Effect of Blood Circulation in the Upper Limb after Flossing Strategy

A very popular method in the field of prevention, sports, and therapy is flossing, working with an elastic band. A number of effects have been reported with this approach, but there are so far only a few studies to objectivize the declared effects. The aim of our study was to determine the change in the blood supply to the musculus biceps brachii during and after the flossing method applied to the upper limb in the area of the shoulder joint. The study recruited 27 healthy respondents (23.3 ± 2.8 years old). Measurement of the blood flow was performed on a Précisé 8008 (Ulrichstein, Germany) a device for measuring transcutaneous oxygen (tcpO2) before, during the 2-min compression therapy applied in the area of the shoulder joint, and after. We noted that both upper limbs, the limb where the application was performed and the opposite limb reached significant changes in the blood flow in musculus biceps brachii. Due to the significant depression of perfusion after only 2 min of flossing, great caution is required when performing the flossing method. The “sponge effect,” which means that after the occlusion is removed, the perfusion increases rapidly, was not confirmed by our study.

Hemodynamic and Neuroendocrinological Responses to Artificial Gravity

The aim of this study was to determine the hemodynamic and neuroendocrinological responses to different levels and protocols of artificial gravity, especially in comparison to what is expected during a moderate bout of exercise. Ten male participants were exposed to artificial gravity using two different protocols: the first was a centrifugation protocol that consisted of a constant phase of 2 Gz for 30 minutes, and the second consisted of an intermittent phase of 2 Gz for two minutes, separated by resting periods for three minutes in successive order. Near infrared spectroscopy (oxyhemoglobin and deoxyhemoglobin) at the prefrontal cortex, Musculus biceps brachii, and Musculus gastrocnemius, as well as heart rate and blood pressure were recorded before, during, and after exposure to artificial gravity. In order to determine effects of artificial gravity on neuroendocrinological parameters (brain-derived neurotrophic factor, vascular endothelial growth factor, and insulin-like growth factor 1), blood samples were taken before and after centrifugation. During the application of artificial gravity the concentration of oxyhemoglobin decreased significantly and the concentration of deoxyhemoglobin increased significantly in the prefrontal cortex and the Musculus biceps brachii muscle. Participants exposed to the continuous artificial gravity profile experienced peripheral pooling of blood. No changes were observed for brain-derived neurotrophic factor, vascular endothelial growth factor, or insulin-like growth factor 1. Intermittent application of artificial gravity may represent a better-tolerated presentation for participants as hemodynamic values normalize during resting periods. During both protocols, heart rate and arterial blood pressure remained far below what is experienced during moderate physical activity.

AN EFFECTIVE TECHNOLOGY TO EVALUATE VIBRATION COMFORTABILITY OF HUMAN BODY BASED ON NEAR-INFRARED SPECTROSCOPY

In the biomedical field, Near-Infrared Spectroscopy (NIRS) is often used to determine the physiological information by the noninvasive detection of the regional tissue oxygen saturation (rSO2). Because the fatigue degree of body could be obviously demonstrated by the oxygen saturation under different vibration conditions, an effective technology to evaluate the vibration comfortability by rSO2 is innovatively proposed in this paper. Without losing generality, the vibration comfortability is analyzed by taking the driving position for example. Different from much more factors in previous approaches, only four main body factors, i.e., brain, musculus biceps brachii, erector spinae and biceps femoris, and three main influence factors on vibration comfortability, i.e., acceleration, frequency, and exposure time, are taken into account in our technology. Under different conditions of the three vibration factors, the rSO2 for the four body factors is detected one by one. Then the relationship among the rSO2, subjective feeling, and the vibration parameters can be obtained by the least square method, and the quantitative evaluation model on vibration comfortability is established. It is found experimentally that the rSO2 trends of musculus biceps brachii, erector spinae and biceps femoris are all greatly increased with the acceleration and frequency, but brain is decreasing obviously. Through our experiment it is verified that this technology can be used in objectively and effectively evaluating under different vibration conditions. This novel technology could provide theoretical support for vibration comfortability assessment and have potential applications in other relative fields.

Expiratory activity in transferred intercostal nerves in brachial plexus injury patients

Involuntary activity of transferred intercostal motor units was examined in patients with brachial plexus injury. Since the internal intercostal nerves were detached from the thorax to reinnervate the musculus biceps brachii, it was possible to record pure intercostal motor activity in humans. Respiratory activity was seen in the latter part of the expiratory phase, thus dividing the phase into two substages (E1 and E2) by the onset of the activity. CO2 rebreathing prolonged the duration of the intercostal motor activity and increased the tidal activity as determined from the integration curve. There was a close linear correlation between these two variables. These observations indicate that expiratory activity and its duration are actively controlled in humans.