Dynamic Balance Ability Research Articles

INFLUÊNCIA DA EMPUNHADURA BIMANUAL SOBRE O EQUILÍBRIO E A COORDENAÇÃO MOTORA EM TENISTAS

ABSTRACT Introduction: There is empirical evidence that training with bimanual grip can improve tennis’s technical and tactical level. However, this practice lacks a scientific study supporting its fundamentals and methodological arguments for effective training. Objective: Investigate the influences of two-handed grip training on balance and motor coordination in tennis players. Methods: The study was conducted by literature data collection, experimental testing, and mathematical statistics. A bimanual grip training protocol was designed and tested on volunteer athletes. Biomarkers were collected, discussed, and analyzed inter- and intra-group statistically. Results: After 5 weeks of basic training, there were significant differences in homeostatic control and physical agility between the experimental and control groups. After training, the dynamic balance ability of the experimental group athletes was significantly improved. Conclusion: The study results show that training, according to the proposed protocol, can benefit athletes' dynamic balance and motor coordination, improving motor coordination and balance in practical sports movements. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

기능적 발목관절 불안정성 축구선수의 신경근 훈련이 발목관절 기능 및 운동 수행능력에 미치는 영향

This study attempted to investigate the functional ankle instability (FAI) of soccer players. In this study, twelve college soccer players were selected as subjects. Before the experiment, based on the ankle joint instability scale (AII, FAAM, idFAI), six subjects with FAI were divided into FAI experimental group, while the other six subjects without FAI were classified as control groups. Firstly, functional movement tests were performed on two groups of subjects, including dynamic balance ability, rear-foot angle and hopping. Then, the two groups of subjects performed neuromuscular training for up to six weeks. When the training was over, we performed the same functional movement tests on both groups. Finally, we analyzed and compared the indicators of the experimental group and the control group before and after the training. The detailed results are as follows: After six weeks of neuromuscular training, there was a tendency for the dorsiflexion of the ankle joint to increase as well as the varus of knee-joint during the drop landing. After six weeks of neuromuscular training, the dynamic stability forward extension of the CON group was increased and the ability of side hop and figure-of-8 hop was improved. After six weeks of neuromuscular training, it was confirmed that the forward extension and figure-of-8 hop in the dynamic stability of the CON group were significantly improved than the FAI group, although we did not point out the differences between the groups before training. These results will provide useful information about the design considered for rehabilitation or prevention of CAI for soccer players.

The Effect of Physical Activity Programs on Dynamic Balance of Older Adults during Covid-19

Dynamic balance has been found to be a very important ability for older adults to improve posture control and prevent falls, injuries and hospitalisation. The aim of this study was to investigate the influence of two different physical activity (PA) programmes on the dynamic balance ability of older adults. A total of 39 people (mean age: 62.31) from Tel-Aviv, Israel, participated in this research, which was initiated a few weeks before the Covid-19 restrictions. They were divided into three groups: 16 people participated in the Harmonic Gymnastics programme; the second group also consisted of 16 people who regularly practised moderate-to-high intensity fitness exercise; the third group included 7 participants who did not practise PA (No PA). Dynamic balance was measured using the Y-Balance Test before and after three months of the programme. The results showed that participants in the two PA groups increased their dynamic balance for both legs, although only the Harmonic Gymnastics group achieved significant results (p = 0.001). In the two PA groups, the number of falls decreased (p = 0.017 for both groups), and the No PA group recorded lower scores for both legs, although the decrease was significant only for the left leg (p = 0.043). The study emphasises the importance of PA for older age groups, especially in Covid-19 conditions, and the importance of the Harmonic Gymnastics PA programme that involves body awareness, coordination, vestibular and proprioceptive abilities.

Exploring the factors associated with decreased dynamic balance ability in older patients with heart failure

BackgroundOlder patients with heart failure (HF) have a higher prevalence of frailty and poorer dynamic balance ability than other community-dwelling older adults. However, the association of frailty and other clinical characteristics with dynamic balance ability in these patients remains unclear. ObjectivesWe aimed to determine the clinical characteristics associated with decreased dynamic balance ability in older patients with HF. MethodsThis observational study included patients aged ≥65 years who could walk independently and were admitted to our university hospitals to undergo a cardiac rehabilitation. The timed up and go test (TUG) was used to evaluate dynamic balance ability. Pearson's and Spearman's correlation analyses were performed to determine the relationships between TUG scores and clinical characteristics. A multiple regression model based on the forced entry method was used to determine independent predictors of TUG scores. ResultsOf the 183 participants in this study (94 women; mean age, 82.5 ± 8.1 years), 116 (61.7%) had frailty. Pearson's and Spearman's correlation analyses revealed that age, frailty, sex, knee extensor muscle strength, maximum calf circumference, and Mini-Mental State Examination–Japanese version (MMSE–J) score were significantly correlated with TUG score (p < 0.001). Further, multiple regression analysis showed that age (p < 0.001), frailty (p = 0.041), knee extensor muscle strength (p = 0.002), and MMSE–J score (p = 0.048) were independent predictors of TUG scores. ConclusionMultiple factors, including age, frailty, knee extensor muscle weakness, and cognitive function impairment are independently associated with decreased dynamic balance ability in older patients with HF.

Comparison of Foot Posture, Joint Position Sense, Dynamic Balance, and Plantar Pressure between Young Adults with and without Obesity

Background Obesity has been suggested as a social issue, but problems in the foot and ankle have not been clearly identified in people with obesity. Purpose To compare foot posture, joint position sense, dynamic balance ability, and plantar pressure in obesity group (OG) and normal weight group (NWG) Study design Cross-sectional study Methods This study included 52 adults (26 for OG and 26 for NWG). All subjects had their foot posture index-6 and joint position sense (20° of inversion, 20° of plantar flexion, 10° of eversion, and 10° of dorsiflexion) measured, as well as their dynamic balance ability using a dynamic balance test and plantar pressure of the medial forefoot during the dynamic balance test. These variables were compared between OG and NWG. Results OG showed significantly larger joint position sense error for eversion and increased plantar pressure of the medial forefoot during the dynamic balance test in the posteromedial direction. Significant differences were unobserved in other variables between the two groups. Conclusions Adults with obesity have deficits in joint position sense and increased plantar pressure of the medial forefoot.

The Effect of Proprioceptive Training Program on Joint Position Senses, Balance Ability and Agility of Male Volleyball Players

This study aimed to find the effects of proprioception training for improving ankle and trunk joint position senses, balance ability, agility and power, and thereby to lay the theoretical ground of proprioceptive training for preventing volleyball players' injuries and improving their athletic performance. As the subjects of this study, 30 male players in Korea Volleyball Federation (KOVO), who had the career as volleyball players, were selected. The active motion mode of the Humac NORM (CSMI, U.S.A.), the isokinetic testing equipment to measure ankle joint and trunk position sense accurately, was used to measure inversion, eversion, plantar flexion, dorsi flexion and trunk flexion joint position. For balance ability, static and dynamic balance ability evaluated. One leg standing with closed eyes test was used to measure static balance, and dynamic balance was measured using Y-balance. Agility was measured using a side step and a 20m dash. In the measurement of the joint position senses, with right ankle inversion 15^o, left & right ankle dorsi flexion 10^o, and left ankle plantar flexion and trunk flexion 15^o, interaction effects were found (p<.01, p<.05). Plantar flexion of the right ankle had the interaction effect (p<.01). In the standing on one foot test to measure static and dynamic balance, the interaction effect was observed (p<.01). Right anterior, right posteromedial, left posteromedial, right composite score, and left composite score had the interaction effect (p<.01, p<.05). Right posteromedial and left posteromedial showed the interaction effect (p<.01, p<.05). The side-step test to measure agility also observed the interaction effect (p<.01). 20M dash also showed the interaction effect (p<.01). This study found that the proprioceptive training program affected improvements in volleyball players' ankle and trunk joint position senses, balance, and agility.

사회서비스 참여 활동이 청년의 신체조성, 기능적 움직임 검사(FMS) 및 신체균형에 미치는 효과

This study was conducted to investigate changes in body composition and body function after performing strength training and balance exercise 3times a week for 12weeks by participating in the Youth Social Service Project for young people in their 20s and 30s who do not have regular exercise experience. As a result of analyzing the effects of functional movement scale(FMS) and measuring static and dynamic body balance ability, the following conclusions were obtained. First, as for the change in body composition between periods, body fat percentage(p.05) and BMI(p.01) of the service use group significantly decreased, and in comparison between groups, muscle mass was significantly lower than that of the control group(p.05) increased. Second, in the functional movement test between periods, the service use group was deep squat(p.001), hurdle step(p.001), inline lunge(p.01), active leg lift(p.001), and rotation. There was a significant increase in stability(p.01) and total score(p.01), and in the comparison between groups, the service use group showed inline lunge(p.001), shoulder mobility(p.001), and total There was a significant increase in score(p.001). Third, in the comparison between periods, the change in body balance significantly increased in the service use group in static balance ability(p.05), dynamic balance ability(p.05), and total score(p.001). In comparison, the service use group significantly increased in static(p.01), dynamic(p.001), and total scores(p.001) than the control group. Summarizing the above conclusions, it is thought that the 12weeks exercise program for the young people who participated in the youth social service project will be helpful in maintaining positive physical function.

8주 동안의 하타요가와 매트 필라테스 트레이닝이 여성의 기초체력, 정적/동적 밸런스 및 코어 근육 활성에 미치는 효과

The purpose of this study was to investigate effect of hatha yoga and pilates mat exercise on physical fitness, static/dynamic balance ability and muscular activation pattern of the lumbar-pelvic-hip complex (LPHC). Participants in this study were divided into three groups; the control group (CG, n=7), hatha yoga exercise group (HG, n=7), and pilates mat exercise group (PG, n=7). Hatha yoga and pilates mat exercise were performed for 1 hour, 3 times a week for 8 weeks. In order to compare the effects of hatha yoga and pilates mat exercise, we confirmed physical fitness, static and dynamic balance ability and muscular activation pattern of LPHC. As results of this study, the hatha yoga exercise program showed a significant increase in the external oblique muscle activity and one leg stance test with eyes closed, but pilates mat exercise program significant increased strength and endurance in the back muscles and sit-up tests, respectively. Our findings suggested that pilates mat exercise might be effective for improving muscle strength and muscular endurance as well as hatha yoga exercise might activate external oblique muscles and improve balance ability in adult women.

프리스타일스키 우수선수들의 세부종목별 균형능력, 하지 근기능 및 유산소 능력 특성 분석

This study aimed to analyze the differences and characteristics of the balance ability, lower extremity muscle function, and aerobic capacity of players in Mogul, Park & Pipe, and Ski Cross among freestyle skiing events, thereby providing basic data for the development of training programs to improve the technical skills of those players in each event. It measured 40 national representative junior skiers, registered in the Korea Ski Association, from the freestyle events of Mogul, Park & Pipe, and Ski Cross.BR Static balance and dynamic balance abilities, and the isokinetic muscular power and muscular endurance of the hip and knee joints were measured for the balance ability and lower extremity muscle function, respectively. In addition, regarding the aerobic capacity, VO₂peak and HRpeak were measured by incremental step-loading tests.BR The results showed that there was a significant difference in the static balance ability of the skiers in each event, (p.01) and the post-hoc analysis results showed that the static balance ability of the Mogul skiers was significantly higher than that of the Park & Pipe and Ski Cross skiers (p.05). It was also found that there was a significant difference in all the items of the lower extremity muscle function of the skiers by event, except the knee joint of 300°/sec (muscular endurance) (p.05). The post-hoc analysis results showed that the lower extremity muscle function of the Mogul skiers was significantly higher than that of the Park & Pipe skiers (p.05) in all items, except the knee joint of 180°/sec Extension and of 300°/sec(muscular endurance) (p.05). In addition, it was found that the Ski Cross skiers had significantly higher 45°/sec Flexion(muscular power) and 300°/sec Flexion(muscular endurance) of hip joints than those of the Park & Pipe skiers (p.05). The comparison of the aerobic capacity showed that there was a significant difference in VO₂peak for each event (p.05).BR In conclusion, the characteristics of physical factors affecting high performance in each of freestyle skiing events were different, and it is considered that subsequent studies need to develop exercise programs for each event and then verify their effects, based on the results of this study.

Walking speed, hip muscles strength, aerobic capacity, and self-perceived locomotion ability most explain walking confidence after stroke: a cross-sectional experimental study.

Identifying the determinants of walking confidence can be crucial in therapeutic terms. On these bases, interventions to improve these factors could improve, in turn, walking confidence. Objective is to explore the relationship between motor impairments and activity limitation measures and walking confidence in people with chronic stroke. Walking confidence was assessed using the modified Gait Efficacy Scale. The independent variables were: strength of the hip flexors and knee flexors/extensors (measured with a dynamometer), lower limb coordination (assessed by the Lower Extremity Motor Coordination Test), dynamic balance (assessed by the Four-Square Step Test), walking speed (from the 10-m Walk Test), aerobic capacity (from the 6-Minute Walk Test), and self-perceived locomotion ability (assessed by the ABILOCO). Pearson correlation was used to explore the relationships between the variables, and multiple linear regression to identify the independent explainers of walking confidence after stroke. Ninety chronic stroke individuals (35 men), with a mean age of 68 (SD 13) years were assessed. All independent variables were significantly correlated with walking confidence. Regarding the regression analysis, these measures explained 44% ( F = 9.21; P < 0.001) of the variance in walking confidence; however, only walking speed, strength of the hip flexor muscles, aerobic capacity, and perceived locomotion ability showed significance. All motor impairment and activity limitation measures correlated with walking confidence. However, the regression analysis highlighted that only walking speed, aerobic capacity, the strength of the hip flexor muscles, and perceived locomotion were independent explainers of walking confidence after stroke.

Age and gender differences in static and dynamic balance of Chinese preschool children.

Objectives: Balance is a crucial ability of early age, but there is conflicting evidence with regard to age and gender differences in preschool children's balance ability. Additionally, there are several tools available to measure balance, yet, wide variation in their use has restricted the capacity to synthesize the reference values. Therefore, the primary purpose of this study was to investigate the balance ability of preschool-aged children and determine how it is moderated by age and gender. The analysis pertained to determining whether different testing methods affect the results of static or dynamic balancing ability to provide a basis for normative balance ability data for healthy boys and girls between 3 and 6years of age. Method: Six hundred and nineteen preschool children (296 boys and 323 girls) aged 3-6years participated in the study. The static balance (SB) was assessed with children standing on one leg (OST) and in a tandem stance (TS) with respect to time. The balance beam test (BBT) and functional reach test (FRT) were used to evaluate dynamic balance (DB) by measuring the time spent and the distance reached, respectively. Result: The results revealed significant differences in OST with respect to gender (η2 = 0.037, p < 0.001), TS (η2 = 0.026, p < 0.001) and FRT (η2 = 0.016, p = 0.002); the girls performed better than boys on most balance tests except on BBT (η2 = 0.000, p = 0.596). Age had positive effects on the static and dynamic balance performance on the OST (η2 = 0.336, p < 0.001), TS (η2 = 0.205, p < 0.001), BBT (η2 = 0.367, p < 0.001) and FRT (η2 = 0.392, p < 0.001). Older children performed better than their younger counterparts. No significant interactions between age groups and sex were found. Conclusion: This study revealed that static and dynamic balance stability in preschool-aged children was affected by gender and age. Gender dimorphism is present in preschool children, older girls displayed better postural stability than boys, and balance performance improved with age. In addition, the study provides age- and gender-specific balance performance reference values for preschool children across multiple methods, which can be used to monitor static and dynamic balance development.

Effect of Ankle Proprioception Training on Preventing Ankle Injury of Martial Arts Athletes.

Martial arts routines originated in China and are a traditional sport of the Chinese nation. They are one of the outstanding sports culture representatives in China since ancient times. Excessively difficult movements in some martial arts routines during competitions or training can cause athlete injuries. The purpose of this article is to study the effect of proprioceptive training of ankle joints on preventing ankle injuries in martial arts athletes. Can ankle strength training and ankle proprioceptive training combined with strength training improve the dynamic and static balance of football players? This article analyzes the mechanism and causes of martial arts athletes' injuries and proposes treatment methods for ankle injuries. In the experimental part of this article, 16 martial arts athletes (8 males and 8 females) were selected as research objects, and they were randomly divided into 4 male and female experimental groups and 4 control groups. The experimental group received ankle muscle strength training for 6 weeks, and the control group received ankle muscle strength training and ankle proprioception training. The experimental results prove that ankle proprioceptive training can improve the dynamic and static balance of martial arts athletes and can effectively prevent the occurrence of ankle injury. In this paper, the dynamic balance ability in the biped standing state with eyes closed was tested, and the reductions of the stability index in the front and back directions of the control group and the experimental group were 0.03 and 0.2, respectively. It can be seen that the stability training effect of the experimental group was obvious.

Effect of Training Interventions in a Virtual Environment on Dynamic and Functional Balance in the Elderly

Background and Aims Balance disorder has been recognized as a leading cause of falls in the elderly. One way to strengthen the balance of the elderly is to use new technologies such as virtual reality. Purpose of this study was to investigate the effect of virtual reality exercises on the dynamic and functional balance of the elderly. Methods The present study was a quasi-experimental research with pre-test and post-test design. Subjects included 24 male aged 60-75 years that were selected by a convenience sampling method from Shabestar city and divided randomly into two virtual and control groups. Participants in the experimental group practiced for 9 weeks, but the control group continued their usual treatment programs. XBox device was used for virtual reality interventions. Also, in order to evaluate the functional and dynamic balance, Berg Balance Scale, and Up and go timed Test were used, respectively. MANCOVA and ANCOVA Tests were used at P&lt;0.05 level to analyze the data. Results MACNOVA test results showed a significant difference (P=0.001) between two groups at least in one balance variable (dynamic and functional). Also, based on the results of ANCOVA test, due to better balance scores in the experimental group, virtual reality practice using Xbox improved their dynamic and functional balance compared to the control group. Conclusion This study provides evidence that dynamic and functional balance is modifiable in elderly people and that they respond to short-time VR training. It is suggested to use virtual reality as well as balance exercises as a suitable method of improving dynamic and functional balance abilities in the elderly.

Effects of quarter heel raising exercise on balance and ankle strength in functional ankle instability subjects.

Background:Functional ankle instability (FAI) is defined as the subjective sensation of instability or “giving way” after an ankle sprain and occurs in approximately 40% of patients with lateral ankle instability. As an ankle joint rehabilitation intervention, heel raising exercises, toe jumping exercises, ankle joint proprioceptive exercises, as well as orthosis and taping are commonly applied to prevent the recurrence of an ankle joint injury. So this study was evaluated effect of quarter heel raising exercise (QHR) on balance and peroneus longus muscle strength in FAI subjects.Methods:Among 26 FAI subjects, 13 with FAI were assigned to the QHR group, and 13 with FAI were assigned to the control group which was no intervention. All of 30 subjects were evaluated Teskscan included static balance ability, Y balance test included dynamic balance ability with three directions which is anterior, posterolateral, posteromedial direction. Commander muscle testing included eversion/inversion strength ratio at pre- and post-intervention.Results:There was a significant interaction between group and time in static, dynamic balance, and strength. In QHR group, there was simple effect on static, dynamic balance, and strength. But control group showed no simple effect on static, dynamic balance, and strength. In the pre- and post-intervention differences between the groups. There was a significant difference in pre-intervention condition between the groups, but no significant difference between the groups in post-intervention in all conditions.Conclusions:QHR exercise is useful for improving the balance ability and muscle strength of the peroneus longus muscle in FAI subjects.

Effect of Pilates and Core Stability Exercise on Bone Mineral Density and Risk of Falls in Elderly Women

PURPOSE: This study aimed to verify the effect of 8-week Pilates and core stability exercises on bone mineral density (BMD) and risk of falls in older adult women. METHODS: A total of 49 healthy women over 60 years of age were randomly classified into three groups: Pilates exercise group (PG, n=17), core stability exercise group (CSG, n=17), and control group (CON, n=12). Pilates and core stability exercise programs were applied in each group for 8 weeks. Before and after the two exercise programs, BMD, Tinetti Performance Oriented Mobility Assessment (Tinetti POMA), and balance ability were measured.RESULTS: There were no differences in BMD among the three groups depending on the application of the exercise program. The balance scores of the Tinetti POMA and total Tinetti POMA scores in both the PG and CSG were higher after the 8-week exercise program. In particular, the gait score of the Tinetti POMA in the PG was higher than that in the CSG. Static and dynamic balance abilities improved in both the PG and CSG.CONCLUSIONS: These results suggest that Pilates and core stability exercises can be effective for improving balance ability, leading to the prevention of falls in older adult women.

Functional progressive resistance exercise versus eccentric muscle control in children with hemiplegia: a randomized controlled trial

BackgroundHistorically, strength exercise in children with CP is not recommended, because it may develop spasticity, which results in difficulty with walking. But, recently increasing studies and systemic reviews have reported that strength exercise can promote muscle strength in children with CP with no negative impact on spasticity. The study is aiming to compare the effect of functional resistance exercise and functional eccentric training on dynamic balance and functional ability in children with hemiplegia. For this purpose, forty participating children diagnosed with spastic hemiplegia were included and their ages ranged from 6 to 13 years. They were randomly allocated into two groups: functional resistance exercise (group I) or eccentric muscle control exercise (group II). The training was conducted three times a week for 6 weeks for both groups. Each group received one of the interventions in addition to designed physical therapy programs. Functional ability and dynamic balance were measured before and after 6 weeks of the intervention by gross motor function measure and functional reach test.ResultsComparison between the two groups before treatment revealed no significant difference in all values of functional ability and dynamic balance. But comparison after treatment in values showed significant improvement in both groups with greater improvements in favor of group I (p < 0.01).ConclusionAdding both functional resistance exercise and eccentric muscle control exercise is beneficial for improving functional ability and dynamic balance with more recommendation for adding functional resistance exercise that showed more significant improvement than eccentric muscle control in children with hemiplegia.

Machine Learning-Based Predicted Age of the Elderly on the Instrumented Timed Up and Go Test and Six-Minute Walk Test.

A decrease in dynamic balance ability (DBA) in the elderly is closely associated with aging. Various studies have investigated different methods to quantify the DBA in the elderly through DBA evaluation methods such as the timed up and go test (TUG) and the six-minute walk test (6MWT), applying the G-Walk wearable system. However, these methods have generally been difficult for the elderly to intuitively understand. The goal of this study was thus to generate a regression model based on machine learning (ML) to predict the age of the elderly as a familiar indicator. The model was based on inertial measurement unit (IMU) data as part of the DBA evaluation, and the performance of the model was comparatively analyzed with respect to age prediction based on the IMU data of the TUG test and the 6MWT. The DBA evaluation used the TUG test and the 6MWT performed by 136 elderly participants. When performing the TUG test and the 6MWT, a single IMU was attached to the second lumbar spine of the participant, and the three-dimensional linear acceleration and gyroscope data were collected. The features used in the ML-based regression model included the gait symmetry parameters and the harmonic ratio applied in quantifying the DBA, in addition to the features of description statistics for IMU signals. The feature set was differentiated between the TUG test and the 6MWT, and the performance of the regression model was comparatively analyzed based on the feature sets. The XGBoost algorithm was used to train the regression model. Comparison of the regression model performance according to the TUG test and 6MWT feature sets showed that the performance was best for the model using all features of the TUG test and the 6MWT. This indicated that the evaluation of DBA in the elderly should apply the TUG test and the 6MWT concomitantly for more accurate predictions. The findings in this study provide basic data for the development of a DBA monitoring system for the elderly.

The Balance Reaction Ability of Teenagers Based on the Evaluation Model of Unbalanced Sports Quotient.

Dynamic balance is particularly important for the maintenance, transformation, and restabilization of various postures of the human body. Combined with the characteristics of unbalanced sports events, although there is no physical contact in sports events, it has intense antagonism due to the constant change of body movement. Athletes need to have the ability of fast movement and continuous high-intensity multibeat confrontation. They need to adjust their body posture any time according to the situation, constantly move their body from one side to the other side in fast movement, and constantly change between being imbalanced and being stable to keep the center of gravity stable and adjust their body posture. Combining with the characteristics of unbalanced sports, this paper is aimed at the problem that young athletes have poor dynamic balance ability and cannot maintain the stability of their body's center of gravity in the process of fast multidirectional movement and braking. The supporting leg needs ankle dorsiflexion, knee flexion, and hip flexion during SEBT testing. Therefore, the lower limb needs sufficient range of motion, strength, proprioception, and neuromuscular control ability to achieve the optimal test results. A randomized controlled experiment was used to test whether there were significant differences in the test indicators between the experimental group and the control group before and after the experiment by using a paired test. The test indicators between the experimental group and the control group before and after the intervention were tested by independent sample test to explore the influence of core balance training on the dynamic balance ability of teenagers in unbalanced sports. Through analysis, it is proved that strengthening balance exercise can significantly improve the functional movements and physical fitness of adolescents, which is of great significance to the development of basic flexibility and stability of joints and the strengthening of weak chain muscles.

Correlation between dynamic balance ability and lower limb muscle strength of university students

Objective: To study the correlation between dynamic balance ability and lower limb muscle strength of university students. Methods: 50 students of Zunyi Medical University (23 boys and 27 girls) were selected as the subjects. The dynamic balance ability of university students was tested by the YBT test system. Isokinetic muscle strength tester tests knee flexion and extension muscle strength under different angular velocity conditions. Results: 1) At different angular velocities, there was a moderate positive correlation between knee flexion and extension muscle strength and YBT reaching all directions. Only when the angular velocity was set to 200° / s, there was a low positive correlation between knee flexion muscle strength and the front side of the YBT test. 2) There is a more significant correlation between the maximum distance of each direction of dynamic balance and the peak torque of knee extensor than that of flexor. Research conclusions: For university students, there is a significant indigenous correlation between the directions of YBT arrival, and the correlation between the posterolateral and the posterolateral is stronger. The stronger the lower limb muscle strength is, the better the dynamic balance ability is, and the correlation between dynamic ability and knee extensor muscle strength is higher, which may be related to the fact that knee flexion control balance can more effectively activate knee extensor muscle group. University students generally have bilateral asymmetry of the lower limbs.

Interrelationship among thigh intermuscular adipose tissue, cross-sectional area, muscle strength, and functional mobility in older subjects.

The aim of this cross-sectional study was to investigate the association between lower limb strength, muscle mass and composition, and balance ability in elders.Thirthy-four older participants (Age: 65.6 ± 4.73 years; male = 10 and female = 24) were assessed for muscle strength (maximal isometric strength of knee extensors and one repetition maximum by leg press, the one repetition maximum [1RM]), balance and gait capacity (Mini-BESTest), body composition by whole-body dual energy x-ray absorptiometry (obtaining Appendicular Skeletal Muscle Mass Index, ASMMI), and magnetic resonance imaging of thigh to evaluate Intermuscular Adipose Tissue (IMAT) and muscle Cross Sectional Area (CSA).Positive correlations between 1RM and ASMMI (rs = 0.64, P < .0001) and thigh CSA (rs = 0.52, P = .0017), but not with thigh IMAT, were found. In addition, significant correlations between knee extensors strength and ASMMI (rs = 0.48, P = .004) and thigh CSA (rs = 0.49, P = .0033) and IMAT (rs = -0.35, P = .043) were observed, whereas no significant correlations between the Mini-BESTest with ASMMI, thigh CSA, and IMAT were observed.Lower limb strength positively correlated with appendicular muscle mass. Further, the maximal isometric strength of knee extensors negatively correlated with thigh IMAT in elderly patients, whereas the dynamic balance ability did not correlate with any of the morphological variables of the muscle (i.e., ASMMI, CSA, and IMAT). A reduced muscle size and strength could affect movement and reduce physical function in older patients. Improving the composition and size of muscle in elder subjects could reduce frailty and risk of falls.