Growth-related sports injuries among young male professional football players in the Netherlands: a prospective cohort study concerning injury incidence, severity and burden.

OBJECTIVES: To investigate the incidence, type and location of growth-related sports injuries (GRSI) in youth professional football in the Netherlands. Secondary, to gain more knowledge on the injury severity and burden of GRSI. METHODS: In this prospective, longitudinal cohort study, 813 players aged 10-18 are included. Data collection is performed by instructing the medical staff of six professional football club academies to register GRSI by means of standardized forms. Training and match exposure are registered individually on a weekly basis. Injury incidence was calculated as number of GRSI per 1000 hours, injury severity as the median number of days lost in categories and injury burden as the number of days lost per 1000 hours. RESULTS: A total of 62 GRSI were documented in the football season 2021-2022. The total incidence of GRSI was 0.62/1000 hours football exposure. Morbus Osgood Schlatter and Morbus Sever were most common types of GRSI, both with incidence rates of 0.22/1000 hours exposure. About 58.3% of the documented GRSI were classified as major (>28 days lost). Within this group, the mean severity was 55 days time-loss to football. CONCLUSIONS: GRSI are relatively common in youth professional football. The most common types are Morbus Sever and Morbus Osgood Schlatter. Morbus Osgood Schlatter has the highest injury severity and burden compared to other types of GRSI.

Findings: GRSI incidence is significant in youth professional football, with M. Osgood Schlatter and M. Sever as the most common types of GRSI. More than half of GRSI are classified as major injuries. The mean injury severity is 55 days-lost due to injury, showing significant injury burden for GRSI. About 20.6% of the GRSI concerns a recurrent injury. GRSI incidence is highest in U13 and U14 players compared to other age groups. GRSI occur more frequently during matches compared to training.Implications: The results of this study provide insight into GRSI incidence and severity for youth professional football during a player's developmental years. The results from this study can be used in practice to recognize and acknowledge GRSI in young professional football players. These data will provide clinicians with prognostic information about expected length of the absence following specific types of GRSI.Caution: The results can most likely be extrapolated to other youth professional football academies. External validity towards other populations such as female professional or amateur youth football requires further validation through prospective studies.

Adherence to an injury prevention program in male amateur football players is affected by players' age, experience and perceptions.

Objectives: Adherence to injury prevention programmes in football remains low, which is thought to drastically reduce the effects of injury prevention programmes. Reasons why (medical) staff and players implement injury prevention programmes, have been investigated, but player's characteristics and perceptions about these programmes might influence their adherence. Therefore, this study investigated the relationships between player's characteristics and adherence and between player's perceptions and adherence following an implemented injury prevention programme. Methods: Data from 98 of 221 football players from the intervention group of a cluster randomised controlled trial concerning hamstring injury prevention were analysed. Results: Adherence was better among older and more experienced football players, and players considered the programme more useful, less intense, more functional and less time-consuming. Previous hamstring injuries, educational level, the programme's difficulty and intention to continue the exercises were not significantly associated with adherence. Conclusion: These player's characteristics and perceptions should be considered when implementing injury prevention programmes.

Extracorporeal Shockwave Therapy for Mid-portion and Insertional Achilles Tendinopathy: A Systematic Review of Randomized Controlled Trials.

BACKGROUND: Extracorporeal shockwave therapy (ESWT) is used commonly to treat pain and function in Achilles tendinopathy (AT). The aim of this study was to synthesize the evidence from (non-) randomized controlled trials, to determine the clinical effectiveness of ESWT for mid-portion Achilles tendinopathy (mid-AT) and insertional Achilles tendinopathy (ins-AT) separately. METHODS: We searched PubMed/Medline, Embase (Ovid), and Cochrane Central, up to January 2021. Unpublished studies and gray literature were searched in trial registers (ACTRN, ChiCTR, ChiCtr, CTRI, DRKS, EUCTR, IRCT, ISRCTN, JPRN UMIN, ClinicalTrials.gov, NTR, TCTR) and databases (OpenGrey.eu, NARCIS.nl, DART-Europe.org, OATD.org). Randomized controlled trials (RCTs) and non-randomized controlled clinical trials (CCTs) were eligible when investigating the clinical effectiveness of ESWT for chronic mid-AT or chronic ins-AT. We excluded studies that focused on treating individuals with systemic conditions, and studies investigating mixed cohorts of mid-AT and ins-AT, when it was not possible to perform a subgroup analysis for both clinical entities separately. Two reviewers independently performed the study selection, quality assessment, data extraction, and grading of the evidence levels. Discrepancies were resolved through discussion or by consulting a third reviewer when necessary. RESULTS: We included three RCTs on mid-AT and four RCTs on ins-AT. For mid-AT, moderate quality of evidence was found for the overall effectiveness of ESWT compared to standard care, with a pooled mean difference (MD) on the VISA-A of 9.08 points (95% CI 6.35-11.81). Subgroup analysis on the effects of ESWT additional to standard care for mid-AT resulted in a pooled MD on the VISA-A of 10.28 points (95% CI 7.43-13.12). For ins-AT, we found very low quality of evidence, indicating that, overall, ESWT has no additional value over standard care, with a standardized mean difference (SMD) of - 0.02 (95% CI - 0.27 to 0.23). Subgroup analysis to determine the effect of ESWT additional to standard care for ins-AT showed a negative effect (SMD - 0.29; 95% CI - 0.56 to - 0.01) compared to standard care alone. CONCLUSIONS: There is moderate evidence supporting the effectiveness of ESWT additional to a tendon loading program in mid-AT. Evidence supporting the effectiveness of ESWT for ins-AT is lacking. TRIAL REGISTRATION: PROSPERO Database; No. CRD42021236107.

No Difference in Clinical Effects When Comparing Alfredson Eccentric and Silbernagel Combined Concentric-Eccentric Loading in Achilles Tendinopathy: A Randomized Controlled Trial.

BACKGROUND: Alfredson isolated eccentric loading and Silbernagel concentric-eccentric loading have both shown beneficial effects on clinical symptoms in midportion Achilles tendinopathy (AT), but they have never been compared directly. PURPOSE: To test for differences in clinical effects at 1-year follow-up between Alfredson and Silbernagel loading in midportion AT. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: A total of 40 recreational athletes were allocated to the Alfredson group (AG) or the Silbernagel group (SG). The primary outcome was the difference in the Victorian Institute of Sports Assessment-Achilles (VISA-A) at 1-year follow-up. Secondary outcomes were the visual analog scale for pain during activities of daily living (VAS-ADL) and sports activities (VAS-sports), the EuroQol 5 Dimensions instrument (EQ-5D), and global perceived effect score. Measurements were performed at baseline and 12-week, 26-week, and 1-year follow-up. Analysis was performed using a linear mixed-regression model with intervention (AG vs SG), time (12 weeks, 26 weeks, and 1 year postoperatively), and intervention-by-time interaction. RESULTS: The VISA-A score improved for both AG and SG, from 60.7 ± 17.1 at baseline to 89.4 ± 13.0 at 1-year follow-up and from 59.8 ± 22.2 to 83.2 ± 22.4, respectively (P < .001 for both). Because the interaction term did not significantly improve the model, we reported a treatment effect without interaction term, indicating a constant difference at each follow-up. The linear mixed model with correction for baseline VISA-A and confounders revealed a nonsignificant treatment effect (2.4 [95% CI, -8.5 to 13.3]; P = .656). In addition, after adjustment for the respective baseline values and confounders, nonsignificant treatment effects were found for the VAS-ADL (-2.0 [95% CI, -11.3 to 7.3]; P = .665) and VAS-sports (1.3 [95% CI, -12.8 to 15.3], P = .858). The EQ-5D subscales improved in both groups. After 1 year, significantly more SG participants considered themselves improved (77.3% [SG] vs 50.0% [AG]; P = .04). CONCLUSION: No differences in clinical effects were found between Alfredson and Silbernagel loading at up to 1-year follow-up. Both programs significantly improved clinical symptoms, and given their high adherence rates, offering either of them as a home-based program with limited supervision appears to be an effective treatment strategy for midportion AT. REGISTRATION: NTR5638 (Netherlands Trial Register number).

Physical Activity in Women With Hypothyroidism on Thyroid Hormone Therapy: Associated Factors and Perceived Barriers and Benefits.

BACKGROUND: The purpose of this study was to analyze factors associated with physical activity (PA) and to identify perceived barriers and benefits of PA among patients with hypothyroidism on thyroid hormone therapy. METHODS: This survey-based cross-sectional study was conducted among members of the Dutch thyroid patient organization. Self-reported data on respondents' PA levels and demographic, clinical, and physical health variables were collected. Moreover, perceived barriers and benefits to PA were identified. Respondents were categorized as physically active when meeting the recommended Dutch PA guidelines and physically inactive otherwise. To compare physically active and inactive respondents, potential confounders were entered into univariate analyses. Factors showing significant correlations (P < .20) were added to a multivariate model to determine the associated factors of PA. RESULTS: About 1724 female respondents (mean age 53.0 [11.6] y) were included; 16.1% reported meeting the PA recommendations. Multivariate analysis showed that factors associated with PA included levothyroxine/liothyronine therapy, comorbidities, self-perceived physical fitness, and diminished physical endurance. Overall, physically related barriers to PA were rated highest. CONCLUSIONS: The vast majority of treated hypothyroid respondents are physically inactive and experience long-term exercise intolerance. Considering the health implications of physical inactivity, promotion of regular PA is of key importance in this population.

Physical activity, sports participation and exercise-related constraints in adult women with primary hypothyroidism treated with thyroid hormone replacement therapy.

Awareness of physical activity (PA) constraints in patients with primary hypothyroidism on thyroid hormone replacement therapy (THR) is important. Hence, this cross-sectional matched case-control study aimed to determine PA and sports participation (SP) in patients with hypothyroidism on THR in comparison to control subjects. Accordingly, survey questions were selected from the National Survey on Injuries and Physical Activity in the Netherlands (IPAN), supplemented with questions related to self-reported clinical characteristics and exercise-related constraints (ERC) of patients. In total, 1,724 female patients (mean age 53.0 years ±11.6) and 1,802 controls (mean age 52.6 ± 13.2) were included. Compared to controls, patients were less likely to comply with the moderate-intensity PA guideline (OR 0.70; 95% CI: 0.611-0.803), although patients were more actively participating in sports (OR 1.40; 95% CI: 1.156-1.706). Two-thirds of patients reported that hypothyroidism was limiting their PA performance. These limitations were more pronounced in patients with autoimmune thyroiditis (AIT) than in patients with hypothyroidism from other aetiology (OR 1.93; 95% CI: 1.518-2.457), representing disease-specific exercise intolerance. In order to establish effective intervention programmes to encourage regular PA in hypothyroid patients on THR with exercise intolerance, further research is warranted to better understand PA barriers.

Lower extremity compression garments use by athletes: why, how often, and perceived benefit.

BACKGROUND: Studies on the benefits of lower extremity compression garments (CGs) have focused on their effects on post-exercise recovery and performance improvement. Less is known about why athletes actually use CGs, the frequency with which they use them, and perceived benefits from using CGs. The purpose of this study was to investigate which athletes use CGs, why athletes use CGs, when CGs are worn by athletes, and, in case of an injury or injury prevention, for which injuries CGs are used. METHODS: This cross-sectional study involved 512 athletes who used lower extremity CGs. Athletes completed a questionnaire on the type of CGs they used, and when and why they used them. They also reported their sports participation, past and current sports injuries, and the perceived benefits of using CGs. RESULTS: 88.1% (n=451) of the athletes were endurance athletes and 11.9% (n=61) were non-endurance athletes. Endurance and non-endurance athletes reported running (84.7%, n=382) and obstacle course racing (24.6%, n=15) the most frequently as primary sports, respectively. The most-used CG was the compression sock (59.2%, n=303). In total, 47.5% (n=246) of the athletes used a CG primarily to prevent re-injury and 14.5% (n=74) to reduce symptoms of a current sports injury. Other primary reported aims were primary prevention (13.6%), post-exercise recovery (14.3%), sports performance improvement (8.8%), and to look good (0.2%). The point prevalence of past and current sports injuries among all athletes was 84.2 and 20.2%, respectively. The most common current sports injuries were shin and calf injuries. Many athletes "always" or "often" used their CGs during training (56.8%, n=279) and competitions (72.9%, n=264). Furthermore, almost 90% of the athletes that aimed to prevent re-injury by using CGs reported that CGs contributed to secondary injury prevention. CONCLUSION: 88% of the CG-users were endurance athletes, of which 85% were runners. All athletes mainly used CGs to prevent injury recurrence, but also to reduce symptoms of a current sports injury. A majority of the athletes reported positive perceived effects from the CGs. CGs were used more during than after sports participation.

Determinants of physical activity in young wheelchair-user with spina bifida.

OBJECTIVE: To explore associations between physical activity and peak oxygen uptake (VO2peak), age, sex, and Hoffer classification in young wheelchair-users with spina bifida. DESIGN: Exploratory study. SUBJECTS: Fifty-three dutch children (age 5-19 years) with spina bifida who use a manual wheelchair. METHODS: For the dependent variable physical activity, data from 2 physical activity monitors were analysed: VitaMove data for 34 participants and Actiheart data for 36 participants. Time sedentary, time physically active, and time in moderate to vigorous physical activity were analysed. The Wheelchair Shuttle Test was used to measure VO2peak. Univariate and multivariate regression analyses were performed. Independent variables were VO2peak, age, sex, and Hoffer classification. RESULTS: Time sedentary and time physically active during a school day were influenced by age (ß=0.326/ß=-0.320) and Hoffer classification (ß=0.409/ß=-0.534) and during a weekend day by Hoffer classification (ß=0.617/ß=-0.428). Time in moderate to vigorous physical activity was influenced by Hoffer classification (ß=-0.527) during a school day and by age (ß=-0.600) during a weekend day. CONCLUSION: Older age and the inability to walk negatively influence physical activity. Sex and VO2peak were not associated with physical activity. These results imply that increasing cardiorespiratory fitness alone will not improve physical activity in young wheelchair-users with spina bifida.

6-Minute Push Test in Youth Who Have Spina Bifida and Who Self-Propel a Wheelchair: Reliability and Physiologic Response.

OBJECTIVE: Despite the common occurrence of lower levels of physical activity and physical fitness in youth with spina bifida (SB) who use a wheelchair, there are very few tests available to measure and assess these levels. The purpose of this study was to determine reliability and the physiologic response of the 6-minute push test (6MPT) in youth with SB who self-propel a wheelchair. METHODS: In this reliability and observational study, a sample of 53 youth with SB (5-19 years old; mean age = 13 years 7 months; 32 boys and 21 girls) who used a wheelchair performed 2 exercise tests: the 6MPT and shuttle ride test. Heart rate, minute ventilation, respiratory exchange ratio, and oxygen consumption were measured using a calibrated mobile gas analysis system and a heart rate monitor. For reliability, intraclass correlation coefficients (ICCs), SE of measurement, smallest detectable change for total covered distance, minute work, and heart rate were calculated. Physiologic response during the 6MPT was expressed as percentage of maximal values achieved during the shuttle ride test. RESULTS: The ICCs for total distance and minute work were excellent (0.95 and 0.97, respectively), and the ICC for heart rate was good (0.81). The physiologic response during the 6MPT was 85% to 89% of maximal values, except for minute ventilation (70.6%). CONCLUSIONS: For most youth with SB who use a wheelchair for mobility or sports participation, the 6MPT is a reliable, functional performance test on a vigorous level of exercise. IMPACT: This is the first study to investigate physiologic response during the 6MPT in youth (with SB) who are wheelchair using. Clinicians can use the 6MPT to evaluate functional performance and help design effective exercise programs for youth with SB who are wheelchair using.

Socio-ecological correlates of physical activity in breast and colon cancer survivors 4 years after participation in a randomized controlled exercise trial (PACT study).

BACKGROUND: Having a physically active lifestyle after cancer diagnosis is beneficial for health, and this needs to be continued into survivorship to optimize long-term benefits. We found that patients, who participated in an 18-week exercise intervention, reported significant higher physical activity (PA) levels 4 years after participation in a randomized controlled trial of supervised exercise delivered during chemotherapy (PACT study). This study aimed to identify social-ecological correlates of PA levels in breast and colon cancer survivors 4 years after participation in the PACT study. METHODS: Self-reported PA levels and potential correlates (e.g. physical fitness, fatigue, exercise history, and built environment) were assessed in 127 breast and colon cancer survivors shortly after diagnosis (baseline), post-intervention and 4 years later. Multivariable linear regression analyses were performed to identify social-ecological correlates of PA 4 years post-baseline. RESULTS: The final model revealed that lower baseline physical fatigue (ß = -0.25, 95% CI -0.26; -0.24) and higher baseline total PA (0.06, 95% CI, 0.03; 0.10) were correlated with higher total PA levels 4 years post-baseline. Higher baseline leisure and sport PA (0.02, 95% CI 0.01; 0.03), more recreational facilities within a buffer of 1 km (4.05, 95% CI = 1.28; 6.83), lower physical fatigue at 4-year follow-up (-8.07, 95% CI -14.00; -2.13), and having a positive change in physical fatigue during the intervention period (0.04, 95% CI 0.001; 0.07) were correlates of sport and leisure PA levels 4 years post-baseline. CONCLUSIONS: This study suggests that baseline and 4-year post-baseline physical fatigue, and past exercise behaviour, were significant correlates of PA 4 years after participation in an exercise trial. Additionally, this study suggests that the built environment should be taken into account when promoting PA. Understanding of socio-ecological correlates of PA can provide insights into how future exercise interventions should be designed to promote long-term exercise behaviour. TRIAL REGISTRATION: Current Controlled Trials ISRCTN43801571, Dutch Trial Register NTR2138. Trial registered on 9 December 2009, http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2138.

The Effects of Lower-Extremity Plyometric Training on Soccer-Specific Outcomes in Adult Male Soccer Players: A Systematic Review and Meta-Analysis.

BACKGROUND: Plyometric training is a specific form of strength training that is used to improve the physical performance of athletes. An overview of the effects of plyometric training on soccer-specific outcomes in adult male soccer players is not available yet. PURPOSE: To systematically review and meta-analyze the effects of plyometric training on soccer-specific outcome measures in adult male soccer players and to identify which programs are most effective. METHODS: PubMed, Embase/Medline, Cochrane, PEDro, and Scopus were searched. Extensive quality and risk of bias assessments were performed using the Cochrane ROBINS 2.0 for randomized trials. A random effects meta-analysis was performed using Cochrane Review Manager 5.3. RESULTS: Seventeen randomized trials were included in the meta-analysis. The impact of plyometric training on strength, jump height, sprint speed, agility, and endurance was assessed. Only jump height, 20-m sprint speed, and endurance were significantly improved by plyometric training in soccer players. Results of the risk of bias assessment of the included studies resulted in overall scores of some concerns for risk of bias and high risk of bias. CONCLUSION: This review and meta-analysis showed that plyometric training improved jump height, 20-m sprint speed, and endurance, but not strength, sprint speed over other distances, or agility in male adult soccer players. However, the low quality of the included studies and substantial heterogeneity means that results need to be interpreted with caution. Future high-quality research should indicate whether or not plyometric training can be used to improve soccer-specific outcomes and thereby enhance performance.

Conservative treatment of anterior chronic exertional compartment syndrome in the military, with a mid-term follow-up.

OBJECTIVES: To assess the outcome of conservative treatment for chronic exertional compartment syndrome (CECS) as it relates to the reduction in surgical fasciotomy and return to active duty in a military population. METHODS: Historic cohort. From 2015 to 2018, 75 surgically eligible patients with pressure-positive anterior CECS (Group 1), or with positive pressures and associated medial tibial stress syndrome (Group 2), underwent a conservative treatment programme emphasising gait retraining of running and marching. Treatment success was defined as return to duty, without surgery. Fifty patients from 2015 to 2017 were surveyed to assess mid-term outcomes. RESULTS: The average duration of conservative treatment was 144.9 (±59.6) days. Initially, 65% (49/75) were able to return to duty; 28% (21/75) were referred for surgery and 7% (5/75) left the armed forces. There was no difference in outcomes between Group 1 and Group 2. Survey response rate, on average after 742 days (SD 267, range 381-1256), was 84% (42/50); 57% (24/42) had continued duty, without surgery; of them, 43% were at the same military specialty, 57% in a physically less demanding job. CONCLUSION: A conservative treatment programme for anterior CECS was able to return 65 % of patients to active duty, without surgery. At 2 years, the success rate decreased slightly, but remained positive at 57%. In this high-risk group, initiating a conservative treatment protocol with an emphasis on gait retraining can significantly reduce the need for surgical fasciotomy. For those that fail conservative treatment, surgical release may still be indicated.

Running Themselves Into the Ground? Incidence, Prevalence, and Impact of Injury and Illness in Runners Preparing for a Half or Full Marathon.

OBJECTIVE: To describe the incidence, prevalence, and impact of running-related injuries (RRIs) and illness symptoms in half marathon and marathon runners during the 16-week period before the Utrecht Marathon. METHODS: In this prospective cohort study, we used the Oslo Sports Trauma Research Center questionnaire to register RRIs and illness symptoms every 2 weeks during the 16-week study period. When an injury or illness occurred, questions were added regarding its nature. We calculated the incidence proportion (the number of new cases divided by the number of runners at risk) and the period prevalence (the number of existing and new cases within a 2-week period, divided by the total number of runners at risk during that period). RESULTS: Of the 161 included runners, 9 out of 10 reported an RRI or illness symptom at some time during the study period. In any 2-week period, 5.6% to 14.8% of the runners reported a new RRI, and 6.3% to 13.8% of the runners reported a new illness symptom. The prevalence of RRIs ranged from 29.2% to 43.5%, and the prevalence of illness symptoms ranged from 28.3% to 71.2%. The most prevalent RRIs were in the lower leg (prevalence range, 5.4%-12.3%) and knee (prevalence range, 2.7%-9.3%). The most prevalent illness symptoms were rhinorrhea/sneezing (prevalence range, 3.9%-12.7%) and coughing (prevalence range, 3.9%-11.9%). The incidence and prevalence of illness symptoms peaked at the same time as the influenza-like illness epidemic of the winter of 2015-2016. CONCLUSION: Nine out of every 10 runners reported an RRI or illness symptom in the lead-up to a half or full marathon. In any 2-week period, up to 1 in 7 runners reported a new RRI or illness symptom. LEVEL OF EVIDENCE: 2b. J Orthop Sports Phys Ther 2019;49(7):518-528. doi:10.2519/jospt.2019.8473.

Low Physical Activity and Cardiorespiratory Fitness in People With Schizophrenia: A Comparison With Matched Healthy Controls and Associations With Mental and Physical Health.

Introduction: The aim of this study was to objectively assess time spent in physical activity (PA) and sedentary behavior (SB) in patients with schizophrenia compared to healthy controls matched for age, gender and socioeconomic status. Associations between both PA and cardiorespiratory fitness (CRF) and mental and physical health parameters in patients with schizophrenia were examined. Materials and Methods: Moderate and vigorous PA (MVPA), moderate PA, vigorous PA, total and active energy expenditure (TEE and AEE), number of steps, lying down and sleeping time was assessed with SenseWear Pro-2 body monitoring system for three 24-h bouts in patients with schizophrenia (n = 63) and matched healthy controls (n = 55). Severity of symptoms (Positive and Negative Syndrome Scale and Montgomery and Åsberg Depression Rating Scale), CRF (peak oxygen uptake, VO2peak), body mass index (BMI), and metabolic syndrome were assessed. Results: Patients with schizophrenia performed less MVPA and moderate activity had lower TEE and AEE, spent more time per day lying down and sleeping, and had poorer CRF compared to healthy controls. The amount of MVPA, but especially CRF was associated with severity of negative symptoms in patients with schizophrenia. Only CRF was associated with BMI. Discussion: The current data offer further evidence for interventions aiming to increase physical activity and decrease sedentary behavior. Given strong associations of CRF with both negative symptoms and BMI, treatment aimed at CRF-improvement may prove to be effective.

Physical activity in wheelchair-using youth with spina bifida: an observational study.

BACKGROUND: Even though typically developing youth are already at risk for physical inactivity, youth with spina bifida may be even at higher risk as a consequence of their reduced mobility. No objective data is available for youth with spina bifida who use a manual wheelchair, so the seriousness of the problem is unknown. The purpose of this observational study was to quantify physical activity in wheelchair-using youth with spina bifida and evaluate the intensity of activities. METHODS: Fifty-three children and adolescents (5-19 years) with spina bifida who use a manual wheelchair for daily life, long distances or sports were included. To assess time spent in several types of activities VitaMove data of 34 participants were used and were presented as time spent sedentary and time spent physically active. This was compared to reference data of typically developing youth. To assess time spent in several intensities Actiheart data of 36 participants were used. The intensities were categorized according to the American College of Sports Medicine, ranging from very light intensity to near to maximal intensity. Data of 25 participants were used to combine type of activity and intensity. RESULTS: Children and adolescents with spina bifida who use a manual wheelchair were more sedentary (94.3% versus 78.0% per 24 h, p < 0.000) and less physically active (5.0% versus 12.2% per 24 h, p < 0.000) compared to typically developing peers. Physical activity during weekend days was worse compared to school days; 19% met the Guidelines of Physical Activity during school days and 8% during weekend days. The intensities per activity varied extensively between participants. CONCLUSIONS: Children and adolescents with spina bifida who use a manual wheelchair are less physically active and more sedentary than typically developing youth. The physical activity levels on school days seem to be more favorable than the physical activity levels on a weekend day. The low levels of physical activity need our attention in pediatric rehabilitation practice. The different intensities during activities indicate the importance of individually tailored assessments and interventions.

Reasons and predictors of discontinuation of running after a running program for novice runners.

OBJECTIVES: To determine the proportion of participants of a running program for novice runners that discontinued running and investigate the main reasons to discontinue and characteristics associated with discontinuation. DESIGN: Prospective cohort study. METHODS: The study included 774 participants of Start to Run, a 6-week running program for novice runners. Before the start of the program, participants filled-in a baseline questionnaire to collect information on demographics, physical activity and perceived health. The 26-weeks follow-up questionnaire was used to obtain information on the continuation of running (yes/no) and main reasons for discontinuation. To determine predictors for discontinuation of running, multivariable logistic regression was performed. RESULTS: Within 26 weeks after the start of the 6-week running program, 29.5% of the novice runners (n=225) had stopped running. The main reason for discontinuation was a running-related injury (n=108, 48%). Being female (OR 1.74; 95% CI 1.13-2.68), being unsure about the continuation of running after the program (OR 2.06; 95% CI 1.31-3.24) and (almost) no alcohol use (OR 1.62; 95%CI 1.11-2.37) were associated with a higher chance of discontinuation of running. Previous running experience less than one year previously (OR 0.46; 95% CI 0.26-0.83) and a higher score on the RAND-36 subscale physical functioning (OR 0.98; 95% CI 0.96-0.99) were associated with a lower chance of discontinuation. CONCLUSIONS: In this group of novice runners, almost one-third stopped running within six months. A running-related injury was the main reason to stop running. Women with a low perceived physical functioning and without running experience were prone to discontinue running.

Effects of High-Intensity Interval Training on Fitness and Health in Youth With Physical Disabilities.

PURPOSE: To investigate the effects of high-intensity interval training (HIT) on physical fitness and cardiometabolic health in youth with physical disabilities. METHODS: For this quasi-experimental study 70 participants were recruited from schools for special education and divided into runners and users of wheelchairs. HIT was performed for 8 weeks, twice a week, containing 30 seconds all-out exercises. RESULTS: Exercise adherence was 84.5%. Following HIT, there were improvements in anaerobic performance, agility, aerobic performance, and systolic and diastolic blood pressure. There were no changes in peak oxygen uptake ((Equation is included in full-text article.)O2peak), arterial stiffness, body composition, lipid profile, and fasting glucose. CONCLUSIONS: Both anaerobic and aerobic performance improved after HIT, with no changes in (Equation is included in full-text article.)O2peak. There were no effects on cardiometabolic health, except for a decrease in blood pressure.

Does a bounding exercise program prevent hamstring injuries in adult male soccer players? - A cluster-RCT.

BACKGROUND: Although the Nordic Hamstring Exercise (NHE) prevents hamstring injury in soccer players effectively, the annual incidence of these injuries still increases. This may be because of poor long-term compliance with the program. Furthermore, the timing and amplitude of gluteal and core muscle activation seem to play an important role in hamstring injury prevention, the NHE program was not designed to improve activation of these muscles. Therefore, we propose plyometric training as an alternative to reduce hamstring injuries in soccer players. PURPOSE: To determine the preventive effect of the Bounding Exercise Program (BEP) on hamstring injury incidence and severity in adult male amateur soccer players. STUDY DESIGN: A cluster-Randomized Controlled Trial. METHODS: Thirty-two soccer teams competing in the first-class amateur league were cluster-randomized into the intervention or control group. Both groups were instructed to perform their regular training program, and the intervention group additionally performed BEP. Information about player characteristics was gathered at baseline and exposure, hamstring injuries and BEP compliance were weekly registered during one season (2016-2017). RESULTS: The data of 400 players were analyzed. In total, 57 players sustained 65 hamstring injuries. The injury incidence was 1.12/1000 hours in the intervention group and 1.39/1000 hours in the control group. There were no statistically significant differences in hamstring injury incidence (OR = 0.89, 95% CI 0.46-1.75) or severity between the groups (P > 0.48). CONCLUSION: In this large cluster-randomized controlled trial, no evidence was found for plyometric training in its current form to reduce hamstring injuries in amateur soccer players.

Prognosis and prognostic factors of running-related injuries in novice runners: A prospective cohort study.

OBJECTIVES: To investigate the prognosis and possible prognostic factors of running-related injuries (RRIs) in novice runners. DESIGN: Prospective cohort study. METHODS: Participants of Start to Run, a 6-weeks course for novice runners in The Netherlands, were asked to participate in this study. Before the start of the course a baseline questionnaire, on demographics, physical activity and perceived health, was sent to runners willing to participate. The 26- or 52-weeks follow-up questionnaires assessed information on RRIs and their duration. Only participants that sustained a RRI during follow-up were included in the analyses. An injury duration of 10weeks or shorter was regarded as a relatively good prognosis, while an injury duration of more than 10weeks was defined as a poor prognosis. To determine the associations between baseline characteristics and injury prognosis and between injury location and injury prognosis, multivariable logistic regression analyses were performed. RESULTS: 347 participants (48.8%) sustained an RRI during follow-up. The RRIs had an overall median duration of eight weeks (range: 1-52weeks). Participants with a previous RRI were more likely to have a poor prognosis (OR 2.31; 95%CI 1.12-4.79), while a calf injury showed a trend towards an association with a relatively good prognosis (OR 0.49; 95%CI 0.22-1.11). CONCLUSIONS: The duration of RRIs in novice runners is relatively long, with only calf injuries being associated with a good prognosis. This emphasizes the need of injury prevention measures in novice runners and adequate support during and after an RRI, especially in runners with a previous injury.

The 2017 Dutch Physical Activity Guidelines.

BACKGROUND: The objective of this study was to derive evidence-based physical activity guidelines for the general Dutch population. METHODS: Two systematic reviews were conducted of English language meta-analyses in PubMed summarizing separately randomized controlled trials and prospective cohort studies on the relation between physical activity and sedentary behaviour on the one hand and the risk of all-cause mortality and incidence of 15 major chronic diseases and conditions on the other hand. Other outcome measures were risk factors for cardiovascular disease and type 2 diabetes, physical functioning, and fitness. On the basis of these reviews, an expert committee derived physical activity guidelines. In deriving the guidelines, the committee first selected only experimental and observational prospective findings with a strong level of evidence and then integrated both lines of evidence. RESULTS: The evidence found for beneficial effects on a large number of the outcome measures was sufficiently strong to draw up guidelines to increase physical activity and reduce sedentary behaviour, respectively. At the same time, the current evidence did not provide a sufficient basis for quantifying how much physical activity is minimally needed to achieve beneficial health effects, or at what amount sedentary behaviour becomes detrimental. A general tenet was that at every level of current activity, further increases in physical activity provide additional health benefits, with relatively larger effects among those who are currently not active or active only at light intensity. Three specific guidelines on (1) moderate- and vigorous-intensity physical activity, (2) bone- and muscle-strengthening activities, and (3) sedentary behaviour were formulated separately for adults and children. CONCLUSIONS: There is an unabated need for evidence-based physical activity guidelines that can guide public health policies. Research in which physical activity is measured both objectively (quantity) and subjectively (type and quality) is needed to provide better estimates of the type and actual amount of physical activity required for health.