Fatigue does not conjointly alter postural and cognitive performance when standing in a shooting position under dual-task conditions.

This study investigated the effects of fatigue on balance control and cognitive performance in a standing shooting position. Nineteen soldiers were asked to stand while holding a rifle (single task - ST). They also had to perform this postural task while simultaneously completing a cognitive task (dual task - DT). Both the ST and DT were performed in pre- and post-fatigue conditions. In pre-fatigue, participants achieved better balance control in the DT than in the ST, thus suggesting that the increased cognitive activity associated with the DT improves balance control by shifting the attentional focus away from a highly automatised activity. In post-fatigue, balance control was degraded in both the ST and DT, while reaction time was enhanced in the first minutes following the fatiguing exercise without affecting the accuracy of response in the cognitive task, which highlights the relative independent effects of fatigue on balance control and cognitive performance.

Static Postural Balance in Modern Pentathletes: A Pilot Study.

Postural balance is a key element of shooting effectiveness, which determines the outcome of modern pentathlon competitions. The aim of the study is to examine the postural balance of 27 pentathletes (12 females and 15 males; mean age: 18.0 ± 1.8 years), and 26 physically active, untrained subjects (12 females and 14 males; mean age: 22.5 ± 1.4 years), and to investigate the impact of footwear on the stability of the shooting position in pentathletes. Methods: Static postural balance was examined during quiet stance in four test conditions (standing in footwear with eyes opened, standing in footwear with eyes closed, standing barefoot with eyes opened, and standing barefoot with eyes closed). During each postural balance measurement, the participant remained still on the platform, with their arms in front of their body. Postural balance in the shooting position was only evaluated in the group of pentathletes. The athlete was asked to assume a comfortable shooting position on the platform and to aim at the target. Standard pentathlon targets and pistols were used in the study. Measurements were carried out twice (barefoot and in footwear). Results: In all conditions, pentathletes achieved lower values of posturographic measures than in the control group. In non-visual conditions, measures describing the surface area of the centre of pressure decreased in pentathletes and increased in the control group. Both pentathletes and non-athletes were equally stable barefoot as in footwear. Footwear did not affect postural sway in the shooting position in pentathletes. Conclusions: Pentathletes were found to have significantly better stance stability and were less vision-dependent in postural balance than untrained subjects. Bearing in mind that the shooting position of pentathletes was as stable barefoot as in footwear, the main factors which were most likely responsible for minimising body oscillations in the pentathletes were their high level of concentration and conscious control of body alignment.

Influence of Running Phases on the Postural Balance of Modern Pentathlon Athletes in a Laser Run Event.

Background: The Laser Run combined event is part of the modern pentathlon, consisting of successive shooting and running phases. The main factor hindering accurate and fast shooting is the increasing fatigue caused by running effort. The aim of this study was to assess the impact of the running phases on the postural balance in the shooting position of pentathletes in a Laser Run event. Methods: 25 modern pentathletes (18.6 ± 1.7 years), members of the Polish Association of Modern Pentathlon, completed a Laser Run event. During each shooting series, a Zebris dynamometric platform recorded the displacement of the centre of pressure (COP). Results: Significant changes in the average velocity of the COP (F = 3.43; p = 0.0223) and the width of the ellipse of the COP shifts area WoE (F = 3.30; p = 0.0259) between the first and the second shooting series were observed. The average velocity of the COP in series I was 72.6 m/s and increased to 84.3 m/s in series II. In turn, the average width of the ellipse of the COP in series I reached 29.1 mm and in series II, 34.1 mm. Conclusions: The fatigue caused by the running phases in the Laser Run affects the stability of the shooting position of pentathletes. Disturbances that occur after the first running phase are maintained at the same level during the subsequent shooting series. The fatigue level does not affect the magnitude of the disturbances of the postural balance in the shooting position.

Differences of Anteroposterior Pelvic Radiographs Between Supine Position and Standing Position in Patients with Developmental Dysplasia of the Hip.

OBJECTIVE: To explore the difference in pelvic tilt and hip joint parameters with developmental dysplasia of the hip (DDH) comparing the anteroposterior (AP) pelvic radiographs taken in supine and standing positions. METHODS: A prospective study of DDH patients undergoing Bernese periacetabular osteotomy (PAO) was conducted. AP pelvic radiographs were taken in supine and standing positions before surgery The pelvic tilt and hip joint parameters from the two radiographs were compared. Contrast parameters included the distance between the pubic symphysis to sacrococcygeal distance (PSSC), lateral center-edge angle (LCEA), Tönnis angle (TA), and angle of sharp (SA). RESULTS: A total of 110 young DDH patients were enrolled, including 32 men and 78 women, aged 18-49 years. The male PSSC was 45.63 ± 13.69 mm in supine position and 36.91 ± 12.33 mm in standing position (P < 0.05). The female PSSC was 56.76 ± 13.54 mm in supine position and 48.62 ± 15.44 mm in standing position (P < 0.05). In this study, LCEA <20° in AP pelvic radiographs in the supine position was found in 52 men and 135 women. For male patients, in supine position and standing position, LCEA were 5.51° ± 11.88° and 4.45° ± 12.22°, respectively (P < 0.05); TA were 20.20° ± 9.63° and 21.30° ± 9.97°, respectively (P < 0.05), and SA comparison showed no significant differences. For female patients, in supine position and standing position, LCEA were 3.07° ± 12.07° and 1.69° ± 12.11°, respectively (P < 0.05), TA were 22.62° ± 9.31° and 23.82° ± 9.45°, respectively (P < 0.05), and SA were 48.01° ± 4.68° and 48.49° ± 4.74°, respectively (P < 0.05). CONCLUSION: Compared with the supine position, the young DDH patients have pelvic tilt backward and a decrease in hip coverage in the standing position.