Effect of workshops for coaches on the motor ability of balance in children practicing sports in late childhood

Background The coach attitude impacts the whole mind and body system of a child athlete from emotional and motivational aspects to motor skills like motor coordination. It translates into the ability to control and stabilize posture. The vestibular system plays an important role in this regulation. This system, next to the visual system and mechanoreceptors, is responsible for balance and control during posture transition. Moreover, the vestibular system is influenced by emotional factors. Therefore the authors of this study focused on the changes in the balance stability of children practicing sport after the implementation of the psychological workshops for coaches. Methods Fifty-nine children at the age of 9–12 practicing soccer, art gymnastic and sport gymnastic were divided into two groups. The experimental group consisted of 31 participants and 28 in the control group. Experimental group children were under the influence of the 3 coaches who attended three workshops over 12 weeks period. Control group children were coached by 5 coaches who attended no workshops. Postural stability tests were performed on children before and after the workshops. Results The statistically significant changes were observed in selected parameters of children’s balance stability after the experiment. The significant difference between the experimental and control group in Overall Stability Index (OSI) (p < 0.0002), Anterior–Posterior Stability Index (AP) (p < 0.01), Medial–Lateral Stability Index (ML) (p < 0.01) with eyes open were observed after the experiment. The results show a significant deterioration in control group contrary to the experimental group where the improvement trend was observed. Moreover, the difference between the groups was observed in OSI parameter (p < 0.005) with eyes closed after the experiment. Conclusion The results obtained by the authors of the current study may support the thesis that educating coaches allows for better results in postural stability of child’s athletes. Nevertheless, this thesis requires further research, with particular emphasis on the age and gender of young athletes.

Association of Foot Sole Sensibility with Quiet and Dynamic Body Balance in Morbidly Obese Women

An important health-related problem of obesity is reduced stance stability, leading to increased chance of falling. In the present experiment, we aimed to compare stability in quiet and in dynamic body balance between women with morbid obesity (n = 13, body mass index [BMI] > 40 Kg/m2, mean age = 38.85 years) and with healthy body weight (lean) (n = 13; BMI < 25 Kg/m2, mean age = 37.62 years), evaluating the extent to which quiet and dynamic balance stability are associated with plantar sensibility. Quiet stance was evaluated in different visual and support base conditions. The dynamic task consisted of rhythmic flexion—extension movements at the hip and shoulder, manipulating vision availability. The plantar sensibility threshold was measured through application of monofilaments on the feet soles. The results showed that the morbidly obese, in comparison with the lean women, had higher plantar sensibility thresholds, and a reduced balance stability in quiet standing. Mediolateral stance stability on the malleable surface was strongly correlated with plantar sensibility in the obese women. Analysis of dynamic balance showed no effect of obesity and weaker correlations with plantar sensibility. Our results suggest that reduced plantar sensibility in morbidly obese women may underlie their diminished stance stability, while dynamic balance control seems to be unaffected by their reduced plantar sensibility.

Effects of pedicle screw number and insertion depth on radiographic and functional outcomes in lumbar vertebral fracture

Background The influence of pedicle screw number and insertion depth on outcomes of lumbar fixation remains uncertain. The purpose of this study was to compare the imaging balance stability and clinical functional improvement of lumbar fracture patients with different pedicle screw numbers and insertion depths. Methods Sixty-five patients undergoing lumbar pedicle screw fixation from January 2016 to January 2018 were enrolled. They were included in long screw (LS) group and short screw (SS) group or 6 screw (6S) group and 4 screw (4S) group. The radiographic outcomes were assessed with lumbar lordosis (LL), segmental lordosis (SL), fractured vertebral lordosis (FL), sacral slope (SS), pelvic incidence (PL), and pelvic tilt (PT). The visual analog scale (VAS) and the Oswestry Disability Index (ODI) score were used for functional assessment. Multiple linear regression was performed to identify the risk factors of FL, SL, and LL correction at the final follow-up. Results FL, SL, and LL were significantly different in all matching subgroups to compare long and short screws and in most matching subgroups to compare 6 and 4 screws. The SS, PT, and PI seem to be similar in all subgroups in different periods. Significant differences of VAS and ODI were found between LS and SS in the 4S group and between 4S and 6S in the SS group. Insertion depth, screw number, BMD, age, and preoperative imaging data were significant factors for imaging balance stability correction at the final follow-up. Conclusions Long screws and 6 screws showed better fracture vertebral restoration and lumbar spinal sagittal stabilities. The surgery type, age, and BMD are important focus points for the treatment of lumbar vertebral fractures.

Whole-Body Balancing Criteria for Biped Robots in Sagittal Plane

In this work, the role of swing limb dynamics in the stabilization of legged systems is investigated. To quantify the contribution of arm swing during whole-body balancing, the balancing capability of a bipedal robotic platform is evaluated computationally during single and double foot contact for two configurations: arms fixed and arms free to move. The balancing capability with each arm configuration is evaluated by constructing its corresponding balance stability boundary, a threshold between balanced and falling states that includes all possible center of mass (COM) states that are balanced with respect to the specified arm and foot contact configuration. In this analysis, the bipedal robotic platform is modeled as a kinematic tree structure with floating-base dynamics in the sagittal plane. In addition to floating-base and joint-space dynamics, the complete COM-space dynamics of the system is established, including the formulation of the angular momentum (and its rate) of each rigid link, as well as a model of actuation dynamics based on motor characteristics. The comparison of the two balance stability regions yields both a quantitative measure of the enhancement in total balance capability and qualitative insights into the mechanism by which arm swing leads to enhanced capability. The role of arm swing angular momentum is also analyzed from the robot’s experimental gait trajectories as a potential means of benchmarking controller performance.