Adolescent flexibility, endurance strength, and physical activity as predictors of adult tension neck, low back pain, and knee injury: a 25 year follow up study

Core Muscle Activity, Exercise Preference, and Perceived Exertion during Core Exercise with Elastic Resistance versus Machine

Objectives. To investigate core muscle activity, exercise preferences, and perceived exertion during two selected core exercises performed with elastic resistance versus a conventional training machine. Methods. 17 untrained men aged 26-67 years participated in surface electromyography (EMG) measurements of five core muscles during torso-twists performed from left to right with elastic resistance and in the machine, respectively. The order of the exercises was randomized and each exercise consisted of 3 repetitions performed at a 10 RM load. EMG amplitude was normalized (nEMG) to maximum voluntary isometric contraction (MVC). Results. A higher right erector spinae activity in the elastic exercise compared with the machine exercise (50% [95% CI 36-64] versus 32% [95% CI 18-46] nEMG) was found. By contrast, the machine exercise, compared with the elastic exercise, showed higher left external oblique activity (77% [95% CI 64-90] versus 54% [95% CI 40-67] nEMG). For the rectus abdominis, right external oblique, and left erector spinae muscles there were no significant differences. Furthermore, 76% preferred the torso-twist with elastic resistance over the machine exercise. Perceived exertion (Borg CR10) was not significantly different between machine (5.8 [95% CI 4.88-6.72]) and elastic exercise (5.7 [95% CI 4.81-6.59]). Conclusion. Torso-twists using elastic resistance showed higher activity of the erector spinae, whereas torso-twist in the machine resulted in higher activity of the external oblique. For the remaining core muscles the two training modalities induced similar muscular activation. In spite of similar perceived exertion the majority of the participants preferred the exercise using elastic resistance.

The health benefits of muscular fitness for children and adolescents: a systematic review and meta-analysis

BACKGROUND

Physical fitness during childhood and adolescence has been identified as an important determinant of current and future health status. While research has traditionally focused on the association between cardio-respiratory fitness and health outcomes, the association between muscular fitness (MF) and health status has recently received increased attention.

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the potential physiological and psychological benefits associated with MF among children and adolescents.

METHODS

A systematic search of six electronic databases (PubMed, SPORTDiscus, Scopus, EMBASE, PsycINFO and OVID MEDLINE) was performed on the 20th May, 2013. Cross-sectional, longitudinal and experimental studies that quantitatively examined the association between MF and potential health benefits among children and adolescents were included. The search yielded 110 eligible studies, encompassing six health outcomes (i.e., adiposity, bone health, cardiovascular disease [CVD] and metabolic risk factors, musculoskeletal pain, psychological health and cognitive ability). The percentage of studies reporting statistically significant associations between MF and the outcome of interest was used to determine the strength of the evidence for an association and additional coding was conducted to account for risk of bias. Meta-analyses were also performed to determine the pooled effect size if there were at least three studies providing standardised coefficients.

RESULTS

Strong evidence was found for an inverse association between MF and total and central adiposity, and CVD and metabolic risk factors. The pooled effect size for the relationship between MF and adiposity was r = -0.25 (95% CI -0.41 to -0.08). Strong evidence was also found for a positive association between MF and bone health and self-esteem. The pooled effect size for the relationship between MF and perceived sports competence was r = 0.39 (95% CI 0.34-0.45). The evidence for an association between MF and musculoskeletal pain and cognitive ability was inconsistent/uncertain. Where evidence of an association was found, the associations were generally low to moderate.

CONCLUSION

The findings of this review highlight the importance of developing MF in youth for a number of health-related benefits.

Influence of Hamstring Tightness in Pelvic, Lumbar and Trunk Range of Motion in Low Back Pain and Asymptomatic Volunteers during Forward Bending

STUDY DESIGN

Cross-sectional study.

PURPOSE

To verify the association of hamstring tightness and range of motion in anterior pelvic tilt (PT), lumbar motion (LM), and trunk flexion (TF) during forward bending.

OVERVIEW OF LITERATURE

Increased hamstring stiffness could be a possible contributing factor to low back injuries. Clinical observations have suggested that hamstring tightness influences lumbar pelvic rhythm. Movement restrictions or postural asymmetry likely lead to compensatory movement patterns of the lumbar spine, and subsequently to increased stress on the spinal soft tissues and an increased risk of low back pain (LBP).

METHODS

Hamstring muscle tightness was measured using the self-monitored active knee extension (AKE) test. A bubble inclinometer was used to determine the range of motion of PT, LM, and TF during forward bending. Statistical analysis included descriptive statistics, comparisons between groups and a correlation between hamstring tightness (AKE) and anterior PT, TF, and regional LM with p≤0.05.

RESULTS

The LBP group was composed of 36 participants, and the asymptomatic group consisted of 32 participants. The mean for PT in the control group was 66.7°, 64.5° for LM and 104.6° for TF. Respective values in the symptomatic group were 57.0°, 79.8°, and 82.2°.

CONCLUSIONS

Participants with LBP showed restriction in the pelvis and TF range of motion, but had higher amplitudes in the lumbar spine during forward bending.

Effects of reallocating time in different activity intensities on health and fitness: a cross sectional study

BACKGROUND

The effects of replacing time in specific activity categories for other categories (e.g. replacing sedentary time with light activity) on health and fitness are not well known. This study used isotemporal substitution to investigate the effects of substituting activity categories in an equal time exchange fashion on health and fitness in young people.

METHODS

Participants were drawn from schools in Camden, London (n = 353, mean age 9.3 ± 2.3 years). Time sedentary, in light and in moderate-to-vigorous activity (MVPA) was measured via accelerometry. The effects of substituting time in activity categories (sedentary, light and MVPA) with equivalent time in another category on health and fitness were examined using isotemporal substitution.

RESULTS

In single and partition models, MVPA was favourably associated with body fat %, horizontal jump distance and flexibility. Time sedentary and in light activity were not associated with health and fitness outcomes in these models. In substitution models, replacing one hour of sedentary time with MVPA was favourably associated with body fat % (B = -4.187; 95% confidence interval (CI), -7.233, -1.142), horizontal jump distance (B = 16.093; 95% CI, 7.476, 24.710) and flexibility (B = 4.783; 95% CI, 1.910, 7.656). Replacing time in light activity with MVPA induced similar benefits but there were null effects for replacing sedentary with light intensity.

CONCLUSION

Substituting time sedentary and in light activity with MVPA was associated with favourable health and fitness. Time in sedentary behaviour may only be detrimental to health and fitness when it replaces time in MVPA in young people.

Physical inactivity is associated with narrower lumbar intervertebral discs, high fat content of paraspinal muscles and low back pain and disability

Introduction

Although physical inactivity has been associated with numerous chronic musculoskeletal complaints, few studies have examined its associations with spinal structures. Moreover, previously reported associations between physical activity and low back pain are conflicting. This study examined the associations between physical inactivity and intervertebral disc height, paraspinal fat content and low back pain and disability.

Methods

Seventy-two community-based volunteers not selected for low back pain underwent magnetic resonance imaging (MRI) of their lumbosacral spine (L1 to S1) between 2011 and 2012. Physical activity was assessed between 2005 and 2008 by questionnaire, while low back pain and disability were assessed by the Chronic Pain Grade Scale at the time of MRI. Intervertebral disc height and cross-sectional area and fat content of multifidus and erector spinae were assessed from MRI.

Results

Lower physical activity levels were associated with a more narrow average intervertebral disc height (β −0.63 mm, 95% confidence interval (CI) −1.17 mm to −0.08 mm, P = 0.026) after adjusting for age, gender and body mass index (BMI). There were no significant associations between physical activity levels and the cross-sectional area of multifidus or erector spinae. Lower levels of physical activity were associated with an increased risk of high fat content in multifidus (odds ratio (OR) 2.7, 95% CI 1.1 to 6.7, P = 0.04) and high-intensity pain/disability (OR = 5.0, 95% CI 1.5 to 16.4, P = 0.008) after adjustment for age, gender and BMI.

Conclusions

Physical inactivity is associated with narrower intervertebral discs, high fat content of the multifidus and high-intensity low back pain and disability in a dose-dependent manner among community-based adults. Longitudinal studies will help to determine the cause and effect nature of these associations.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0629-y) contains supplementary material, which is available to authorized users.

Sport-specific trunk muscle profiles in soccer players of different skill levels

INTRODUCTION

Physical fitness and trunk stability are essential factors for successful soccer competition.

MATERIALS AND METHODS

We investigated the impact of soccer exposure on the trunk muscle profile of players of different skill levels. Professional and amateur soccer players were examined for trunk flexibility and maximum isometric muscle strength in the midseason period 2011.

RESULTS

24 professional soccer players who had not participated in any specific trunk muscle training programmes had significantly higher isometric trunk muscle strength in the sagittal plane (Ext: p = 0.003, Flex: p = 0.014), the frontal plane (Lat. right: p = 0.001, left: p = 0.003) and the transverse plane (Rotation right and left: p < 0.001) than 83 amateur soccer players. Professional players also had higher trunk flexibility in the sagittal plane (Flex: p = 0.001) and the transverse plane (Rotation right: p = 0.02, left: p = 0.002) than amateur players. The side of the dominant kicking leg had no influence on muscle strength and flexibility of the trunk.

CONCLUSION

Trunk flexibility and stability as necessary factors for avoiding physical overstress and injuries are differently trained in player of different soccer skill levels.

Low back pain in adolescent and associated factors: A cross sectional study with schoolchildren

OBJECTIVE

To determine the prevalence of low back pain nonspecific and associated factors in schoolchildren.

METHOD

This cross-sectional study investigated 343 adolescents, aged between 12 and 15 years, of both sexes of public schools. The questionnaire included questions regarding sociodemographic characteristics, type of school transportation, body mass index and low back pain. The outcome was defined as discomfort localized below the costal margin and above the inferior gluteal folds in the last 12 months.

RESULTS

The prevalence of low back pain in the last year was 57% (n=195) among participants, with no significant difference between the sexes (OR 1.13, 95% CI 0.93 to 1.37). Advancing age and body mass index were associated with the presence of low back pain in the bivariate analysis. The remaining seated at school in usual days was considered one of the main activities that trigger symptoms that lasted up to seven days for the majority (80%) of adolescents.

CONCLUSIONS

The high prevalence of low back pain presented, indicating that it is a common condition among these adolescents. There was no difference between the sexes, but had influence of age and body mass index. Our results point to the need for the development epidemiological studies of low back pain among children and adolescents.

[Influence of flexibility and gender on the posture of school children]

Objective:

To evaluate whether flexibility and gender influence students' posture.

Method:

Evaluation of 60 female and male students, aged 5 to 14 years, divided into two groups: normal flexibility (n=21) and reduced flexibility (n=39). Flexibility and posture were assessed by photogrammetry and by the elevation of the lower limbs in extension, considering the leg angle and the postural evaluation. Descriptive statistics (mean and standard deviation) were used for data analysis. Analysis of variance (ANOVA) was applied to assess the joint influence of flexibility and gender on the posture-dependent variables. After verifying an interactive effect between the variables of gender and flexibility, multiple comparisons using the t test were applied.

Results:

Flexibility influenced the symmetry angle of the knee (p<0.05) and anteroposterior body tilt (p<0.05). Gender did not influence postural angles (p>0.05). There was an interactive effect between the variables of gender and flexibility on the knee symmetry angle (p<0.02). Male students with reduced flexibility had greater asymmetry of the knee when compared to the other subgroups.

Conclusion:

Posture was influenced by an isolated effect of the variable of flexibility and by an interactive effect between gender and flexibility.

[Nonspecific low back pain in young adults: associated risk factors]

OBJECTIVE

The aim of the study was to evaluate potential risk factors related to low back pain in the daily routines of two sets of youths: individuals complaining of chronic low back pain and a control group.

METHODS

The sample consisted of 198 university-age students (male and female) aged between 18 and 29. In accordance with back pain diagnoses, they were separated into two groups: with or without nonspecific chronic low back pain. Both groups were evaluated by a "blinded" observer with no knowledge to the presence or otherwise of lower back pain. Questionnaires concerning clinical-demographic characteristics, life style, quality of life (SF-36 questionnaire), pain visual analogical scales (VAS), and physical examination were applied.

RESULTS

A univariate analysis showed a statistically significant association (P<0.05) with the presence of low back pain and some factors. There was a negative association between low back pain and the following variables: BMI, health self-assessment, VAS and some SF-36 domains (physical functioning, body pain, general health, vitality, social functioning). There was a positive correlation with the following variables: global pain by VAS, presence of diffuse pain and number of tender points. However, the multivariate analysis showed statistically significant correlations (P<0.05) between low back pain and few variables: global pain VAS and number of tender points.

CONCLUSION

Some variables related to chronic diffuse pain and lower quality of life might be associated to chronic low back pain in young adults. However, longitudinal studies are necessary.

Are flexibility and muscle-strengthening activities associated with a higher risk of developing low back pain?

OBJECTIVES

To examine the association between participation in flexibility or muscle-strengthening activities with the development of low back pain.

DESIGN

Observational cohort study.

METHODS

The cohort included 4610 adults, 17% female, between 20 and 81 years of age (mean 46.6, standard deviation 4.96). The cohort was followed for a mean of 4.9 years for self-reported low back pain. All participants reported at baseline whether they performed flexibility or muscle-strengthening activities, including specific sub-types.

RESULTS

Neither general performance of flexibility or muscle-strengthening activities were associated with a higher incidence of low back pain compared to those who did not perform these activities. Those who reported stretching, as a specific flexibility activity were at a higher risk of developing low back pain compared with those who performed no flexibility exercises, reported callisthenic flexibility activities, or attended exercise classes. Those who reported using weight training machines, as part of muscle-strengthening activities, had a higher risk of reporting low back pain, compared with those who did not perform muscle-strengthening activities or performed callisthenic or free weight activities.

CONCLUSIONS

In this sample, stretching or use of weight training machines is associated with increased risk of developing low back pain compared to use of free weights, callisthenics or exercise classes.

The effect of baduanjin on promoting the physical fitness and health of adults

The purpose of study was to assess the efficacy of a 16-week Baduanjin qigong training intervention in promoting physical fitness and health for adults. An experimental design was adopted, and subjects were assigned randomly into an experimental group (n = 55) and a control group (n = 55). In the intervention group comprised of adults, there were no significant variations in blood glucose, blood lipid, blood pressure, heart rate variability, and vital capacity indices. The body weight and body mass index (BMI) dropped in the intervention group. Compared with the control group, the skinfold thicknesses decreased at lower corner of scapula, triceps brachii, and abdomen, with a statistical significance (P < 0.001; P = 0.005; P = 0.003). By comparing the physical fitness indices, it was found that the increase of the results of sit-and-reach test in the intervention group had statistical significance (P = 0.001). In conclusion, it was found by our trial that Baduanjin exercise could significantly improve the physical flexibility and subcutaneous adipose accumulation in the healthy adults.

Current Evidence for the Impact of Physical Fitness on Health Outcomes in Youth

Physical fitness is tightly linked to our ability to be physically active, and poor fitness is tied to increased risk of lifestyle diseases such as diabetes and cardiovascular disease in adulthood. In 2011, the Institute of Medicine appointed an expert committee to review the evidence between physical fitness and health outcomes in youth. Specifically, experimental and longitudinal studies published between 2000 and 2010 were reviewed in the areas of body composition, cardiorespiratory fitness, musculoskeletal fitness, and flexibility. Specific fitness tests that were linked to health risk factors or health outcomes in each of these areas were identified. Recommendations for the best fitness test items for use in schools and also for a national survey were given. In addition, guidance was provided for interpretation of fitness test scores along with recommendations for areas of needed future research. Key findings from the final report “Fitness Measures and Health Outcomes in Youth” will be reviewed.

Neck/shoulders pain and its relation to the use of tv/computer/videogame and physical activity in school students from Bauru

Objective The objective was to determine the prevalence of musculoskeletal pain in the neck/shoulders of school children and its relationship with the level of physical activity and sedentary activities (time spent on TV and computer and/or video game). Materials and methods We conducted a cross-sectional study with a sample of 524 5th to 8th grade students (278 boys and 246 girls), enrolled in all five urban elementary schools in the municipality of Bauru (SP), aged between 10 and 14 years old. Sociodemographic data, sedentary activities – time spent on TV and computer and/or videogame - and level of physical activity - was collected through a Physical Activity Questionnaire for Children (PAQ-C). Results The results showed that the prevalence of localized pain in the neck/shoulders was of 30.1% for boys and girls. It was also found that there is a predominance of onset of pain reported in neck/shoulders in boys related to the frequency and amount of hours a day watching TV and hours on the computer, whereas in girls the association was with frequency and amount of hours they watch TV daily. Conclusions It can be concluded that the pain in the neck/shoulders are common in children and that understanding the relationship between variables enables valuable elements of measures aimed at maintaining, improving and promoting the welfare of students.

Muscle strength in adolescent men and future musculoskeletal pain: a cohort study with 17 years of follow-up

OBJECTIVES

Musculoskeletal pain is highly prevalent throughout adulthood with a major impact on health, function and participation in the society. Still, the association between muscle strength and development of musculoskeletal pain is unclear. We aimed to study whether overall muscle strength in adolescent men is inversely associated with self-reported musculoskeletal pain in adulthood.

DESIGN

Cohort study with baseline data from the Swedish Conscription Register and outcome information from the random population-based Swedish Living Conditions Surveys.

SETTING

Sweden, 1970-2005.

PARTICIPANTS

5489 men who at age 17-19 years tested their isometric muscle strength (hand grip, arm flexion and knee extension) during the compulsory conscription.

OUTCOME MEASURES

The men were surveyed regarding self-reported musculoskeletal pain; mean follow-up time of 17 (range 1-35) years. Our primary outcome was a self-report of musculoskeletal pain, and secondary outcomes were a report of 'severe pain', 'pain in back/hips', 'pain in neck/shoulders' or 'pain in arms/legs', respectively. We categorised muscle strength into three groups: low, average and high, using the 25th-75th percentile to define the reference category (average). We estimated relative risks using log binomial regression with adjustment for smoking, body mass index, education and physical activity.

RESULTS

In the adjusted model, men with low overall muscle strength had decreased risk of self-reported musculoskeletal pain (0.93, 95% CI 0.87 to 0.99). We observed no such association in men with high strength (0.99, 0.93 to 1.05). Furthermore, no statistically significant increase or decrease in risk was observed for any of the secondary outcomes.

CONCLUSIONS

In men, low overall isometric muscle strength in youth was not associated with an increased risk of future musculoskeletal pain. Contrarily, we observed a slightly decreased risk of self-reported musculoskeletal pain in adulthood. Our results do not support a model in which low muscle strength is a risk factor for future musculoskeletal pain.

The effects of a moderate exercise program on knee osteoarthritis in male wistar rats

OBJECTIVE(S)

Osteoarthritis (OA) or degenerative joint disease is the commonest form of arthritis and can lead to joint pain, decrease in joint's range of motion, loss of function, and ultimately disability. Exercise is considered as one of the non-pharmacological treatments of OA. But the effects of exercise on knee joint cartilage remain ambiguous. The aim of the present study was to investigate the effect of a four-week moderate treadmill exercise on rats' knee osteoarthritis.

MATERIALS AND METHODS

Eighteen male Wistar rats (173 ± 1 g, 8 weeks old) were randomly divided into three groups (n = 6): Intact control, monosodium iodoacetate (MIA) only (OA), and training. The osteoarthritis model was induced by intra-articular injection of monosodium iodoacetate (MIA). Subjects followed a moderate-intensity exercise program for 28 days. Rats were killed after 28 days and histological assessment was done on their knee joints. One-way ANOVA (P<0.05) and post-hoc Tukey test was used for the statistical analysis.

RESULTS

Histological assessment on 3 measurements of, depth ratio of lesions (P=0.001), total cartilage degeneration width (P=0.001), and significant cartilage degeneration width (P=0.001), demonstrated that moderate exercise for 4 weeks could surprisingly almost treat OA symptoms of rats' knee joints.

CONCLUSION

The findings of the present study indicate that a moderate treadmill exercise program exert a beneficial influence on rats' knee osteoarthritis.

Efeitos de um programa de exercícios no desempenho de crianças nos testes de flexibilidade e impulsão vertical

Esse estudo investigou o efeito de um programa de exercícios na flexibilidade e impulsão vertical de escolares. 61 crianças (30 meninos) foram divididas em Grupo Controle Masculino (GCM), Grupo Intervenção Masculino (GIM), Grupo Controle Feminino (GCF) e Grupo Intervenção Feminino (GIF). O GIM e GIF foram submetidos a um programa de exercícios durante as aulas de Educação Física Escolar com duração de 12 semanas. Foram realizados os testes de "sentar-e-alcançar" e impulsão vertical anteriormente às 12 semanas e após o término deste programa. Os resultados indicaram que o GIF e o GIM aumentaram significativamente o desempenho nos testes de impulsão vertical e "sentar-e-alcançar" após o programa de intervenção (P<0,05). No GCM e GCF não foram verificadas diferenças significativas no desempenho do teste de impulsão vertical e "sentar-e-alcançar" (P>0,05). O programa de intervenção utilizado nesse estudo foi eficiente em aumentar a flexibilidade e impulsão vertical de crianças.

Risk factors for the onset of nonspecific low back pain in office workers: a systematic review of prospective cohort studies

OBJECTIVE

The purpose of this study was to systematically review prospective cohort studies to identify risk factors for the onset of low back pain (LBP) in office workers.

METHODS

Online searches were conducted on PubMed, CINAHL Plus with full text, ScienceDirect, PEDro, ProQuest, and Scopus databases from 1980 to November 2011 using the following keywords: low back pain paired with risk or prognostic factors and office or computer or visual display unit (VDU) or visual display terminal (VDT). The methodological quality of each study was assessed using a 21-item checklist, which was divided into 2 parts: the internal validity (11 items) and descriptive quality (10 items) of studies. Strength of evidence for risk factors associated with the development of nonspecific LBP was assessed by defining 5 levels of evidence based on the number of studies and the quality score of studies.

RESULTS

Eighteen full-text articles were identified, and 15 were excluded. A total of 3 articles were judged to meet the selection criteria and were included in the methodological quality assessment. Risk factors were divided into 3 groups: individual, work-related physical, and work-related psychosocial risk factors. There was strong evidence that history of LBP is a predictor of the onset of LBP. Limited evidence was found that the combination of postural risk factors and job strain is associated with the onset of LBP.

CONCLUSION

After review of 3 high-quality prospective studies on the association between risk factors and the onset of nonspecific LBP in office workers, few risk factors were found to predict the onset of LBP in office workers.

Improving general flexibility with a mind-body approach: a randomized, controlled trial using neuro emotional Technique®

General flexibility is a key component of health, well-being, and general physical conditioning. Reduced flexibility has both physical and mental/emotional etiologies and can lead to musculoskeletal injuries and athletic underperformance. Few studies have tested the effectiveness of a mind-body therapy on general flexibility. The aim of this study was to investigate if Neuro Emotional Technique® (NET), a mind-body technique shown to be effective in reducing stress, can also improve general flexibility. The sit-and-reach test (SR) score was used as a measure of general flexibility. Forty-five healthy participants were recruited from the general population and assessed for their initial SR score before being randomly allocated to receive (a) two 20-minute sessions of NET (experimental group); (b) two 20-minute sessions of stretching instruction (active control group); or (c) no intervention or instruction (passive control group). After intervention, the participants were reassessed in a similar manner by the same blind assessor. The participants also answered questions about demographics, usual water and caffeine consumption, and activity level, and they completed an anxiety/mood psychometric preintervention and postintervention. The mean (SD) change in the SR score was +3.1 cm (2.5) in the NET group, +1.2 cm (2.3) in the active control group and +1.0 cm (2.6) in the passive control group. Although all the 3 groups showed some improvement, the improvement in the NET group was statistically significant when compared with that of either the passive controls (p = 0.015) or the active controls (p = 0.021). This study suggests that NET could provide an effective treatment in improving general flexibility. A larger study is required to confirm these findings and also to assess longer term effectiveness of this therapy on general flexibility.

Obesity and physical fitness in California school children

BACKGROUND

Obesity rates have reached epidemic proportions in the United States and California. Thus, the California Department of Education began a series of steps to address the increase in obesity and decline in fitness in the 6.3 million public school children in California. We evaluated serial changes in obesity and fitness in California school children following implementation of prevention steps in all California public schools.

METHODS

The California Department of Education implemented changes in school nutrition and exercise programs aimed at reducing obesity and improving fitness. Outcome results were monitored by performing Physical Fitness Testing on 8.4 million students (5th, 7th, and 9th grade) for body composition, aerobic capacity, flexibility, and upper body, abdominal, and truncal strength using the Cochran-Armitage trend test and multivariable logistic regression models.

RESULTS

Overall fitness improved from 2003 to 2008. Serial changes in body composition, aerobic capacity, flexibility, and upper body, abdominal, and truncal strength improved or remained stable within school as students progressed from 5th to 7th to 9th grade. However, students entering 5th grade were more obese every year, and this early obesity was not reversible within the school programs.

CONCLUSIONS

Following prevention measures within California public schools, obesity and fitness levels have stabilized. However, continued increases in early entrance (5th grade) obesity will require additional efforts directed at preschool and elementary students to completely stop and reverse this obesity epidemic.

A pilot study to profile the lower limb musculoskeletal health in children with obesity

PURPOSE

: Evidence suggests a negative effect of obesity on musculoskeletal health in children. A pilot study was undertaken to investigate the presence of musculoskeletal impairments in children with obesity and to explore the relationships among body mass index, physical activity, and musculoskeletal measures.

METHODS

: Lower limb musculoskeletal health (pain, power, balance, flexibility, and range of motion), physical activity, and screen time were assessed using standardized methods.

RESULTS

: Seventeen children (mean age = 12.21 years) participated. Mean values for lower limb musculoskeletal measures are presented. Moderate negative correlations were found between body composition and range of motion, flexibility, and strength. Genu valgum deformity was moderately positively correlated to body mass index.

CONCLUSIONS

: The results of this pilot study suggest that children who are obese may present with musculoskeletal impairments of the lower limb. Clinicians working with children who are obese should conduct a thorough musculoskeletal assessment and consider the presence of impairments when promoting physical activity.

Aptidão física relacionada à saúde de escolares brasileiros: dados do projeto esporte Brasil

OBJETIVO: Analisar a aptidão física de escolares brasileiros, de acordo com uma avaliação referenciada por critérios de saúde. MÉTODOS: Estudo epidemiológico transversal, de base escolar, conduzido em 7.507 escolares (4.114 meninos e 3.393 meninas), de sete a 10 anos de idade. Foram mensuradas as variáveis: massa corporal, estatura, flexibilidade (sentar-e-alcançar), força/resistência muscular (abdominal modificado um minuto) e aptidão cardiorrespiratória (corrida/caminhada nove minutos). Os critérios e a classificação utilizados para os testes motores foram recomendados pelo Physical Best. RESULTADOS: Baixa aptidão física foi encontrada nos escolares, apresentando risco à saúde para flexibilidade (meninos: 58,3%; meninas: 51,2%, p < 0,001), força/resistência muscular (meninos: 75,3%; meninas: 73,8%, p < 0,001) e aptidão cardiorrespiratória (meninos: 80,8%; meninas: 77,6%, p < 0,001). Na classificação geral, nos três testes motores, foi observada alta prevalência de escolares (~96%) que não atingiu os pontos pré-estabelecidos para um nível satisfatório de aptidão física. CONCLUSÃO: Programas efetivos de intervenção na promoção de mudanças nos padrões de aptidão física são necessários, visando contribuir para o desenvolvimento mais adequado dos níveis de desempenho motor, principalmente com iniciativas de políticas públicas em bairros, parques e condomínios que possibilitem a prática de atividades físicas e esportes.

The association between physical activity and neck and low back pain: a systematic review

The effect of physical activity on neck and low back pain is still controversial. No systematic review has been conducted on the association between daily physical activity and neck and low back pain. The objective of this study was to evaluate the association between physical activity and the incidence/prevalence of neck and low back pain. Publications were systematically searched from 1980 to June 2009 in several databases. The following key words were used: neck pain, back pain, physical activity, leisure time activity, daily activity, everyday activity, lifestyle activity, sedentary, and physical inactivity. A hand search of relevant journals was also carried out. Relevant studies were retrieved and assessed for methodological quality by two independent reviewers. The strength of the evidence was based on methodological quality and consistency of the results. Seventeen studies were included in this review, of which 13 were rated as high-quality studies. Of high-quality studies, there was limited evidence for no association between physical activity and neck pain in workers and strong evidence for no association in school children. Conflicting evidence was found for the association between physical activity and low back pain in both general population and school children. Literature with respect to the effect of physical activity on neck and low back pain was too heterogeneous and more research is needed before any final conclusion can be reached.

Health-related physical fitness and weight status in Hong Kong adolescents

Background

This study was designed to investigate the relation between health-related physical fitness and weight status in Hong Kong adolescents.

Methods

3,204 students aged 12-18 years participated in the Hong Kong Student Obesity Surveillance (HKSOS) project in 2006-2007. Anthropometric measures (height, weight) and health-related fitness (push-up, sit-up, sit-and-reach, 9-minute run) were assessed. Body mass index (BMI) was computed to classify participants into normal weight, underweight (Grade I, II/III), overweight, and obese groups. The associations of health-related physical fitness with BMI and weight status were examined by partial correlation coefficients and analysis of covariance, respectively.

Results

More boys than girls were overweight or obese (18.0% vs 8.7%), but more girls than boys were underweight (22.3% vs 16.7%). Boys performed significantly (P < 0.001) better in sit-up (38.8 vs 31.6 times/min) and 9-minute run (1632.1 vs 1353.2 m), but poorer in sit-and-reach (27.4 vs 32.2 cm) than girls. All four physical fitness tests were significantly positively correlated with each other in both sexes, and BMI was only weakly correlated with sit up and sit-and-reach tests in boys. Decreasing performance (P for trend < 0.05) was observed from normal weight to overweight and obese for push-up, sit-up, and 9-minute run in both sexes. From normal weight to Grade I and Grade II/III underweight, decreasing performance (P for trend < 0.05) for sit-up and sit-and-reach in both sexes and for push-up in boys was observed.

Conclusions

The relations between BMI and health-related physical fitness in adolescents were non-linear. Overweight/obese and underweight adolescents had poorer performance in push-up and sit-up tests than normal weight adolescents. Different aspects of health-related physical fitness may serve as immediate indicators of potential health risks for underweight and overweight adolescents.

The association between obesity and low back pain: a meta-analysis

This meta-analysis assessed the association between overweight/obesity and low back pain. The authors systematically searched the Medline (National Library of Medicine, Bethesda, Maryland) and Embase (Elsevier, Amsterdam, the Netherlands) databases until May 2009. Ninety-five studies were reviewed and 33 included in the meta-analyses. In cross-sectional studies, obesity was associated with increased prevalence of low back pain in the past 12 months (pooled odds ratio (OR) = 1.33, 95% confidence interval (CI): 1.14, 1.54), seeking care for low back pain (OR = 1.56, 95% CI: 1.46, 1.67), and chronic low back pain (OR = 1.43, 95% CI: 1.28, 1.60). Compared with non-overweight people, overweight people had a higher prevalence of low back pain but a lower prevalence of low back pain compared with obese people. In cohort studies, only obesity was associated with increased incidence of low back pain for > or =1 day in the past 12 months (OR = 1.53, 95% CI: 1.22, 1.92). Results remained consistent after adjusting for publication bias and limiting the analyses to studies that controlled for potential confounders. Findings indicate that overweight and obesity increase the risk of low back pain. Overweight and obesity have the strongest association with seeking care for low back pain and chronic low back pain.

How do we define the condition 'recurrent low back pain'? A systematic review

Recurrent low back pain (recurrent LBP) is a common condition, however, it is unclear if uniform definitions are used in studies investigating the prevalence and management of this condition. The aim of this systematic review was to identify how recurrent LBP is defined in the literature. A literature search was performed on MEDLINE, EMBASE, CINAHL, AMED, and PEDro. Studies were considered eligible if they investigated a cohort of subjects with recurrent LBP or if they were measuring the prevalence of recurrent LBP. Two independent reviewers assessed inclusion of studies and extracted definitions of recurrent LBP. Forty-three studies met the inclusion criteria. The majority of studies (63%) gave an explicit definition of recurrent LBP; however, the definitions varied greatly and only three definitions for recurrent LBP were used by more than one study. The most common feature given as part of the definition was the frequency of previous episodes of low back pain. Only 8% (3/36) of studies used previously recommended definitions for recurrent LBP. Large variation exists in definitions of recurrent LBP used in the literature, making interpretation of prevalence rates and treatment outcomes very difficult. Achieving consensus among experts in this area is required.

A prospective investigation of biomechanical risk factors for patellofemoral pain syndrome: the Joint Undertaking to Monitor and Prevent ACL Injury (JUMP-ACL) cohort

BACKGROUND

Patellofemoral pain syndrome is one of the most common chronic knee injuries; however, little research has been done to determine the risk factors for this injury.

HYPOTHESIS

Altered lower extremity kinematics and kinetics, decreased strength, and altered postural measurements will be risk factors.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

A total of 1597 participants were enrolled in this investigation and prospectively followed from the date of their enrollment (July 2005, July 2006, or July 2007) through January 2008, a maximum of 2.5 years of follow-up. Each participant underwent baseline data collection during their pre-freshman summer at the United States Naval Academy. Baseline data collection included 3-dimensional motion analysis during a jump-landing task, 6 lower extremity isometric strength tests, and postural alignment measurements (navicular drop and Q angle).

RESULTS

Risk factors for the development of patellofemoral pain syndrome included decreased knee flexion angle, decreased vertical ground-reaction force, and increased hip internal rotation angle during the jump-landing task. Additionally, decreased quadriceps and hamstring strength, increased hip external rotator strength, and increased navicular drop were risk factors for the development of patellofemoral pain syndrome.

CONCLUSION

Multiple modifiable risk factors for patellofemoral pain syndrome pain have been identified in this investigation. To decrease the incidence of this chronic injury, the risk factors for patellofemoral pain syndrome need to be targeted in injury prevention programs.

CLINICAL RELEVANCE

Prevention programs should focus on increasing strength of the lower extremity musculature along with instructing proper mechanics during dynamic movements to decrease the incidence of patellofemoral pain syndrome.

Exercise reduces the intensity and prevalence of low back pain in 12-13 year old children: a randomised trial

QUESTION

Does an eight-week exercise program reduce the intensity and prevalence of low back pain in 12-13 year old children? Does it decrease the childhood physical risk factors for low back pain and promote a sense of well-being?

DESIGN

Randomised trial with concealed allocation and assessor blinding.

PARTICIPANTS

Seventy-two 12-13 year old children, who had complained of low back pain in the past three months.

INTERVENTION

The experimental group completed eight exercise classes of 40-45 minutes duration over eight weeks conducted by a physiotherapist, whilst the control group received no intervention.

OUTCOME MEASURES

The primary outcome was pain intensity measured on a 10-cm visual analogue scale. Secondary outcomes included 3-month prevalence of pain, childhood physical risk factors for low back pain, and sense of well-being. Measures were taken at baseline (Month 0), post-intervention (Month 3), and three months later (Month 6).

RESULTS

Pain intensity over the past month had decreased by 2.2 cm (95% CI 1.0 to 3.5) more for the experimental group than the control group at Month 3 and was still 2.0 cm (95% CI 0.5 to 3.5) less than the control group at Month 6. The absolute risk reduction for 3-month prevalence in low back pain in the experimental group was 24% (95% CI 4 to 41) compared with the control group at Month 3, and 40% (95% CI 18 to 57) at Month 6. There were also statistically-significant between-group differences in neural mobility.

CONCLUSION

Exercise is effective in reducing the intensity and prevalence of low back pain in children.

TRIAL REGISTRATION

Clinical trials NCT00786864.

Neck/shoulder pain in adolescents is not related to the level or nature of self-reported physical activity or type of sedentary activity in an Australian pregnancy cohort

Background

An inconsistent relationship between physical activity and neck/shoulder pain (NSP) in adolescents has been reported in the literature. Earlier studies may be limited by not assessing physical activity in sufficient detail. The aim of this study was to comprehensively examine the association between NSP and the level and nature of physical activity, and type of sedentary activity in adolescents.

Methods

A cross-sectional analysis using data from 924 adolescents in the Western Australian Pregnancy Cohort (RAINE) study was performed. Complete data were available for 643 adolescents (54.6% female) at the 14-year follow-up. Physical activity was measured using a detailed self-report electronic activity diary requiring participants to input details of all physical activities over the day in segments of 5 minutes for a one-week period. Physical activity levels were categorised as: sedentary, light, moderate, or vigorous based on metabolic energy equivalents. Nature of activity was determined by assigning each activity to categories based on the amount of movement (static/dynamic) and the main posture assumed for the activity (standing/sitting/lying). Type of sedentary activity was characterised by exposure time to watching TV, using a computer, and reading. Logistic regression was used to explore the association between NSP and activity.

Results

Females reported a higher prevalence of lifetime, 1-month and chronic NSP than males (50.9 vs 41.7%, 34.1 vs 23.5%, and 9.2 vs 6.2% respectively). No consistent, dose-response relationship was found between NSP and the level, nature, and type of physical activity.

Conclusion

Self-reported one month and lifetime NSP prevalence in adolescents is not related to the level or intensity of physical activity or the type of sedentary activity over a one week period.

Fitness, motor competence, and body composition are weakly associated with adolescent back pain

STUDY DESIGN

Cross-sectional survey.

OBJECTIVES

To assess the associations between adolescent back pain and fitness, motor competence, and body composition.

BACKGROUND

Although deficits in physical fitness and motor control have been shown to relate to adult back pain, the evidence in adolescents is less clear.

METHODS AND MEASURES

In this cross-sectional study, 1608 "Raine" cohort adolescents (mean age, 14 years) answered questions on lifetime, month, and chronic prevalence of back pain, and participated in a range of physical tests assessing aerobic capacity, muscle performance, flexibility, motor competence, and body composition.A history of any diagnosed back pain in the adolescent was obtained from the primary caregiver.

RESULTS

After multivariate logistic regression analysis, increased likelihood of back pain in boys was associated with greater aerobic capacity, greater waist girth, and both reduced and greater flexibility. Back pain in girls was associated with greater abdominal endurance, reduced kinesthetic integration, and both reduced and greater back endurance. Lower likelihood of back pain was associated with greater bimanual dexterity in boys and greater lower extremity power in girls.

CONCLUSION

Physical characteristics are commonly cited as important risk factors in back pain development. Although some factors were associated with adolescent back pain, and these differed between boys and girls, they made only a small contribution to logistic regression models for back pain. The results suggest future work should explore the interaction of multiple domains of risk factors (physical, lifestyle, and psychosocial) and subgroups of adolescent back pain, for whom different risk factors may be important.

High-level physical activity in childhood seems to protect against low back pain in early adolescence

BACKGROUND

The evidence on the impact of physical activity on back pain in children and adolescents has been contradicting. It has also been shown that the physical activity cannot accurately be estimated in children using questionnaires.

PURPOSE

The aim of this study was to establish if physical activity in childhood had any impact on back pain reporting in early adolescence (3 years later), using an objective instrumental measurement of physical activity.

STUDY DESIGN

Prospective cohort study.

PATIENT SAMPLE

Representative random sample of Danish children from the city of Odense sampled at age 9 years and followed-up at age 12 years.

OUTCOME MEASURES

The 1-month period prevalence of back pain (neck pain, mid back pain, and low back pain) was established using a structured interview.

METHODS

Physical activity was assessed with the MTI-accelerometer. The accelerometer provides a minute-by-minute measure of the physical activity performed. An overall measure of physical activity and time spent in high activity were studied in relation to back pain using logistic regression. The analyses were performed on the total sample and then stratified on back pain (yes/no) at baseline.

RESULTS

High physical activity (HPA) levels seem to protect against future low back pain and appear to actually "treat" and reduce the odds of future mid back pain. When comparing the least active children to the most active children, the least active had a multivariate odds ratio of 3.3 of getting low back pain and 2.7 of getting mid back pain 3 years later. When stratified on back pain at baseline, this effect on mid back pain was especially noticeable in children who had had mid back pain already at baseline, with an odds ratio of 7.2.

CONCLUSIONS

HPA in childhood seems to protect against low back pain and mid back pain in early adolescence. Larger prospective studies with repetitive follow-ups and preferably intervention studies should be performed, to see if these findings can be reproduced.

Avaliação da flexibilidade muscular entre meninos e meninas de 7 e 8 anos

A flexibilidade muscular tem importante papel na prevenção de algumas patologias musculoesqueléticas, além de influenciar a postura. A criança em desenvolvimento apresenta maior flexibilidade. O objetivo deste foi avaliar a flexibilidade de crianças de 7 e 8 anos e a existência de diferença entre sexo e idade para essa variável. Foram avaliadas 230 crianças das escolas municipais da cidade de Amparo, SP. A amostra constituiu-se de 130 meninas e 100 meninos saudáveis, com índice de massa corporal menor que o 85º percentil, que não praticavam esporte institucionalizado ou exercício físico em freqüência maior que duas vezes e/ou 3 horas por semana. A flexibilidade foi medida pelo teste da distância do 3º dedo ao solo. Os dados foram tratados estatisticamente para verificar a existência de diferenças de sexo e idade, adotando-se o nível de significância de 5%. Foi encontrada diferença significante de sexo (p=0,05), tendo as meninas apresentado maior distância (29,15±8,80 cm) 3º dedo-solo que os meninos (27,41±10,01 cm). Não houve diferenças entre as idades (p=0,725). As meninas apresentaram menor flexibilidade que os meninos.

Fitness, motor competence and body composition as correlates of adolescent neck/shoulder pain: an exploratory cross-sectional study

Background

Adolescent neck/shoulder pain (NSP) is a common and sometimes debilitating problem. Several risk factors for this condition have been investigated, but no studies have previously evaluated associations between fitness, motor competence, body composition and adolescent NSP.

Methods

1608 males and females of mean age 14 years answered questions on their history of NSP (4 measures), and were tested for aerobic fitness, upper and lower limb power, trunk endurance, grip strength, shoulder flexibility, motor competence and anthropometric factors. Univariate and multivariate logistic regressions were used to test for associations between NSP and physical variables.

Results

There were significant gender differences for most physical and pain variables. After multivariate analysis, males had lower odds of NSP if they had reduced back endurance [OR: 0.66 (95% CI: 0.46–0.97)], reduced persistent control [0.42 (0.19–0.95], and increased muscle power [0.33 (0.12–0.94)], and higher odds of NSP if they had a higher basketball throw [2.47 (1.22–5.00)] and jump performance [3.47 (1.55–7.74)]. Females had lower odds for NSP if they had a reduced jump performance [0.61(0.41–0.92)], a better basketball throw [0.60(0.40–0.90)], lower shoulder flexibility [0.54 (0.30–0.98)] and a higher aerobic capacity [0.61 (0.40–0.93)], and higher odds for NSP if they had greater abdominal endurance [1.57(1.07–2.31)] and greater bimanual dexterity [1.77(1.18–2.65)]. Females showed a U shaped relationship between NSP and back endurance [low: 2.12 (1.20–3.74); high 2.12 (1.18–3.83)].

Conclusion

Adolescent NSP was associated with fitness and motor competence, although the associations varied with gender, and their strength was limited.

Physical activity and low-back pain in schoolchildren

Design of the experiment is to study the cross-sectional sample with retrospective information. The objective is to identify the types of physical activity associated with the decreased occurrence of low-back pain (LBP) in schoolchildren. Physical activity may be hypothesized to possess a potential for LBP prevention. The possible connection between LBP and specific sports activities is however sparsely documented. A total of 546, 15- to 16-year-old schoolchildren filled a questionnaire on current physical activities and LBP occurrence and severity. In multiple logistic regressions, the association of LBP with exposure variables was corrected for body height and weight (data from school health service files) and for anthropometric and school furniture parameters. More than half of the children reported pain or discomfort in the low-back region during the preceding 3 months, and 1/4 experienced a decreased functioning or need of care because of LBP. LBP correlated with physical inactivity, e.g. time spent on homework and hours watching TV or video, and with a series of sports activities, e.g. jogging, handball playing and gymnastics. Among sports activities, only swimming and the number of hours per week participating in soccer were associated with a decreased LBP prevalence. With the exception of swimming and soccer, the types of sport reported by this schoolchild population do not offer themselves for consideration as tools for LBP prevention. Based on the associations found with indicators of physical inactivity, attempts to motivate the children to increase their general physical activity level should be considered for trial.

School fitness tests as predictors of adult health-related fitness

Relationships between adolescent physical fitness and adult health-related fitness were investigated. Forty-five subjects (20 males, 25 females) participated in physical fitness tests in 1976 and again in 2001. The adolescent physical fitness tests were distance running (2,000 m for boys or 1,500 m for girls), 50 m run, pull-ups (boys) or flexed arm hangs (girls), shuttle run, a 30-sec sit-up test, standing broad jump, hand grip-test, and sit-and-reach test. The adult health-related physical fitness index (APFI), stratified by sex, was formed by summing the z-scores of a bicycle ergometer test, sit-up test, hand-grip test, and sit-and-reach test. Height- and weight-adjusted correlations between adolescence and adulthood for exactly similar tests for men and women were, respectively, 0.74 (95% CI, 0.44-0.89) and 0.53 (95% CI, 0.17-0.76) in sit-and-reach tests, 0.41 (95% CI, -0.04 to 0.72) and 0.55 (95% CI, 0.20-0.78) in sit-up tests, and 0.53 (95% CI, 0.11-0.44) and 0.44 (95% CI, 0.05-0.71) in hand-grip tests. When all adolescent tests were put in regression analysis together with BMI in 2001, the significant explanatory factors for APFI were distance running ability and the sit-and-reach test for men and sit-up test, flexed arm hang, and BMI in 2001 for women.