Computer-associated health complaints and sources of ergonomic instructions in computer-related issues among Finnish adolescents: a cross-sectional study.

BACKGROUND: The use of computers has increased among adolescents, as have musculoskeletal symptoms. There is evidence that these symptoms can be reduced through an ergonomics approach and through education. The purpose of this study was to examine where adolescents had received ergonomic instructions related to computer use, and whether receiving these instructions was associated with a reduced prevalence of computer-associated health complaints. METHODS: Mailed survey with nationally representative sample of 12 to 18-year-old Finns in 2001 (n = 7292, response rate 70%). In total, 6961 youths reported using a computer. We tested the associations of computer use time and received ergonomic instructions (predictor variables) with computer-associated health complaints (outcome variables) using logistic regression analysis. RESULTS: To prevent computer-associated complaints, 61.2% reported having been instructed to arrange their desk/chair/screen in the right position, 71.5% to take rest breaks. The older age group (16-18 years) reported receiving instructions or being self-instructed more often than the 12- to 14-year-olds (p < 0.001). Among both age groups the sources of instructions included school (33.1%), family (28.6%), self (self-instructed) (12.5%), ICT-related (8.6%), friends (1.5%) and health professionals (0.8%). Receiving instructions was not related to lower prevalence of computer-associated health complaints. CONCLUSIONS: This report shows that ergonomic instructions on how to prevent computer-related musculoskeletal problems fail to reach a substantial number of children. Furthermore, the reported sources of instructions vary greatly in terms of reliability.

Force production and EMG activity of neck muscles in adolescent headache.

PURPOSE: This study compared the maximal force, EMG/force ratio and co-activation characteristics of the neck-shoulder muscles between 30 adolescents with migraine-type headache, 29 with tension-type headache, and 30 headache-free controls. METHOD: Force was measured with surface electromyography (EMG) from the cervical erector spinae (CES), the sternocleidomastoid (SCM) and trapezius muscles during the maximal isometric neck flexion, neck extension and shoulder flexion. RESULTS: Girls with migraine-type headache had higher EMG/force ratios between the EMG of the left agonist SCM muscle and the corresponding maximal neck flexion (p = 0.030) and neck rotation force to the right side (p = 0.024) than the girls with tension-type headache. Migrainous girls had more co-activation of right antagonist CES muscle during maximal neck flexion force than the girls without headache (p = 0.015). Neck force production showed no significant differences between girls. Girls with tension-type headache displayed lower left shoulder flexion force than girls with migraine-type headache (p = 0.005) or with no headache (p = 0.005). In boys, no significant differences were observed. CONCLUSIONS: Girls with tension-type headache and migraine-type headache have differences in neuromuscular function in the neck-shoulder muscles. The data amplify our knowledge of the neck-shoulder muscle dysfunction in adolescent headache, and may encourage the use of specific rehabilitation methods in the management of different types of headache.

Neck flexor muscle fatigue in adolescents with headache: an electromyographic study.

BACKGROUND: Muscular disorders of the neck region may be of importance for the etiology of tension-type headache. However, in adolescents, there are no data on the association between neck muscle fatigue and headache. AIM: To study differences in fatigue characteristics of the neck flexor muscles in adolescents with and without headache. METHODS: A population-based sample of 17-year-old adolescents with migraine-type headache (N=30), tension-type headache (N=29) and healthy controls without headache (N=30) was examined. Surface EMG data were recorded from the sternocleidomastoid (SCM) muscles bilaterally during an isometric neck flexor endurance test. The spectral median frequency (MF) change during the total endurance time (TMF) and the initial time of 30s (IMF) was calculated. The intensity of discomfort in the neck area was assessed with the visual analogue scale (VAS). RESULTS: The rate of decline in TMF of both SCM muscles was significantly increased in the tension-type headache group compared with controls (right SCM, P=0.030, OR 2.0, 95% 1.2-3.7; left SCM, P=0.009, OR 2.5, 95% 1.4-4.9), while no significant differences were found between controls and subjects with migraine. The rate of decline in IMF, the total endurance time (P=0.050), and VAS did not differ significantly among the study groups. CONCLUSIONS: This preliminary finding shows that increased neck flexor muscle fatigue in adolescents seems to be associated with tension-type headache.

Repeatability of electromyography and force measurements of the neck muscles in adolescents with and without headache.

BACKGROUND: Reliable measurements are needed to study the dysfunction of the neck muscles. The aim of this study was to determine the intra-tester repeatability of EMG and isometric force measurements of the neck muscles in adolescents with headache and headache-free controls. METHODS: A group of 30 adolescents with migraine-type headache, 29 with tension-type headache, and 30 headache-free controls were recruited. Maximal isometric neck muscle force with simultaneous recording of surface EMG from the cervical erector spinae and the sternocleidomastoideus muscles was measured twice during one day. FINDINGS: For all groups, intra-class correlation coefficients (ICC) and coefficients of variation (CV) showed acceptable repeatability of all measurements. (Force measurements: ICC 0.98-0.99, CV 0.7-3.7%; EMG measurements: ICC 0.95-0.99, CV 4.9-10.1%.) On the individual level, variation between the consecutive measurements was found to be low in all groups. INTERPRETATION: The present EMG and force measurements of neck muscles indicate acceptable intra-tester repeatability in adolescents. The repeatability was comparable in migraine- and tension-type headache and headache-free groups. The EMG and the force measurements offer the possibility to investigate neck muscle dysfunction in adolescent headache.

Risk factors for development of non-specific musculoskeletal pain in preteens and early adolescents: a prospective 1-year follow-up study.

BACKGROUND: Musculoskeletal pain symptoms are common in children and adolescents. These symptoms have a negative impact on children's physical and emotional well-being, but their underlying aetiology and risk factors are still poorly understood. Most of the previous cohort studies were conducted among mid and/or late adolescents and were mainly focused on a specific pain location (e.g. low back pain or neck pain). The purpose of this study is to estimate occurrence of new-onset pain symptoms, in all musculoskeletal locations, in preteens and early adolescents and investigate risk factors for development of these symptoms. METHODS: 1756 schoolchildren (mean age 10.8) were recruited from schools in southern Finland. Information was extracted as to whether they experienced musculoskeletal pain and a total of 1192 children were identified as free of musculoskeletal pain symptoms. Information was collected on factors which could potentially predict the development of musculoskeletal pain: headache, abdominal pain, sadness/feeling down, day-time tiredness, difficulty in falling asleep, waking up during nights, level of physical activity and hypermobility. These children were followed-up 1-year later and those with new episodes of non-traumatic and traumatic musculoskeletal pain symptoms were identified. RESULTS: A total of 1113 schoolchildren (93% of baseline pain-free children) were found at one-year follow-up. New episodes of musculoskeletal pain were reported by 21.5% of these children. Of them 19.4% reported non-traumatic pain and 4.0% reported traumatic pain. The neck was the most commonly reported site with non-traumatic pain, while the lower limb was the most common site for traumatic pain. The independent risk factors for non-traumatic musculoskeletal pain were headache (OR = 1.68, [95% CI 1.16-2.44]) and day-time tiredness (OR = 1.53, [95% CI 1.03-2.26]). The risk factors for traumatic musculoskeletal pain were vigorous exercise (OR = 3.40 [95% CI 1.39-8.31]) and day-time tiredness (OR = 2.97 [95% CI 1.41-6.26]). CONCLUSION: This study highlights that there may be two types of pain entities with both distinct and common aspects of aetiology. For primary prevention purposes, school healthcare professionals should pay attention to preteens and early adolescents practicing vigorous exercise (predictor of traumatic pain), reporting headache (predictor of non-traumatic pain) and reporting day-time tiredness (predictor of both types of pain).

Risk factors for traumatic and non-traumatic lower limb pain among preadolescents: a population-based study of Finnish schoolchildren.

BACKGROUND: The child's lower limb is the most commonly reported musculoskeletal location with pain and also the most commonly injured site in sports. Some potential risk factors have been studied, but the results are inconsistent. We hypothesized that distinction of traumatic from non-traumatic pain would provide a clearer picture of these factors. The aim of this study is to assess factors associated with lower extremity pain and its impact on preadolescents in a population-based cohort. METHODS: A structured pain questionnaire was completed by 1756 schoolchildren of third and fifth grades to assess musculoskeletal pain, psychosomatic symptoms, subjective disabilities, school absence and frequency of exercise. In addition, hypermobility and physical fitness were measured. RESULTS: The knee was the most common site of pain followed by the ankle-foot and thigh. Of the children who reported pain in their lower extremity, approximately 70% reported at least one disability and 19% reported school absence attributed to their pain during the previous three-month period. Children with traumatic pain had a higher subjective disability index than those with non-traumatic pain (P = 0.02). Age less than 11 years, headache, abdominal pain, depressive feelings, day tiredness, and vigorous exercise were more common in children with lower limb pain than those free of it. In the stratified analysis, younger age was related to both traumatic and non-traumatic pain groups. Vigorous exercise was positively associated with traumatic pain, while subjects with non-traumatic pain had more frequent psychosomatic symptoms. CONCLUSION: Risk factors and consequences of traumatic and non-traumatic lower limb pain are not similar. Traumatic lower limb pain is associated with practicing vigorous exercise and high level of physical fitness, while non-traumatic pain is more correlated with psychosomatic symptoms. These differences might be one of the reasons for the discrepancy of previous research conclusions. The two conditions need to be treated as different disorders in future studies.

Contributing factors to the persistence of musculoskeletal pain in preadolescents: a prospective 1-year follow-up study.

A 1-year follow-up of two preadolescent age cohorts with musculoskeletal pain at least once a week was conducted to analyze predictive factors for the persistence of musculoskeletal pain. Of the 564 children with pain at baseline, representing one third of the sample studied, 515 (91.3%) could be followed and 452 (80.1%) children with complete data were included for the logistic regression analysis. A structured questionnaire included questions on pain and also on several psychosomatic symptoms and amount of exercise. Joint hypermobility together with the questionnaire data were included in the logistic regression analysis. One half of subjects with pain at baseline still reported pain at follow-up, indicating persistent pain. Boys had a lower risk for the persistence of pain than girls and the risk for the persistence of pain increased 1.2 times per age year. When further adjusted for all the other studied risk determinants, high subjective disability index due to pain (OR 3.2, 95% CI 1.5-6.6) and day tiredness (OR 1.9, 95% CI 1.2-3.0) were the most significant predictors. This might indicate that psychological distress contributes to the persistence of non-specific musculoskeletal pain of different locations in preadolescents. In clinical work not only pain but its interference with daily activities should be noticed.

Prognosis of non-specific musculoskeletal pain in preadolescents: a prospective 4-year follow-up study till adolescence.

Musculoskeletal pain is common in children but studies on the outcome and predictive factors for persistence/recurrence of these symptoms are scarce. A baseline cross-sectional survey of 1,756 schoolchildren (mean age 10.8) identified 564 (32.1%) children with musculoskeletal pain. At baseline, these children were evaluated using a structured questionnaire and examined for hypermobility and physical fitness. The children were re-evaluated after one year, and four years (at adolescence) using the same pain questionnaire. At 1-year follow-up, 53.8% (95% CI 48.8-58.8) of the children reported pain persistence (persistent preadolescent musculoskeletal pain). At 4-year follow-up, 63.5% (95% CI 58.7-68.1) of them had musculoskeletal pain. Neck was the site with most persistent/recurrent musculoskeletal pain. Those with persistent preadolescent musculoskeletal pain had approximately three times higher risk of pain recurrence (OR=2.90 [95% CI 1.9-4.4]). In the univariate analysis, female gender, older age group (11+), hypermobility, co-existence of psychosomatic symptoms, having high disability index, and reporting combined musculoskeletal pain at baseline predicted pain recurrence at adolescence. In the multivariate analysis, age, headache, hypermobility and having combined musculoskeletal pain were found as independent predictors. Statistically significant sex interactions were found for age, depressive feelings, waking up during nights and hypermobility. More psychosomatic symptoms predicted pain recurrence in girls than in boys, and hypermobility was a strong predictor in females only. Musculoskeletal pain in preadolescents is not a self-limiting phenomenon and more studies are still warranted to explore its determinants aiming to improve the long-term outcome of these symptoms.

Neck pain in adolescence. A 4-year follow-up of pain-free preadolescents.

The main aim of this study was to explore the occurrence and changes of neck pain in pain-free preadolescents. The evaluation was performed at 1- and 4-year follow-ups. Of the pain-free preadolescents, 366 (71.9%) completed structured pain questionnaires at 1 and 4 years. The occurrence of neck pain at least once a month was 21.3 and 43.4% and at least once a week was 6.3 and 19.4%. Sex difference was found only at the 4-year follow-up, when subjects were 13-16-year-old. Neck pain was then more common among girls than boys (P < 0.001). The intensity of pain increased with the frequency of pain (P < 0.001). Of those with neck pain, 28% had used painkillers. The proportion increased with the frequency of neck pain (P = 0.054). Neck pain occurred more often with some other musculoskeletal pain than as a single pain. The frequency of neck pain correlated with the frequency of headache (r = 0.39 [95% confidence interval (CI), 0.30-0.47]) and with the disability (r = 0.26 [95% CI, 0.16-0.35]). This study strengthens the results of the previous cross-sectional studies that occurrence of neck pain increases with age, and that neck pain becomes more common among girls than boys in adolescence. Among preadolescents who were originally pain-free, there was only a small proportion who reported frequent neck pain at both 1 and 4 years. It also showed that the frequency of neck pain reflects the intensity of pain fairly well.

Perceived relative importance of pain-related functions among patients with low back pain.

OBJECTIVE: The aim of this study was to evaluate the relationship between the functional status of patients with low back pain and the perceived importance of pain-related everyday functions assessed in the Oswestry Disability Index. DESIGN: The sample was based on 219 successive adult patients with low back pain referred to a tertiary clinic. PATIENTS: A total of 168 patients (76.6%) participated in the study, mean age 48.2 years (standard deviation 11.6). METHODS: In a questionnaire the patients were asked to complete the Oswestry Disability Index and the same domains using visual analogue scales. Subjects were also asked to assess the relative importance of these domains by using a visual analogue scale. RESULTS: Sleeping, walking and personal care were the 3 most important functions for both men and women. Patients with low back pain gave more importance to most of the functional abilities that are needed in everyday life and self-management than to the intensity of pain. However, when the patients reported their current experience in functions, greatest difficulty was experienced in lifting. CONCLUSION: Development of outcome measure instruments for patients with low back pain could benefit from taking into account patients' perceptions. In addition, functional measures should be weighted according to the relative importance of each function to the patients.

Do ergonomically designed school workstations decrease musculoskeletal symptoms in children? A 26-month prospective follow-up study.

Workstations at school are among several factors that contribute to musculoskeletal symptoms among school-aged children. The aim of this study was to investigate the effects of ergonomically designed workstations on schoolchildren's musculoskeletal symptoms as compared to conventional workstations. In the first 14-month phase of the study (2002-2003, two schools), 42 from the intervention and 46 from the control school participated. In the total follow-up of 26 months (2002-2004), 23 in the intervention group and 20 in the control group participated. Anthropometrics and musculoskeletal symptoms were measured. In general, the ergonomically designed school workstations did not decrease present neck-shoulder, upper back, low back and lower limbs strain and pain, compared to conventional ones during follow-ups.

Neck muscles' cross-sectional area in adolescents with and without headache - MRI study.

BACKGROUND: Cervical musculature may play an important role in the genesis of tension-type headache. However, there are no reports on a possible association between the morphometrical features of the neck flexion and extension muscles and adolescence headache. AIM: To examine differences in neck flexion and extension muscles cross-sectional area (CSA) in adolescents with and without headache. METHODS: A population-based sample of 17-year-old adolescents with migraine (N=19), tension-type headache (N=24) and healthy controls without headache (N=22) was examined. CSA of the neck muscles was measured from axial T1-weighted magnetic resonance images (MRI). RESULTS: Boys with tension-type headache showed significantly smaller CSA of right sternocleidomastoid muscle than boys with migraine and girls with tension-type headache showed significantly smaller CSA of combined right sternocleidomastoid and scalenus muscles than girls with migraine. In addition, boys with migraine had significantly larger CSA of both right sternocleidomastoid and combined right sternocleidomastoid and scalenus muscles, and left semispinalis capitis muscle and combined left semispinalis and splenius muscles than boys without headache. In boys and girls no other significant differences were observed in the CSA of neck flexion or extension muscles. CONCLUSIONS: This preliminary work demonstrates that both girls and boys with tension-type headache and migraine have differences in the size of neck flexion muscles, especially unilaterally. In boys, unilaterally increased size of neck flexion and extension muscles is associated with migraine. These findings, if confirmed in further studies, may have important diagnostic and therapeutic implications for rehabilitation of adolescents with headache.

Onset, prognosis and risk factors for widespread pain in schoolchildren: a prospective 4-year follow-up study.

Little is known about the epidemiology of widespread pain (WSP) in children and adolescents. This study aims to estimate the new-onset and prognosis of WSP in schoolchildren and investigate factors predicting its development. A prospective study was conducted among 1756 schoolchildren (age 10-12 years) in Southern Finland. At baseline, information was collected on WSP, regional musculoskeletal pain symptoms, depressiveness, fatigue, sleep problems, physical activity and joint hypermobility. These children were contacted again 1 year and 4 years later to determine the outcome and the new-onset of WSP. A total of 1282 children (73%) of the baseline study population were found at both follow-ups. Of the children who had WSP at baseline, 31% and 30% reported persistence/recurrence of symptoms at 1- and 4-year follow-up, respectively. However, only 10% of these children reported WSP at both 1 and 4 years. Of the children who were free of WSP at baseline, 18% reported new-onset WSP at 1-year follow-up and 3% reported these symptoms at both follow-up times. The independent baseline risk factors of WSP were older age (OR 1.3 95% CI 1.0-1.8), female gender (OR 1.4, 1.1-1.9), depressiveness (OR 1.5, 1.1-2.2) and regional back pain symptoms (Neck pain: OR 1.7, 1.1-2.4; Upper back pain: OR 2.1, 1.1-4.1; Lower back pain: OR 3.0, 1.6-5.7). Both psychological factors and somatic pain symptoms predict future development of WSP in adolescents.

Non-specific neck pain in schoolchildren: prognosis and risk factors for occurrence and persistence. A 4-year follow-up study.

This study investigated the natural course of neck pain (NP) in 9-12-year-olds during a 4-year follow-up. Risk factors for the occurrence and persistence of weekly NP were explored separately for boys and girls. At baseline, 1756 schoolchildren completed a questionnaire eliciting musculoskeletal pain symptoms, other physical, and psychological symptoms and frequency of physical activity, and were tested for joint hypermobility. Symptoms during the preceding three months were asked using a five-level frequency classification. Re-evaluation was performed after one and four years using identical questionnaires. During follow-up, 24% reported none, 71% fluctuating, and 5% persistent weekly NP. The frequency of NP at baseline was linearly related to weekly NP during follow-up in both genders (P<0.001). Furthermore, a significant increasing linear trend towards a more persistent course of NP was seen in children with weekly other musculoskeletal and/or other physical and psychological symptoms at baseline. Among originally neck pain-free pre-/early adolescents, weekly other musculoskeletal pain symptoms (only in girls) and other physical and psychological symptoms (in both genders) predicted the occurrence of weekly NP during follow-up. In conclusion, neck pain in schoolchildren tends to fluctuate, but there also seems to exist a subgroup (5%) with persistent NP already in pre-/early adolescents, or even earlier. Co-occurrence of frequent other musculoskeletal symptoms and/or markers of psychological stress with frequent NP are risk indicators for a more persistent course, at least within next few years. Since adult chronic NP problems might originate in childhood, further studies are needed, including preventive interventions.

Frequent computer-related activities increase the risk of neck-shoulder and low back pain in adolescents.

BACKGROUND: Neck-shoulder pain (NSP) and low back pain (LBP) increased among adolescents in the 1990s and the beginning of 2000. A potential risk factor for this increase is the use of information and communication technology. We studied how the use of computers, the Internet, and mobile phones, playing digital games and viewing television are related to NSP and LBP in adolescents. METHODS: Mailed survey with nationally representative samples of 14-, 16-, and 18-year-old Finns in 2003 (n = 6003, response rate 68%). The outcome variables were weekly NSP and LBP. RESULTS: NSP was perceived by 26% and LBP by 12%. When compared with non-users, the risk of NSP was 1.3 (adjusted odds ratios) when using computers > 2-3 h/day, and 1.8 when using 4-5 h/day; 2.5 when using computers > or = 42 h/week, and 1.7 when using the Internet > or = 42 h/week. Compared with non-users, the risk of LBP was 2.0 when using computers > 5 h/day, 1.7 when using > or = 42 h/week, 1.8 when using the Internet > or = 42 h/week, and 2.0 when playing digital games > 5 h/day. Times spent on digital gaming, viewing television, and using mobile phones were not associated with NSP, nor were use of mobile phones and viewing television with LBP after adjusting for confounding factors. CONCLUSIONS: Frequent computer-related activities are an independent risk factor for NSP and LBP. Daily use of computers exceeding 2-3 h seems to be a threshold for NSP and exceeding 5 h for LBP. Computer-related activities may explain the increase of NSP and LBP in the 1990s and the beginning of 2000.

Lower limb pain in a preadolescent population: prognosis and risk factors for chronicity--a prospective 1- and 4-year follow-up study.

OBJECTIVE: To determine the short-term and long-term prognosis of preadolescent lower limb pain and to assess factors that contribute to pain persistence at 1-year follow-up and pain recurrence at 4-year follow-up. METHODS: A 1- and 4-year follow-up was conducted of a population-based 10- and 12-year old cohort of schoolchildren with lower limb pain at baseline. RESULTS: Of the baseline students with lower limb pain, 32% reported pain persistence at 1-year follow-up and 31% reported pain recurrence at 4-year follow-up. Vigorous exercise was the only statistically significant predictor of lower limb pain persistence at 1-year follow-up (odds ratio [OR]: 2.43; 95% confidence interval [CI]: 1.16-5.05), whereas at 4-year follow-up (at adolescence), hypermobility was predictive of pain recurrence (OR: 2.93; 95% CI: 1.13-7.70). Traumatic lower extremity pain had a 50% lower risk for pain recurrence compared with nontraumatic pain (OR: 0.48; 95% CI: 0.19-0.92). CONCLUSION: Trauma-induced lower extremity pain in preadolescents has a favorable long-term natural course. Children's involvement in vigorous exercise predicts short-term outcome of lower limb pain, whereas hypermobile children have a worse long-term prognosis.

Back, neck, and shoulder pain in Finnish adolescents: national cross sectional surveys.

OBJECTIVES: To study changes in pain of the back and neck in adolescents between 1985 and 2001 and pain of the neck, shoulder, and lower back between 1991 and 2001. DESIGN: Biennial nationwide postal surveys, 1985-2001, and annual classroom surveys, 1996-2001. SETTING: Finland. PARTICIPANTS: 62 677 12, 14, 16, and 18 year olds and 127 217 14-16 year olds. MAIN OUTCOME MEASURES: Pain in the back and neck, neck and shoulder, or lower back, at least weekly. RESULTS: Prevalence of pain in the back and neck was greater in the 1990s than in the 1980s and increased steadily from 1993 to 1997. Pain of the neck and shoulder and pain of the lower back was much more common in 1999 than in 1991 and in 2001 than in 1999. Pain was more common among girls and older groups: pain of the neck and shoulder affected 24% of girls and 12% of boys in 14 year olds, 38% of girls and 16% of boys in 16 year olds, and 45% of girls and 19% of boys in 18 year olds; pain in the lower back affected 8% of girls and 7% of boys in 14 year olds, 14% of girls and 11% of boys in 16 year olds, and 17% of boys and 13% of girls in 18 year olds. CONCLUSION: Pain in the neck, shoulder, and lower back is becoming more common in Finnish adolescents. This pain suggests a new disease burden of degenerative musculoskeletal disorders in future adults.