Tina Junge

Motor performance as predictor of physical activity in children - The CHAMPS Study-DK

PURPOSE Physical activity (PA) is associated with several health benefits in children, and PA habits developed in childhood tend to persist into adulthood. PA may be the foundation of a healthy lifestyle, and motor performance has been shown to be positively associated with PA in cross-sectional studies. The purpose of this study was to explore the longitudinal relation between motor performance and PA in a 3-yr follow-up study. METHODS Longitudinal analyses were performed using data from 673 participants (44% boys, 6-12 yr old) who had been included in the Childhood Health Activity and Motor Performance School study-DK. Baseline motor performance tests consisted of vertical jump, shuttle run, hand grip strength, backward balance, precision throw, and cardiovascular fitness. Composite z-scores were generated to express health-related fitness and performance-related fitness. PA was measured by accelerometer at baseline and at 3-yr follow-up and was expressed as a percentage of time in moderate-to-vigorous PA. RESULTS Cardiovascular fitness, vertical jump, health-related fitness, and performance-related fitness showed significant positive associations with 3-yr follow-up measures of PA in both sexes. Furthermore, shuttle run showed significant inverse associations with follow-up measures of PA for both sexes. CONCLUSIONS Cardiorespiratory fitness, shuttle run, vertical jump, health-related fitness, and performance-related fitness were significantly associated with time spent in moderate-to-vigorous PA at 3-yr follow-up. The clinical relevance of the results indicates that cardiorespiratory fitness and shuttle run in childhood may be important determinants of PA in adolescence.

Field assessment of balance in 10 to 14 year old children, reproducibility and validity of the Nintendo Wii board

BackgroundBecause body proportions in childhood are different to those in adulthood, children have a relatively higher centre of mass location. This biomechanical difference and the fact that children’s movements have not yet fully matured result in different sway performances in children and adults. When assessing static balance, it is essential to use objective, sensitive tools, and these types of measurement have previously been performed in laboratory settings. However, the emergence of technologies like the Nintendo Wii Board (NWB) might allow balance assessment in field settings. As the NWB has only been validated and tested for reproducibility in adults, the purpose of this study was to examine reproducibility and validity of the NWB in a field setting, in a population of children.MethodsFifty-four 10–14 year-olds from the CHAMPS-Study DK performed four different balance tests: bilateral stance with eyes open (1), unilateral stance on dominant (2) and non-dominant leg (3) with eyes open, and bilateral stance with eyes closed (4). Three rounds of the four tests were completed with the NWB and with a force platform (AMTI). To assess reproducibility, an intra-day test-retest design was applied with a two-hour break between sessions.ResultsBland-Altman plots supplemented by Minimum Detectable Change (MDC) and concordance correlation coefficient (CCC) demonstrated satisfactory reproducibility for the NWB and the AMTI (MDC: 26.3-28.2%, CCC: 0.76-0.86) using Centre Of Pressure path Length as measurement parameter. Bland-Altman plots demonstrated satisfactory concurrent validity between the NWB and the AMTI, supplemented by satisfactory CCC in all tests (CCC: 0.74-0.87). The ranges of the limits of agreement in the validity study were comparable to the limits of agreement of the reproducibility study.ConclusionBoth NWB and AMTI have satisfactory reproducibility for testing static balance in a population of children. Concurrent validity of NWB compared with AMTI was satisfactory. Furthermore, the results from the concurrent validity study were comparable to the reproducibility results of the NWB and the AMTI. Thus, NWB has the potential to replace the AMTI in field settings in studies including children. Future studies are needed to examine intra-subject variability and to test the predictive validity of NWB.

Risk Factors for Knee Injuries in Children 8 to 15 Years: The CHAMPS Study DK.

INTRODUCTION Knee injuries are frequent in children, with most studies reporting traumatic knee injuries. Evidence of risk factors for knee injuries in children is sparse. The purpose of this study was to report the extent of traumatic and overuse knee injuries in children and to evaluate intrinsic and extrinsic factors for risk of these injuries. METHODS Weekly musculoskeletal pain, sport participation, and sports type were reported by 1326 school children (8-15 yr). Knee injuries were classified as traumatic or overuse. Multinomial logistic regression was used for analyses. RESULTS During the study period, 952 (15% traumatic and 85% overuse) knee injuries were diagnosed. Period prevalence for traumatic and overuse knee injuries were 0.8/1000 and 5.4/1000 sport participations, respectively. Participation in tumbling gymnastics was a risk factor for traumatic knee injuries (OR, 2.14). For overuse knee injuries, intrinsic risk factors were sex (girls OR, 1.38) and previous knee injury (OR, 1.78), whereas participation in soccer (OR, 1.64), handball (OR, 1.95), basket (OR, 2.07), rhythmic (OR, 1.98), and tumbling gymnastics (OR, 1.74) were additional risk factors. For both injury types, sport participation above two times per week increased odds (OR, 1.46-2.40). CONCLUSIONS Overuse knee injuries were the most frequent injury type. For traumatic knee injuries, participation in tumbling gymnastics was a risk factor. Risk factors for overuse knee injuries were being a girl; previous knee injury; and participation in soccer, handball, basket, and rhythmic and tumbling gymnastics. Further risk factors for both types of injury were participation in sports above two times per week. Although growth-related overuse knee injuries are a self-limiting condition, a major part of children are affected by these injuries with unknown short- and long-term consequences.

Altered knee joint neuromuscular control during landing from a jump in 10-15 year old children with Generalised Joint Hypermobility. A substudy of the CHAMPS-study Denmark

Generalised Joint Hypermobility (GJH) is considered an intrinsic risk factor for knee injuries. Knee neuromuscular control during landing may be altered in GJH due to reduced passive stability. The aim was to identify differences in knee neuromuscular control during landing of the Single-Leg-Hop-for-Distance test (SLHD) in 25 children with GJH compared to 29 children without GJH (controls), all 10-15years. Inclusion criteria for GJH: Beighton score⩾5/9 and minimum one hypermobile knee. EMG was recorded from the quadriceps, the hamstring and the calf muscles, presented relative to Maximum Voluntary Electrical activity (MVE). There was no difference in jump length between groups. Before landing, GJH had 33% lower Semitendinosus, but 32% higher Gastrocnemius Medialis activity and 39% higher co contraction of the lateral knee muscles, than controls. After landing, GJH had 36% lower Semitendinosus activity than controls, all significant findings. Although the groups performed equally in SLHD, GJH had a Gastrocnemius Medialis dominated neuromuscular strategy before landing, plausibly caused by reduced Semitendinosus activity. Reduced Semitendinosus activity was seen in GJH after landing, but with no compensatory Gastrocnemius Medialis activity. Reduced pre and post-activation of the Semitendinosus may present a risk factor for traumatic knee injuries as ACL ruptures in GJH with knee hypermobility.

Single leg mini squat: an inter-tester reproducibility study of children in the age of 9-10 and 12-14 years presented by various methods of kappa calculation.

BackgroundMultiple studies suggest that reduced postural orientation is a possible risk factor for both patello-femoral joint pain (PFP) and rupture of the anterior cruciate ligament (ACL). In order to prevent PFP and ACL injuries in adolescent athletes, it is necessary to develop simple and predictive screening tests to identify those at high risk. Single Leg Mini Squat (SLMS) is a functional and dynamic real-time screening test, which has shown good validity and reproducibility in evaluation of postural orientation of the knee in an adult population. The aim of this study was to determine the inter-tester reproducibility of SLMS in the age group of 9–10 and 12–14 years by evaluating postural orientation of the ankle, knee, hip and trunk. Further on, this study exemplify the divergence of kappa values when using different methods of calculating kappa for the same dataset.MethodsA total of 72 non-injured children were included in the study. Postural orientation of the ankle, knee, hip and trunk for both legs was determined by two testers using a four-point scale (ordinal, 0–3). Prevalence, overall agreement as well as four different methods for calculating kappa were evaluated: linear weighted kappa in comparison with un-weighted kappa, prevalence-adjusted bias-adjusted kappa (PABAK) and quadratic weighted kappa.ResultsThe linear weighted kappa values ranged between 0.54-0.86 (overall agreement 0.86-0.97), reflecting a moderate to almost perfect agreement. When calculating un-weighted kappa (with and without PABAK) and quadratic weighted kappa, the results spread between 0.46-0.88, 0.50-0.94, and 0.76-0.95, reflecting the various results when using different methods of kappa calculation.ConclusionsThe Single Leg Mini Squat test has moderate to almost perfect reproducibility in children aged 9–10 and 12–14 years when evaluating postural orientation of the ankles, knees, hips and trunk, based on the excellent strength of agreement as presented by linear weighted kappa. The inconsistency in results when using different methods of kappa calculation demonstrated the linear weighted kappa being generally 15% lower than the quadratic weighted values. On average, prevalence-adjusted bias-adjusted kappa increased the un-weighted kappa values by 7% and 12% by children aged 9–10 and 12–14, respectively.

Hypermobility in Adolescent Athletes: Pain, Functional Ability, Quality of Life, and Musculoskeletal Injuries

STUDY DESIGN: Cross‐sectional. BACKGROUND: Generalized joint hypermobility (GJH) may increase pain and likelihood of injuries and also decrease function and health‐related quality of life (HRQoL) in elite‐level adolescent athletes. OBJECTIVE: To assess the prevalence of GJH in elite‐level adolescent athletes, and to study the association of GJH with pain, function, HRQoL, and musculoskeletal injuries. METHODS: A total of 132 elite‐level adolescent athletes (36 adolescent boys, 96 adolescent girls; mean ± SD age, 14.0 ± 0.9 years), including ballet dancers (n = 22), TeamGym gymnasts (n = 57), and team handball players (n = 53), participated in the study. Generalized joint hypermobility was classified by Beighton score as GJH4 (4/9 or greater), GJH5 (5/9 or greater), and GJH6 (6/9 or greater). Function of the lower extremity, musculoskeletal injuries, and HRQoL were assessed with self‐reported questionnaires, and part of physical performance was assessed by 4 postural‐sway tests and 2 single‐legged hop‐for‐distance tests. RESULTS: Overall prevalence rates for GJH4, GJH5, and GJH6 were 27.3%, 15.9%, and 6.8%, respectively, with a higher prevalence of GJH4 in ballet dancers (68.2%) and TeamGym gymnasts (24.6%) than in team handball players (13.2%). There was no significant difference in lower extremity function, injury prevalence and related factors (exacerbation, recurrence, and absence from training), HRQoL, or lengths of hop tests for those with and without GJH. However, the GJH group had significantly larger center‐of‐pressure path length across sway tests. CONCLUSION: For ballet dancers and TeamGym gymnasts, the prevalence of GJH4 was higher than that of team handball players. For ballet dancers, the prevalence of GJH5 and GJH6 was higher than that of team handball players and the general adolescent population. The GJH group demonstrated larger sway in the balance tests, which, in the current cross‐sectional study, did not have an association with injuries or HRQoL. However, the risk of having (ankle) injuries due to larger sway for the GJH group must be studied in future longitudinal studies.

Sway as predictor of injuries in children

Introduction Poor postural control measured as sway performance is an intrinsic risk of injury and re-injury among adults. This has not been investigated in children. Objective To investigate the associations between balance, measured as sway performance, and the risk of both acute and overuse injuries in a population of children. Hypothesis: Excessive sway increases the risk of injury. Design The current study is part of The Childhood Health, Activity and Motor Performance School Study-Denmark (CHAMPS Study-DK II), a natural experiment with a prospective, quasi-experimental study design. The follow-up period between baseline measures of sway and registration of injuries was 1 year and 3 months. Setting 10 public schools participated in the study, in the municipality of Svendborg. Participants 1096 participants, 48.7% male, aged 8–14, mean age 11.2. Risk factor assessment The independent variable in the current study is balance measured as sway. Sway was measured on a force platform as centre of pressure path length excursion during four tests: Eyes open: Bilateral stance (test 1), unilateral stance on dominant (test 2) and non-dominant leg (test 3). Eyes closed: Bilateral stance (test 4). Main outcome measurements Primary outcome was overuse and traumatic injuries, with special emphasis on ankle and knee sprains. Complaints were registered by SMS-track on a weekly basis, and after a telephone interview, clinicians examined and diagnosed the children with complaints. Injuries were diagnosed using ICD-10. Results Injuries: 2276, traumatic injuries: 714, ankle sprains: 164, knee sprains: 42. Preliminary multivariate analysis taking into account competing risk showed significant odds ratios (OR) at test 1; A) 1.003 per cm increase of sway; B) overall traumatic injury OR=3.0, ankle sprain OR=5.5 for sway longer than 400 cm/minute. Conclusion Children with an excessive sway has an increased risk of traumatic injuries, this warrants further research into treating reduced balance in children.

The effect and importance of physical activity on behavioural and psychological symptoms in people with dementia: A systematic mixed studies review:

Background People with dementia may benefit from the effect of physical activity on behavioural and psychological symptoms of dementia. Qualitative synthesis of the importance of physical activity might complement and help clarify quantitative findings on this topic. The purpose of this systematic mixed studies review was to evaluate findings from both quantitative and qualitative methods about the effect and importance of physical activity on behavioural and psychological symptoms of dementia in people with dementia. Methods The systematic literature search was conducted in EMBASE, CINAHL, PubMed, PEDro and PsycINFO. Inclusion criteria were: people with a light to moderate degree of dementia, interventions including physical activity and outcomes focusing on behavioural and psychological symptoms of dementia or quality of life. To assess the methodological quality of the studies, the AMSTAR and GRADE checklists were applied for the quantitative studies and the CASP qualitative checklist for the qualitative studies. Results A small reduction in depression level and improved mood were seen in some quantitative studies of multi-component physical activity interventions, including walking. Due to high heterogeneity in the quantitative studies, a single summary of the effect of physical activity on behavioural and psychological symptoms of dementia should be interpreted with some caution. Across the qualitative studies, the common themes about the importance of physical activity were its ‘socially rewarding’ nature, the ‘benefits of walking outdoors’ and its contribution to ‘maintaining self-hood’. Conclusion For people with dementia, there was a small, quantitative effect of multi-component physical activity including walking, on depression level and mood. People with dementia reported the importance of walking outdoors, experiencing the social rewards of physical activity in groups, as well as physical activity were a means toward maintaining self-hood.

The effect of long-term, group-based physical, cognitive and social activities on physical performance in elderly, community-dwelling people with mild to moderate dementia:

Background Elderly people with dementia are known to be less physically active compared with elderly, healthy people, emphasizing the need for interventions in order to maintain a high level of independence in activities of daily living. The aim was to evaluate the effect of long-term, group-based rehabilitation including physical activity on physical performance in elderly, community-dwelling people with mild to moderate dementia. Methods A quasi-experimental study of 18 elderly, community-dwelling people, diagnosed with mild to moderate dementia, participated in an ongoing rehabilitation programme based on integrated physical, cognitive and social activities. The outcome measure was physical performance: the 30-second sit-to-stand test, Guralnik balance test, 10-metre walking speed test, timed 6-metre walk test and a timed dual task walk test. The repeated measure ANOVA was used to analyse any overall differences between related means. Results No significant effect of time was found for the five outcome measures during the entire period. The variation in the estimate of most outcome scores was higher within subjects than between subjects during the period. Profile plots illustrated that three of the participants, who experienced severe cognitive deterioration, markedly declined in all physical performance tests. Conclusion The expected, progressive deterioration in physical performance was delayed in a small group of home-dwelling people with mild to moderate dementia participating in long-term, group-based rehabilitation. Long-term, group-based rehabilitation may have the overall potential to delay deterioration in activities of daily living performance in home-dwelling people with mild to moderate dementia; however, more studies with larger samples are needed to confirm the findings of this study.

Generalised joint hypermobility and knee joint hypermobility: prevalence, knee joint symptoms and health-related quality of life in a Danish adult population

Several biomechanical factors, such as knee joint hypermobility (KJH), are suggested to play a role in the etiology of knee joint symptoms and knee osteoarthritis. Nevertheless, the prevalence or consequences of KJH solely or included in the classification of generalized joint hypermobility (GJHk) is unknown for a general population. Therefore, the objectives were to report the prevalence of self‐reported GJHk and KJH, as well as the association of these conditions to knee joint symptoms, severity and duration of symptoms, and health‐related quality of life (HRQoL) in a Danish adult population.