Central fatigue typically refers to an exercise-associated impairment in central nervous system function, typically demonstrated by reduced muscle activation during maximal voluntary contraction. This month, MSSE features two basic research investigations of “central fatigue” as a performance limiting factor. Pageaux et al. reason that since central fatigue occurs at both spinal and supraspinal levels, and that supraspinal fatigue develops “upstream” of the primary motor cortex, then prolonged mental exertion might impair muscle activation by increasing central fatigue produced during endurance exercise. Although the findings did not support the hypothesis, the authors speculate that mental fatigue and central fatigue associated with exercise are not manifestations of the same central mechanism.
In the other paper, Temesi et al. investigate whether sleep deprivation exacerbate the central fatigue associated with submaximal steady-state exercise performed to exhaustion. Prolonged submaximal exercise did lead to central fatigue, as reflected by a reduction in knee extensor force during maximal voluntary contraction, but sleep deprivation did not aggravate central fatigue even though exercise time to exhaustion (performance) was degraded by sleep deprivation. Despite the fact that the hypotheses in both studies are refuted, both papers advance understanding of central fatigue and describe useful approaches for future studies.
Also featured this month, Kulmala et al. describe biomechanical differences between forefoot strike and rearfoot strike pattern runners. The authors observe that forefoot strike runners exhibit lower patellofemoral contact force and less knee frontal plane movement during running than did the rearfoot strike pattern runners, and they speculate that those differences could provide forefoot strike pattern runners some protection against running-related knee injuries. This new paper contributes to MSSE’s considerable archive of research reports on biomechanical risk factors in the etiology running injuries. One of the earliest of those investigations was reported by Messier et al. [Etiologic factors associated with patellofemoral pain in runners. Med Sci Sports Exerc. 1991, 23(9): 1008-1015], who identified anatomical features that appeared to be predictive of risk of injury in runners. Since its publication over 20 years ago, that article has remained MSSE’s most highly cited on the topic, including seven citations so far this year, and we are featuring it for your review again this month.
This issue marks my last as Editor-in-Chief, and I hope that readers have found my News and Views useful and informative. I want to thank all of MSSE’s editorial team and especially our contributing authors for their support throughout my term, and readers can be confident that the journal is in very good hands with new Editor-in-Chief Bruce Gladden.