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Yumeng Li, Shuqi Zhang and Christina Odeh

The purposes of the study were (1) to compare postural sway between participants with Parkinson’s disease (PD) and healthy controls and (2) to develop and validate an automated classification of PD postural control patterns using a machine learning approach. A total of 9 participants in the early stage of PD and 12 healthy controls were recruited. Participants were instructed to stand on a force plate and maintain stillness for 2 minutes with eyes open and eyes closed. The center of pressure data were collected at 50 Hz. Linear displacements, standard deviations, total distances, sway areas, and multiscale entropy of center of pressure were calculated and compared using mixed-model analysis of variance. Five supervised machine learning algorithms (ie, logistic regression, K-nearest neighbors, Naïve Bayes, decision trees, and random forest) were used to classify PD postural control patterns. Participants with PD exhibited greater center of pressure sway and variability compared with controls. The K-nearest neighbor method exhibited the best prediction performance with an accuracy rate of up to 0.86. In conclusion, participants with PD exhibited impaired postural stability and their postural sway features could be identified by machine learning algorithms.

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Seth T. Strayer, Seyed Reza M. Moghaddam, Beth Gusenoff, Jeffrey Gusenoff and Kurt E. Beschorner

Pressure offloading is critical to diabetic foot ulcer healing and prevention. A novel product has been proposed to achieve this offloading with an insole that can be easily modified for each user. This insole consists of pressurized bubbles that can be selectively perforated and depressurized to redistribute weight to the nonulcer region of the foot. However, the effect of the insole design parameters, for example, bubble height and stiffness, on offloading effectiveness is unknown. To this end, a 3-dimensional finite element model was developed to simulate contact between the rearfoot and insole. The geometry of the calcaneus bone and soft tissue was based on the medical images of an average male patient, and material properties and loading conditions based on the values reported in the literature were used. The model predicts that increasing bubble height and stiffness leads to a more effectively offloaded region. However, the model also predicts that increasing stiffness leads to increasing contact pressures on the surrounding soft tissue. Thus, a combination of insole design parameters was determined, which completely offloads the desired region, while simultaneously reducing the contact pressure on the surrounding soft tissue. This design is expected to aid in diabetic foot ulcer healing and prevention.

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Heloisa Suzano de Almeida, Flávia Porto, Marcelo Porretti, Gabriella Lopes, Daniele Fiorot, Priscila dos Santos Bunn and Elirez Bezerra da Silva

This systematic review verified the effect of dance on postural control in people with Parkinson’s disease (PD) and investigated whether this practice can be as effective over a short period as when it is performed over a longer period in relation to the postural control of this population. The search was performed in April 2019 in nine databases. Only randomized/quasi-randomized controlled trials with participants with idiopathic PD were included. The meta-analysis of the 11 articles included, with 13 results, showed that the 211 participants with PD, who belonged to the group performing dance, had a standardized mean difference of postural control 0.82 [0.52, 1.12] greater than the 182 participants who were in a control situation. The statistically significant results of this meta-analysis indicate that dance can improve postural control in people with PD in a short period of time and therefore contribute to the prevention of falls.

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Waynne F. Faria, Filipe R. Mendonça, Géssika C. Santos, Sarah G. Kennedy, Rui G.M. Elias and Antonio Stabelini Neto

Purpose: To analyze the effects of 2 combined training methods on the cardiometabolic risk factors in adolescents. Methods: A total of 76 adolescents (16.1 [1.1] y, n = 44 female) were randomized into groups of moderate-intensity continuous training combined with resistance training (MICT + RT), high-intensity interval training combined with resistance training (HIIT + RT), or control. The training sessions were performed twice weekly for 12 weeks. The outcomes evaluated included body fat percentage, waist circumference, fasting blood glucose, fasting insulin, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, glycated hemoglobin, insulin resistance index, blood pressure, peak oxygen consumption (VO2peak), and cardiometabolic risk Z score. Results: The intervention groups presented a significant reduction in the cardiometabolic risk Z score after 12 weeks of the combined exercise program. In relation to the cardiometabolic risk Z score between groups, the HIIT + RT group presented a significant intervention effect when compared with the control group (Cohen d = 0.23; P < .05). Significant intervention effects were found when comparing the MICT + RT and control groups for body fat percentage, high-density lipoprotein, and VO2peak. Between the HIIT + RT and control groups, significant intervention effects were found for body fat percentage, blood pressure, and VO2peak. There were not significant differences between the HIIT + RT and MICT + RT groups. Conclusion: Twelve weeks of HIIT + RT and MICT + RT were effective in significantly reducing the cardiometabolic risk in these adolescents.

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Jason M. Avedesian, Tracey Covassin and Janet S. Dufek

Recent evidence suggests previously concussed athletes are at greater risk for lower-extremity (LE) injuries than are controls. However, little is known regarding the influence of sports-related concussion (SRC) on landing biomechanics that may provide a mechanistic rationale for LE injury risk. The purpose of this investigation was to examine LE drop-landing biomechanics in adolescent athletes with and without a previous SRC history. Participants included 10 adolescent athletes with an SRC history and 11 controls from multiple sports. Three-dimensional kinematic and kinetic data associated with LE injury risk were analyzed across 5 trials for 30- and 60-cm landing heights. Multivariate analyses indicated group differences in landing patterns from the 30- (P = .041) and 60-cm (P = .015) landing heights. Follow-up analyses indicated that concussed adolescent athletes demonstrated significantly less ankle dorsiflexion and knee flexion versus controls when performing drop landings. Our findings suggest that previously concussed adolescent athletes complete drop-landing maneuvers with ankle and knee joint kinematic patterns that suggest greater risk for LE injury. While limitations such as sport variety and explicit LE injury history are present, the results of this study provide a possible biomechanical rationale for the association between SRC and LE injury risk.

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Pedro Ángel Latorre-Román, Juan Francisco Fernández-Povedano, Jesús Salas-Sánchez, Felipe García-Pinillos and Juan Antonio Párraga-Montilla

This study aimed to evaluate spatial and temporal perception in endurance runners as a mechanism of pacing control in comparison with other athletes (soccer players). A group of 38 endurance runners and 32 soccer players participated in this study. Runners displayed lower time differences and lower error than soccer players. Taking the athletic levels of endurance runners into consideration, significant differences (p = .011, Cohen’s d = 1.042) were found in the time differences (higher level group = 33.43 ± 29.43 vs. lower level group = 123.53 ±102.61). Significant correlations were found between time differences and performance in a Cooper test (r = −.546) and with the best time in a half marathon (r = .597). Temporal and spatial perception can be considered as a cognitive skill of endurance runners.

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Erika D. Van Dyke, Aaron Metzger and Sam J. Zizzi

Little research has integrated mindfulness and perfectionism, particularly within sports wherein athletes are judged on performance to a standard of perfection. The current study had two primary aims: (a) to explore profiles of mindfulness and perfectionism among intercollegiate gymnasts through a person-centered approach and (b) to analyze differences in objective performance across the resulting profiles. The analytic sample consisted of 244 NCAA gymnasts who completed self-report measures of mindfulness and perfectionism. Competitive performance records (i.e., national qualifying scores) were then gathered for participating gymnasts. Cluster analyses revealed a three-cluster solution; however, significant performance differences were not observed across the three profiles due to lower than desired power. Small to moderate effect size estimates provided some evidence that perfectionism may be adaptive to gymnastics performance. Elite-level athletes were represented across three distinct profiles, suggesting that more than one profile of characteristics may be adaptive for reaching high levels of performance.

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Kara K. Palmer, Danielle Harkavy, Sarah M. Rock and Leah E. Robinson

Purpose: Motor skill interventions are effective for improving young children’s fundamental motor skills, but less is known regarding if boys and girls equally benefit from these interventions. The purpose of this study was to compare changes in preschool-aged boys’ and girls’ fundamental motor skills across an intervention. Methods: Sixty-eight children (M age = 4.4 years, SD = 0.44) participated in the study and completed the Test of Gross Motor Development 2nd Edition before and after a 600-minute Children’s Health Activity Motor Program (CHAMP) intervention. All girls’ (n = 27) and a random subsample of boys’ (n = 27) total, locomotor subtest, object control skill subtests, and individual skills were compared before (pre) and after (post) CHAMP. Potential sex differences in treatment effects were examined by sex by treatment interactions from repeated measures ANOVA, and potential sex differences in individual skills before, after, and across (change) were examined using MANOVAs. Results: Boys and girls had similar motor skills before and after the intervention. Boys and girls had higher scores at posttest, and CHAMP was equally effective for boys and girls. Boys outperformed girls on the run and kick (p < .05) at posttest. Conclusion: Findings support that CHAMP improves skills for both preschool boys and girls.

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Kristin Suorsa, Anna Pulakka, Tuija Leskinen, Jaana Pentti, Andreas Holtermann, Olli J. Heinonen, Juha Sunikka, Jussi Vahtera and Sari Stenholm

Background: The accuracy of wrist-worn accelerometers in identifying sedentary time has been scarcely studied in free-living conditions. The aim of this study was to compare daily sedentary time estimates between a thigh-worn accelerometer, which measured sitting and lying postures, and a wrist-worn accelerometer, which measured low levels of movement. Methods: The study population consisted of 259 participants (M age = 62.8 years, SD = 0.9) from the Finnish Retirement and Aging Study (FIREA). Participants wore an Axivity AX3 accelerometer on their mid-thigh and an Actigraph wActiSleep-BT accelerometer on their non-dominant wrist simultaneously for a minimum of 4 days in free-living conditions. Two definitions to estimate daily sedentary time were used for data from the wrist-worn accelerometer: 1) the count cutpoint, ≤1853 counts per minute; and 2) the Euclidean Norm Minus One (ENMO) cutpoint, <30 mg. Results: Compared to the thigh-worn accelerometer, daily sedentary time estimate was 63 min (95% confidence interval [CI] = −53 to −73) lower by the count cutpoint and 50 min (95% CI = 34 to 67) lower by the ENMO cutpoint. The limits of agreement in daily sedentary time estimates between the thigh- and cutpoint methods for wrist-worn accelerometers were wide (the count cutpoint: −117 to 243, the ENMO cutpoint: −212 to 313 min). Conclusions: Currently established cutpoint-based methods to estimate sedentary time from wrist-worn accelerometers result in underestimation of daily sedentary time compared to posture-based estimates of thigh-worn accelerometers. Thus, sedentary time estimates obtained from wrist-worn accelerometers using currently available cutpoint-based methods should be interpreted with caution and future work is needed to improve their accuracy.