Chronic traumatic encephalopathy associated with cumulative soccer heading exposure: A review of the recent literature / 体力科学

Soccer is the most popular sport worldwide, with over 265 million participants. Soccer is unique in that the ball can be directed deliberately and purposefully with the head, an act referred to as ‘heading’. In recent years, there has been concern about the association between repetitive subconcussive head impacts associated with heading and chronic traumatic encephalopathy. Heading causes immediate changes in biochemical and electrophysiological markers of traumatic brain injury, and some studies have reported brain structural changes and dysfunction in former soccer players. In 2019, it was reported that the mortality associated with neurodegenerative diseases was about 3.5 times higher among former professional soccer players. Following that, in early 2020, the guidance have been published to limit heading by age in some regions including England and Scotland. In this review, we will expound the immediate and long-term effects of heading associated with chronic traumatic encephalopathy and the measures that should be taken into consideration in the practice of soccer instruction, based on the latest findings.

The effect of taping on pain-related somatosensory evoked potentials (pSEPs) / 体力科学

Taping is widely used in sports medicine to prevent injury, protect affected sites post injury and relieve pain. However, it is not clear whether taping affects the perception of noxious stimulation because in previous studies, it was difficult to selectively activate Aδ fibers. A recently developed, useful, new tool named intra-epidermal electrical stimulation (IES) can preferentially activate Aδ fibers. We aimed to clarify the effect of taping on pain-related somatosensory evoked potentials (pSEPs) using IES. We recorded pSEPs following IES of the right medial forearm in twelve healthy volunteers. pSEPs were recorded from 9 electrodes on the scalp under control, elastic-taping and white-taping conditions. Under the control condition, subjects relaxed on a comfortable reclining seat without taping, whereas under the taping conditions, they were subjected to taping along the forearm with tension (elastic-taping) and without tension (white-taping). Subjects were asked to assign a visual analog scale (VAS) score after each session. The peak amplitudes of N2-P2 were significantly lower under the elastic-taping and white-taping conditions than those under the control condition. VAS was significantly lower elastic-taping condition than those under the control and white-taping conditions. Moreover, there was a significant positive correlation between the amplitude of N2-P2 and VAS. We revealed that taping along the forearm decreased pSEPs and subjective pain perception under the white-taping and elastic-taping conditions. The underlying mechanism of pain relief was the distraction effect in both taping conditions. In addition, elastic-taping with tension changes afferent inputs mainly from the skin, and this might more effectively decrease the subjective pain perception than that achieved under the white-taping condition.

The effect of elastic-taping on long-latency somatosensory evoked potentials (SEPs) / 体力科学

Taping is widely used by sports trainers to prevent injury and to protect affected sites post-injury. However, it is not clear whether taping affect the perception of somatosensory stimulation. We sought to clarify the effect of taping on somatosensory stimulation using somatosensory evoked potentials (SEPs). We recorded SEPs following transcutaneous electrical stimulation of the right medial forearm in ten healthy volunteers. SEPs were recorded from 9 electrodes on the scalp under control, elastic-taping and white-taping conditions. Subjects relaxed on a comfortable reclining seat without taping in the control condition, while they were subjected to taping along the muscle of forearm with tension (elastic-taping) and without tension (white-taping) in the taping conditions. Results showed that the peak amplitude of N140 did not differ significantly among the three conditions but the peak amplitude of P250 was significantly lower in the elastic-taping condition than control and white-taping conditions. Elastic-taping with tension along the muscles changes various afferent inputs from muscle spindle or skin, and this may affect the perception of somatosensory stimulation.