Lower limb muscle fatigability is not associated with changes in movement strategies for balance control in the upright stance

Investigations Concerning the Influence of Sleep Disorders on Postural Stability in Young Men

Lack of sleep is a factor that disrupts the receptors’ reception of information from the environment and contributes to the emergence of problems with maintaining balance. The main aim of the study was to determine whether sleep disorders affect postural stability in young men. The study participants were 76 male students who were divided into groups with good and poor sleep quality. The division was made based on the results obtained from the questionnaire of the Pittsburgh Sleep Quality Index (PSQI). In each group, postural stability had been tested using three main tests: Sensory Organization Test (SOT); Motor Control Test (MCT); and Adaptation Test (ADT). The results of the analysis show that the obtained results differ in the examined groups under the SOT test. Different values of the tested parameters were noted among people with poor sleep quality and compared with the values of those who sleep well, which translates into a difference in the ability to maintain balance. The greatest impact is observed when using visual and a vestibular system to maintain a stable posture. It was confirmed that the lack of sleep significantly disturbs postural stability.

Assessing Post-Driving Discomfort and Its Influence on Gait Patterns

Professional drivers need constant attention during long driving periods and sometimes perform tasks outside the truck. Driving discomfort may justify inattention, but it does not explain post-driving accidents outside the vehicle. This study aims to study the discomfort developed during driving by analysing modified preferred postures, pressure applied at the interface with the seat, and changes in pre- and post-driving gait patterns. Each of the forty-four volunteers drove for two hours in a driving simulator. Based on the walking speed changes between the two gait cycles, three homogeneous study groups were identified. Two groups performed faster speeds, while one reduced it in the post-steering gait. While driving, the pressure at the interface and the area covered over the seat increased throughout the sample. Preferred driving postures differed between groups. No statistical differences were found between the groups in the angles between the segments (flexed and extended). Long-time driving develops local or whole-body discomfort, increasing interface pressure over time. While driving, drivers try to compensate by modifying their posture. After long steering periods, a change in gait patterns can be observed. These behaviours may result from the difficulties imposed on blood circulation by increasing pressure at this interface.

Effects of standing and walking on plantar pressure distribution in recreational runners before and after long-distance running

With marathon-running grew in popularity, the effect of long-distance running on plantar pressure has been more attractive. It has been proposed that long-distance running influences the deviation in the center of pressure (COP) during standing and the changes to plantar pressure during walking. The objective of this study was to observe the effects on the COP motion amplitude of static standing and the plantar pressure distribution of walking after long-distance running. The influence of a 10-km run on changes to plantar pressure was assessed during standing and walking. Plantar pressure was measured before and immediately after running. In the study, seven males and five females participated in barefoot tests of static standing and dynamic walking. In the static standing tests, COP was measured under the following four ordered conditions: (1) bipedal, eyes open, standing; (2) bipedal, eyes closed, standing; (3) unipedal, eyes open, standing and (4) unipedal, eyes closed, standing. Under each condition, the data was collected while a stable standing posture for 10 s. In the dynamic walking tests, the contact duration and plantar pressure were recorded. The standing tests results revealed no significant differences between males and females while slight differences before vs. after running. Running for a single time had no effect on COP deviation during standing. The walking tests results revealed an initial landing on the lateral heel. After landing on the lateral heel, the females quickly transferred to the medial heel. The movement of the pressure to the medial heel was slower in males than females. After running, the pressure of females was more inward, while that of males was more outward under the metatarsal zones in the propulsion phase.