Dynamic Balance Control Research Articles

Dynamic neuromuscular stabilization and its efficiency on sports performance

Neuromuscular stability is necessary for optimal sport performance. Stability is not achieved only by abdominal muscles, spine extensors and gluteals, but it is accomplished by precise coordination of these muscles and intra-abdominal pressure by the central nervous system. A primary role of the core muscles stability is to raise the intra-abdominal pressure and to increase the tension in the thoracolumbar fascia. Postural core instability is associated with poor dynamic balance control and with a high risk of injury or fall. Dynamic neuromuscular stabilization (DNS) is a rehabilitative approach to optimize the movement system based upon the scientific principles of developmental kinesiology and provides an effective tool in rehabilitation of sport injuries.

Effect of a Sensorimotor Training Program for Aerial Maneuvers in Junior Surfers

The purpose of this study was to examine the impact of a sensorimotor training program on maximum ankle dorsiflexion (ankle DF), coordination, dynamic balance and postural control, and lower-limb muscle power, in competitive junior surfers, and its relation to parameters of sensorimotor control required to perform aerial maneuvers. Twelve junior competitive surfers followed a 7-week sensorimotor training program, being assessed pre- and post-program with the knee-to-wall test (KW), Y-Balance test—lower quarter (YBT-LQ), and the countermovement jump test (CMJ). Post-training assessment revealed positive effects on the KW (ankle DF) distance, which increased approximately 2 cm (p < 0.001) for both ankles, and all scores for the YTB-LQ (coordination, dynamic balance, and postural control) variables increased, being significant (p < 0.005) for some reach distances (YBT-LQ—Anterior Left, YBT-LQ—Postero-medial Left, and YTB-LQ Anterior Right). YBT-LQ Anterior Reach Asymmetry also improved by decreasing 1.62 cm (p < 0.001) and the CMJ height (lower limb muscle power) increased 2.89 cm (p < 0.001). The training program proved to effectively enhance parameters of physical performance for this sample, including ankle DF, coordination, dynamic balance, postural control, and lower limb muscle power. This tailored-made task approach can help to optimize surfing performance capabilities and contribute to reducing the risk of injuries while performing aerials.

Anticipatory postural adjustment deficits in children with developmental coordination disorder during a self-induced prehension task while standing on one leg

Effective postural control is essential for motor skill development, yet the specific nature of anticipatory control in children with Developmental Coordination Disorder (DCD) remains poorly understood for complex or dynamic stability tasks. This study investigated anticipatory postural adjustments (APA) during a self-initiated dynamic stability task. The Can Placement Task (CPT)—a self-initiated dynamic stability task—was performed by 23 children with DCD and 30 typically developing (TD) children aged 9–12 years. The task involved standing on one leg while also repositioning a can on the floor. Center of pressure (COP) movement was recorded by two force platforms during the five phases of the movement. The ground reaction force measured external support during both descent to pick up the can and ascent after replacing the can. The study used a mixed-design approach with group (DCD, TD) as a between-subject factor and condition (can position close or far) and phase of movement as within-subject. Distinct movement control characteristics were shown for children with DCD including a greater range of COP movement and higher COP velocity in the anterior-posterior direction prior to movement initiation compared with TD. The DCD group also relied more on external support during both the downward and upward phases of the CPT and needed more trials to complete the task. Only two significant interaction effects involving Group and the within-subject factors emerged. Children with DCD swayed significantly more at specific phases of the task, especially when coming up and restoring balance, and did not adapt COP velocity as a function of reaching distance. Dynamic control of posture in children with DCD is impaired as they struggle to generate the effective APAs necessary to maintain dynamic stability which leads to greater reliance on external support and more corrective movements. The CPT provides a valuable assessment of posture and dynamic balance control during a complex prehension movement performed on one leg; the task highlights distinct movement patterns between children with and without DCD.

Examining the effects of non-immersive virtual reality game-based training on knee hyperextension control and balance in chronic stroke patients: a single-blind randomized controlled study.

Post-stroke hemiparesis can lead to decreased mobility, gait disturbances, impaired balance, postural instability, limitations in activities of daily living (ADL), and long-term disability. The aim of this study was to examine the effect of non-immersive virtual reality game-based training (nIVRGT) in addition to conventional rehabilitation in stroke patients on dynamic balance, knee hyperextension control, and ADL. Twenty-five chronic stroke patients aged between 51 and 70 were included in the study. Stroke patients were randomized to a control group (n = 12) and a study group (n = 13). Individuals in control group participated conventional physiotherapy and rehabilitation program for 60min, 3 days a week for 6 weeks. individuals in the study group received 40min of conventional physiotherapy and rehabilitation program plus 20min nIVRGT. Functional Reach Test, Timed Up and Go Test, Computerized Gait Evaluation System and Barthel Index were used in the evaluation. The study group improved significantly in dynamic balance, knee control, and ADL (p < 0.05). In the control group, significant improvements were observed in dynamic balance and knee control (p < 0.05), except ADL (p > 0.05). The study group improved in dynamic balance compared with the control group (p < 0.05). Knee control and ADL improved similarly in both groups (p > 0.05). Our results showed that conventional and additional nIVRGT rehabilitation improved dynamic balance and knee hyperextension control in chronic stroke. However, it was observed that the non-immersive virtual reality (nIVR) approach was more effective in improving dynamic balance in stroke patients than conventional rehabilitation alone. NCT05907473.

Stroke impairs the proactive control of dynamic balance during predictable treadmill accelerations.

We maintain balance during gait using both proactive and reactive control strategies. Damage to the brain from a stroke impairs reactive balance, but little is known about how a stroke impacts proactive control during walking. Identifying stroke-related impairments to proactive control could inform the design of interventions to improve balance and reduce fall risk. Therefore, we determined if people with and without stroke differ in their ability to use proactive strategies during predictable treadmill accelerations. Groups of 14 adults with and without stroke walked with single-belt accelerations at random (every one to five strides) and regular (every three strides) intervals. We quantified the effects of the perturbations as changes to center of mass (COM) speed and used mechanical leg work to quantify the proactive strategies to slow the COM. Participants without stroke reduced peak COM speed better than those with stroke when perturbations were at regular intervals (-0.023 versus -0.001 m/s; p=0.007). They also reduced positive leg work more during the perturbation step than the group post-stroke (-7.7% versus -1.9%; p=0.004). Together, these results demonstrate that the sensorimotor impairments resulting from a stroke impair the ability to generate effective proactive adjustments to reduce the destabilizing effects of predictable perturbations.

Figure Skating Musculoskeletal Injury: Evidence across Disciplines, Mechanisms, and Future Directions.

This review provides a synopsis of current injury patterns, potential mechanisms, and off-ice exercise prevention considerations as the sport of figure skating evolves. The lifetime prevalence of injury for all skaters is estimated to be 79.5%, with the most common sites being spine and lower extremity. Singles skaters more often develop chronic injuries compared to acute (68.9% vs 31.1%), whereas non-singles skaters more often experience acute injuries. Lower limb stress fracture prevalence ranges from 10% to 21.4% across disciplines. Emerging contributors include training volume, technical difficulty and repetition of complex elements (multirotational jumps, lifts, holds), extreme ranges of movement about the spine and hip, age and experience level, and functional capacity (dynamic strength, flexibility, balance, and neuromotor control). Prevention programs in competitive figure skaters may include monitoring of training volumes, emphasis on technique, appropriate boot fit, and strength and conditioning content to prepare for increasing neuromotor, balance, and power demands of the sport.

Metronome-Guided Balance Exercises to Aid in Dynamic Balance and Postural Control in a Novel Genetic Presentation of Niemann–Pick Disease Type C: A Case Report

Abstract Niemann–Pick disease type C is a rare progressive lysosomal lipid storage disorder. The disorder is characterized by a range of neurological consequences and complications at different points of its progression including spasticity, incoordination, ataxia, supranuclear gaze palsy, asthenia, and balance impairment, with a higher risk of falls. Among various approaches to managing such a debilitating condition, the role of physical therapy in managing the symptoms of such patients is often limited or underreported in the literature. A combination of spasticity and ataxia leads to impaired timing of agonist–antagonist control. Therefore, balance loss and falls are the most prevalent symptoms. We advocated a 12-week metronome-guided balance training program. Niemann–Pick type C disease is a rare genetic phenomenon that often presents with multi-system changes at structural and functional levels for the patient. Metronome-guided balance training is beneficial for improving dynamic balance variables, including movement velocity, center of gravity sway velocity, and step width.

Biomechanical and Physiological Variables in Dynamic and Functional Balance Control during Single-Leg Loading in Individuals with Chronic Ankle Instability: A Scoping Review.

This scoping review summarizes the tasks and outcomes in dynamic and functional balance assessments of individuals with chronic ankle instability, focusing on the physiological and biomechanical characteristics. A comprehensive literature search was conducted in PubMed, Scopus, Web of Science, and MEDLINE databases in September 2023 and revised in April 2024. Studies evaluating dynamic and functional balance in chronic ankle instability using clinical tests, as well as biomechanical and physiological outcomes, were included. Out of 536 publications, 31 met the screening criteria. A history of ankle sprain was the main focus of the inclusion criteria (28 articles, 90%). The star excursion balance test, emphasizing maximum reach distance, was the most common quantitative task (12 articles, 66%). Physiological data mainly came from electromyography studies (7 articles, 23%), while biomechanical variables were often assessed through center of pressure studies using force plates (17 articles, 55%). The preferred quantitative clinical assessment was the star excursion balance test, focusing on normalized reach outcomes. Qualitative functional balance assessments emphasize landing activities and center of pressure displacement. Electromyography is commonly used to analyze the tibialis anterior and peroneus longus muscles. However, there is a lack of qualitative data on dynamic balance control, including morphological characteristics and the center of mass adaptation.

APPLICATION OF ANALYTICAL EXERCISES AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION FOR STATIC, DYNAMIC BALANCE AND POSTURAL CONTROL IMPROVEMENT

Purpose: to assess the recovery of static, dynamic balance and postural control while overcoming muscle imbalance after an anterior cruciate ligament reconstruction by applying analytical exercises. Material and methods: Material: 15 men (mean age 25.16) were observed in the span of 14 weeks (three and a half months) after anterior cruciate ligament reconstruction. They underwent physiotherapy, including analytical kinetic chain exercises in hospital, ambulatory and at home conditions. Research, measurement, and evaluation methods include range of motion in the knee joint, manual muscle testing (MMT), static and dynamic balance tests, and postural control tests. Statistical methods include statistical data grouping, Cronbach’s test, descriptive method, testing of statistical hypotheses, and correlation analysis. The data was processed with SPSS v.24.0 for Windows. Results: The results show a change in the static postural control with a 1/4-point deviation from the standard. This requires the inclusion of additional sensorimotor exercises in combination with other specific and general strengthening exercises. Conclusion: From the performed observation and the obtained results, compared to those of 20 healthy men, the following conclusion has been drawn: the analytical exercises for lower extremities lead to the overcoming of dysfunction and increased stability in the extremities. The physiotherapy programme should include sensory stimulation exercises tailored for strengthening the weakened muscles and should contribute to the overcoming of muscle imbalance.

Wearable accelerometers reveal objective assessment of walking symmetry and regularity in idiopathic scoliosis patients.

Scoliosis is a multifaceted three-dimensional deformity that significantly affects patients' balance function and walking process. While existing research primarily focuses on spatial and temporal parameters of walking and trunk/pelvic kinematics asymmetry, there remains controversy regarding the symmetry and regularity of bilateral lower limb gait. This study aims to investigate the symmetry and regularity of bilateral lower limb gait and examine the balance control strategy of the head during walking in patients with idiopathic scoliosis. The study involved 17 patients with idiopathic scoliosis of Lenke 1 and Lenke 5 classifications, along with 17 healthy subjects for comparison. Three-dimensional accelerometers were attached to the head and L5 spinous process of each participant, and three-dimensional motion acceleration signals were collected during a 10-meter walking test. Analysis of the collected acceleration signals involved calculating five variables related to the symmetry and regularity of walking: root mean square (RMS) of the acceleration signal, harmonic ratio (HR), step regularity, stride regularity, and gait symmetry. Our analysis reveals that, during the walking process, the three-dimensional motion acceleration signals acquired from the lumbar region of patients diagnosed with idiopathic scoliosis exhibit noteworthy disparities in the RMS of the vertical axis (RMS-VT) and the HR of the vertical axis (HR-VT) when compared to the corresponding values in the healthy control (RMS-VT: 1.6±0.41 vs. 3±0.47, P<0.05; HR-VT: 3±0.72 vs. 3.9±0.71, P<0.05). Additionally, the motion acceleration signals of the head in three-dimensional space, including the RMS in the anterior-posterior and vertical axis, the HR-VT, and the values of step regularity in both anterior-posterior and vertical axis, as well as the values of stride regularity in all three axes, are all significantly lower than those in the healthy control group (P<0.05). The findings of the analysis suggest that the application of three-dimensional accelerometer sensors proves efficacious and convenient for scrutinizing the symmetry and regularity of walking in individuals with idiopathic scoliosis. Distinctive irregularities in gait symmetry and regularity manifest in patients with idiopathic scoliosis, particularly within the antero-posterior and vertical direction. Moreover, the dynamic balance control strategy of the head in three-dimensional space among patients with idiopathic scoliosis exhibits a relatively conservative nature when compared to healthy individuals.

Multimodal training protocols on unstable rather than stable surfaces better improve dynamic balance ability in older adults

BackgroundThere has been growing interest in using unstable devices in training protocols. This study aimed to assess the effectiveness of two multimodal exercise interventions (i.e., on stable and unstable surfaces) on dynamic balance control and lower limb strength in older adults.MethodsSixty-two older adults were randomly assigned to two intervention groups (N = 20, stable group; N = 19, unstable group), and to a control group (N = 18). In this single-blinded randomized controlled study, the two intervention groups underwent a 12-week training program twice a week for 45 min, consisting of strength and balance exercises. The stable (ST) group performed the training program over stable surfaces, while the unstable (UNST) group over unstable surfaces. Dynamic balance was assessed by computing the center of pressure (CoP) trajectory while a driven movable platform induced an unexpected perturbation of the base of support. Specifically, we considered the following CoP-related parameters within a 2.5-s temporal window from the beginning of the perturbation: displacement (Area95), mean velocity (Unit Path), anterior–posterior first peak (FP), post perturbation variability (PPV), and maximal oscillations (ΔCoPMax). The dominant quadriceps strength was measured through an isometric maximal voluntary contraction on an instrumented chair.ResultsFour out of five CoP-related parameters (i.e., Area95, Unit Path, ΔCoPMax, and PPV) significantly improved in the UNST group from a minimum of 14.28% (d = 0.44) to a maximum of 52.82% (d = 0.58). The ST group significantly improved only in two (i.e., ΔCoPMax, and PPV) out of five CoP-related parameters with an enhancement of 12.48% (d = 0.68) and 19.10% (d = 1.06). Both intervention groups increased the maximal isometric quadriceps strength (UNST:17.27%, d = 0.69; ST:22.29%, d = 0.98). The control group did not show changes in any of the parameters considered.ConclusionsStable surfaces promoted faster increments of muscular strength. Unstable surfaces were more effective in enhancing dynamic balance efficiency. These findings suggested the employment of multimodal training on unstable rather than stable surfaces to potentially lower the incidence of falls in older adults.Trial registrationNCT 05769361, retrospectively registered 13 March 2023, https://clinicaltrials.gov/study/NCT05769361?lat=45.3661864&lng=11.8209139&locStr=Padova,%20Italy&distance=50&page=11&rank=107.

Combined effects of Tai-Chi gait with mediolateral ground support perturbation on dynamic balance control

Tai-Chi (TC) is a broadly used exercise that appeared to decrease the risk of falls. However, biomechanical mechanisms underlying the reduced fall risks following TC exercise remain unclear and hinder the ability to optimize TC intervention to target specific balance deficit disorders. In addition, combining TC gait exercise with ground support perturbation may be a viable approach to further challenge balance control compared to TC gait alone. The purpose of this study was to compare dynamic stability and limb support force production during comfortable walking speed (CWS), TC gait, and TC gait with medial (MED) and lateral (LAT) ground support perturbations in older and younger adults. Ten older adults and ten younger adults performed CWS, TC gait, LAT, and MED. Conditions involving TC gait showed decreased margin of stability (MoS) (main effect of condition, p ​< ​0.01) and increased vertical force impulse compared to CWS (p ​< ​0.01). Medial ground support perturbation induced the smallest MoS among all conditions. Older adults showed increased MoS compared to younger adults (p ​< ​0.01). These findings provided insight into how key balance control characteristics are modulated during TC exercise and indicate that combining ground support perturbation with TC may further challenge dynamic stability.

Effect of Progressive Balance Control Strategies on Chronic Ankle Instability in Middle-Aged Obese Women.

Chronic ankle instability (CAI) is a disease characterized by persistent feelings of instability in the ankle joint and a propensity for recurrent ankle sprains. It is often caused by ligamentous laxity or neuromuscular deficits. Middle-aged obese females represent a demographic subset at increased risk for CAI due to factors such as reduced proprioception and increased loading on the ankle joint. The gaps in the current evidence suggest that more research is needed on middle-aged obese females, who are particularly vulnerable to CAI due to physiological changes associated with poor balance. This study aims to determine the effect of progressive balance control strategies on CAI in middle-aged obese women. In this experimental study, 72 patients with CAI in middle-aged women were selected randomly using a simple random sampling method. Females aged 35-45 with a body mass index (BMI) greater than 27 kg/m2 and a history of ankle sprains greater than one and having residual symptoms. The experimental group (Group B) received progressive balance control strategies, and the conventional group (Group A) received conventional balance exercises. Foot and ankle ability measure (FAAM) scale, push-and-release test (PART), single-leg stance test (SLST), evaluations, and star excursion balance test (SEBT) were used for pre- and posttreatment. The experimental group post-intervention for static balance, dynamic balance, and postural control tests showed extremely significant improvement with a p-value of <0.0001. Between groups A and B, the dynamic balance was considered very significant, with a p-value of 0.0001. In the single-leg stance test, Group B's result was significantly greater than that ofGroup A's (63.4 + 16.1 and 63.4 + 16.1). PART results indicate that Group B is more significant than Group A (0.76 and 0.51, respectively). The study concluded that progressive balance control strategy training is effective in middle-aged obese women with CAI.

The effect of progressive exercise prescription for group exercise guidance for Taiwan seniors and Integrated Care for old People: Post-event movement observation

PurposeThis study is aimed at the seniors of the “2022 Taiwan Senior Citizens Fitness Club Subsidy Plan” with a sample. MethodThe doctor will diagnose and confirm whether the physical condition suits participation. Then, the professional sports instructor will design and arrange a progressive fitness enhancement group course suitable for the Senior person's physical fitness, conducted four times a week, every 2 h, for three months of group course training. Afterward, four group course instructors analyzed the motor ability of the three periods through a video, divided into 21 evaluation indicators. The data collection will be from January to May 2023. In addition, the Integrated Care for Old People (ICOPE) was used to assess the situation. ResultThe results showed that all indexes were significantly better than those in week one at week 6. All indexes at week 12 were significantly better than those in week one and week 6 (p < .001), and the benefit of all indicators was the largest (Cohen's d: 2.79–5.11), the reliability of the scores of each index ICC (0.73–0.94). ConclusionProgressive and multifaceted guidance on how to safely and effectively enhance the physical activity of senior citizens may be the most suitable method. Through progressive energy enhancement, the participants' physical activity and cognitive function can be improved, especially the overall rhythm of the music, which can be combined with high and low impact, dynamic and static balance control, agility, flexibility, and extensibility to achieve the benefits of health promotion.

Hierarchical Energy Management of DC Microgrid with Photovoltaic Power Generation and Energy Storage for 5G Base Station

For 5G base stations equipped with multiple energy sources, such as energy storage systems (ESSs) and photovoltaic (PV) power generation, energy management is crucial, directly influencing the operational cost. Hence, aiming at increasing the utilization rate of PV power generation and improving the lifetime of the battery, thereby reducing the operating cost of the base station, a hierarchical energy management strategy based on the improved dung beetle optimization (IDBO) algorithm is proposed in this paper. The first control layer provides bus voltage control to each power module. In the second control layer, a dynamic balance control strategy calculates the power of the ESSs using the proportional–integral (PI) controller and distributes power based on the state of charge (SOC) and virtual resistance. The third control layer uses the IDBO algorithm to solve the DC microgrid’s optimization model in order to achieve the minimum daily operational cost goal. Simulation results demonstrate that the proposed IDBO algorithm reduces the daily cost in both scenarios by about 14.64% and 9.49% compared to the baseline method. Finally, the feasibility and effectiveness of the proposed hierarchical energy management strategy are verified through experimental results.

Associations of lower-limb muscle strength performance with static and dynamic balance control among older adults in Taiwan.

Aging is an inevitable process of life development. These physical changes can cause a decline in the functional adaptability and health status of older adult individuals. The purpose of this study was to investigate the association of lower-limb muscle strength performance with static and dynamic balance control among older adults in Taiwan. We conducted a cross-sectional study and reviewed data derived from the National Physical Fitness Survey in Taiwan 2015-2016. A total of 20,846 Taiwanese older adult individuals aged 65 years old or older were recruited as study participants. Demographic characteristics, anthropometric assessments, lifestyle habits, and health-related physical fitness measurements from this dataset were analyzed using the chi-square test, one-way analysis of variance, and linear regression analysis. Lower-limb muscle strength performance was classified into 4 groups based on quartile (Quartile 1 [Q1], Quartile 2 [Q2], Quartile 3 [Q3], and Quartile 4 [Q4]) values. Increased lower-limb muscle strength levels were significantly associated with static balance in men (Q2: β = 2.539, p < 0.0001; Q3: β = 4.590, p < 0.0001; Q4: β = 7.700, p < 0.0001) and women (Q2: β = 2.022, p < 0.0001; Q3: β = 4.179, p < 0.0001; Q4: β = 6.920, p < 0.0001) after adjusting for potential confounders. In addition, we observed that increased lower-limb muscle strength levels were significantly associated with dynamic balance in men (Q2: β = -1.661, p < 0.0001; Q3: β = -2.434, p < 0.0001; Q4: β = -3.091, p < 0.0001) and women (Q2: β = -1.660, p < 0.0001; Q3: β = -2.548, p < 0.0001; Q4: β = -3.196, p < 0.0001) after adjusting for potential confounders. Lower-limb muscle strength was the most important factor, as it was an improved method for static and dynamic balance control in both genders.

Discriminant ability of novel cognitive-motor assessments to distinguish between fallers and non-fallers – Preliminary findings

Introduction&#x0D; Falls are a major cause for injuries in older adults and are associated with motor and cognitive impairments (Hsu, 2012). Thus, sensitive assessment tools capturing subtle changes in motor and cognitive functioning are crucial for the prediction of falls. Aim of this study was to test the ability of a novel, instrumented, cognitive-motor assessment battery, to distinguish between older persons who experienced a fall in the past 12 months (fallers) and persons who did not (non-fallers) as well as its added value to predict fall status compared to gold-standard clinical fall risk assessments.&#x0D; Methods&#x0D; This is a secondary analysis using baseline data of an international randomized controlled trial. Participants (age &gt; 60, categorized in two groups: fallers and non-fallers) performed five instrumented tests (Reaction time test (psychomotor speed), Flexibility test (mental flexibility), Go/No-Go task (inhibition), Sway test (postural control), and Coordinated Stability test (dynamic balance control), as well as the Timed-up and Go (TUG) test as a gold standard assessment. Binominal logistic regression analyses were conducted for each cognitive-motor assessment separately to identify test variables significantly associated with group assignment which could then be included in a further logistic regression model. Furthermore, a Receiver Operating Characteristic (ROC) analysis was performed.&#x0D; Results&#x0D; Preliminary results of n = 38 showed among the instrumented assessments only inhibition (p = .016) and dynamic balance control (p = .014) were significantly associated with fall status and therefore included in the second regression model. In this second model, both functions contributed significantly in predicting fall status (inhibition: p = .040, dynamic balance control: p = .028). This regression model was statistically significant and resulted in a good amount of explained variance (χ2(2) = 14.283 (p = .001), R2 = .418) with a sensitivity of 84.2% and a specificity of 73.7%. Similarly, the ROC analysis showed significant Area under the Curve (AUC) values only for inhibition (AUC = .751, p = .008) and dynamic balance control (AUC = .765, p = .005), whereas the AUC value of the TUG test remained non-significant (AUC = .681, p = .056).&#x0D; Discussion/Conclusion&#x0D; Based on this preliminary analysis, two tests of the novel instrumented cognitive-motor assessment battery assessing inhibition and dynamic balance control were able to distinguish between fallers and non-fallers and these tests showed better discriminative properties compared with the TUG. This supports the results of previous research which showed only limited discriminant validity of the TUG in terms of fall risk (Schoene et al., 2013). Therefore, the cognitive-motor assessments might provide an added value for clinical fall risk assessment. The study is still ongoing, and thus, the complete results (of N = 145) will be presented at the conference.&#x0D; References&#x0D; Hsu, C. L., Nagamatsu, L. S., Davis, J. C., &amp; Liu-Ambrose, T. (2012). Examining the relationship between specific cognitive processes and falls risk in older adults: A systematic review. Osteoporosis International, 23, 2409-2424. https://doi.org/10.1007/s00198-012-1992-z&#x0D; Schoene, D., Wu, S. M. S., Mikolaizak, A. S., Menant, J., Smith, S. T., &amp; Delbaere, K. (2013). Discriminative ability and predictive validity of the timed up and go test in identifying older people who fall: Systematic review and meta-analysis. Journal of the American Geriatrics Society, 61, 202-208. https://doi.org/10.1111/jgs.12106

Concurrent activation potentiation improves lower-limb maximal strength but not dynamic balance control in rugby players.

Concurrent activation potentiation (CAP) increases athletic performance by activating muscles not involved in the performed activity. Among the CAP strategies, jaw clenching is the most practical to implement in sports contexts. Muscle strength and balance control are essential among rugby players to cope tackles. Besides combat sports, mouthguard has become mandatory also in rugby. Therefore, this study aimed to understand whether mouthguard jaw-clenching could improve rugby players' dynamic balance and quadriceps isometric strength. Thirteen rugby players were tested under maximal-bite (MB) and no-bite (NB) conditions. During standing balance tests, an electro-actuated platform with a force plate screwed on it allowed for the perturbation of the support base of the rugby players. A verbal signal warned the subject that the perturbation was coming, mentally recalling an in-field expected collision. In the first 2.5s window after the perturbation, the center of pressure (CoP) displacement and mean velocity were measured. The first peak, the maximal oscillations, and the standard deviation of the anterior-posterior CoP trajectory were calculated within the same time window. In the isometric leg-extension test, a custom-built chair instrumented with a uni-axial load cell allowed to collect the maximal strength and rate of force development (RFD). Mouthguard jaw-clenching did not affect CoP-related parameters but increased maximal strength (p < 0.05) and RFD (0-50ms: p < 0.01; 50-100ms: p < 0.001; 100-150ms: p < 0.05) in the isometric leg-extension test. Mouthguard jaw-clenching alone could be useful to increase lower-limb maximal isometric strength and RFD but did not improve dynamic balance performance in a sport-oriented postural balance test.

Effect of gender, leg dominancy and body mass index on Y-balance performance among young healthy adults

This study investigated the influence of the sex, dominant leg and BMI on dynamic balance control of young adults (mean age; 20 ± 1.56) using the Y-balance test-lower quarter (YBT-LQ). This cross-sectional study included 218 participants (105 men and 103 women) who were recruited as a convenient sample of young, normal adults. The examination was implemented in one session, with three trials in each direction on each leg. The maximum reach distance of the three trials in each direction was used for statistical analysis. The reported reach distances were also normalized for each participant's leg length. Males' right leg values in the posteromedial (PM), posterolateral (PL), and composite directions were substantially longer than females' (p&lt;0.05), and no significant difference between both sexes in anterior (AT) direction (p&gt;0.05). In all directions, there were no significant differences between both sexes for the left leg (p&gt;0.05), and no significant differences between the right values of the dominant and non-dominant legs (p&gt;0.05). However, the left values of the non-dominant legs were longer than the dominant leg in directions (p&lt;0.05). The right leg values of the AT, PM, and composite values of the average BMI subjects was greater than the over-weight and obese subjects (p&lt;0.05), and the left leg values of the AT and composite values of the average BMI subjects was greater than over-weight and obese subjects (p&lt;0.05). Males have a longer right leg reach distance in the PM, PL directions, and composite value compared to females. The right leg dominant participants have longer reach distance of the left leg in all directions. When compared to over-weight and obese participants, average body weight subjects have bilaterally larger reach distance in the AT and composite directions.

Step Width Estimation in Individuals With and Without Neurodegenerative Disease Via a Novel Data-Augmentation Deep Learning Model and Minimal Wearable Inertial Sensors.

Step width is vital for gait stability, postural balance control, and fall risk reduction. However, estimating step width typically requires either fixed cameras or a full kinematic body suit of wearable inertial measurement units (IMUs), both of which are often too expensive and time-consuming for clinical application. We thus propose a novel data-augmented deep learning model for estimating step width in individuals with and without neurodegenerative disease using a minimal set of wearable IMUs. Twelve patients with neurodegenerative, clinically diagnosed Spinocerebellar ataxia type 3 (SCA3) performed over ground walking trials, and seventeen healthy individuals performed treadmill walking trials at various speeds and gait modifications while wearing IMUs on each shank and the pelvis. Results demonstrated step width mean absolute errors of 3.3 ± 0.7cm and 2.9 ± 0.5cm for the neurodegenerative and healthy groups, respectively, which were below the minimal clinically important difference of 6.0cm. Step width variability mean absolute errors were 1.5cm and 0.8cm for neurodegenerative and healthy groups, respectively. Data augmentation significantly improved accuracy performance in the neurodegenerative group, likely because they exhibited larger variations in walking kinematics as compared with healthy subjects. These results could enable clinically meaningful and accurate portable step width monitoring for individuals with and without neurodegenerative disease, potentially enhancing rehabilitative training, assessment, and dynamic balance control in clinical and real-life settings.