Baseline anthropometry, flexibility and strength characteristics and future low-back pain in adolescent athletes and nonathletes

Age-Related Differences in the Limited Range of Motion of the Lower Extremity and Their Relation to Low Back Pain in Young Baseball Players: A Cross-Sectional Study of 1215 Players

BACKGROUND

Age-related differences in the limited range of motion of the lower extremities and their relationship with low back pain in juvenile athletes have not been well assessed. This study investigated the relationship between low back pain and limited range of motion of the hip and knee in young baseball players during the baseball season.

RESULTS

Participants comprised 1215 baseball players (216 pitchers, 999 fielders) aged 6-16 years who underwent medical checkups (self-completed questionnaire and physical examination). Of the 1215 players, 255 (21.0%) experienced seasonal low back pain requiring rest during the previous year. The prevalence of low back pain and a positive Thomas test, straight-leg-raising test, and heel-to-buttock test increased with age. Univariate analysis revealed that a positive heel-to-buttock test in both the throwing and non-throwing arm sides in the 11-12 age group and a positive Thomas test in the throwing arm side in the 13-14 age group were associated with seasonal low back pain (P = 0.0051, P = 0.021, and P = 0.048, respectively). Multivariate analysis, adjusted for factors associated with low back pain, showed significant associations between the positive heel-to-buttock test (odds ratio 1.75, 95% confidence interval 1.11-2.79; P = 0.016) and low back pain in players aged 11-14 years.

CONCLUSIONS

A positive heel-to-buttock test is potentially associated with low back pain among juvenile baseball players. Particular attention should be paid to the limited range of motion of the knee joint and tightness of the quadriceps femoris muscle among baseball players with low back pain aged 11-14 years.

Incidence, prevalence and risk factors for low back pain in adolescent athletes: a systematic review and meta-analysis

OBJECTIVE

To investigate the incidence, prevalence, risk factors and morphological presentations of low back pain (LBP) in adolescent athletes.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Medline, Embase, CINAHL via EBSCO, Web of Science, Scopus.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies evaluating the incidence and/or prevalence of LBP in adolescent athletes across all sports.

RESULTS

There were 80 studies included. The pooled incidence estimate of LBP in adolescent athletes was 11% (95% CI 8% to 13%, I²=0%) for 2 years, 36.0% (95% CI 4% to 68%, I²=99.3%) for 12 months and 14% (95% CI 7% to 22%, I²=76%) for 6 months incidence estimates. The pooled prevalence estimate of LBP in adolescent athletes was 42% (95% CI 29% to 55%, I²=96.6%) for last 12 months, 46% (95% CI 41.0% to 52%, I²=56%) for last 3 months and 16% (95% CI 9% to 23%, I²=98.3%) for point prevalence. Potential risk factors were sport participation, sport volume/intensity, concurrent lower extremity pain, overweight/high body mass index, older adolescent age, female sex and family history of LBP. The most common morphology reported was spondylolysis. Methodological quality was deemed high in 73% of cross-sectional studies and in 30% of cohort studies. Common reasons for downgrading at quality assessment were use of non-validated survey instruments and imprecision or absence of LBP definition.

SUMMARY/CONCLUSION

LBP is common among adolescent athletes, although incidence and prevalence vary considerably due to differences in study methodology, definitions of LBP and data collection.

PROSPERO REGISTRATION NUMBER

CRD42020157206.

Associations between core stability and low back pain in high school baseball players: A cross-sectional study

BACKGROUND

Reduced core stability is a potential risk factor for low back pain in athletes. However, the association between core stability and low back pain in high school baseball players has not been thoroughly studied. The purpose of this study was to investigate the relationship between core stability and low back pain and its clinical characteristics in high school baseball players.

METHODS

Participants comprised 812 high school baseball players who had undergone annual medical evaluations, comprising a self-completed questionnaire and a physical examination. We investigated the relationships between low back pain during the season and on the day of medical evaluations and core stability using a cross-sectional study design. Core stability was assessed using the Sahrmann core stability test.

RESULTS

Reduced core stability was confirmed in 358 (44.1%) of all players, 98 (49.5%) pitchers, and 260 (42.3%) fielders. In total, 352 players (43.3%) reported incidents of seasonal low back pain during the previous year. Thirty-five pitchers (17.7%) and 153 fielders (24.9%) reported low back pain on the day of the medical evaluations. No significant associations were seen between low back pain throughout the season and reduced core stability. After adjusting for confounding factors (total amount of practice per week, hamstring tightness and quadriceps tightness) using logistic regression modeling, a significant association between presence of low back pain during lumbar extension movement and reduced core stability was found (odds ratio, 2.57; 95% confidence interval, 1.08-6.62; P = 0.033) in pitchers.

CONCLUSIONS

High school baseball pitchers with reduced core stability showed a higher probability of reporting low back pain during lumbar extension movement. Evaluation of core stability should be considered in high school baseball players, especially in pitchers.

Influences of limited flexibility of the lower extremities and occurrence of low back pain in adolescent baseball players: A prospective cohort study

BACKGROUND

Limited flexibility of the lower extremities, such as hamstring tightness, has long been suggested as a physical risk factor for low back pain among adolescent athletes. However, few prospective cohort studies have examined the direction of causality for this relationship. This prospective cohort study investigated the relationship between limited flexibility of the lower extremities and the occurrence of low back pain among high school baseball players.

METHODS

Participants comprised 335 high school baseball players from 43 high school baseball teams who had undergone baseline medical evaluations (a self-completed questionnaire and physical examination). Occurrence of low back pain during a 1-year follow up, and associations with measurements of flexibility of the lower extremities such as straight-leg-raising angle (hamstring tightness), Thomas test (iliopsoas tightness), heel-buttock-distance (quadriceps tightness), and passive range of motion of the hip were investigated.

RESULTS

In total, 296 players (88.4%) participated in the 1-year follow-up survey, with 147 of the 296 players (49.7%) reporting the occurrence of low back pain during follow-up. The number of players with low back pain during follow-up peaked in November, then decreased and was lowest in June. After adjusting for factors associated with low back pain using logistic regression modeling, a significant association between hamstring tightness on the non-throwing arm side and low back pain (odds ratio 2.86, 95% confidence interval 1.17-6.94; P = 0.018) was found.

CONCLUSIONS

Hamstring tightness on the non-throwing arm side was identified as a potential risk factor for low back pain in high school baseball players. These results may provide guidance in the development of future prevention programs.

Orthopaedic medical examination for young amateur athletes: a repeated cross-sectional study from 2014 to 2018

OBJECTIVES

Medical examinations for adult elite athletes are performed all over the world, however, no studies in the relevant English literature have reported on orthopaedic medical examinations for young amateur athletes. The purpose of this study was to report the results of orthopaedic medical examinations of the spine and lower extremities in young amateur athletes.

METHODS

This repeated cross-sectional study from 2014 to 2018 included a total of 323 young amateur athletes (age, 12-18 years) who were active in one of the following four sports: boxing, canoeing, weightlifting and track and field. The orthopaedic medical examination consisted of six assessments (physical examinations, the generalised joint laxity, muscle and joint tightness, static alignment and muscle volume of the lower extremities and the medial longitudinal arch of the foot). Questions regarding pain in the spine and lower extremities were also performed.

RESULTS

Among 323 young amateur athletes, 17 (5.3%) had received orthopaedic treatment at the time of the medical examination, with spondylolysis being the most common cause (29.4%, 5/17). Among 306 young athletes who had not received orthopaedic treatment, 61 (19.9%) had at least one positive finding in physical examinations or had pain in the spine or lower extremities. Anterior drawer test of the ankle and Kemp test for the spine accounted for 34% and 28% of positive findings, respectively. Low back pain and knee pain accounted for 58% and 16% of pain, respectively.

CONCLUSIONS

The present study showed that approximately one-fifth of young amateur athletes who had not received orthopaedic treatment had pain in the spine and lower extremities and positive findings in physical examinations that may require orthopaedic treatments. In addition to the early detection of injuries, orthopaedic medical examinations for young amateur athletes provide an opportunity to educate such athletes.

Trunk Lateral Flexor Endurance and Body Fat: Predictive Risk Factors for Low Back Pain in Child Equestrian Athletes

Low back pain (LBP) is the most common overuse musculoskeletal injury suffered by child equestrian athletes (CEA). Despite this, little is known about the risk factors related to LBP in these athletes, and very limited research has been conducted on this topic. This study was designed to investigate predictive risk factors for LBP in CEA. The purposes of this research were to determine whether anthropometric, range of motion (ROM), core endurance and sagittal spinal morphotype measures are risk factors for LBP and to establish a diagnostic cutoff value for those factors associated with LBP. Nineteen CEA between the ages of 12 and 17 years were voluntarily recruited. Potential risk factors evaluated included corporal composition, lower limb ROM, core endurance and sagittal spinal measures. Associations and predictions were calculated between these risk factors and the LBP during the last 12 months. Almost half of the CEA have suffered at least one episode of LBP. Two risk factors and cutoff values were identified as predictors of LBP in CEA: having a high body fat higher than 23% (p = 0.01) and trunk lateral flexor endurance lower to 65 s (p = 0.021), body fat being the strongest predictor.

Comparisons of hamstring flexibility between individuals with and without low back pain: systematic review with meta-analysis

Background: There is no robust evidence on the contribution of reduced hamstring flexibility to the development of low back pain (LBP) in cohort studies.Purpose: To investigate whether individuals with LBP have impaired hamstring flexibility and stiffness and what measures have been used to compare hamstring flexibility and stiffness between individuals with and without LBP.Methods: A systematic literature search was undertaken in PubMed, EMBASE, MEDLINE, CINAHL, SCOPUS, and Cochrane databases from inception to April 2018. The GRADE system was used to determine the quality of evidence for each measure evaluated in meta-analysis.Results: Respectively, seventeen and two studies having acceptable methodological quality were analyzed with regard to hamstring flexibility and stiffness. Four measures were identified for hamstring flexibility and five for stiffness. Meta-analyses were undertaken in straight leg raising (SLR), sit and reach and knee extension in 90° hip flexion for hamstring flexibility and for hamstring stiffness measures of stiffness at 50° SLR and gradient of stiffness from 20° to 50° SLR (M_e-grad). Significantly reduced hamstring flexibility or increased stiffness (P < .05) was detected in SLR, 90/90 knee extension and M_e-grad. However, the validity of measures for hamstring flexibility was problematic and GRADE scores for all measures in the meta-analyses were very low.Conclusion: There have been four measures for hamstring flexibility and five for stiffness to evaluate individuals with and without LBP. It was impossible to conclude whether individuals with LBP have impaired hamstring flexibility and stiffness due to very low quality of evidence for meta-analyses.

Prefabricated foot orthoses compared to a placebo intervention for the treatment of chronic nonspecific low back pain: a study protocol for a randomised controlled trial

BACKGROUND

Prefabricated foot orthoses are used to treat chronic nonspecific low back pain, however their effectiveness and potential mechanism of action is unclear. The primary aims of the study are to investigate the effectiveness of prefabricated foot orthotic devices for reducing pain and improving function in people with chronic nonspecific low back pain over 52 weeks.

METHODS

This study is a participant and assessor blinded, parallel-group, superiority randomised (1:1) controlled trial. The study will recruit 60 participants aged 18 to 65 years with chronic nonspecific low back pain. Participants will undergo randomisation to a control group (The Back Book) or an intervention group (prefabricated foot orthoses and The Back Book). The primary outcome measures will be change in pain and function from baseline to 12 (primary time point), 26, and 52 weeks. Secondary outcome measures include: gluteus medius muscle activity and transversus abdominis muscle thickness from baseline to 12 weeks, physical activity over 12, 26, and 52 weeks, and correlation between foot type and change in measures of pain and function. Number of hours per day and week that the prefabricated orthoses are worn, as well as, adverse events will be self-reported by participants. Data will be analysed using the intention-to-treat principle.

DISCUSSION

This trial will primarily evaluate the effectiveness of prefabricated foot orthotic devices for reducing pain and improving function in people with chronic nonspecific low back pain over 52 weeks. It is expected that this study will provide clinicians and researchers with an understanding of the role that prefabricated foot orthoses may have in the treatment of chronic nonspecific low back pain and a potential mechanism of action, and whether foot type influences the outcome.

TRIAL REGISTRATION

ACTRN12618001298202.

Restriction in lateral bending range of motion, lumbar lordosis, and hamstring flexibility predicts the development of low back pain: a systematic review of prospective cohort studies

Background

Low back pain (LBP) is an increasingly common condition worldwide with significant costs associated with its management. Identification of musculoskeletal risk factors that can be treated clinically before the development of LBP could reduce costs and improve the quality of life of individuals. Therefore the aim was to systematically review prospective cohort studies investigating lower back and / or lower limb musculoskeletal risk factors in the development of LBP.

Methods

MEDLINE, EMBASE, AMED, CINAHL, SPORTDiscus, and the Cochrane Library were searched from inception to February 2016. No age, gender or occupational restrictions of participants were applied. Articles had to be published in English and have a 12 month follow-up period. Musculoskeletal risk factors were defined as any osseous, ligamentous, or muscular structure that was quantifiably measured at baseline. Studies were excluded if participants were pregnant, diagnosed with cancer, or had previous low back surgery. Two authors independently reviewed and selected relevant articles. Methodological quality was evaluated independently by two reviewers using a generic tool for observational studies.

Results

Twelve articles which evaluated musculoskeletal risk factors for the development of low back pain in 5459 participants were included. Individual meta-analyses were conducted based on risk factors common between studies. Meta-analysis revealed that reduced lateral flexion range of motion (OR = 0.41, 95% CI 0.24-0.73, p = 0.002), limited lumbar lordosis (OR = 0.73, 95% CI 0.55-0.98, p = 0.034), and restricted hamstring range of motion (OR = 0.96, 95% CI 0.94-0.98, p = 0.001) were significantly associated with the development of low back pain. Meta-analyses on lumbar extension range of motion, quadriceps flexibility, fingertip to floor distance, lumbar flexion range of motion, back muscle strength, back muscle endurance, abdominal strength, erector spinae cross sectional area, and quadratus lumborum cross sectional area showed non-significant results.

Conclusion

In summary, we found that a restriction in lateral flexion and hamstring range of motion as well as limited lumbar lordosis were associated with an increased risk of developing LBP. Future research should aim to measure additional lower limb musculoskeletal risk factors, have follow up periods of 6-12 months, adopt a standardised definition of LBP, and only include participants who have no history of LBP.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1534-0) contains supplementary material, which is available to authorized users.

Low Back Pain in Athletes Is Associated with General and Sport Specific Risk Factors: A Comprehensive Review of Longitudinal Studies

We aimed to examine systematically the available evidence on risk factors of low back pain (LBP) in athletes. We performed search without language restriction in PubMed, Ovid, Google Scholar, Scopus, and CINAHL. Longitudinal studies that examined possible risk factors of LBP in athletes were included in this systematic review. Based on methodological quality of studies, a best-evidence synthesis was conducted. Seven longitudinal studies were included, four of which had high methodological quality. Results showed that previous LBP, decreased lumbar flexion, and decreased lumbar extension are positively associated with LBP. There was moderate evidence for hip flexor tightness and high body weight as a risk factor. We found insufficient evidence for association between forward bending, previous injury, and amount of training per week, active years, age, and sex with LBP. In conclusion this study would provide a list of risk factors for LBP in athletes, though it showed a strong evidence for only a few including decrease lumbar flexion or extension, previous LBP, and high body weight. This review indicated a high heterogeneity of study characteristics including assessed risk factors and statistical techniques might limit the quality of evidence.

Morphology of the abdominal muscles in ballet dancers with and without low back pain: a magnetic resonance imaging study

OBJECTIVES

To evaluate the morphology of transversus abdominis and obliquus internus abdominis muscles and the ability to "draw in" the abdominal wall, in professional ballet dancers without low back pain, with low back pain or both hip region and low back pain.

DESIGN

Observational study.

METHODS

Magnetic resonance images of 31 dancers were taken at rest and during voluntary abdominal muscle contraction. Measurements included the thickness of transversus abdominis and obliquus internus abdominis muscles, lateral slide of the anterior extent of the transversus abdominis muscles (transversus abdominis slide) and reduction in total cross sectional area of the trunk.

RESULTS

The transversus abdominis and obliquus internus abdominis muscles were thicker in male dancers and the right side was thicker than the left in both genders. There was no difference in muscle thickness as a proportion of the total thickness, between dancers with and without pain, although there was a trend for female dancers with low back pain only to have a smaller change in transversus abdominis muscle thickness with contraction than those without pain. Transversus abdominis slide was less in female dancers than in male dancers. When gender was ignored, the extent of transversus abdominis slide was less in dancers with low back pain only. Reduction in trunk cross sectional area with contraction was not different between genders or groups.

CONCLUSIONS

This study provides evidence that the abdominal muscles (transversus abdominis and obliquus internus abdominis) are asymmetrical in dancers and although the abdominal muscles are not different in structure (resting thickness) in dancers with LBP, there is preliminary evidence for the behavioural change of reduced slide of transversus abdominis during the 'draw in' of the abdominal wall.

Hip flexibility is the main determinant of the back-saver sit-and-reach test in adolescents

Although flexibility field tests are commonly used in research, sport, and school settings, there is no conclusive evidence about what they actually assess. The first aim of this study was to assess the contributions of the main joints involved in the back-saver sit-and-reach test using angular kinematic analysis. The second aim was to measure the inter-method agreement between the back-saver sit-and-reach test and the sit-and-reach test. A total of 138 adolescents (57 females, 81 males) aged 14.5 +/- 1.7 years performed the back-saver sit-and-reach test and the sit-and-reach test. Hip, lumbar, and thoracic angles were assessed by angular kinematic analysis while the participants were performing the back-saver sit-and-reach test. Stepwise linear regression models and the Bland-Altman method were used. The hip angle independently explained 42% (P < 0.001) of the variance in the back-saver sit-and-reach test, the lumbar angle explained an additional 30% (P < 0.001) of the variance, and the thoracic angle an additional 4% (P < 0.001). The inter-method mean difference between back-saver sit-and-reach (BSSR) and sit-and-reach (SR) measures (BSSR - SR) was 0.41 cm (P = 0.21). The results suggest that hip flexibility is the main determinant of the back-saver sit-and-reach test score in adolescents, followed by lumbar flexibility. The back-saver sit-and-reach test can therefore be considered an appropriate and valid test for assessing hip and low-back flexibility in this age group. The back-saver sit-and-reach and sit-and-reach tests provide comparable values.

Nonspecific low back pain during childhood: a retrospective epidemiological study of risk factors

OBJECTIVES

In contrast to what was believed in the past, nonspecific low back pain is a fairly frequent condition in children, whose pathophysiology remains unclear as yet. Although many factors have been implicated in its development, results are often contradictory.

METHODS

Our study aims to examine most of the reasons investigated in the international literature, as well as the previously unexamined impact of passive smoking in its clinical appearance. It is a retrospective study that investigates the symptom of nonspecific low back pain during a 12-month period before the visit of children to our department. The research included 692 children aged 7.5 to 14 years. The data were collected using a semi-structured questionnaire, which included a mix of open and closed questions, followed by physical examination during their visit.

RESULTS

A total of 153 children were considered to present nonspecific low back pain during the previous year. The determinant factors appear to be greater age, the male sex, larger height, increased weight, dissatisfaction with school chairs, the clinical presentation of back pain in at least 1 parent, and coexisting anatomic orthopedic conditions. On the contrary, the weight of the school bag, the way in which it was carried and participation in sports, as well as the time spent by children in front of the TV or PC playing video or play station games, did not appear to have a statistically significant correlation with its appearance. In general, passive smoking does not appear to be a risk factor (P[r] = 0.341), and does not seem to play a leading role in the etiology of the condition. Furthermore, even the heaviness of parental smoking (over 20 cigarettes a day) does not seem to alter the appearance of the disease. The effect of nonspecific low back pain in children's activities was measured using Hannover Functional Ability and Rolland Morris questionnaires, appropriately modified to childhood, where he found a moderate or severe restriction of activity in 23.52% (score >5) and 19.61% (score >6), respectively.

CONCLUSIONS

The data analysis shows that nonspecific low back pain in children is a benign disorder with an unknown pathophysiological mechanism. Many anthropometric characteristics and environmental factors are implicated, but to a different degree each time. Passive smoking as well as the heaviness thereof does not appeal to play in important role in its clinical presentation. Further investigation is deemed necessary to determine the existence of other risk factors, as well as the level of their participation in the condition's pathophysiology.

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.

Low back pain in 15- to 16-year-old children in relation to school furniture and carrying of the school bag

STUDY DESIGN

Cross-sectional sample with longitudinal information.

OBJECTIVE

To estimate the relationship between the occurrence of low back pain (LBP) and various types of school furniture and anthropometric dimensions in schoolchildren, and physical loading by school bag carrying.

SUMMARY OF BACKGROUND DATA

Some types of school furniture may be hypothesized to prevent or cause LBP. Despite strong opinions in the public debate about a possible relationship between use of various types of school furniture and LBP, scientific research on this matter is sparse.

METHODS

Five hundred forty-six schoolchildren aged 14 to 17 years answered a questionnaire about sitting positions during school hours and the presence and severity of LBP. Furthermore, the anthropometric dimensions and the weight of the school bags were measured. The types and dimensions of the school furniture were described and measured. In multivariate analyses was adjusted for physical activity and other possible risk factors.

RESULTS

More than half of the adolescents experienced LBP during the preceding 3 months, and 24.2% reported reduced daily function or care seeking because of LBP. LBP occurrence was not associated with the types or dimensions of the school furniture or body dimensions, but was positively associated with carrying the school bag on 1 shoulder [OR: 2.06 (1.29-3.31)].

CONCLUSION

The present study does not support the hypothesis of different types of school furniture being a causative or preventing factor for LBP. Carrying the school bag in an asymmetric manner may play a role.

Low-back pain in adolescents is associated with poor hip mobility and high body mass index

The objective of this cross-sectional study was to investigate whether body mass index (BMI) and hip mobility are associated with low-back pain (LBP) in adolescents. The study population included all adolescents in 8th and 9th grades in a rural and in an urban area in Eastern Norway. Eighty-eight adolescents participated (mean age 14.7 years), making the response rate 84%. LBP was assessed by a questionnaire answered in the classrooms as pain/discomfort in the low back during the preceding year. Body height and weight were measured, and BMI was calculated. Hip mobility was measured as active movements by a goniometer. The level of significance was set to P< or =0.05. In bivariate analysis for the whole group, LBP was associated positively with a higher than mean BMI, while LBP among boys was associated with a less than mean hip flexion, internal rotation, and hamstrings flexibility. In multiple regression analyses, adjusting for gender and well-being, LBP was associated with a higher than mean BMI, a less than mean hamstrings flexibility, and a less than mean hip flexion. The results suggest further prospective research to investigate whether poor hip mobility and high BMI may predict juvenile LBP.

The effect of dance training on joint mobility, muscle flexibility, speed and agility in young cross-country skiers--a prospective controlled intervention study

We evaluated a short-term (3 months) and a long-term (8 months) effect of dance training on joint mobility and muscle flexibility of the spine, hip and ankle and on speed and agility in young cross-country skiers. Twenty elite cross-country skiers - aged 12-15 years - participated in the study. Five males and five females received dance training (intervention group) and five males and five females did not dance (reference group). Joint mobility and muscle flexibility of the spine, hip and ankle joints were measured using a goniometer, a kyphometer, a measuring tape and a ruler. Two sports-related functional tests - the slalom-test and the hurdle-test - were also performed. These measurements/tests were performed before the start of the dancing period and after 3 and 8 months. The subjects from the intervention group increased their speed with 0.3 s after 3 (P = 0.05) and 8 months (P = 0.02), respectively, when measured with the slalom-test. They also improved their speed and agility according to the hurdle-test after 3 months with 0.8 s (P = 0.000) and 8 months with 0.6 s (P = 0.01). Furthermore, they increased flexion-extension of the thoracic spine with 7.5 degrees after 3 months (P = 0.05) and with 9 degrees degrees after 8 months (P = 0.03) and lateral flexion of the spine with 0.04 m (P = 0.005) and 0.03 m (P = 0.02) after 3 and 8 months, respectively. The reference group was impaired or unchanged in the studied parameters after both 3 and 8 months. We conclude that dance training has a positive effect on speed and agility and on joint mobility and muscle flexibility in flexion-extension and lateral flexion of the spine in young cross-country skiers.

Access to pedestrian roads, daily activities, and physical performance of adolescents

STUDY DESIGN

A cross-sectional study using a questionnaire and physical tests was performed.

OBJECTIVE

To study how access to pedestrian roads and daily activities are related to low back strength, low back mobility, and hip mobility in adolescents.

SUMMARY OF BACKGROUND DATA

Although many authorities express concern about the passive lifestyle of adolescents, little is known about associations between daily activities and physical performance.

METHODS

This study compared 38 youths in a community lacking access to pedestrian roads with 50 youths in nearby area providing excellent access to pedestrian roads. A standardized questionnaire was used to obtain data about pedestrian roads, school journeys, and activities from the local authorities and the pupils. Low back strength was tested as static endurance strength, low back mobility by modified Schober techniques, and hip mobility by goniometer. For statistical analyses, a P value of 0.05 or less determined significance.

RESULTS

In the area using school buses, the pupils had less low back extension, less hamstring flexibility, and less hip abduction, flexion, and extension than pupils in the area with pedestrian roads. Multivariate analyses showed no associations between walking or bicycling to school and anatomic function, but regular walking or bicycling to leisure-time activities associated positively with low back strength, low back extension, hip flexion, and extension. Distance by school bus associated negatively with hip abduction, hip flexion, hip extension, and hamstring flexibility (P<0.001). Time spent on television or computer associated negatively but insignificantly with low back strength, hamstring flexibility, hip abduction, and flexion (P<0.1).

CONCLUSION

The results indicate that access to pedestrian roads and other lifestyle factors are associated with physical performance.

Cumulative incidence of lumbar disc diseases leading to hospitalization up to the age of 28 years

STUDY DESIGN

A cohort study of 12,000 persons with a follow-up period ranging from birth to the age of 28 years.

OBJECTIVES

To determine the cumulative incidence of lumbar disc disease leading to hospitalization in a well-defined geographic population, with special emphasis on age of onset and differences between the genders and among disease categories.

SUMMARY OF BACKGROUND DATA

There are few published reports on low back pain in adolescence, and most of them are cross-sectional in design.

METHODS

The Finnish National Hospital Discharge Register was used to identify all possible cases of lumbar disc disease. Copies of all hospital records regarding the diagnosis and course of the disease were collected and the hospitalizations were classified into three categories: 1) confirmed herniated nucleus pulposus (HNP), 2) unconfirmed HNP (sciatica symptoms without visible herniation), and 3) other low back diseases. The patients were classified according to the highest category of diagnosis achieved by each.

RESULTS

Symptomatic low back pain leading to hospitalization first appeared around the age of 15 years, and the incidence rose more sharply from the age of 19, especially in men with other low back diseases. Men were hospitalized more than twice as often as women.

CONCLUSIONS

Lumbar disc diseases leading to hospitalization begin early.

Lumbar mobility in former élite male weight-lifters, soccer players, long-distance runners and shooters

OBJECTIVE: To investigate the long-term effects of different loading conditions in sports and work on lumbar mobility. DESIGN: Factors associated with lumbar mobility were sought by examining sports experience, occupational history, back pain history, anthropometric characteristics, and lumbar magnetic resonance images in 114 former Finnish male élite athletes: 30 soccer players, 29 weight-lifters, 27 long-distance runners, and 28 shooters, aged 45-68 yr. BACKGROUND: Back pain and aging reduce spinal mobility, whereas some sports may increase it. Little is known about the effects of common loading conditions found in work and sports, that do not require extremes of spinal motion on lumbar mobility later in life. METHODS: Sports and occupational histories were obtained from a standardized interview. Lumbar mobility was measured by the flexicurve method. Disc degeneration was evaluated from lumbar magnetic resonance images. The results were analysed with analysis of variance and covariance and multiple regression models. RESULTS: The athlete groups did not differ significantly in lumbar sagittal mobility. Higher body-mass index was associated with less flexion, reduced disc height with less extension, as was a high lifetime number of low back pain episodes. Occupations characterized by varying work postures and light lifting were associated with greater mobility, and heavy work with lesser mobility. CONCLUSIONS: Participation in sports with clearly different loading patterns, that do not emphasize extremes of spinal range of motion, do not appear to lead to significant differences in back mobility in later adulthood, but occupational loading factors and disc height narrowing appear to influence spinal mobility.