Biomedical subjects

Arja Häkkinen

Publications and source records attributed to Arja Häkkinen.

At least 19 recordsLinked to original sources

PubMed2007

Reoperations after first lumbar disc herniation surgery; a special interest on residives during a 5-year follow-up.

BACKGROUND: The overall rate of operations after recurrent lumbar disc herniation has been shown to be 3-11%. However, little is known about the rate of residives. Thus the aim of this study was to explore the cumulative rates of re-operations and especially residive disc herniations at the same side and level as the primary disc herniation after first lumbar disc herniation surgery and the factors that influence the risk of re-operations over a five year follow-up study. METHODS: 166 virgin lumbar disc herniation patients (mean age 42 years, 57% males) were studied. Data on patients' initial disc operations and type and timing of re-operations during the follow-up were collected from patient files. Back and leg pain on visual analog scale and employment status were collected by questionnaires. RESULTS: The cumulative rate of re-operations for lumbar disc herniation was 10.2% (95% Cl 6.0 to 15.1). The rate of residives at initial site was 7.4% (95% Cl 3.7 to 11.3) and rate of lumbar disc herniations at other sites was 3.1% (95% Cl 0.6 to 6.2). The occurrence of residive lumbar disc herniations was evenly distributed across the 5 years. Neither age, gender, preoperative symptoms, physical activity nor employment had effect on the probability of re-operation. CONCLUSION: Seven percent of the lumbar disc patients had a residive lumbar disc operation within five years of their first operation. No specific factors influencing the risk for re-operation were found.

Adult↗

PubMed2006

Evaluation of repeatability of pressure algometry on the neck muscles for clinical use.

Neck and shoulder pain is a common disorder which is often associated with a low-pressure pain threshold (PPT) of muscle tissues as manifested by hyperalgesia on palpation or the use of a pressure algometer. The objective of the present study was to evaluate the intratester repeatability of pressure algometer (Force-Five) on the neck and shoulder area in women with neck pain. The study was cross-sectional with single-group repeated measurements. PPT measurements in 20 women with chronic non-specific neck pain were measured on consecutive days at the levator scapulae, at two points on the trapezius muscles on each side and at the sternum as the only non-muscular site. The intratester repeatability of the PPT measurements was satisfactory or good (Intraclass correlation coefficient (ICC 0.78-0.93). The coefficient of repeatability ranged from 16.8 to 24.4N/cm2 and the coefficient of variation ranged from 10% to 22%, depending on the site tested. Considerable individual variation was observed when consecutive measures were analysed against their mean. On the group level the repeatability of the measurements allows the pressure algometer to be used for research purposes. However, on the individual level, due to the considerable variation found in the PPT results, caution is advised when interpreting the results in clinical practice.

Chronic Disease↗

PubMed2006

Changes in the total Oswestry Index and its ten items in females and males pre- and post-surgery for lumbar disc herniation: a 1-year follow-up.

To study the characteristics and changes in the total Oswestry Disability Index (ODI) and in its ten component items in female and male patients pre- and post-surgery for lumbar disc herniation. Ninety-eight patients [mean (SD) age 43 (13), 61% males] undergoing lumbar disc herniation surgery were selected for this clinical 12-month follow-up. Subjective disability and back and leg pain were assessed by ODI version 1.0 and the visual analog scale. Pre-operatively females had a significantly higher mean (SD) total ODI [59(3)] than males [51(2)] (P = 0.030). Females were more disabled in the walking, sex life, social life and travelling items of the ODI compared to males. The total Oswestry decreased by 38 (95% CI - 44 to - 31) in females and by 34 (- 39 to - 30) in males at the 1-year follow-up. Most of the improvement (88% in females and 80% in males) occurred during the first 6 weeks; thereafter the changes were minor. In males the changes were greatest in pain, social life and travelling and in females in walking, social life and travelling. Internal consistency value of ODI was 0.88 (95% CI 0.82-0.91). Item analysis of the ODI showed that all the items except pain had high corrected item correlation. As recovery following lumbar disc surgery occurred to a great extent during the first 6 weeks, the early post-operative outcome appears to be quite a reliable indicator of the overall post-operative outcome over the 1-year follow-up. The ODI proved to capture a wide range of disability in these lumbar disc surgery patients, thereby supporting the future use of the index. The "pain intensity" component, which collects data on the use of painkillers in version 1.0 of the ODI did not support the item structure of the index in this study. The use of ODI version 2.0 might remove this problem.

Adolescent↗

PubMed2006

Repeatability of a computerized muscle tonometer and the effect of tissue thickness on the estimation of muscle tone.

The aim of the present study was to assess the intrarater repeatability of the computerized muscle tonometer (CMT), which is a computer-driven device designed to measure and register the tone of connective tissues. The second aim was to evaluate the effect of muscle thickness on results and repeatability as well as sensitivity, which was done by comparison to a mechanical hand-held tonometer (HHT). Participants were ten healthy male volunteers. The thickness of soft tissues was measured with ultrasound and the CMT was used to evaluate the muscle tone of thigh muscles 10, 15 and 20 cm and the HHT 15 cm above the patella on both sides. Great individual variability in muscle thickness and tone was noted. Muscle thickness increased proximally on the thigh and thus the mean distance travelled by the indenter of the CMT also increased from distal to proximal from 22 to 26 mm and the work done increased from 116 to 161 mJ. Intraclass correlation (ICC) for travel and work ranged from 0.85 to 0.92 and 0.94 to 0.98, respectively. Repeatability coefficients increased somewhat at proximal measurement sites. ICC for the HHT was 0.78. The CMT also showed a considerably higher range of results, indicating greater resolution power. Despite the twofold pressure used with the HHT the distance measured was on average 60% lower compared to the CMT. In conclusion, the repeatability of the CMT was found to be good. Muscle thickness greatly affected the results and should therefore be taken into consideration when measuring muscle tone. Work was a more reliable unit of measurement than travel, which has been commonly used to describe muscle tone.

Adult↗

PubMed2006

Acute heavy-resistance exercise-induced pain and neuromuscular fatigue in elderly women with fibromyalgia and in healthy controls: effects of strength training.

OBJECTIVE: To examine heavy-resistance exercise-induced acute neuromuscular fatigue, blood lactate concentration, and muscle pain in elderly women with fibromyalgia (FM) and in healthy controls before and after a period of strength training. METHODS: Thirteen elderly women with FM (mean+/-SD age 60+/-2 years) and 10 healthy women (mean+/-SD age 64+/-3 years) performed a heavy-resistance fatiguing protocol (5 sets of leg presses with 10 repetitions maximum) before and after a 21-week strength training period. Maximal isometric force and electromyography (EMG) activity of leg extensors and blood lactate concentration were measured during the loading. Pain was assessed by visual analog scale. RESULTS: The strength training led to large increases in maximal force and EMG activity of the muscles and contributed to the improvement in loading performance (average load/set) at week 21. The fatiguing loading sessions typically applied in strength training before and after the experimental period caused remarkable and comparable acute decreases in maximal force and increases in blood lactate concentration in both groups. Acute exercise-induced muscle pain increased similarly in both groups, and the pain level in women with FM was lowered after the 21-week training period. CONCLUSION: The increased strength in women with FM improved high-load performance and also seemed to attenuate perceived pain. Acute exercise-induced neuromuscular changes and the time course of muscle pain in women with FM were comparable with findings in healthy controls, which suggests a typical fatiguing process and a similar trainability of the muscles in elderly women with FM.

Aged↗

PubMed2006

Neuromuscular function and balance of prepubertal and pubertal blind and sighted boys.

AIM: To compare the neuromuscular function and balance of blind prepuberty- and puberty-aged boys to those with normal sight. METHODS: Thirty-three prepubertal (aged 9-13 y) and pubertal (aged 15-18 y) blind and sighted boys were tested for muscle mass thickness, electromyography and maximal isometric strength, dynamic explosive actions, and balance. RESULTS: There was no difference in the muscle mass thickness, maximal strength or vertical jump between the blind and sighted boys. However, fitness-ball throwing and five-jump distances were significantly shorter in both blind groups compared to the sighted groups. One-leg stance of the prepuberty-aged sighted boys was 109 (67) s and in blind boys 32 (12) s, and in the puberty-aged boys 120 (57) s and 31 (8) s, respectively. When vision was blocked in the sighted boys, differences between the blind and sighted boys disappeared. CONCLUSION: The results showed comparable performance between prepubertal and pubertal blind and sighted boys in the static physical fitness tests. However, balance and performance in dynamic multi-joint tests did not improve similarly in the blind groups compared to sighted groups, indicating that maturation, learning and experience by themselves cannot compensate for the loss of sight.

Adolescent↗

PubMed2006

Physical fitness profiles in young Finnish men during the years 1975-2004.

PURPOSE: This population-based study describes fitness profiles in aerobic capacity (N = 387088) during the years 1975-2004, muscle performance (N = 280285) from 1982 to 2003, and body anthropometry (N = 324911) from 1993 to 2004 among the Finnish conscripts at the age of 20 yr. METHODS: Endurance performance was tested by the 12-min running test. Muscle fitness tests consisting of sit-ups, push-ups, pull-ups, a back-muscle test, and standing long jump were scored to muscle fitness index (MFI). RESULTS: The mean body mass of the conscripts increased from 70.8 to 75.2 kg (P < 0.01) during the years 1993-2004. The mean distance of the conscripts" 12-min running test increased first by 4% from 1975 to 1979, but after it that decreased by 12% (from 2760 m to 2434 m, P < 0.001) compared with the year 2004. MFI increased during the first decade of the follow-up, but thereafter, the number of conscripts who achieved excellent and good MFI decreased from 66.8 to 41.2% (P < 0.001) during the years 1992-2004. The physical ability of the conscripts to meet military service declined during the last 15 yr. CONCLUSION: Both the increase in body mass and the decrease in physical fitness may lead to serious health problems in the future.

Adult↗

PubMed2005

Health related quality of life after lumbar disc surgery: a prospective study of 145 patients.

PURPOSE: This study compared health related quality of life (HRQOL) among lumber disc surgery patients to general population, and assessed the relationships between HRQOL and other outcome measures 2 and 14 months after surgery. METHODS: The 15D instrument was use to measure HRQOL in 145 lumber disk surgery patients. Subjective outcome was also assessed by the Oswestry index, Short Depression Inventory (SDI) and pain, and objective outcome by trunk muscle strength and mobility of the spine. RESULTS: The mean (SD) 15D score among the patients 2 months after surgery was 0.880 (0.104) compared to 0.941 (0.076) among general population (p = 0.016). The 15D, Oswestry and SDI scores remained unchanged during the follow-up, while the improvements in the spine mobility and trunk muscle strength were significant. Back pain decreased by 68% and leg pain by 74% from preoperative level to 2 months check-up. Leg pain further decreased during the following 12 months, while back pain remained unchanged. HRQOL was associated with age, pain, Oswestry and SDI indices, but not with physical function. CONCLUSION: HRQOL measured by 15D was lower in lumber disc surgery patients compared to general population. 15D was associated with the subjective outcome measures of pain, Oswestry and SDI indices, but not with the objective measures of physical function. Thus, a combination of "disease specific" and "generic" measures is recommended to be used to obtain more accurate information about the overall welfare of individual.

Abdominal Muscles↗

PubMed2005

Effects of home strength training and stretching versus stretching alone after lumbar disk surgery: a randomized study with a 1-year follow-up.

OBJECTIVE: To assess the adherence to and effects of a 12-month combined strength and stretching home exercise regimen versus stretching alone, on patient outcome after lumbar disk surgery. DESIGN: Randomized controlled trial. SETTING: Departments of physical medicine and rehabilitation and orthopedics at a Finnish hospital. PARTICIPANTS: Patients (N=126) were randomized into either a combined strength training and stretching group (STG, n=65) or a control group (CG, n=61). INTERVENTION: The STG was instructed to perform strength training and both the STG and CG were instructed in the same stretching and stabilization exercises for 12 months. MAIN OUTCOME MEASURES: Pain on the visual analog scale (VAS), the Oswestry and the Million disability indexes, isometric and dynamic trunk muscle strength, mobility in the lumbar spine, and straight-leg raising were measured. RESULTS: The trial was completed by 71% and 77% of the patients from the STG and the CG, respectively. The mean strength training frequency decreased from 1.5 to 0.6 times a week in the STG during the intervention. The mean stretching frequency decreased from 3.7 to 1.6 times a week in both groups. Median back and leg pain varied between 17 and 23 mm (VAS), and the Million and Oswestry indices varied between 14 and 23 points 2 months postoperatively. No statistically significant changes took place in these outcome measures during the 12-month follow-up in both groups. The changes in isometric trunk extension favored the STG ( P =.016) during the first 2 months. However, during the whole 12-month training period, both dynamic and isometric back extension and flexion strength, as well as mobility of the spine and repetitive squat-test results, improved significantly in both groups, and no differences were found in any of the physical function parameters between the STG and CG. CONCLUSIONS: At the 12-month follow-up, no statistically significant changes were found in the physical function, pain, or disability measures between the groups. In the STG, training adherence with regard to training frequency and intensity remained too low to lead to specific training-induced adaptations in the neuromuscular system. Progressive loading, supervision of training, and psychosocial support is needed in long-term rehabilitation programs to maintain patient motivation.

Adult↗

PubMed2005

Decreased muscle strength and mobility of the neck in patients with rheumatoid arthritis and atlantoaxial disorders.

OBJECTIVE: To compare neck muscle strength and mobility of the cervical spine in rheumatoid arthritis (RA) patients with and without atlantoaxial (AA) disorders (anterior atlantoaxial subluxation [AAS], AA impaction). DESIGN: Clinical cross-sectional study. SETTING: Outpatient rheumatology and rehabilitation clinics in a Finnish hospital. PARTICIPANTS: Patients with RA (N=124; mean age +/- standard deviation, 62+/-12y [corrected]) on a waiting list for orthopedic surgery. Thirty (24%) patients presented with AA disorders (16 with anterior AAS, 8 with AA impaction, 6 with a combination of anterior AAS and AA impaction). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Neck function was measured by isometric neck strength and mobility tests, neck pain by a visual analog scale, erosion of the hands and feet by radiography, and the patients' function by the Health Assessment Questionnaire (HAQ). RESULTS: Maximal neck muscle strength against flexion, extension, and rotation was lower in patients with AA disorders compared with the other patients in both women (P=.012) and men (P=.017). Mobility was lowest in the AA impaction group in all measured directions (P<.001). Peripheral erosive disease was more frequent in the group with AA disorders. They also had longer disease duration and were more disabled (HAQ) than the other patients. CONCLUSIONS: Neck muscle strength is significantly decreased in patients with AA disorders. Mobility of the cervical spine is most limited in patients with AA impaction, but can be normal in cases with solitary anterior AAS.

Arthritis, Rheumatoid↗

PubMed2005

Effect of long-term neck muscle training on pressure pain threshold: a randomized controlled trial.

Muscle tenderness has been measured in several studies to evaluate effectiveness of treatment methods, but only short-term results have been reported so far. The aim of the present study was to evaluate the long-term effects of two different muscle training methods on the pressure pain threshold of neck muscles in women with neck pain. Altogether 180 woman with chronic, non-specific neck pain were randomized into three groups: neck muscle endurance training, neck muscle strength training and control groups. The main outcome measures included pressure pain threshold measurement at six muscle sites and on the sternum. Neck pain was assessed by a visual analogue scale (VAS). At the 12-month follow-up statistically significantly higher pressure pain threshold values were obtained in both training groups at all muscle sites compared to the baseline, while no significant change occurred in the controls. Significantly higher changes in pressure pain threshold were detected at all six sites in the strength training group and at four out of six sites in the endurance training group compared to the control group. This is the first study to show an increase in pressure pain thresholds as a result of long-term muscle training. A decrease in neck pain was associated with reduced pressure pain sensitivity in neck muscles, showing that the pressure pain threshold may be a useful outcome measure of the effectiveness of neck muscle rehabilitation.

Adult↗

PubMed2005

Neuromuscular performance characteristics of open-wheel and rally drivers.

The purpose of the present study was to investigate neuromuscular performance characteristics in open-wheel and rally drivers using the cross-sectional study design. The subjects (N = 28) consisted of experienced international-level open-wheel drivers (n = 9), experienced international-level rally drivers (n = 9) and a physically active nondriving male control group (n = 10). In 3 separate test sessions, speed, muscle strength, and endurance tests were performed. The rally drivers had higher (p < 0.05) grip, shoulder flexion, and ankle plantar flexion strength, as compared to the control group. The open-wheel drivers showed higher strengths (p < 0.05) than the controls in neck forces, grip, shoulder flexion, and leg extension. The rally drivers were stronger (p < 0.05) than the open-wheel drivers in grip, plantar flexion, and trunk extension forces, whereas the open-wheel drivers were stronger (p < 0.01) than the rally drivers in neck lateral flexions and extension forces. Thus, competitive long-term open-wheel and rally drivers differ specifically in neuromuscular performance. For practice, these findings suggest that rally drivers should concentrate on training hand, ankle, and trunk muscles, whereas open-wheel drivers should train neck muscles, especially, and all other muscle groups rather equally.

Adult↗

PubMed2004

A home-based two-year strength training period in early rheumatoid arthritis led to good long-term compliance: a five-year followup.

OBJECTIVE: To evaluate the impact of a 2-year home-based strength-training program on physical function in patients with early rheumatoid arthritis (RA) after a subsequent 3-year followup. METHODS: Seventy patients with early RA were randomized to perform either strength training (experimental group [EG]) or range-of-motion exercises (control group [CG]). Maximal strength values were recorded by dynamometers. The Modified Disease Activity Score (DAS28), pain, Health Assessment Questionnaire (HAQ), walking speed, and stair-climbing speed were also measured. RESULTS: The maximum strength of assessed muscle groups increased by 19-59% in the EG during the training period and remained at the reached level throughout the subsequent 3 years. Muscle strength improved in the CG by 1-31%, but less compared with the EG. During the 2-year training period, DAS28 decreased by 50% and 45% and pain by 67% and 39% in the EG and CG, respectively. The differences in muscle strength, DAS28, and HAQ were significantly in favor of the EG both at the 2-year and 5-year followup assessments. CONCLUSIONS: The improvements achieved during the 2-year strength-training period were sustained for 3 years in patients with early RA.

Arthritis, Rheumatoid↗

PubMed2004

Normative values for the Health Assessment Questionnaire disability index: benchmarking disability in the general population.

OBJECTIVE: The Health Assessment Questionnaire (HAQ) disability index (DI) has been commonly used in rheumatology to quantify functional disability in patient groups, but current general population values of this index are not available. This study was undertaken to establish normative values for the HAQ DI in a general population and to analyze its correlates. METHODS: The HAQ DI (range of scores 0-3) was measured in a random sample of 1,530 adults in the Central Finland District. Prevalence rates of disability by strata of age, sex, education level, body mass index (BMI), and health behaviors (including smoking and exercise habits) were calculated. Pearson's product-moment correlation coefficient and ordinary least squares regression were used to analyze the data. RESULTS: The estimated population mean HAQ DI was 0.25 (95% confidence interval 0.22-0.28), and 32% of respondents had at least some disability. Both for men and for women, functional disability increased exponentially with age. The HAQ DI was correlated with pain (r = 0.58) and global self assessment (r = 0.61). The prevalence of disability decreased with increasing number of years of education, lower BMI, and increasing frequency of physical exercise. CONCLUSION: Almost one-third of the general population has some functional disability. Functional disability is associated in part with lifestyle choices and increases with age in a nonlinear manner. The normative values of the HAQ DI that we have presented could be used as a reference benchmark for clinical and epidemiologic studies using this measure of disability.

Adult↗

PubMed2004

Decreased isometric neck strength in women with chronic neck pain and the repeatability of neck strength measurements.

OBJECTIVES: To evaluate neck flexion, extension, and, especially, rotation strength in women with chronic neck pain compared with healthy controls and to evaluate the repeatability of peak isometric neck strength measurements in patients with neck pain. DESIGN: Cross-sectional. SETTINGS: Rehabilitation center and physical and rehabilitation medicine department at a Finnish hospital. PARTICIPANTS: Twenty-one women with chronic neck pain and healthy controls matched for sex, age, anthropometric measures, and occupation. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Peak isometric strength of the cervical muscles was tested in rotation, flexion, and extension. RESULTS: Significantly lower flexion (29%), extension (29%), and rotation forces (23%) were produced by the chronic neck pain group compared with controls. When the repeated test results were compared pairwise against their mean, considerable variation was observed in the measures on the individual level. Intratester repeatability of the neck muscle strength measurements was good in all the 4 directions tested in the chronic neck pain group (intraclass correlation coefficient range,.74-.94). The coefficient of repeatability was 15N, both in flexion and extension, and 1.8 Nm in rotation. On the group level, improvement up to 10% due to repeated testing was observed. CONCLUSIONS: The group with neck pain had lower neck muscle strength in all the directions tested than the control group. This factor should be considered when planning rehabilitation programs. Strength tests may be useful in monitoring training progress in clinical settings, but training programs should be planned so that the improvement in results is well above biologic variation, measurement error, and learning effect because of repeated testing.

Adult↗

PubMed2004

Decreased neck muscle strength is highly associated with pain in cervical dystonia patients treated with botulinum toxin injections.

OBJECTIVES: To compare the isometric neck muscle strength of cervical dystonia patients treated with botulinum toxin injections with that of healthy control subjects and to evaluate the association between neck strength, neck pain, and disability in these patients. DESIGN: Clinical cross-sectional study. SETTING: Outpatient rehabilitation and neurology clinics in a Finnish hospital. PARTICIPANTS: Twenty-three patients with cervical dystonia with botulinum toxin-treated neck muscles and 23 healthy control subjects. INTERVENTIONS: Not applicable. Main outcome measures Isometric neck strength was measured by a special neck strength measurement system. Disability was measured by the Neck Disability Index, and pain and symptoms of cervical dystonia by a visual analog scale. RESULTS: Isometric neck strength in all directions measured was significantly lower (25%-44%) in the cervical dystonia patients than in the healthy controls. Neck pain levels reported during the strength tests (r range, -.36 to -.70) and neck pain experienced during the preceding week (r range, -.52 to -.63) were inversely associated with isometric strength results. The difference between sides in rotation strength was 35% in the patient group (P<.001), whereas no significant difference between sides was found in the healthy controls. Fifty-one percent of the patients reported moderate or severe disability. Pain, stiffness, and incorrect position of the head were the most prominent symptoms. CONCLUSIONS: Cervical dystonia patients with botulinum toxin-treated neck muscles showed significantly lower maximal neck strength than healthy controls. The patients also had a statistically significant difference between sides in neck rotation strength. Thus, strength measures may be useful to detect disturbance in the function of the neck muscles.

Botulinum Toxins, Type A↗

PubMed2004

Association of neck pain, disability and neck pain during maximal effort with neck muscle strength and range of movement in women with chronic non-specific neck pain.

Several studies have reported lower neck muscle strength in patients with chronic neck pain compared to healthy controls. The aim of the present study was to evaluate the association between the severity of neck pain and disability with neck strength and range of movement in women suffering from chronic neck pain. One hundred and seventy-nine female office workers with chronic neck pain were selected to the study. The outcome was assessed by the self-rating questionnaires on neck pain (visual analogue scale, Vernon's disability index, Neck pain and disability index) and by measures of the passive range of movement (ROM) and maximal isometric neck muscle strength. No statistically significant correlation was found between perceived neck pain and the disability indices and the maximal isometric neck strength and ROM measures. However, the pain values reported during the strength tests were inversely correlated with the results of strength tests (r=-0.24 to -0.46), showing that pain was associated with decreased force production. About two-thirds of the patients felt pain during test efforts. Pain may prevent full effort during strength tests and hence the production of maximal force. Thus in patients with chronic neck pain the results do not always describe true maximal strength, but rather the patients' ability to bear strain, which may be considerably influenced by their painful condition. The results of the present study suggest that rehabilitation in cases of chronic neck pain should aim at raising tolerance to mechanical strain.

Adult↗

PubMed2004

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.

Adolescent↗