Effects of foot orthoses on running kinetics and kinematics: A systematic review and meta-analysis.

BACKGROUND: Foot orthoses (FOs) are often prescribed by clinicians to treat foot and ankle conditions, prevent running injuries, and enhance performance. However, the lack of higher-order synthesis of clinical trials makes it challenging for clinicians to adopt an evidence-based approach to FOs' prescriptions. RESEARCH QUESTION: Do FOs with different modifications alter lower extremity running kinematics and kinetics? METHODS: A systematic search of seven databases was conducted from inception to February 2023. The analysis was restricted to healthy adults without foot musculoskeletal impairments and studies that compared the FOs effects with the controls. The methodological quality of the 35 studies that met the eligibility criteria was evaluated using the modified Downs and Black checklist. The random effects model estimated the standardized mean difference (SMD) with 95% confidence intervals and effect sizes. Sub-group analyses based on FOs type were performed to assess the potential effects of the intervention. RESULTS: Our findings indicated that both custom and off-the-shelf arch-support FOs reduced peak plantar pressure at the medial heel (SMD=-0.35, and SMD=-1.03), lateral heel (SMD=-0.50, and SMD=-0.53), and medial forefoot (SMD=-0.20, and SMD=-0.27), but increased plantar pressure at the mid-foot (SMD=0.30, and SMD=0.56). Compared with the controls, significant increases (SMD=0.36) in perceived comfort were found with custom FOs. A reduction (SMD=-0.58) in initial ankle inversion was found when a raised heel cup was integrated with arch-support FOs. A medial post integrated with arch support exhibited a reduced ankle (SMD=-1.66) and tibial (SMD=-0.63) range of motion. Custom FOs, however, unfavorably affected the running economy (SMD=-0.25) and perceived exertion (SMD=0.20). SIGNIFICANCE: Although FOs have been reported to have some positive biomechanical effects in healthy populations without musculoskeletal impairments or running-related issues, they need to be optimized and generalized to achieve better running performance and prevent injury.

Biomechanical effects of foot orthoses on jump landing performance: A systematic review.

Jumping is involved in a wide range of sports and activities, and foot orthoses (FO) are suggested to enhance performance and prevent injury. The aim of this systematic review was to investigate whether using FO with different modifications affects jump landing biomechanics and improves performance in healthy individuals. The search strategy included 7 databases that identified 19 studies. The study quality was evaluated using a modified Downs and Black index. The primary outcome measures were joint kinematics, kinetics, muscle activity, vertical jump height, and horizontal jump distance. Our findings indicated that incorporating arch support with a rearfoot post and softer forefoot region into FO may improve several biomechanical variables during jump landing activities. Improvements in vertical ground reaction force loading rates, knee and ankle kinematics, and muscle cocontraction during jumping with FO could enhance jumping performance. In addition, improvements in hip, knee, ankle, and tibial kinematics and vertical ground reaction force loading rates during landing could reduce impact forces and related injuries. Although a limited number of studies have addressed the effects of FO on vertical jump height and horizontal jump distance, inserting such FO inside shoes with optimum bending stiffness could facilitate jumping performance. A rigorous exploration of the effect and mechanism of FO designs on jumping performance could benefit jumping-related activities and prevent ankle and knee injuries.

Greater foot and footwear mechanical work associated with less ankle joint work during running.

Footwear energy storage and return is often suggested as one explanation for metabolic energy savings when running in Advanced Athletic Footwear. However, there is no common understanding of how footwear energy storage and return facilitates changes in muscle and joint kinetics. The purpose of this study was to evaluate the magnitude and timing of foot, footwear and lower limb joint powers and work while running in Advanced and Traditional Athletic Footwear. Fifteen runners participated in an overground motion analysis study. Since footwear kinetics are methodologically challenging to quantify, we leveraged distal rearfoot power analyses ('foot + footwear' power) and evaluated changes in the magnitude and timing of foot + footwear power and lower limb joint powers. Running in Advanced Footwear resulted in greater foot + footwear work, compared to Traditional Shoes, and lower positive ankle work, potentially reducing the muscular demand on the runner. The timing of foot + footwear power varied only slightly across footwear. There are exciting innovation opportunities to manipulate the timing of footwear energy and return. This study demonstrates the research value of quantifying time-series foot + footwear power, and points industry developers towards footwear innovation opportunities.

Examining the joint coordination during dynamic balance learning using vector coding and statistical parametric mapping analyses.

We aimed to examine the changes in balance performance, kinematic variables, and joint coordination of the lower extremities during the Y-balance learning task. Twenty female university students completed five consecutive blocks of Y-balance learning from days 3 to 7 (135 trials). Pre-tests and tests were performed on days 1 and 9. Maximum reach distance, peak joint angle, and joint coordination in the anterior (AL), posterolateral (PL), and posteromedial (PM) directions were measured to determine the efficacy of Y-balance performance. A repeated measures ANOVA was performed for the maximum reach distance across learning blocks to confirm whether learning had occurred. Our results indicated that the maximum reach distance on day 5 was longer than that on other learning days. The maximum reach distance significantly increased in the PL and PM directions after learning. The hip flexion (PL/PM), abduction (PM), internal rotation (PM), and external rotation (PL) angles increased after learning. The knee joint flexion angle increased in both AL and PL directions. Only the ankle dorsiflexion angle increased in the AL direction. Joint coordination indicated that the knee and hip joints performed simultaneously during internal rotation. Ankle-knee joint coordination was performed using dorsiflexion and flexion strategies. Statistical parametric mapping analysis indicated significant differences in the ankle sagittal plane in the AL direction, hip horizontal and hip/knee sagittal planes in the PL direction, and hip/knee sagittal and hip frontal/horizontal planes in the PM direction. These data suggest that the dynamic balance ability of the novice participants improved in relation to changes in coordination patterns after learning. The results of this study can be applied to other populations to improve their dynamic balance and prevent fall injuries.

Computational Biomechanics of Sleep: A Systematic Mapping Review.

Biomechanical studies play an important role in understanding the pathophysiology of sleep disorders and providing insights to maintain sleep health. Computational methods facilitate a versatile platform to analyze various biomechanical factors in silico, which would otherwise be difficult through in vivo experiments. The objective of this review is to examine and map the applications of computational biomechanics to sleep-related research topics, including sleep medicine and sleep ergonomics. A systematic search was conducted on PubMed, Scopus, and Web of Science. Research gaps were identified through data synthesis on variants, outcomes, and highlighted features, as well as evidence maps on basic modeling considerations and modeling components of the eligible studies. Twenty-seven studies (n = 27) were categorized into sleep ergonomics (n = 2 on pillow; n = 3 on mattress), sleep-related breathing disorders (n = 19 on obstructive sleep apnea), and sleep-related movement disorders (n = 3 on sleep bruxism). The effects of pillow height and mattress stiffness on spinal curvature were explored. Stress on the temporomandibular joint, and therefore its disorder, was the primary focus of investigations on sleep bruxism. Using finite element morphometry and fluid-structure interaction, studies on obstructive sleep apnea investigated the effects of anatomical variations, muscle activation of the tongue and soft palate, and gravitational direction on the collapse and blockade of the upper airway, in addition to the airflow pressure distribution. Model validation has been one of the greatest hurdles, while single-subject design and surrogate techniques have led to concerns about external validity. Future research might endeavor to reconstruct patient-specific models with patient-specific loading profiles in a larger cohort. Studies on sleep ergonomics research may pave the way for determining ideal spine curvature, in addition to simulating side-lying sleep postures. Sleep bruxism studies may analyze the accumulated dental damage and wear. Research on OSA treatments using computational approaches warrants further investigation.

Training effects of set- and repetition-interval rest time on recumbent-boxing exercise: Could virtual reality improve further?

This study examined the influence of set-interval and repetition-interval rest time of virtual reality (VR) boxing game in supine-lying posture. Fifty healthy middle-aged adults were randomly assigned into VR and non-VR groups to perform six different exercise protocols with varying set-interval and repetition-interval rest times (S0R0, S0R1/3, S0R2/3, S40R0, S40R1/3, and S40R2/3). Analysis on the non-VR group showed significant differences between exercise protocols for average heart rate (p < 0.001), maximum ventilation volume (p < 0.001), respiratory quotient (p < 0.001), oxygen pulse (p < 0.001), and excess post-exercise oxygen consumption (EPOC) (p = 0.003). VR appeared to have no further improvement on physical training effects in middle-aged adults, while the participants reported negative experience that might be associated with the over-exertion. Future study might need to explore game design elements that can accommodate high-exertion exercises.

Computer-aided screening of aspiration risks in dysphagia with wearable technology: a Systematic Review and meta-analysis on test accuracy.

Aspiration caused by dysphagia is a prevalent problem that causes serious health consequences and even death. Traditional diagnostic instruments could induce pain, discomfort, nausea, and radiation exposure. The emergence of wearable technology with computer-aided screening might facilitate continuous or frequent assessments to prompt early and effective management. The objectives of this review are to summarize these systems to identify aspiration risks in dysphagic individuals and inquire about their accuracy. Two authors independently searched electronic databases, including CINAHL, Embase, IEEE Xplore® Digital Library, PubMed, Scopus, and Web of Science (PROSPERO reference number: CRD42023408960). The risk of bias and applicability were assessed using QUADAS-2. Nine (n = 9) articles applied accelerometers and/or acoustic devices to identify aspiration risks in patients with neurodegenerative problems (e.g., dementia, Alzheimer's disease), neurogenic problems (e.g., stroke, brain injury), in addition to some children with congenital abnormalities, using videofluoroscopic swallowing study (VFSS) or fiberoptic endoscopic evaluation of swallowing (FEES) as the reference standard. All studies employed a traditional machine learning approach with a feature extraction process. Support vector machine (SVM) was the most famous machine learning model used. A meta-analysis was conducted to evaluate the classification accuracy and identify risky swallows. Nevertheless, we decided not to conclude the meta-analysis findings (pooled diagnostic odds ratio: 21.5, 95% CI, 2.7-173.6) because studies had unique methodological characteristics and major differences in the set of parameters/thresholds, in addition to the substantial heterogeneity and variations, with sensitivity levels ranging from 21.7% to 90.0% between studies. Small sample sizes could be a critical problem in existing studies (median = 34.5, range 18-449), especially for machine learning models. Only two out of the nine studies had an optimized model with sensitivity over 90%. There is a need to enlarge the sample size for better generalizability and optimize signal processing, segmentation, feature extraction, classifiers, and their combinations to improve the assessment performance. Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/), identifier (CRD42023408960).

Modified lumbo-pelvic exercise to alleviate mild stress urinary incontinence in middle-aged females.

Urinary incontinence is one of the common clinical problems of females passing middle age. Traditional pelvic floor muscle training to alleviate urinary incontinence is too dull and unpleasant. Therefore, we were motivated to purpose a modified lumbo-pelvic exercise training incorporating simplified dancing components with pelvic floor muscle training. The objective of this study was to evaluate the 16-week modified lumbo-pelvic exercise program that incorporated dance and abdominal drawing-in maneuvers. Middle-aged females were randomly assigned into the experimental (n = 13) and control (n = 11) groups. Compared to the control group, the exercise group significantly reduced body fat, visceral fat index, waistline, waist-hip ratio, perceived incontinence score, frequency of urine leakage, and pad testing index (p < 0.05). In addition, there were significant improvements in pelvic floor function, vital capacity, and muscle activity of the right rectus abdominis (p < 0.05). This indicated that the modified lumbo-pelvic exercise program can promote benefits of physical training and alleviate urinary incontinence in middle-aged females.

Pilot testing of a simplified dance intervention for cardiorespiratory fitness and blood lipids in obese older women.

INTRODUCTION: Dance interventions require long learning periods and exert high joint loading. Therefore, a simple dance intervention is required. AIMS: To examine the effects of simplified dance on body composition, cardiorespiratory fitness, and blood lipid levels in obese older women. METHOD: Twenty-six obese older women were randomly assigned to exercise and control groups. The dance exercise involved pelvic tilt and rotation with basic breathing techniques. Anthropometry, cardiorespiratory fitness, and blood lipid levels were measured at baseline and after the 12-week training. RESULTS: The exercise group had lower total cholesterol and low-density lipoprotein cholesterol levels and improved VO2max after the 12-week training than at baseline; however, no significant difference was observed for the control group. Additionally, the exercise group had lower triglycerides and higher high-density lipoprotein cholesterol than the control group. CONCLUSIONS: Simplified dance interventions have the potential to improve blood composition and aerobic fitness in obese older women.

Training and retention effects of paced and music-synchronised walking exercises on pre-older females: an interventional study.

BACKGROUND: Physical activity at pre-older ages (55-64 years) can greatly affect one's physical fitness, health, physical-activity behaviour, and quality of life at older ages. The objective of this study was to conduct a 24-week walking-exercise programme among sedentary pre-older females and investigate the influence of different walking cadences on cardiorespiratory fitness and associated biomarkers. METHODS: A total of 78 pre-older sedentary female participants were recruited and randomly assigned to normal (n = 36), paced (n = 15), music-synchronised (n = 15) walking, and no-exercise control (n = 12) groups, respectively. The normal, paced, and music-synchronised walking groups walked at a cadence of 120 steps/min, 125 steps/min, and 120-128 steps/min, respectively, under supervised conditions. Anthropometric characteristics, step length, nutrient intake, blood pressure and composition, and cardiorespiratory fitness were measured at baseline, the 12th week of the programme, the 24th week of the programme (completion), and after a 12-week retention period, which began immediately upon completion of the programme and did not feature any supervised exercises. RESULTS: All walking conditions improved high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, step length, maximum oxygen consumption (VO2max), and oxidative capacity at anaerobic threshold (all P < 0.001); however, after the 12-week retention period only the training effects of HDL-C (P < 0.05) and VO2max (P < 0.05) remained robust. Additionally, music-synchronised walking was found to reduce the fat ratio (P = 0.031), while paced walking was found to reduce body mass (P = 0.049). CONCLUSIONS: The significant pre-post changes in health-related outcomes across the 24-week walking intervention, including improved blood composition, longer step length, and better cardiorespiratory capacity, show that this intervention is promising for improving health and fitness. When, during the retention period, the participants resumed their usual lifestyles without supervised exercise, most physiological biomarkers deteriorated. Thus, for sedentary middle-aged females, persistent behavioural change is necessary to retain the health benefits of physical exercise.

Biomechanical Analysis on Skilled Badminton Players during Take-Off Phase in Forehand Overhead Strokes: A Pilot Study.

Different movement speeds can contribute to different joint loading in sports. Joint contact force is the actual force acting on the articular surface, which could predict performance and injury, but is rarely reported for badminton overhead strokes. Through an approach using musculoskeletal modelling, six male elite badminton players performed forehand overhead strokes at different movement speeds (fast (100%) vs. moderate (90%)). The synchronized kinematics and ground reaction force (GRF) data were measured using a motion capturing system and a force platform. All kinematics and GRF information were input into the AnyBody musculoskeletal modelling to determine the three-dimensional hip, knee and ankle contact forces. Paired t-tests were performed to assess the significant differences among the GRF, joint kinematics and contact force variables between the movement speed conditions. The results showed that when compared with the moderate movement condition, participants performing faster stroke movements induced larger first and second vertical peaks and larger first horizontal peak but lower second horizontal peak, and it also led to higher peak ankle lateral and distal contact forces, knee lateral and distal contact forces, and hip distal contact forces. Additionally, fast movements corresponded with distinct joint angles and velocities at the instant of initial contact, peak and take-off among the hip, knee and ankle joints compared with moderate movement speeds. The current results suggest that changes in joint kinematics and loading could contribute to changes in movement speeds. However, the relationship between lower limb joint kinematics and contact forces during overhead stroke is unclear and requires further investigation.

Effects of Shoe Midfoot Bending Stiffness on Multi-Segment Foot Kinematics and Ground Reaction Force during Heel-Toe Running.

We investigated how midfoot stiffness of running shoes influences foot segment kinematics and ground reaction force (GRF) during heel-toe running. Nineteen male rearfoot strike runners performed overground heel-toe running at 3.3 m/s when wearing shoes with different midfoot bending stiffnesses (low, medium, and high) in a randomized order. A synchronized motion capture system (200 Hz) and force plate (1000 Hz) were used to collect the foot-marker trajectories and GRF data. Foot kinematics, including rearfoot-lab, midfoot-rearfoot, forefoot-rearfoot, and forefoot-midfoot interactions, and kinetics, including GRF characteristics, were analyzed. Our results indicated that high midfoot stiffness shoes reduced the forefoot-rearfoot range of motion (mean ± SD; high stiffness, 7.8 ± 2.0°, low stiffness, 8.7 ± 2.1°; p < 0.05) and forefoot-midfoot range of motion (mean ± SD; high stiffness, 4.2 ± 1.1°, medium stiffness, 4.6 ± 0.9°; p < 0.05) in the frontal plane. No differences were found in the GRF characteristics among the shoe conditions. These findings suggest that an increase in midsole stiffness only in the midfoot region can reduce intersegmental foot medial-lateral movements during the stance phase of running. This may further decrease the tension of the foot muscles and tendons during prolonged exercises.

Effects of midsole thickness on ground reaction force, ankle stability, and sports performances in four basketball movements.

Changes in midsole thickness can influence cushioning and rearfoot stability in running, but no information has been established in basketball. This study aimed to investigate whether midsole thickness would alter ground reaction force, ankle stability and performance-related indicators in four basketball manoeuvres. Fifteen university basketball athletes performed lateral shuffle, forward sprint, counter-movement jump (CMJ) and drop landing in basketball shoes of five midsole thicknesses (Thinnest, Thin, Medium, Thick, Thickest). One-way repeated-measures ANOVA was performed on each of the biomechanics and performances variables and Friedman test was performed on comfort perceptions. Our findings found a significant midsole thickness effect on the lower extremity biomechanics (p < 0.05), with better traction (p = 0.019) and greater plantarflexion (p = 0.019) while sprinting with thinner shoe conditions. Thicker basketball shoes led to greater rearfoot inversion (p = 0.004) and a more significant inversion velocity peak (p = 0.019) during lateral shuffling. No significant difference in peak impact force or peak loading rate was observed between shoes during drop landing. These findings suggest that participants wearing basketball shoes with thicker midsole may lead to ankle instability during lateral shuffling manoeuvres. Wearing basketball shoes with thinner midsoles may be beneficial for sprint and jump performances.

Cardiorespiratory function, resting metabolic rate and heart rate variability in coal miners exposed to hypobaric hypoxia in highland workplace.

Background: Owing to intermittent/acute exposure to hypobaric hypoxia, highland miners may often suffer, the physiological characteristics between highland and lowland miners, however, are rarely reported. The objective of this study was to compare the physiological characteristics of coal miners working at disparate altitudes. Methods: Twenty-three male coal mining workers acclimating to high altitude for 30 ± 6 days in Tibet (highland group; approx. 4500 m above sea level; 628.39 millibar), and 22 male coal mining workers in Hebei (lowland group; less than 100 m above sea level; 1021.82 millibar) were recruited. Tests were conducted to compare ventilatory parameters, circulation parameters, resting metabolic rate (RMR), and heart rate variability (HRV) indices between the two groups in resting state. Results: Ventilation volume per minute (VE) of the highland group was markedly raised compared to that of the lowland group (11.70 ± 1.57 vs. 8.94 ± 1.97 L/min, p = 0.000). In the meanwhile, O2 intake per heart beat (VO2/HR) was strikingly decreased (3.54 ± 0.54 vs. 4.36 ± 0.69 ml/beat, p = 0.000). Resting metabolic rate relevant to body surface area (RMR/BSA) was found no significant difference between the two groups. Evident reduction in standard deviation of NN intervals (SDNN) and remarkable increase in ratio of low- and high- frequency bands (LF/HF) were manifest in highland miners compared to that of lowland ones (110.82 ± 33.34 vs. 141.44 ± 40.38, p = 0.008 and 858.86 ± 699.24 vs. 371.33 ± 171.46, p = 0.003; respectively). Conclusions: These results implicate that long-term intermittent exposure to high altitude can lead miners to an intensified respiration, a compromised circulation and a profound sympathetic-parasympathetic imbalance, whereas the RMR in highland miners does not distinctly decline.

An evaluation of temporal and club angle parameters during golf swings using low cost video analyses packages.

The purpose of this study was to compare swing time and golf club angle parameters during golf swings using three, two dimensional (2D) low cost, Augmented-Video-based-Portable-Systems (AVPS) (Kinovea, SiliconCoach Pro, SiliconCoach Live). Twelve right-handed golfers performed three golf swings whilst being recorded by a high-speed 2D video camera. Footage was then analysed using AVPS-software and the results compared using both descriptive and inferential statistics. There were no significant differences for swing time and the golf phase measurements between the 2D and 3D software comparisons. In general, the results showed a high Intra class Correlation Coefficient (ICC > 0.929) and Cronbach's Coefficient Alpha (CCA > 0.924) reliability for both the kinematic and temporal parameters. The inter-rater reliability test for the swing time and kinematic golf phase measurements on average were strong. Irrespective of the AVPS software investigated, the cost effective AVPS can produce reliable output measures that benefit golf analyses.

Pulmonary Capacity, Blood Composition and Metabolism among Coal Mine Workers in High- and Low-Altitude Aboveground and Underground Workplaces.

(1) Background: While previous studies revealed how underground mining might adversely affect the cardiopulmonary functions of workers, this study further investigated the differences between under- and aboveground mining at both high and low altitudes, which has received little attention in the literature. (2) Methods: Seventy-one healthy male coal mine workers were recruited, who had worked at least 5 years at the mining sites located above the ground at high (>3900 m; n = 19) and low (<120 m; n = 16) altitudes as well as under the ground at high (n = 20) and low (n = 16) altitudes. Participants' heart rates, pulmonary functions, total energy expenditure and metabolism were measured over a 5-consecutive-day session at health clinics. (3) Results: Combining the results for both above- and underground locations, workers at high-altitude mining sites had significantly higher peak heart rate (HR), minimum average HR and training impulse as well as energy expenditure due to all substances and due to fat than those at low-altitude sites. They also had significantly higher uric acid, total cholesterol, creatine kinase and N-osteocalcin in their blood samples than the workers at low-altitude mining sites. At underground worksites, the participants working at high-altitude had a significantly higher average respiratory rate than those at low-altitude regions. (4) Conclusion: In addition to underground mining, attention should be paid to high-altitude mining as working under a hypoxia condition at such altitude likely presents physiological challenges.

Gender and Age Differences in Performance of Over 70,000 Chinese Finishers in the Half- and Full-Marathon Events.

(1) Background: The aim of the present study was to examine the characteristics of over 70,000 long-distance finishers over the last four years in Chinese half- and full-marathon events; (2) Methods: The available data of all finishers (n = 73,485; women, n = 17,134; men, n = 56,351) who performed half- and full-marathon events in Hangzhou from 2016 to 2019 were further analyzed for the characteristics of gender, age and average running speed; (3) Results: The total men-to-women ratio was the lowest in the half-marathon event (1.86) and the highest in the full-marathon event (17.42). Faster running performance in males than in females and faster average running speed in short-distance runners were shown. Gender and race distance were observed to have the most significant effects on average running speed (p < 0.01). For both male and female finishers, the slowest running speed was shown in older age groups (p < 0.01) during the full marathon. Our results indicated that the gender difference in performance was attenuated in the longer race distances and older age groups; (4) Conclusions: Understanding the participation and performances across different running distances would provide insights into physiological and biomechanical characteristics for training protocols and sports gear development in different groups.

Physical Fitness of Chinese Primary School Students across the Coronavirus (COVID-19) Outbreak: A Retrospective Repeated Cross-Sectional Study.

Social distancing measures against COVID-19 imposed restrictions on students that may have affected their physical health and fitness. The objective of this study was to investigate the change in physical fitness of primary school students across the coronavirus outbreaks from 2019 to 2021. This was a retrospective repeated cross-sectional study. We obtained the annual physical and fitness assessment data measured every November for all students at the same primary school in Guangzhou, China. There was a total of 6371 observations in the dataset for three years. The physical fitness of the students was evaluated with an overall physical fitness score, body mass index (BMI), lung vital capacity, physical flexibility (via a sit-and-reach test) and sports task performances (sprint, shuttle run, rope-jumping, and sit-up). Generalised estimating equations were used to determine any significant changes from 2019 to 2021, adjusted for confounders. After the COVID-19 outbreak in 2021, there was a significant elevation in BMI of 0.64 kg/m2 in 2020 and 0.39 kg/m2 in 2021 (p < 0.001). The overall physical fitness score was significantly increased by 2.1 and 4.1 points, respectively, in 2020 and 2021 (p < 0.001). Lung vital capacity and rope-jumping performance were significantly improved in both 2020 and 2021 compared with 2019, and sit-up performance was marginally significantly improved in 2020 and significantly improved in 2021. However, students demonstrated poorer flexibility and sprint and shuttle run performance in 2021 compared with 2019. A health promotion programme during and after COVID-19, including online physical education classes, television broadcasts, and a rope-jumping campaign, could account for these positive outcomes, along with the ease of administering rope-jumping and sit-ups at home.

Shoe Bending Stiffness Influence on Lower Extremity Energetics in Consecutive Jump Take-Off.

Objective: This study examined the influence of shoe bending stiffness on lower extremity energetics in the take-off phase of consecutive jump. Methods: Fifteen basketball and volleyball players wearing control shoes and stiff shoes performed consecutive jumps. Joint angle, angular velocity, moments, power, jump height, take-off velocity, take-off time, and peak vertical ground reaction force data were simultaneously captured by motion capture system and force platform. Paired t-tests were performed on data for the two shoe conditions that fit the normal distribution assumptions, otherwise Wilcoxon signed-rank tests. Results: There are significant differences (P < 0.05) in take-off velocity and take-off time between stiff and control shoe conditions; the stiff shoes had faster take-off velocity and shorter take-off time than control shoes. There was no significant difference between two conditions in jump height (P = 0.512) and peak vertical ground reaction force (P = 0.589). The stiff shoes had significantly lower MTP dorsiflexion angle and greater joint work than the control shoes (P < 0.05). The MTP range of motion and maximum angular velocity in stiff shoe condition were significantly lower than those in control shoe condition (P < 0.01). However, there are no significant differences between two conditions in kinetics and kinematics of the ankle, knee, and hip joint. Conclusions: The findings suggest that wearing stiff shoes can reduce the effect of participation of the MTP joint at work and optimize the energy structure of lower-limb movement during consecutive jumps.

Health Risks and Musculoskeletal Problems of Elite Mobile Esports Players: a Cross-Sectional Descriptive Study.

BACKGROUND: Mobile-gaming athletes sit in the same posture for prolonged periods, contributing to significant health risks. This study investigated the health profiles, fatigue, pain and complaints, and musculoskeletal problems of full-time mobile-gaming athletes. METHODS: A total of 50 elite mobile-gaming athletes were involved in this study. They were the starting lineup players from all ten professional teams competing in a top-tier multiplayer online battle arena tournament. A survey was conducted to evaluate their fatigue patterns, pain levels, and complaints. A descriptive analysis was conducted to evaluate the athletes' health profiles [body mass index (BMI), fat ratio], fatigue, number of complaints, and musculoskeletal problems. The associations of career duration with BMI, fat ratio, and the total number of confirmed injuries were then determined using Spearman's rank correlation test. RESULTS: A total of 46% and 44% of the participants felt tired frequently and occasionally, while 34% and 58% experienced eyestrain frequently and occasionally, respectively. More than 30% of the participants reported headache and rhinitis. A longer esports career duration was associated with a reduction in BMI (r = -0.272, p = 0.056). Career duration had no significant association with smoking habits (p = 0.666), alcohol habits (p = 0.655), coffee habits (p = 0.946), rounds of games for which the player could maintain concentration (p = 0.253), ease of eyestrain (p = 0.569), tiredness (p = 0.510), dizziness (p = 0.071), or leg numbness (p = 0.318). CONCLUSION: The findings of this study stress the significance of esports injuries and indicate preventive measures for both athletes and recreational players.