THE ESTIMATION OF THE EFFECT OF EXPERTISE ON POSTURAL CONTROL IN SHOOTING TASK WITH SAMPLE ENTROPY

We aimed to determine the interdependence between functional and dynamic stability of young basketball players. Eight elite biathlon experts, 15 moderate experienced subjects and 15 novices took part in the experiment. The postural sway and complexity of COP signal and its decomposed trajectories were measured using force plate. Results indicate that highly trained group of elite biathlon athletes was characterized by decreased values describing body sway and increased value of Sample Entropy during quiet stance. However, that situation was changed during maintaining a shooting position and during aiming at the target. These results lead to the conclusion that Sample Entropy could be used to estimate the attentional involvement in postural control according to skill development in sport performance

Just do it? When to do what you judge you ought to do

While it is generally believed that justification is a fallible guide to the truth, there might be interesting exceptions to this general rule. In recent work on bridge-principles, an increasing number of authors have argued that truths about what a subject ought to do are truths we stand in some privileged epistemic relation to and that our justified normative beliefs are beliefs that will not lead us astray. If these bridge-principles hold, it suggests that justification might play an interesting role in our normative theories. In turn, this might help us understand the value of justification, a value that's notoriously difficult to understand if we think of justification as but a fallible means to a desired end. We will argue that these bridge-principles will be incredibly difficult to defend. While we do not think that normative facts necessarily stand in any interesting relationship to our justified beliefs about them, there might well be a way of defending the idea that our justified beliefs about what to do won't lead us astray. In turn, this might help us understand the value of justification, but this way of thinking about justification and its value comes with costs few would be willing to pay

GENDER EFFECTS ON POSTURAL SWAY DURING RIFLE AIMING

Eight male and eight female subjects without prior shooting experience took part in the experiment. The aim of this study was to determine gender effects on postural sway characteristics and rambling and trembling components during rifle aiming. Subjects were tested with the use of force platform in quiet standing, in shooting position, and in shooting position with additional visual feedback, three times in each condition. Rambling (RM) –Trembling (TM) signal decomposition was used to process the data. Center of the pressure sway range (COPra), mean velocity (COPvel), COP root mean square (RMS), and the rambling and trembling displacement length (RMlen, TRlen) in the anterior-posterior (AP) and medial-lateral (ML) directions were analyzed variables. The results showed significant changes in behaviour due to increased levels of task difficulty effect of gender

Knee Joint Position Sense in Physically Active Patients after ACL Reconstruction

The term “proprioception” is defined as the conduction of sensory information deriving from proprioceptors that have an impact on conscious sensations, posture and trans-segmental sense. An ACL injury may lead to functional knee joint instability. According to research, this may result in impaired movement sensation and joint position. The purpose of this study was to evaluate the joint position sense (JPS) in patients before arthroscopic ACL reconstruction and 5 months after the surgery. The examinations were conducted in a group of twelve specifically selected male patients. The examination procedure consisted of JPS measurement in both lower limbs (the operated and the healthy one) during active extension in a range of angles: 30, 45, 60°. The level of significance was: p < 0.05. The analysis of variance performed for repeated measurements (ANOVA) did not indicate any statistically significant differences of JPS in comparisons made between the operated and the healthy limb. Statistical values for the absolute, relative, and variable errors were p = 0.7684, p = 0.1546, p = 0.5694 respectively. The obtained results do not indicate any limitation of proprioception in patients with ACL injury before the intervention or half a year later

A preliminary investigation into the impact of shock wave therapy and sonotherapy on postural control of stepping tasks in patients with Achilles tendinopathy

ObjectiveThe outcomes of physical therapy are commonly assessed with subjective scales and questionnaires. Hence, a continuous search to identify diagnostic tests that would facilitate objective assessment of symptom reduction in those patients with Achilles tendinopathy who undergo mechanotherapy. The main aim of this study was to evaluate and compare the effectiveness of shock wave and ultrasound treatments, using objective posturographic assessment during step-up and step-down initiation.Materials and methodsThe patients with non-insertional Achilles tendinopathy and pain lasting for more than 3 months were randomly assigned to one of the experimental groups, i.e., radial shock wave therapy (RSWT), ultrasound therapy, or placebo ultrasound. All groups also received deep friction massage as the primary therapy. The transitional locomotor task was performed with the affected and unaffected limb in random order, on two force platforms under two conditions (step-up and step-down). The recording of center of foot pressure displacements was divided into three phases: quiet standing before step-up/step-down, transit, and quiet standing until measurement completion. Pre-intervention measurements were performed and then short-term follow-ups at weeks 1 and 6 post-therapy.ResultsThe three-way repeated measures ANOVA showed few statistically significant two-factor interactions between therapy type, time point of measurement and the type of the locomotor task. Significant increases in postural sway were observed in the entire study population throughout the follow-up period. Three-way ANOVAs revealed a group effect (shock wave vs. ultrasound) on almost all variables of the quiet standing phase prior to step-up/step-down initiation. Overall, postural stability before the step-up and step-down tasks appeared to be more efficient in patients who had undergone RSWT compared to the ultrasound group.ConclusionObjective posturographic assessment during step-up and step-down initiation did not demonstrate therapeutic superiority of any of the three therapeutic interventions used in patients with non-insertional Achilles tendinopathy.Clinical Trial Registration: The trial was prospectively registered in the Australian and New Zealand Clinical Trials Registry (no. ACTRN12617000860369; registration date: 9.06.2017)

The Impact of the Swedish Massage on the Kinesthetic Differentiation in Healthy Individuals

Background: Swedish massage is one of the common treatments to provide optimal start and readiness of athletes. The ability of kinesthetic differentiation (KD) is crucial in sport performance. This skill allows to adapt demanded muscle forces to optimize the motor tasks, and it is responsible for the precision. In the literature, there is no evidence how Swedish massage influences the kinesthetic differentiation.Purpose: The objective of the study was to evaluate the impact of Swedish massage on the kinesthetic differentiation and muscle strength of hand grip.Methods: Thirty participants took part in this investigation (17 women and 13 men). The assessment consisted of KD tests conducted on the dominant (DH) and nondominant hand (NDH) after 15 minutes of hand and forearm Swedish massage. The procedure consisted of 13 trials for each extremity. The first three were done for 100% of the participants’ capabilities (Fmax), the next five trials were done using 50% of maximum force (50% of Fmax), and in the last five trials, the participants tried to use only 50% of their previous force (1/2 of 50%). Finally, the absolute force production error (FPE) was calculated for 50% (FPE_50%) and 25% (FPE_25%).Results: The two-way repeated measure analysis of variance ANOVA did not reveal any statistically significant changes in maximal strength grip and KD between pre- and postmassage intervention in both DH and NDH hand. Correlations showed strong relationship between pre- and postmassage for maximum force (r = 0.92, p = .01 for DH, and r = 0.94, p = .01 for NDH), and only for the FPE_50% (r = 0.67, p = .01 for DH, and r = 0.71, p = .01 for NDH).Conclusions: The results obtained indicated that the application of the Swedish massage did not affect the kinesthetic differentiation in this particular young adult group

The Effects of Cryotherapy on Proprioception System

Proprioception plays an important role in the complex mechanism of joint control. Contemporary sport activities impose extremely high physical demands on athletes. Winter sports are played in areas with excessively low temperatures. Moreover, many athletes are subjected to treatments that involve local lowering of the body temperature before, during, and after physical activity. This work reviews the current knowledge regarding the influence of local cryotherapy on the proprioception system. The reviewed literature identified several tests that evaluate different aspects of proprioception. There is no universally agreed protocol, or clear set of criteria for test conditions. The outcomes of different tests and assessments of cryotherapy procedures using different cold modalities are poorly correlated. In general, the published results on the mechanism of cryotherapy effects on proprioception are not uniquely conclusive and are frequently contradictory. Additional high-quality research is required to explicitly answer the following questions: (1) whether local cryotherapy influences all aspects of proprioception; (2) whether the current methods of evaluation are adequate for the exploration of the relationship between cryotherapy and proprioception; and (3) whether the application of local cryotherapy is safe for athletes regarding proprioception. The review clearly showed that there is no comprehensive model relating cryotherapy and proprioception