Academic performance and musculoskeletal pain in adolescents with uncorrected vision problems.

BACKGROUND: Undetected vision problems are common in school children, and a prevalence of up to 40% has previously been reported. Uncorrected vision and lack of optimal eye wear can have a significant impact on almost all aspects of everyday life, such as development and learning, academic performance, pain and discomfort, and quality of life. This study aimed to analyze the relationship between uncorrected vision problems, educational outcomes, and musculoskeletal pain symptoms. METHODS: A total of 152 school children (15.1 ± 0.8 years, mean ± SD; 40% males) were included in the study. All participants were recruited from a free-of-charge school vision testing program in Kathmandu, Nepal. Academic grades were collected from the school records of the participants' nationwide final grade examinations. A questionnaire was used to record the use of digital devices, screen time, and associated symptoms, including musculoskeletal pain (Wong-Baker FACES Pain Rating Scales). RESULTS: A total of 61 children (40%) had uncorrected vision, with a cycloplegic refraction of SER - 0.53 ± 0.52 (mean ± SD). Children with uncorrected vision had significantly more third division grades (26 vs. 9%, p = 0.004) and shoulder pain in general/during screen use (66 vs. 43/40%, p = 0.008/0.003; 2.1/1.9 vs. 1.1/1.0 mean pain score, p = 0.002/0.001) compared with children with normal vision. Sex based subanalyses showed that only girls with uncorrected vision had more third division grades (25 vs. 4%, p = 0.006), and only boys with uncorrected vision had more shoulder pain in general/during screen use (76 vs. 28/31%, p < 0.001; 2.2/2.4 vs. 0.7 mean pain score, p < 0.001), compared with children with normal vision. CONCLUSIONS: The results of this study showed that even small refractive errors may impact educational outcomes and musculoskeletal pain in adolescents. Most of the participating children had low myopia, easily corrected with glasses. This suggests that regular eye examinations are important in school children, and there is a need for raised awareness among parents, and school- and healthcare personnel.

Laboured reading and musculoskeletal pain in school children - the role of lifestyle behaviour and eye wear: a cross-sectional study.

BACKGROUND: Lifestyle behaviour in children and adolescents has become increasingly sedentary and occupied with digital work. Concurrently, there has been an increase in the prevalence of headache, neck- and low back pain, which are leading causes of disability globally. Extensive near work and use of digital devices are demanding for both the visual system and the upper body head-stabilizing musculature. Uncorrected vision problems are present in up to 40% of Nordic school children, and a lack of corrective eye wear may cause eyestrain, musculoskeletal pain and headache. The aim of this study was to investigate associations between laboured reading, musculoskeletal pain, uncorrected vision, and lifestyle behaviours in children and adolescents. METHODS: This was a cross-sectional study with a total of 192 Norwegian school children aged 10-11 and 15-16 years. As a part of a school vision testing program, the children completed an online questionnaire about general and ocular health, socioeconomic status, academic ambition, near work and related symptoms, upper body musculoskeletal pain, and physical and outdoor activities. RESULTS: The 15-16-year-olds had a more indoor, sedentary, digital-based lifestyle with higher academic demands, compared with the 10-11-year-olds. Concurrently, reading became more laboured and upper body musculoskeletal pain increased with age. Girls reported more symptoms, higher academic ambitions, and more time spent on schoolwork and reading, compared with boys. Non-compliance in wearing prescribed eye wear (glasses or contact lenses), increased use of near digital devices, and experiencing visual stress (glare) were positively associated with laboured reading and upper body musculoskeletal pain. CONCLUSIONS: A screen-based lifestyle with high academic demands challenges the ability to sustain long hours of static, intensive near work. Extensive near work tires the visual system and upper body musculature and provokes laboured reading and musculoskeletal pain symptoms. This study emphasizes the importance of regular eye examinations in school children, and the need to raise awareness among children, parents, and school- and health personnel about the importance of optimal vision and visual environment for academic performance and health.

Headache and musculoskeletal pain in school children are associated with uncorrected vision problems and need for glasses: a case-control study.

Musculoskeletal pain and headache are leading causes of years lived with disability, and an escalating problem in school children. Children spend increasingly more time reading and using digital screens, and increased near tasks intensify the workload on the precise coordination of the visual and head-stabilizing systems. Even minor vision problems can provoke headache and neck- and shoulder (pericranial) pain. This study investigated the association between headaches, pericranial tenderness, vision problems, and the need for glasses in children. An eye and physical examination was performed in twenty 10-15 year old children presenting to the school health nurse with headache and pericranial pain (pain group), and twenty age-and-gender matched classmates (control group). The results showed that twice as many children in the pain group had uncorrected vision and needed glasses. Most children were hyperopic, and glasses were recommended mainly for near work. Headache and pericranial tenderness were significantly correlated to reduced binocular vision, reduced distance vision, and the need for new glasses. That uncorrected vision problems are related to upper body musculoskeletal symptoms and headache, indicate that all children with these symptoms should have a full eye examination to promote health and academic performance.

Discomfort glare and psychological stress during computer work: subjective responses and associations between neck pain and trapezius muscle blood flow.

PURPOSE: Exposure to additional environmental stress during computer work, such as visual and psychological demands, is associated with increased eye and neck discomfort, altered moods, and reduced well-being. The aim of this study is to elucidate further how subjective responses in healthy, young females with normal binocular vision are affected by glare and psychological stress during computer work, and to investigate possible associations between trapezius muscle blood flow and neck pain development. METHODS: 43 females participated in a laboratory experiment with a within-subject design. Four 10-min computer work conditions with exposure to different stressors were performed at an ergonomically optimal workstation, under the following series of conditions: no additional stress, visual stress (induced as direct glare from a large glare source), psychological stress, and combined visual and psychological stress. Before and immediately after each computer work condition, questionnaires regarding different visual and eye symptoms, neck and shoulder symptoms, positive and negative state moods, perceived task difficulty, and perceived ambient lighting were completed. Associations between neck pain and trapezius muscle blood flow were also investigated. RESULTS: Exposure to direct glare induced greater development of visual/eye symptoms and discomfort, while psychological stress exposure made participants feel more negative and stressed. The perception of work lighting during glare exposure was closely related to perceived stress, and associations between visual discomfort and eyestrain, and neck pain were observed in all conditions. Furthermore, participants with high trapezius muscle blood flow overall reported more neck pain, independent of exposure. CONCLUSIONS: Exposure to visual and psychological stresses during computer work affects the development of symptoms and negative moods in healthy, young females with normal binocular vision, but in different ways. The results also demonstrate the complex interactions involved in symptom development and lighting appraisal during computer work. When optimizing computer workstations, the complexity of the field must be taken into account, and several factors, including visual conditions, must be considered carefully.

Effect of Direct Glare on Orbicularis Oculi and Trapezius During Computer Reading.

PURPOSE: Unfavorable visual conditions during computer work may affect development of both eyestrain and musculoskeletal pain in the neck and shoulder area. The aim of the study was to investigate how direct glare affects symptom development, muscle activity, and muscle blood flow in m. orbicularis oculi and m. trapezius during reading on a computer screen. METHODS: Fifteen healthy young adults with normal binocular vision read text on a computer screen at an optimized computer workplace, 30 minutes with glare exposure and 30 minutes with appropriate lighting. Postural angles were continuously registered. Development of eye symptoms and musculoskeletal pain in the neck and shoulder area were recorded using VAS scales. Muscle activity and muscle blood flow were measured continuously using electromyography and photoplethysmography, respectively. RESULTS: Glare exposure resulted in significantly more pronounced eye pain, increased orbicularis muscle activity, and increased trapezius blood flow compared to reading with appropriate lighting. There were no significant differences in posture between the two light conditions. There were also significant associations between orbicularis oculi activity and both trapezius blood flow and neck pain during both conditions. CONCLUSIONS: Results from the current study show that direct glare conditions cause increased eyestrain and orbicularis oculi contraction during reading on a computer screen. This study also indicates that exposure to direct glare affects the trapezius muscle, possibly by an interaction between the visual system, sympathetic nervous system, and head-stabilizing muscles. In addition, there were associations between the use of orbicularis oculi, trapezius blood flow, and development of neck pain independent of the lighting.

Reliability of muscle blood flow measurements in orbicularis oculi.

PURPOSE: Orbicularis oculi muscle tension and muscle blood flow have been shown to be objective measures of eyestrain during visually demanding activities, such as computer work. In line with this, positive associations between eye-related pain and muscle blood flow in orbicularis oculi have been observed. A hypothesis regarding work situations with cognitive tasks and low-level muscle activity, such as computer work, proposes that muscle pain originates from the blood vessel-nociceptor interactions of the connective tissue of the muscle. Noninvasive muscle blood flow measurements in the orbicularis oculi muscle are preferable to using an invasive technique. The aim of this study was to test reproducibility and stability of muscle blood recordings in orbicularis oculi using photoplethysmography. METHODS: In the reproducibility tests, 12 subjects were tested twice within 1 to 5 weeks. To study the stability of the method, six of the subjects were randomly selected and tested four more times within 2 to 6 weeks. Test subjects were doing identical visually demanding computer work for 10 minutes in each test. RESULTS: The short-term repeatability of muscle blood flow measurements was considered good, but the stability of blood flow recordings over time in orbicularis oculi was low because of a greater within-subject maximum variability compared with between-subject average variability. CONCLUSIONS: Investigators should be aware of the effect of time, possibly attributed to confounding factors such as environmental changes and mental stress, when comparing photoplethysmography muscle blood flow recordings.

Eye-related pain induced by visually demanding computer work.

PURPOSE: Eye strain during visually demanding computer work may include glare and increased squinting. The latter may be related to elevated tension in the orbicularis oculi muscle and development of muscle pain. The aim of the study was to investigate the development of discomfort symptoms in relation to muscle activity and muscle blood flow in the orbicularis oculi muscle during computer work with visual strain. METHODS: A group of healthy young adults with normal vision was randomly selected. Eye-related symptoms were recorded during a 2-h working session on a laptop. The participants were exposed to visual stressors such as glare and small font. Muscle load and blood flow were measured by electromyography and photoplethysmography, respectively. RESULTS: During 2 h of visually demanding computer work, there was a significant increase in the following symptoms: eye-related pain and tiredness, blurred vision, itchiness, gritty eyes, photophobia, dry eyes, and tearing eyes. Muscle load in orbicularis oculi was significantly increased above baseline and stable at 1 to 1.5% maximal voluntary contraction during the working sessions. Orbicularis oculi muscle blood flow increased significantly during the first part of the working sessions before returning to baseline. There were significant positive correlations between eye-related tiredness and orbicularis oculi muscle load and eye-related pain and muscle blood flow. Subjects who developed eye-related pain showed elevated orbicularis oculi muscle blood flow during computer work, but no differences in muscle load, compared with subjects with minimal pain symptoms. CONCLUSIONS: Eyestrain during visually demanding computer work is related to the orbicularis oculi muscle. Muscle pain development during demanding, low-force exercise is associated with increased muscle blood flow, possible secondary to different muscle activity pattern, and/or increased mental stress level in subjects experiencing pain compared with subjects with minimal pain.

Effects of congestive heart failure on Ca2+ handling in skeletal muscle during fatigue.

Skeletal muscle weakness and decreased exercise capacity are major symptoms reported by patients with congestive heart failure (CHF). Intriguingly, these skeletal muscle symptoms do not correlate with the decreased heart function. This suggests that CHF leads to maladaptive changes in skeletal muscles, and as reported most markedly in slow-twitch muscles. We used rats at 6 weeks after infarction to measure expression of key proteins involved in SR Ca(2+) release and uptake in slow-twitch soleus muscles. We also measured force and myoplasmic free [Ca(2+)] ([Ca(2+)](i)) in intact single fibers of soleus muscles. CHF rats showed clear signs of severe cardiac dysfunction with marked increases in heart weight and left ventricular end-diastolic pressure compared with sham operated rats (Sham). There were small, but significant, changes in the content of proteins involved in cellular Ca(2+) handling in CHF muscles: slight increases in SR Ca(2+) release channels (ie, the ryanodine receptors) and in SR Ca(2+)-ATPase. Tetanic force and [Ca(2+)](i) were not significantly different between CHF and Sham soleus fibers under resting conditions. However, during the stimulation period there was a decrease in tetanic force without changes in [Ca(2+)](i) in CHF fibers that was not observed in Sham fibers. The fatigue-induced changes recovered rapidly. We conclude that CHF soleus fibers fatigue more rapidly than Sham fibers because of a reversible fatigue-induced decrease in myofibrillar function.