Effects of error rates and target sizes on neck and shoulder biomechanical loads during augmented reality interactions

Augmented reality (AR) interactions have been associated with increased biomechanical loads on the neck and shoulders. To provide a better understanding of the factors that may impact such biomechanical loads, this repeated-measures laboratory study evaluated the effects of error rates and target sizes on neck and shoulder biomechanical loads during two standardized AR tasks (omni-directional pointing and cube placing). Twenty participants performed the two AR tasks with different error rates and target sizes. During the tasks, angles, moments, and muscle activity in the neck and shoulders were measured. The results showed that the target sizes and error rates significantly affected angles, moments, and muscle activity in the neck and shoulder regions. Specifically, the presence of errors increased neck extension, shoulder flexion angles and associated moments. Muscle activity in the neck (splenius capitis) and shoulder (anterior and medial deltoids) also increased when the errors were introduced. Moreover, interacting with larger targets resulted in greater neck extension moments and shoulder abduction angles along with higher muscle activity in the splenius capitis and upper trapezius muscles. These findings indicate the importance of reducing errors and incorporating appropriate target sizes in the AR interfaces to minimize risks of musculoskeletal discomfort and injuries in the neck and shoulders.

Status of resource recycling stations in Taiwan and recycling work-related health effects

Resource recycling has become an integral part of environmental protection efforts. At present, the development of Taiwan's resource recovery and related works are quite mature. However, laborers or volunteers working in resource recycling stations may be exposed to different types of hazards during the recycling process. These hazards can be divided into biological, chemical, and musculoskeletal problems. These hazards are usually related to the work environment and work habits; therefore, a related control strategy is needed. Tzu Chi's recycling business has been running for over 30 years. In addition to leading the trend of resource recycling in Taiwan, many elderly people have also participated in Tzu Chi recycling stations as volunteers. These older volunteers may be more sensitive to exposure to hazards, and thus the focus of this review is to illustrate the possible hazards and health impacts of resource recovery work and to recommend relevant interventions to improve occupational health during resource recovery work.

Influence of design of dentist's chairs on body posture for dentists with different working experience

BACKGROUND

Musculoskeletal disorders (MSD) are a common health problem among dentists. Dental treatment is mainly performed in a sitting position. The aim of the study was to quantify the effect of different ergonomic chairs on the sitting position. In addition, it was tested if the sitting position of experienced workers is different from a non-dental group.

METHODS

A total of 59 (28 m/31f) subjects, divided into two dentist groups according to their work experience (students and dentists (9 m/11f) < 10 years, dentists (9 m/10f) ≥ 10 years) and a control group (10 m/10f) were measured. A three-dimensional back scanner captured the bare back of all subjects sitting on six dentist's chairs of different design. Initially, inter-group comparisons per chair, firstly in the habitual and secondly in the working postures, were carried out. Furthermore, inter-chair comparison was conducted for the habitual as well as for the working postures of all subjects and for each group. Finally, a comparison between the habitual sitting posture and the working posture for each respective chair (intra-chair comparison) was conducted (for all subjects and for each group). In addition, a subjective assessment of each chair was made. For the statistical analysis, non-parametric tests were conducted and the level of significance was set at 5%.

RESULTS

When comparing the three subject groups, all chairs caused a more pronounced spinal kyphosis in experienced dentists. In both conditions (habitual and working postures), a symmetrical sitting position was assumed on each chair. The inter-chair comparisons showed no differences regarding the ergonomic design of the chairs. The significances found in the inter-chair comparisons were all within the measurementerror and could, therefore, be classified as clinically irrelevant. The intra-chair comparison (habitual sitting position vs. working sitting position) illustrated position-related changes in the sagittal, but not in the transverse, plane. These changes were only position-related (forward leaned working posture) and were not influenced by the ergonomic sitting design of the respective chair. There are no differences between the groups in the subjective assessment of each chair.

CONCLUSIONS

Regardless of the group or the dental experience, the ergonomic design of the dentist's chair had only a marginal influence on the upper body posture in both the habitual and working sitting postures. Consequently, the focus of the dentist's chair, in order to minimize MSD, should concentrate on adopting a symmetrical sitting posture rather than on its ergonomic design.

Workplace musculoskeletal problems in occupational therapy students

Background

Workplace musculoskeletal disorders are the leading cause of morbidity and disability in the Australian workforce. Over one in five occupational therapists report workplace musculoskeletal disorders, with almost half reporting workplace musculoskeletal symptoms. In other health professions, students and novice clinicians (≤5 years practice) experience greater risk but little is known about occupational therapy students.

Methods

In this cross-sectional study, a survey including the self-reported Standardised Nordic Musculoskeletal Questionnaire was administered to occupational therapy students post work-based training. Musculoskeletal problems were defined as aches, pains, numbness or discomfort. Questions explored body sites affected, prevalence, impact on activity, need for medical assistance, demographic and workplace information. Prevalence was reported using descriptive statistics. Factors associated with workplace musculoskeletal problems over the previous 12 months and last 7 days were examined using logistic regression modelling.

Results

Response rate was 53% (n = 211/397). One-third of respondents (33.6%, n = 71/211) reported a workplace musculoskeletal problem over 12 months. Nearly half (47.9%, n = 34/71) of these students reported a problem over the last 7 days. Neck was the most commonly affected area reported for musculoskeletal problems over the past 12 months (24.2%, n = 51/211) and shoulder areas affected over the past 7 days (10.9%, n = 23/211). Musculoskeletal problems preventing daily activities were reported most commonly from lower back problems over 12 months (23.9%, n = 17/71) and for shoulder problems over the last 7 days (21.9%, n = 7/32). Shoulders and knees were the most common body areas requiring medical attention. Previous musculoskeletal problems and female gender were associated with reported problems over 12 months and last 7 days (p < 0.05). Non-standard joint mobility (OR = 3.82, p = 0.002) and working in psychosocially focused caseloads (including mental health or case management) (OR = 3.04, p = 0.044) were also associated with reporting musculoskeletal problems over the last 7 days.

Conclusions

One in three occupational therapy students already experience workplace musculoskeletal problems impacting daily activities and requiring medical assistance prior to graduation. High prevalence of musculoskeletal problems in this study calls for educators and researchers to find sustainable strategies to address these problems, with particular consideration to the impact of previous disorders and working in psychosocially focused caseloads on musculoskeletal health.

The orthopaedic aspect of spastic cerebral palsy

Spastic Cerebral Palsy (CP) is the most common form of CP, comprising of 80% of all cases. Spasticity is a type of hypertonia that clinically manifests as dynamic contractures. The dynamic contracture along with the reduced level of physical activity in a child with CP leads to secondary structural and morphological changes in spastic muscle, causing real musculotendinous shortening, known as fixed contractures. When fixed muscle contractures are not treated early, progressive musculoskeletal deformities develop. As a consequence, spastic CP from a static neurological pathology becomes a progressive orthopaedic pathology which needs to be managed surgically. Orthopaedic surgical management of CP has evolved from previous "multi-event single level" procedures to a "single event multilevel" procedures, with changes in selection and execution of treatment modalities. There is increasing evidence that multilevel surgery is an integral and essential part of therapeutic management of spastic CP, but more research is needed to ensure effectiveness of this intervention on all domains of physical disability in CP.

Low back pain among nurses working in clinical settings of Africa: systematic review and meta-analysis of 19 years of studies

BACKGROUND

Nurses in Africa are arguably the most important frontline healthcare workers available in most healthcare facilities, performing a broad range of tasks. Such tasks are considerably presumed in the causation of workload. Nursing is listed among the highly risky professions for developing low back pain. The nursing profession is ranked within the top ten professions which have a great risk of low back pain. Hence, this review aimed to ascertain whether low back pain is a significant concern for nurses in African healthcare facilities.

METHODS

A comprehensive literature search of different databases with no date limit was conducted from September to November 2018 using the PRISMA guideline. The quality of the included studies was assessed using a 12-item rating system. Subgroup and sensitivity analyses were performed. Cochran's Q and the I2 test were used to assess heterogeneity. The presence of publication bias was evaluated by using Egger's test and visual inspection of the symmetry in funnel plots.

RESULT

In this review, 19 studies from different African regions with a total sample size of 6110 nurses were included. All the studies were carried out between 2000 and 2018. Among these, the lowest and the highest prevalence were found to be 44.1 and 82.7% respectively. The estimation of the prevalence rate of low back pain among nurses using the random-effects model was found to be 64.07% (95% CI: 58.68-69.46; P-value < 0.0001). Heterogeneity of the reviewed studies was I2 = 94.2% and heterogeneity Chi-squared = 310.06 (d.f = 18), P-value < 0.0001. The subgroup analyses showed that the highest prevalence of LBP among nurses was from West African region with prevalence rates of 68.46% (95% CI: 54.94-81.97; P-value < 0.0001) and followed by North Africa region with prevalence rate of 67.95% (95% CI: 55.96-79.94; P-value < 0.0001).

CONCLUSION

Even though the overall prevalence of the present study is lower when compared to the Western and Asian studies, it indicated that the prevalence of low back pain among nurses is substantial.

Postgraduates' Perspective of Pediatric Dental Chair: A Questionnaire Study

The posture and positioning of pediatric dentist will greatly depend upon the type of dental chair they chose while treating children. Pediatric dentists working on a traditional adult chair for treating children frequently lean forward for close proximity to oral cavity; as a result of this poor posture, they are more prone to suffer from musculoskeletal disorders. Proper positioning of dentist during treatment will improve not only their comfort but also their career longevity. The aim of the study was to assess the comfort and need of pediatric dental chair compared with traditional adult dental chair for treatment and better management of children.

Study design

This is a questionnaire survey for postgraduate students consisting of 14 multiple-choice questions in English format. The questionnaire was structured to know whether the pediatric dental chair is beneficial compared to traditional adult dental chair while treating children.

Results and conclusion

Out of 92 responded members, 99% had an opinion that a pediatric dental chair is needed for treating children. They concluded that pediatric dental chair had many advantages over traditional adult dental chair while treating children and acceptance of pediatric dental chair among postgraduates is overwhelming.

How to cite this article

Reddy ER, Raju SS, Merum K, et al. Postgraduates' Perspective of Pediatric Dental Chair: A Questionnaire Study. Int J Clin Pediatr Dent 2020;13(3):251-254.

Effective interventions for preventing work related physical health complaints in nursing students and novice nurses: A systematic review

From the start of their career, nursing students and novice nurses are at risk of developing physical health problems due to high physical workload, which may lead to early exit from nursing. To provide an overview of interventions preventing physical health problems in early career, a systematic review was performed. A comprehensive search of the literature was conducted up to December 2017. Primary outcome of interest was education/work dropout. Secondary outcomes were musculoskeletal symptoms. Independent authors selected studies, appraised quality and extracted data. After screening 7111 titles and abstracts, eleven studies were included. Seven studies evaluated interventions for moving/handling training. Four evaluated other interventions. None focused on our primary outcome education/work dropout. All studies reported on physical complaints among student nurses only. Overall, risk of bias was high and clinical heterogeneity prohibited pooling of data. Intervention effects were small and inconsistent. In conclusion, evidence for the effectiveness of interventions in the nursing curricula for the prevention/treatment of physical complaints is scarce and where available conflicting. We recommend high quality research on dropout due to physical health problems, as well as on the prevention/treatment of physical complaints.

Place of Residence, Working Conditions and the Burden of Back Pain among Hired Farmworkers in the United States

Objectives: Back pain is the leading occupational health problem among agricultural workers. Current study aimed to assess the burden of farm work-related back pain and to investigate its associations with living residence location and work conditions among farmworkers. Methods: We used the National Agricultural Workers Survey (NAWS) data from 1999 to 2004, 2008-2010, and 2014. Work-related back pain was defined as a back pain that was developed when performing farm work in the 12 months prior to the interview, and it caused pain or discomfort for at least five consecutive days. To assess the associations of place of residence and working conditions (i.e. work equipment and access to toilet and water for washing hands at work) with back pain, we analyzed the data using mixed-effects logistic regression models while adjusting for age, gender, race, birthplace (US vs. foreign country), education, marital status, work authorization (yes vs. no), below poverty income, whether the worker was hired by a farm labor contractor or not, and weekly working hours. Results: The standardized annual back pain prevalence during the study period ranged from 2.6% to 11.3%. In the adjusted model, farmworkers who lived in a residence located on the farm, who did not have access to toilet at work, and who paid for work equipment had higher odds of back pain than their counterparts. Conclusion: Back pain is particularly common among farmworkers with poor working and living conditions. Interventions should target the identified high-risk groups to mitigate their burden of back pain.

Musculoskeletal Problems Among Greek Perioperative Nurses in Regional Hospitals in Southern Peloponnese : Musculoskeletal Problems in Perioperative Nurses

The surgery unit is a particularly labor-intensive environment in the hospital. Studies reflect the correlation of labor risk factors for musculoskeletal injuries among nurses but few have investigated the relationship to perioperative nurses. The purpose of this study is the identification and definition of ergonomic risk factors in the operating room and their connection with musculoskeletal disorders in perioperative nurses in regional hospitals in Greece. Forty four Greek perioperative nurses working in regional hospitals in southern Peloponnese participated. Anonymous self-administered questionnaire was used to collect the data, which consisted of three parts (investigating musculoskeletal symptoms, description of work, psychometric evaluation). The analysis was done with the statistical program SPSS.19. Symptoms of musculoskeletal problems emerged. Specifically, 54.4% in the lumbar, 47.7% in the neck, 45.5% in the shoulder, followed by smaller percentages of the hip, knee, elbow and ankle. 6.8% of participants indicated no musculoskeletal symptoms in the last year while 74.9% of those who had symptoms presented them in two or more areas. Activities rated as a major problem among others were the manual handling, tools with weight and vibration etc. 100% of respondents agreed that the work in the surgery unit is demanding and has anxiety. The lack of support from the government (81.8%), combined with the low perioperative nurses (6.8%) having the opportunity to participate in administrative decisions concerning them were related to problems in the organization and management of work. Apart from engineers target factors, a main aim should be the organization of work within the framework of a national policy based on European directives on the protection and promotion of the health and safety of workers.

Screening for musculoskeletal problems in Japanese schoolchildren: a cross-sectional study nested in a cohort

OBJECTIVES

To clarify the frequency of musculoskeletal problems in public elementary and junior high school children and to determine the advantages and problems of musculoskeletal examinations.

STUDY DESIGN

School-based cross-sectional study nested in a cohort.

METHODS

We examined 41,376 public elementary and junior high school children (aged 6-15 years) in Miyazaki, Japan, from 2008 to 2014. Participation was voluntary. Participants received an in-school primary musculoskeletal examination (clinical examination with check items and a questionnaire) and a secondary examination at an orthopaedic outpatient clinic as indicated. Estimated prevalence rates for musculoskeletal problems were calculated from the results of both examinations.

RESULTS

The total estimated prevalence of musculoskeletal problems was 8.6%. Prevalence by school grade ranged from 3.2% to 13.7%. Estimated prevalence rates increased as grade increased and were higher in junior high school students than in elementary school students. The secondary examination identified musculoskeletal problems on the back (65.4%), knee (8.1%), ankle or feet (7.3%) and elbow (5.4%). Of those referred for a secondary examination, 44.4% had not reported musculoskeletal complaints on the initial questionnaire. Overall, 69.8% of problems diagnosed in the secondary examination were previously undiagnosed.

CONCLUSIONS

School-based musculoskeletal examination enables early detection of abnormal growth and disorders of the locomotive organs and is expected to support children's musculoskeletal growth and development. We recommend musculoskeletal examinations as part of school check-ups in Japan. Our findings suggest musculoskeletal examinations should be conducted for students in higher elementary school grades and for all junior high school students. Evaluation should include both direct clinical examination and questionnaires.

An analytical ergonomic risk evaluation of body postures during daily cleaning tasks in horse stables

BACKGROUND

Musculoskeletal disorders (MSDs) are a common reason for health problems and sick leave in many professions. A work arena where MSDs have not been sufficiently studied is stable work. Here many heavy and repetitive work tasks are performed manually with old-fashioned working tools.

OBJECTIVE

The aim of this study was to use an analytical approach to identify, evaluate and grade ergonomic problems in physical work performed during daily activities in horse stables and relate these to MSDs among the workers and to the design of the tools.

METHODS

Three common work tasks were studied to identify, evaluate and grade ergonomic problems; mucking out, sweeping and bedding replacement. Used methods were Hierarchical Task Analysis, Heuristic Evaluation and Rapid Entire Body Assessment.

RESULTS

Several high-risk operations were found in mucking out boxes and disposal of bedding material. The problems consisted of awkward working postures such as a twisted and bent back, arms in an elevated position, wrists in extreme joint positions and handling of heavy loads.

CONCLUSIONS

By using an analytical approach it is possible to identify presumptive ergonomic problems without extensive empirical research. In most high-risk operations, long-shafted tools or a wheelbarrow were used, which emphasize a need to develop tools with better ergonomic design to improve the working situation. The limitation is that the ergonomics problems found are not finally validated. The results show where deeper empirical research is needed, both regarding how MSDs occur and how tools and environment contribute to physical problems.

Musculoskeletal problems and fluoride exposure: A cross-sectional study among metal smelting workers

Frequent and repetitive activities in job and awkward postures are shown as major contributors of musculoskeletal problems in most of the occupational health studies; however, efforts to explore newer risk factor are important to plan interventional measures. In this backdrop, this study examined contribution of fluoride exposure to musculoskeletal complaints. A cross-sectional interviewer-administered questionnaire survey was conducted involving 180 randomly selected subjects from a metal smelting industry. Clinical examination of the subjects was also performed to assess their health status and morbidity details. Assessment of personal exposure to particulate and gaseous fluoride at workplace was conducted. Urinary fluoride level was also examined in post-shift samples collected from study subjects. The mean age of the study subjects was 39.1 (±6.7) years. Majority of the workers (42.5%) were engaged in pot room. About 54% workers were suffering from backache and 66% subjects had joint pain. Exposure of workers to both particulate and gaseous fluoride and post-working shift urinary fluoride level was significantly higher in pot-room workers in comparison with all other workers. It was observed that age (odds ratio (OR): 1.62; 95% confidence interval (CI): 1.18-2.34), drinking untreated water (OR: 1.51; 95% CI: 1.03-2.76), working in pot room (OR: 1.44; 95% CI: 1.13-1.91) and urinary fluoride level (OR: 2.71; 95% CI: 1.81-3.75) had significant effects on musculoskeletal complaints. This study concludes that along with other predictors such as nature of work, posture at work and age of worker, exposure to fluoride also has significant role in the occurrence of musculoskeletal morbidity.

Soreness during non-music activities is associated with playing-related musculoskeletal problems: an observational study of 731 child and adolescent instrumentalists

QUESTION

Is exposure to non-music-related activities associated with playing-related musculoskeletal problems in young instrumentalists? Is non-music-activity-related soreness associated with playing-related musculoskeletal problems in this group of instrumentalists?

DESIGN

Observational study using a questionnaire and physical measures.

PARTICIPANTS

859 instrumentalists aged 7 to 17 years from the School of Instrumental Music program.

RESULTS

Of the 731 respondents who completed the questionnaire adequately, 412 (56%) experienced instrument-playing problems; 219 (30%) had symptoms severe enough to interfere with normal playing. Children commonly reported moderate exposure to non-music-related activities, such as watching television (61%), vigorous physical activity (57%), writing (51%) and computer use (45%). Greater exposure to any non-music activity was not associated with playing problems, with odds ratios ranging from 1.01 (95% CI 0.7 to 1.5) for watching television to 2.08 (95% CI 0.5 to 3.3) for intensive hand activities. Four hundred and seventy eight (65%) children reported soreness related to non-music activities, such as vigorous physical activity (52%), writing (40%), computer use (28%), intensive hand activities (22%), electronic game use (17%) and watching television (15%). Non-music-activity-related soreness was significantly associated with instrument playing problems, adjusting for gender and age, with odds ratios ranging from 2.6 (95% CI 1.7 to 3.9) for soreness whilst watching television, to 4.3 (95% CI 2.6 to 7.1) for soreness during intensive hand activities.

CONCLUSION

Non-music-activity-related soreness co-occurs significantly with playing problems in young instrumentalists. The finding of significant co-occurrence of music and non-music-related soreness in respondents in this study suggests that intervention targets for young instrumentalists could include risk factors previously identified in the general child and adolescent population, as well as music-specific risk factors. This is an important consideration for the assessment and management of the musculoskeletal health of young musicians.

Musicians' medicine: musculoskeletal problems in string players

There is increasing attention to medical problems of musicians. Many studies find a high prevalence of work-related musculoskeletal disorders in musicians, ranging from 73.4% to 87.7%, and string players have the highest prevalence of musculoskeletal problems. This paper examines the various positions and movements of the upper extremities in string players: 1) basic postures for holding instruments, 2) movements of left upper extremity: fingering, forearm posture, high position and vibrato, 3) movements of right upper extremity: bowing, bow angles, pizzicato and other bowing techniques. These isotonic and isometric movements can lead to musculoskeletal problems in musicians. We reviewed orthopedic disorders that are specific to string players: overuse syndrome, muscle-tendon syndrome, focal dystonia, hypermobility syndrome, and compressive neuropathy. Symptoms, interrelationships with musical performances, diagnosis and treatment of these problems were then discussed.