more active in distal movements of forearm pronation and supination; UT was more active in shoulder abduction. Conclusion In this female with BPBP, Motion Browser demonstrated that the native LT in the affected limb contributed to distal movements. Her results suggest that sacrificing her trapezius as a muscle or nerve donor may affect her distal functionality. Clinicians should exercise caution when considering nerve transfers in children with BPBP and consider individualized assessment of functionality before pursuing surgery.

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.

scholarly journals Alterations in Shoulder Kinematics and Associated Muscle Activity in People With Symptoms of Shoulder Impingement

2000 ◽  
Vol 80 (3) ◽  
pp. 276-291 ◽  
Author(s):  
Paula M Ludewig ◽  
Thomas M Cook
Keyword(s):  
Occupational Exposure ◽  
Muscle Activity ◽  
Load Condition ◽  
Trapezius Muscle ◽  
Electromyographic Activity ◽  
Serratus Anterior Muscle ◽  
Serratus Anterior ◽  
Shoulder Impingement ◽  
Upper Trapezius ◽  
Load Conditions

AbstractBackground and Purpose. Treatment of patients with impingement symptoms commonly includes exercises intended to restore “normal” movement patterns. Evidence that indicates the existence of abnormal patterns in people with shoulder pain is limited. The purpose of this investigation was to analyze glenohumeral and scapulothoracic kinematics and associated scapulothoracic muscle activity in a group of subjects with symptoms of shoulder impingement relative to a group of subjects without symptoms of shoulder impingement matched for occupational exposure to overhead work. Subjects. Fifty-two subjects were recruited from a population of construction workers with routine exposure to overhead work. Methods. Surface electromyographic data were collected from the upper and lower parts of the trapezius muscle and from the serratus anterior muscle. Electromagnetic sensors simultaneously tracked 3-dimensional motion of the trunk, scapula, and humerus during humeral elevation in the scapular plane in 3 hand-held load conditions: (1) no load, (2) 2.3-kg load, and (3) 4.6-kg load. An analysis of variance model was used to test for group and load effects for 3 phases of motion (31°–60°, 61°–90°, and 91°–120°). Results. Relative to the group without impingement, the group with impingement showed decreased scapular upward rotation at the end of the first of the 3 phases of interest, increased anterior tipping at the end of the third phase of interest, and increased scapular medial rotation under the load conditions. At the same time, upper and lower trapezius muscle electromyographic activity increased in the group with impingement as compared with the group without impingement in the final 2 phases, although the upper trapezius muscle changes were apparent only during the 4.6-kg load condition. The serratus anterior muscle demonstrated decreased activity in the group with impingement across all loads and phases. Conclusion and Discussion. Scapular tipping (rotation about a medial to lateral axis) and serratus anterior muscle function are important to consider in the rehabilitation of patients with symptoms of shoulder impingement related to occupational exposure to overhead work.

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