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1.
Tara Reilly Evan Walsh Barry Stockbrugger 《Journal of Science and Medicine in Sport》2019,22(5):591-595
Objectives
The Canadian Army fitness objective is FORCE COMBAT?. This consists of a 5 km march (35 kg) between 50–60 min, and the annual FORCE physical employment standard as a circuit without the usual 5 min rest intervals (FORCE circuit) in full fighting order (25 kg). The objective of this research was to determine the number of practice attempts required to establish reliability of FORCE COMBAT?. Additionally, this study aims to identify the minimal detectable change once reliability is established.Design
The study used a within participant design.Methods
33 Canadian Army members were divided into two groups. Group 1 performed four maximum effort attempts of FORCE COMBAT? completely. Group 2 performed only the FORCE circuit component, not the loaded march. On the fifth trial, the tasks of the groups were switched. Variability within and between trials of the FORCE circuit of FORCE COMBAT? were analysed based on six statistical factors of reliability.Results
Four statistical factors indicated that one maximal effort practice attempt of FORCE COMBAT? is required, as reflected in the variability of performance between trials 1 and 2. The minimum detectable change, highlighting inherent measurement error of the test was 89.18 s with 95% confidence.Conclusions
Results suggest that Canadian Army members should complete one FORCE COMBAT? in completion at maximal effort, before formal assessment. Further, members performing within 89 s of the recommended completion time, on FORCE COMBAT? should be offered a re-attempt (in its entirety). 相似文献2.
Objective
To examine the association between sedentary leisure-time and all-cause mortality and differences in survival time.Design
Prospective cohort study.Methods
Information on sedentary leisure-time, defined as TV viewing and/or sitting reading, was collected from 72 003 Swedish adults who were 45–83 (median 60) years of age and completed a self-administered questionnaire at baseline and were followed up for 17 years through linkage with the Swedish Death Register.Results
The association between sedentary leisure-time and all-cause mortality was modified by age with a more pronounced association in middle-aged (<60 years of age) than in older adults (≥60 years of age) (p-interaction < 0.001). During follow-up, 3358 and 15 217 deaths occurred in the middle-aged and older age group, respectively. The multivariable-adjusted hazard ratios for the highest (>6 h/day) versus lowest category (<1 h/day) of sedentary leisure-time were 1.72 (95% confidence interval [CI] 1.29–2.30) in middle-aged adults and 1.19 (95% CI 1.05–1.36) in older adults. This corresponded to a difference in survival time of respectively 2.4 (95% CI ?4.1 to ?0.8) years and 1.5 (95% CI ?2.2 to ?0.7) years.Conclusions
Prolonged sedentary leisure-time was associated with a significantly decreased survival time up to 2.4 years in middle-aged adults. 相似文献3.
Shaun Porter Noah D. Silverberg Naznin Virji-Babul 《Journal of Science and Medicine in Sport》2019,22(4):397-402
Objectives
To examine the neurophysiological correlates and brain network organization underlying physical and cognitive exertion in active young adults.Design
Repeated measures.Methods
Thirteen healthy adults completed three exertion tasks in a counterbalanced order: a graded working memory task (anti-saccade and serial addition task (ASAT)), a graded exercise task (cycling on a stationary bicycle) (EX) and a combined graded working memory and exercise task (ASAT + EX). All three tasks were performed under five levels of increasing difficulty. Continuous EEG was recorded in each session. Heart rate, perceived exertion and accuracy on the working memory task were recorded throughout. Power spectrum analysis and graph theoretical analysis was applied to the EEG data.Results
Heart rate and perceived exertion increased with exercise load and in both the EX only and ASAT + EX tasks. Overall accuracy was equally high for the ASAT and ASAT + EX tasks. Analysis of EEG data showed there was an increase in theta power associated with the ASAT + EX task and increase in functional connectivity in the frontal regions of the brain compared with ASAT only task. Accuracy decreased in the last two blocks when the task was most difficult. This decrease in accuracy was associated with a decrease in theta power and a decrease in functional connectivity.Conclusions
Combined physical and mental exertion results in significant changes in perceived exertion, EEG theta power and network organization in healthy adults and will be valuable in revealing residual neurocognitive deficits after sports related concussion. 相似文献4.
Sally J. McLaine Marie-Louise Bird Karen A. Ginn Thomas Hartley James W. Fell 《Journal of Science and Medicine in Sport》2019,22(5):516-520
Objectives
To determine the relationship and predictive value of isometric shoulder strength in the development of shoulder pain in young swimmers.Design
Prospective, cohort study.Methods
Shoulder flexion, extension, external and internal rotation strength tests were performed in elevation on 85 swimmers (14–20 years; 48 females) without current shoulder pain using a hand-held dynamometer. Following testing, swimmers were emailed questionnaires to determine if significant shoulder pain developed within 24 months subsequent to testing. The differences between shoulders that did and did not develop pain and the predictive ability of shoulder strength and strength ratios were investigated using Mann Whitney U tests and receiver operating characteristic curves.Results
Thirty-seven swimmers (47%) returned questionnaires and 18 reported shoulder pain. A comparison of individual shoulders (27 with pain reported and 47 without) determined that shoulder extension strength was lower and flexion:extension strength ratio was higher for male swimmers (n = 36 shoulders) who reported shoulder pain compared to those who did not (p = 0.04). The predictive value of extension strength was fair (0.72; p = 0.03) for males with a cut-off value for extension strength calculated at 13.5% body mass. There were no differences between the two groups in shoulder rotation strength, age, training hours or previous pain history.Conclusions
Shoulder extension strength, a functional test for swimmers, was associated with and predictive of the development of shoulder pain in male swimmers. Low shoulder extension strength may be a risk factor for the development of shoulder pain in swimmers, proposing a direction for injury prevention and future investigation. 相似文献5.
Kimberley L. Way Rachelle N. Sultana Angelo Sabag Michael K. Baker Nathan A. Johnson 《Journal of Science and Medicine in Sport》2019,22(4):385-391
Objectives
Greater arterial stiffness and poor 24 h blood pressure (BP) are recognized as indicators of poor cardiovascular health. Evidence has shown that high intensity interval training (HIIT) may be a superior alternative to moderate intensity continuous training (MICT) for improving cardiovascular disease risk factors such as cardiorespiratory fitness and vascular function. However, there are limited data comparing the effect of HIIT to MICT on central arterial stiffness and/or 24 h BP response. The purpose of this study was to compare HIIT versus MICT on central arterial stiffness and 24 h BP outcomes by systematic review and meta-analysis.Design
A systematic review and meta-analysis was conducted.Methods
Eligible studies were exercise training interventions (≥4 weeks) that included both HIIT and MICT and reported central arterial stiffness, as measured by pulse wave velocity and augmentation index and/or 24 h BP outcome measures.Results
HIIT was found to be superior to MICT for reducing night-time diastolic BP (ES: ?0.456, 95% CI: ?0.826 to ?0.086 mmHg; P = 0.016). A near-significant greater reduction in daytime systolic (ES: ?0.349, 95% CI: ?0.740 to 0.041 mmHg; p = 0.079) and diastolic BP was observed with HIIT compared to MICT (ES: ?0.349, 95% CI: ?0.717 to 0.020 mmHg; p = 0.063). No significant difference was found for other BP responses or arterial stiffness outcomes.Conclusions
HIIT leads to a superior reduction in night-time diastolic BP compared to MICT. Furthermore, a near-significant greater reduction in daytime BP was found with HIIT compared to MICT. No significant difference was observed for changes to central arterial stiffness between HIIT and MICT. 相似文献6.
Cassandra S. Thompson Claire E. Hiller Siobhan M. Schabrun 《Journal of Science and Medicine in Sport》2019,22(4):425-429
Objectives
To compare soleus spinal reflex excitability, presynaptic inhibition and recurrent inhibition between chronic ankle instability (CAI), acute Lateral Ankle Sprain coper (LAS-coper) and healthy populations. The relationship between spinal reflex excitability and pain and perceived instability in people with CAI was also examined.Design
Cross-sectional laboratory experiment.Methods
Twelve individuals with CAI, twelve ‘copers’ and twelve healthy age, limb and gender-matched controls participated. Soleus H-reflex recruitment curves, pre-synaptic excitability and recurrent inhibition of the spinal-reflex pathway were examined during static double- and single-leg stance. Reporting of pain and perceived instability were used to perform a regression analysis on measures of soleus spinal excitability in people with CAI, LAS-coper and healthy controls.Results
Soleus spinal reflex excitability was greater during single-leg stance in CAI compared to healthy and coper individuals (p = <0.001). Pre-synaptic inhibition was three-times less in CAI participants compared to both healthy controls and copers (p = <0.001). There were no differences between healthy and coper participants in spinal-level measures of sensorimotor control. Reports of pain explained 15–16% of the variance in soleus spinal reflex excitability and presynaptic inhibition during single and double-leg stance, while perceived instability explained 20% of the variance in spinal reflex during single leg stance only.Conclusions
CAI participants presented with an inability to suppress soleus spinal reflexes during tasks with increased postural threat; likely due to disinhibition of pre-synaptic mechanisms. Pain and perceived instability may contribute to changes in spinal-level sensorimotor control in CAI. 相似文献7.
Amanda J.L. Watson Anna Timperio Helen Brown Kylie D. Hesketh 《Journal of Science and Medicine in Sport》2019,22(4):438-443
Objectives
To assess the feasibility and efficacy of a 6-week pilot active break program (ACTI-BREAK) on academic achievement, classroom behaviour and physical activity.Design
Pilot cluster randomised controlled trial.Methods
374 children in Year 3 and 4 (74% response) were recruited from six schools across Melbourne, Australia. Schools were randomised to the ACTI-BREAK intervention or usual teaching practice. The intervention involved teachers incorporating 3 × 5 min active breaks into their classroom routine daily. Academic achievement was assessed using 1-min tests in reading and mathematics; classroom behaviour at the individual and whole class level was observed by teachers; and physical activity levels were assessed using accelerometers. Multilevel mixed effects linear regression models were conducted using intention to treat (ITT) and per protocol (PP) analyses.Results
Significant intervention effects were found for classroom behaviour at the individual level (ITT B = 16.17; 95% CI: 6.58, 25.76); effects were stronger for boys (B = 21.42; 95% CI: 10.34, 32.49) than girls (B = 12.23; 95% CI: 1.52, 22.92). No effect was found for classroom behaviour at the whole class level, reading, math or physical activity. PP findings were similar.Conclusions
Implementing active breaks during class time may improve classroom behaviour, particularly for boys. There was no evidence to suggest that implementing active breaks had any adverse effect on academic achievement or classroom behaviour, which may encourage classroom teachers to incorporate active breaks into their routine. 相似文献8.
Lisa A. Bell Elly A. Fletcher Anna Timperio Peter Vuillermin Kylie Hesketh 《Journal of Science and Medicine in Sport》2019,22(5):568-573
Objectives
Higher physical activity (PA) levels in adults are associated with lower cardiovascular disease risk, however it is unclear whether this association is evident in children younger than five years. Given that cardiovascular disease has early life origins, this study systematically reviews evidence of associations between PA and cardiovascular disease risk factors among children aged 3–5.5 years.Design
Systematic review.Method
A systematic search of multiple data bases was conducted to identify published papers reporting associations between any measure of PA and cardiovascular disease risk factors. Inclusion criteria: English language; peer-reviewed; original quantitative research; mean age or majority of sample to be between 3.0–5.5 years. Studies where the sample was characterised by a health condition (e.g. obese, hypertensive) were not eligible for inclusion.Results
Twelve papers met the inclusion criteria. At least one study for each cardiovascular disease risk factor except inflammation was included. PA was not associated with insulin resistance, and inconsistently associated with the remaining cardiovascular disease risk factors. Studies were mostly cross-sectional and methodologically heterogeneous. Longitudinal and experimental study designs and objective measurement of PA may help provide a clearer indication of the interplay between PA and cardiovascular disease risk in the preschool population. 相似文献9.
Pontus Henriksson Marja H. Leppänen Hanna Henriksson Christine Delisle Nyström Cristina Cadenas-Sanchez Anna Ek Jonatan R. Ruiz Francisco B. Ortega Marie Löf 《Journal of Science and Medicine in Sport》2019,22(5):574-579
Objectives
Although physical fitness is considered a marker of health in youth, little is known whether physical fitness in pre-school age is related to later body composition. Thus, this study investigated (i) associations of physical fitness at 4.5 years of age with body composition 12 months later and (ii) whether improvements in physical fitness during the 12-month follow-up were associated with changes in body composition.Design
This study included 142 children, measured at 4.5 and 5.5 years, from the control group of the MINISTOP trial.Methods
Physical fitness (cardiorespiratory fitness, lower- and upper-body muscular strength and motor fitness) was measured using the PREFIT test battery. Body composition was assessed using air-displacement plethysmography.Results
In adjusted regression analyses, greater cardiorespiratory fitness, lower-body muscular strength and motor fitness at 4.5 years were associated with a lower fat mass index at 5.5 years (standardized β= ?0.182 to ?0.229, p ≤ 0.028). Conversely, greater cardiorespiratory fitness, lower- and upper-body muscular strength as well as motor fitness at 4.5 years of age were associated with a higher fat-free mass index (standardized β = 0.255–0.447, p ≤ 0.001). Furthermore, improvements in cardiorespiratory fitness, lower-body muscular strength and motor fitness during the 12-month follow-up period were associated with decreases in fat mass index and/or % fat mass.Conclusions
In conclusion, the results of this study provide evidence of the importance of physical fitness early in life. Nevertheless, further studies are needed in order to clarify the influence of physical fitness in the pre-school age with later health outcomes. 相似文献10.
Erin K. Howie Leo Ng Darren Beales Joanne A. McVeigh Leon M. Straker 《Journal of Science and Medicine in Sport》2019,22(4):456-461
Objectives
The purpose of this study was to identify early life factors that were associated with childhood and adolescent organized sport participation trajectories.Design
Participants were in the Raine Study, a pregnancy cohort in Western Australia recruited from 1989 to 1991.Methods
Three organized sport trajectories over ages 5–17 years were previously identified for girls (n = 824: consistent participators, dropouts, and non-participators in sport) and boys (n = 855: consistent participators, dropouts, joiners — those who joined sport in adolescence). Physical, psychological and social factors were measured from birth to age 5.Results
For girls and boys, children who were breastfed, were taller, did not have behavior problems, and attended childcare were more likely to consistently participate. Girls who had a previous injury (Relative risk ratio 1.55: 95% confidence interval 1.05, 2.29 vs never been injured) or who had parents who had worries about their child’s health (1.56: 1.00, 2.42 vs no worries) were more likely to be in the dropout trajectory. Boys born preterm (2.00, 2.06, 3.76 vs full-term), did not have a previous injury (0.72, 0.53, 0.97 those with injury vs never been injured), had more difficult temperament (1.63, 1.02, 2.60 vs easy temperament), and higher family dysfunction (1.49, 1.06, 2.08) were more likely to be in the dropout trajectory.Conclusions
Early life factors were associated with membership in sport trajectories. Physical, psychological, and social factors may serve as early warning signs for parents and practitioners that children may be at higher risk of dropping out of sports. 相似文献11.
Baruch Vainshelboim Ricardo M. Lima Elisabeth Edvardsen Jonathan Myers 《Journal of Science and Medicine in Sport》2019,22(4):403-407
Objectives
To evaluate the association between cardiorespiratory fitness (CRF), lung cancer incidence and cancer mortality in men.Design
Prospective cohort study.Methods
Maximal exercise testing was performed in 4920 men (59.2 ± 11.4 years) free from malignancy at baseline. Multivariate Cox hazard models adjusted for established cancer risk factors including smoking were analyzed for lung cancer incidence and cancer mortality among those who were diagnosed with lung cancer. Population attributable risks (PAR) of low CRF (<5 METs) were determined.Results
During 12.7 ± 7.5 years follow-up, 105 (2.1%) participants were diagnosed with lung cancer and 83 (79%) of those died from cancer after 3.6 ± 4.6 years from diagnosis. CRF was inversely and independently associated with cancer outcomes. A 1-MET increase and categories of moderate and high CRF were associated with 10%, 47% and 65% reduction in lung cancer incidence (p = 0.002), and 13%, 58% and 76% reduction in cancer mortality (p = 0.002), respectively. Also, individuals who were diagnosed with lung cancer and were at moderate or high CRF categories at baseline exhibited longer survival time (p < 0.001). The PARs% for lung cancer incidence and cancer mortality were 8.7% and 18.5%, respectively.Conclusions
Higher CRF is associated with lower lung cancer incidence in men. Among individuals who were diagnosed with lung cancer, higher CRF was associated with reduced cancer mortality and longer survival time. These results support the protective benefits of higher CRF in the prevention of lung cancer outcomes. Eliminating low CRF as a risk factor would potentially prevent considerable lung cancer morbidity and mortality. 相似文献12.
Luke Hogarth Carl Payton Vaughan Nicholson Jemima Spathis Sean Tweedy Mark Connick Emma Beckman Peter Van de Vliet Brendan Burkett 《Journal of Science and Medicine in Sport》2019,22(5):526-531
Objectives
The International Paralympic Committee has mandated that International Sport Federations develop sport-specific classification systems that are evidence-based. This study examined the predictive and convergent validity of instrumented tapping tasks to classify motor coordination impairments in Para swimming.Design
Cross-sectional.Methods
Thirty non-disabled participants and twenty-one Para swimmers with brain injury completed several instrumented tapping tasks as an assessment of upper and lower limb motor coordination. Para swimmers also completed a maximal freestyle swim to obtain a performance measure. The predictive and convergent validity of instrumented tapping tasks was examined by establishing differences in test measures between participants with and without brain injury and defining the strength of association between test measures and maximal freestyle swim speed in Para swimmers, respectively.Results
Random forest successfully classified 96% of participants with and without brain injury using test measures derived from instrumented tapping tasks. Most test measures had moderate to high correlations (r = 0.54 to 0.72; p < 0.01) with maximal freestyle swim speed and collectively explained up to 72% of the variance in maximal freestyle swim performance in Para swimmers with brain injury.Conclusions
The results of this study evidence the predictive and convergent validity of instrumented tapping tasks to classify motor coordination impairments in Para swimmers with brain injury. These tests can be included in revised Para swimming classification to improve the objectivity and transparency in determining athlete eligibility and sport class for these Para athletes. 相似文献13.
14.
Ida J. Berglund Sara E. Sørås Bård E. Relling Kari M. Lundgren Ida A. Kiel Trine Moholdt 《Journal of Science and Medicine in Sport》2019,22(5):607-610
Objectives
It is suggested that individuals will not reach their heart rate maximum (HRmax) at an incremental cardiorespiratory fitness (CRF) test and commonly five beats per minute (bpm) are added to the highest heart rate (HR) reached. To our knowledge, there is not sufficient data justifying such estimation. Our aim was to assess whether individuals reached HRmax in an incremental CRF test to exhaustion.Design and methods
Fifty-one males and 57 females (aged 22–70 years) completed both an incremental CRF test (gradual increase in speed and/or inclination until volitional exhaustion) and a test designed to reach HRmax (with repeated work bouts at high intensity before maximal exertion) ≥48 h apart. We investigated the relationship between the highest HR in the two tests using hierarchical linear regression analysis, with HRmax from the HRmax test as a dependent variable, and the highest HR reached at the CRF test (HRcrf), whether maximum oxygen uptake was reached on the CRF test, CRF, sex and age as independent variables.Results
HRmax was 2.2 (95% confidence interval, 1.5–2.9) bpm higher in the test designed to reach HRmax than in the CRF test (p < 0.001). Only HRcrf significantly predicted HRmax, with no contribution of the other variables in the model. HRmax was predicted from the highest HR reached in an incremental CRF test by multiplying HRcrf with 0.967, and adding 8.197 (HRmax = 8.197 + [0.967 × HRcrf]) beats/min.Conclusion
Non-athletes reached close to HRmax in a standard CRF test. 相似文献15.
Wen-Shiuan Shih Chueh-Hung Wu Tyng-Guey Wang 《Journal of Science and Medicine in Sport》2019,22(4):392-396
Objectives
Among symptomatic dancers, sonographic abnormalities are common. Whether asymptomatic dancers have any abnormalities remains unknown. Some dancers became cyanosis over distal feet after ballet training. The hemodynamic changes at the feet in ballet are not clearly understood.Design
Cross-sectional study.Methods
In 25 dancers and 14 non-dancers, B-mode ultrasonography was used to measure cross-sectional areas (CSA) of tendons of deep posterior compartment muscles. Doppler ultrasonography was used to measure peak velocity (Vpeak) of posterior tibial artery in three ankle postures: the neutral position, passively and forced actively plantar flexion (en pointe). The big toe oxygen saturation was recorded in neutral position and during 1-min en pointe. Single-leg standing heel rise test was performed to represent the muscle function.Results
The CSA of FHL was larger in dancers (0.26 cm2 [0.20, 0.30] vs 0.21 cm2 [0.17, 0.24], p < 0.01), while other tendons were not different (all p > 0.05). Higher Vpeak was recorded in passively plantar flexion than in neutral position (p < 0.01, in both groups). The blood flow was undetectable during en pointe, more frequently in dancers (54.9% vs 14.3%, p < 0.01). Oxygen saturation decreased during en pointe more prominently in dancers (85% [80, 90] vs 94% [84, 97], p < 0.01). There was no significant difference in muscle function.Conclusions
US showed the FHL tendon thickening and en pointe-related vascular compromise in pre-professional dancers, even when they are asymptomatic. 相似文献16.
Joseph M. Northey Kate L. Pumpa Clare Quinlan Ashley Ikin Kellie Toohey Disa J. Smee Ben Rattray 《Journal of Science and Medicine in Sport》2019,22(5):580-585
Objectives
The current study investigated the effects of two exercise interventions on cognitive function amongst breast cancer survivors.Design
Pilot randomised-controlled trial.Methods
Seventeen female cancer survivors (mean: 62.9 ± 7.8 years) were randomised into three groups: high-intensity interval training (HIIT, n = 6); moderate-intensity continuous training (MOD, n = 5); or wait-list control (CON, n = 6). The HIIT and MOD groups exercised on a cycle ergometer 3 days/week for 12-weeks. Primary outcomes were cognitive function assessments utilising CogState. Secondary outcomes were resting middle cerebral artery blood flow velocity, cerebrovascular reactivity and aerobic fitness (VO2peak). Data were analysed with General Linear Mixed Models and Cohen’s d effect sizes were calculated.Results
All 17 participants who were randomised were available for follow-up analysis and adherence was similar for HIIT and MOD (78.7 ± 13.2% vs 79.4 ± 12.0%; p = 0.93). Although there were no significant differences in the cognitive and cerebrovascular outcomes, HIIT produced moderate to large positive effects in comparison to MOD and CON for outcomes including episodic memory, working memory, executive function, cerebral blood flow and cerebrovascular reactivity. HIIT significantly increased VO2peak by 19.3% (d = 1.28) and MOD had a non-significant 5.6% (d = 0.72) increase, compared to CON which had a 2.6% decrease.Conclusions
This study provides preliminary evidence that HIIT may be an effective exercise intervention to improve cognitive performance, cerebrovascular function and aerobic fitness in breast cancer survivors. Considering the sample size is small, these results should be confirmed through larger clinical trials. 相似文献17.
Andrew Murray Alec Buttfield Andrew Simpkin John Sproule Anthony P. Turner 《Journal of Science and Medicine in Sport》2019,22(4):488-493
Objectives
It is commonplace to consider accelerometer load and any resultant neuromuscular fatigue in training programs. With these data becoming accepted in sport alongside wellness questionnaires this study aimed to investigate if a deeper analysis of the accelerometry data can provide actionable insight into training-induced disruptions.Design
Accelerometer data from Collegiate American Football athletes (n = 63) were collected during training and matches across a regular season.Methods
These data were processed to: identify instances of high speed running, extract step waveforms from those sections, and determine the variability of those waveforms via a within- and between-section co-efficient of multiple determination. Athletes completed wellness questionnaires prior to sessions that were used to flag areas of muscle soreness as well as fatigue, or disturbed sleep quality. Linear mixed models were used to assess associations between inter stride variability and flags in wellness/soreness markers.Results
An increase in acute (7d) load saw an increased stride variability in these athletes. Feeling less fatigued and/or lower muscle soreness was associated with higher stride variability.Conclusions
The assessment of variability has the potential to identify athletes who are displaying physical symptoms that would indicate the need to modify training. 相似文献18.
Robert C. Lynall J. Troy Blackburn Kevin M. Guskiewicz Stephen W. Marshall Prudence Plummer Jason P. Mihalik 《Journal of Science and Medicine in Sport》2019,22(5):503-508
Objectives
Despite evidence for increased musculoskeletal injury after concussion recovery, there is a lack of dynamic balance assessments that could inform management and research into this increased injury risk post-concussion. Our purpose was to identify tandem gait dynamic balance deficits in recreational athletes with a concussion history within the past 18-months compared to matched controls.Design
Cross-sectional, laboratory study.Methods
Fifteen participants with a concussion history (age: 19.7 ± 0.9 years; 9 females; median time since concussion 126 days, range 28–432 days), and 15 matched controls (19.7 ± 1.6 years; 9 females) with no recent concussion history participated. We measured center-of-pressure (COP) outcomes (velocity, path length, speed, dual-task cost) under 4 tandem gait conditions: (1) tandem gait, (2) tandem gait, eyes closed, (3) tandem gait, eyes open, cognitive distraction, and (4) tandem gait, eyes closed, cognitive distraction.Results
The concussion history group demonstrated slower tandem gait velocity compared to the control group (4.0 cm/s difference), thus velocity was used as a covariate when analyzing COP path length and speed. The concussion history group (23.5%) demonstrated greater COP speed dual-task cost than the control group (16.3%) during the eyes closed dual-task condition. No other comparisons were statistically significant.Conclusions
There may be subtle dynamic balance differences during tandem gait that are detectable after return-to-activity following concussion, but the clinical significance of these findings is unclear. Longitudinal investigations should identify acute movement deficits in varying visual and cognitive scenarios after concussion in comparison with recovery on traditional concussion assessment tools while also recording musculoskeletal injury outcomes. 相似文献19.
Jonathan M.D. Staynor Sean D. Byrne Jacqueline A. Alderson Cyril J. Donnelly 《Journal of Science and Medicine in Sport》2019,22(4):420-424
Objectives
Appropriate statistical analysis of clustered data necessitates accounting for within-participant effects to ensure results are repeatable and translatable to real-world applications. This study aimed to compare statistical output and injury risk interpretation differences from two statistical regression models built from a clinical movement sidestepping database. A “naïve” regression model, which does not account for within-participant effects, was compared with an appropriately applied mixed effects model.Design
Comparative study.Methods
Three-dimensional unplanned sidestepping joint angle data (trunk, hip, and knee) from 35 males (112 observations) were used to model peak knee valgus moments and anterior cruciate ligament injury risk during the impact phase of stance. Both statistical models were cross-validated using a k-fold analysis.Results
The naïve regression returned inflated goodness of fit statistics (R2 = 0.50), which was evident following cross-validation (predicted R2 = 0.43). Following cross-validation, the mixed effects model (predicted R2 = 0.40) explained a similar amount of variance, despite containing three less predictors. The naïve model produced inaccurate parameter estimates, overestimating the effects of certain kinematic parameters by as much as 79 %.Conclusions
A regression model naïvely applied to clustered observations of sidestepping data resulted in erroneous parameter estimates and goodness of fit statistics which have the potential to mislead future research and real-world applications. It is important for sport and clinical scientists to use statistically appropriate mixed effects models when modelling clustered motion capture data for injury biomechanics research to protect the translatability of the findings. 相似文献20.
Ewelina Lulińska-Kuklik Mary-Jessica Nancy Laguette Waldemar Moska Magdalena Weber-Rajek Krzysztof Ficek Ryszard Puchala Paweł Cięszczyk Marek Sawczuk Alison Victoria September Agnieszka Maciejewska-Skrendo 《Journal of Science and Medicine in Sport》2019,22(4):408-412