Effects of Limb Dominance on Postural Balance in Sportsmen Practicing Symmetric and Asymmetric Sports: A Pilot Study

The current literature shows no consensus regarding the difference between the dominant leg (D-Leg) and the non-dominant leg (ND-Leg) in terms of postural control. This lack of consensus could stem from motor experience (i.e., symmetric or asymmetric motricity) and/or the physiological state induced by physical exercise. This study aimed to investigate the acute effects of fatiguing exercise on postural control when standing on the D-Leg and the ND-Leg, in athletes practicing symmetric (SYM) and asymmetric (ASYM) sports. Thirty healthy male participants were recruited and divided into two groups, (SYM n = 15) and (ASYM n = 15, on the basis of the motricity induced by the sport they practice. Monopedal postural control was assessed for the D-Leg and the ND-Leg before and after the fatigue period (which consisted of repeating squats until exhaustion). A force platform was used to calculate the spatio-temporal characteristics of the displacements of the center of foot pressure (COP). A significant fatigue effect was observed in both groups on the D-Leg and the ND-Leg for all the COP parameters. There was a tendency (p = 0.06) between the ASYM and SYM groups on the D-Leg, concerning the relative increase in the COP velocity in the frontal plane after the fatigue period. The fatigue condition disturbed postural control in both the SYM and ASYM groups on the D-Leg and ND-Leg. This disturbing effect related to fatigue tends to be more marked in athletes practicing asymmetric sports than in athletes practicing symmetric sports on the D-Leg.

New Training Tasks for Stepwise Loading in Isometric Bodyweight Squat with Active Posture Control

Isometric bodyweight squats are fundamental exercises in athletic training and rehabilitation. Previously, we measured muscle activity in a normal squat posture (NSP) and a squat posture with the center of foot pressure (COP) intentionally shifted forward as far as possible (forward-shifted posture: FSP), and the muscle activity patterns varied significantly according to the COP location. This study focused on stepwise loading as a training strategy. Ten healthy male participants performed isometric bodyweight squats in a previous study, adopting the NSP and FSP, with three knee flexion angles (30°, 60°, and 90°). The muscle activities of the vastus medialis (VM), semitendinosus, tibialis anterior (TA), and gastrocnemius muscle lateral head were measured using surface electromyogram. This study further explored the relationship between COP shifting and knee flexion angles on electromyogram changes using three-dimensional diagrams. In one-way repeated measures analysis of variance by ranks, knee flexion angles affected the muscle activities of the VM and TA in the NSP and muscle activities of the VM in the FSP. Combining these findings, stepwise loading tasks were created to train individual target muscles. The ten male participants examined all the tasks, and the feasibility was confirmed accordingly.

Postural control in male ten-pin bowlers of different level of competitiveness

Ten-pin bowling is considered a highly skilled recreational activity with players demonstrating various anthropometric and physiological characteristics. The purpose of the current study was to assess both static and dynamic body balance, in ten-pin bowlers of different level of competitiveness. Thirty four ten-pin bowlers who competed at a high (Level-A, n=17) and a lower level (Level-B, n=17) as well as eighteen individuals without experience in ten-pin bowling (Non-bowlers) participated in the study. Static balance was determined based on the anteroposterior (APd) and mediolateral displacement (MLd) of the center-of-foot-pressure (CoP) that was recorded during single-leg-stance with open and close eyes as well as with open eyes and head extension. Dynamic balance was determined based on the APd and MLd of CoP as well as the normalized distances reached during execution of the Star Excursion Balance Test (SEBT) in the posterior, posterolateral and lateral directions. Significantly better dynamic balance, in terms of the distances reached during SEBT execution, was demonstrated by Level-A bowlers compared to Level-B bowlers and Non-bowlers. The differences between groups regarding APd and MLd, during both static and dynamic balance testing, were in general not significant. Our findings revealed that ten-pin bowlers who compete at a higher level demonstrate better dynamic balance ability. Sports scientists and coaches should be aware of these differences to optimize performance or distinguish ten-pin bowlers with different level of competitiveness.

Trends in the Analysis of Static Balance

The aim of the paper was to discuss the trends in the analysis of static balance and relation between physiological parameters and characteristics of posturograms. Static balance is ability to keep steady posture in certain stance [2, 3]. Posturography is one of most popular research methods of static balance [10, 11]. During the last decade it was maintained that the most informative dependent variables defining postural stability were the amplitude of the center of foot pressure (COP) sway in anterior-posterior and mediolateral directions, the length of the COP pathway and the area of the COP sway [9, 15]. The output of the posturograms registered during quiet standing is irregular and erratic [14]. Therefore, methods analyzing the structure of the posturograms are very topical for physiology and Rehabilitation science. The scientists attempt to determine certain noise and oscillation patterns in the posturogram [20]. According to researchers [14], the structure and roughness or smoothness of the posturogram could reflect the changes in postural control system. It is still questionable which of the methods analyzing the posturogram outcomes could be the most informative and useful for the diagnostics of postural control disorders. It is important to be able to repeat the scientific study, but it is still complicated to solve tasks related to postural control disorders diagnostics and the evaluation of the treatment means effectiveness. It is important to define the relation between physiological parameters and characteristics of posturograms in order to apply the posturography for balance disorders diagnostics. We suppose that methods of posturogram structure analysis could improve the differential balance disorders diagnostics essentially.Keywords: static balance, static posturography, center of foot pressure.

Treatment Resort Extended with Modern Feedback Exercises Using Virtual Reality to Improve Postural Control in Patients Aged 65+ with an Increased Risk of Falls. Preliminary Study

Introduction: The aim of the study was to learn the influence of treatment resort extended with modern exercises with feedback using virtual reality for postural control and reducing the risk of falls in people aged 65+. Material and Methods: Seventy four people (46 women, 28 men; aged 65-84) participated for three weeks in spa therapy, which was extended with physical exercises using feedback based on virtual reality to improve postural control and reduce the risk of falls. Postural control tests, “get up and go” test (TUG) and test standing up from the chair for 30 seconds were performed to assess the progress of the therapy. Results: After treatment in the Romberg trial performed on the stabilometric platform with open and closed eyes, a statistically significant improvement in most parameters indicating improved postural control was noted, including reduction of path length and surface area of center of foot pressure (COP), reduction of the length and speed of bowel movements COP in the frontal and sagittal planes. A statistically significant reduction in the time of the TUG test and increase the number of repetitions of standing up from the chair in 30 seconds were also noted. Statistical significance was assumed at the level of p≤0.05. Conclusions: Treatment resort enriched with exercises using virtual reality and feedback contributes to improving postural control and reducing the risk of falls in people aged 65+. The results of the study should be confirmed in high-quality therapeutic experiments, including control groups.