The Effects of Two Different Fatigue Protocols on Lower Extremity Kinematics and Kinetics During an Unanticipated Running Stop-Jump

Altered neuromuscular control strategies and biomechanical movement risk factors are most likely to contribute to the increased incidence of non-contact ACL injury for female athletes. Neuromuscular control strategies and movement patterns are further altered when the effects of fatigue are present. The purpose of this study was to determine neuromechanical differences between two fatigue protocols [Slow Linear Oxidative Fatigue Protocol (SLO-FP) and Functional Agility Short-Term Fatigue Protocol (FASTFP)] when performing a running stop-jump task (RS). A sample of convenience of fifteen Division I female soccer players (age= 19.2 ± 0.8 years; height= 1.67 ± 0.05 m; mass= 61.7 ± 8.1 kg) participated in this study. Participants performed five successful trials of a RS task pre and post fatigue protocols. For the SLO-FP, a VO2peak test was conducted prior to the fatigue protocol. Five minutes after the conclusion of VO2pcak test subjects started the fatigue protocol by performing a 30-minute interval run with six intervals. The FAST-FP consisted of 4 sets of a functional circuit that included: L-Drill, Ladder, Vertical Jumps, and step-ups. Repeated 2 (time) x 2 (protocol) ANOVAs were conducted to assess task and fatigue differences. Alpha level was set at .05. During SLOFP participants had increased internal varus moment at initial contact (0.064±0.09Nm/Kgm) when compared with the FAST-FP (0.024±0.06Nm/kgm), p=0.033. Participants were in significantly lower hip flexion at initial contact post-fatigue (44. 7±8.1 °) when compared with pre-fatigue (50.1±9.5°), p=0.001 as well as at peak vertical ground reaction force post-fatigue (44.7±8.4°) when compared with pre-fatigue (50.4±10.3°), p=0.001; at peak posterior ground reaction force post-fatigue (45.2±8.6°) when compared with pre-fatigue (51.1±10.8°), p=0.001; at peak knee flexion post-fatigue (38.7±8.7°) when compared with pre-fatigue (45.1±11.6°), p=0.001, and at max hip flexion post-fatigue (47.3±8.2°) when compared with pre-fatigue (53.3±10.95°), p=0.001. During SLO-FP subjects had increased knee extension moment (2.0l±.32Nm/K.gm) when compared with the FASTFP (1.9±.36Nm/Kgm), p=0.033. Both protocols induced similar changes to our subjects lower extremity biomechanics, the FAST-FP induced changes in as little as five minutes whereas the SLO-FP took 45 minutes to induce similar biomechanical changes. Our results demonstrated a decrease in hip and knee flexion angles at post-fatigue condition. Landing in an upright position has been shown to increase anterior tibial shear force, which augments the loads on the ACL

Jealousy, Transmission and Recovery

Recovery is a performance project by Natalie Cursio and Shannon Bott that premiered in Melbourne, Australia in late 2015. In the credits I am listed as ‘Director / Choreographer’ but I was not involved at the beginning of the project and nor did I see the premiere. My relative absence from Recovery has led me to conceive of my relationship to it as being that of a jealous lover. In turn, I ask how the experience of jealousy may be useful in re-negotiating the role of the choreographer—and choreography—through time. The writing evokes the biological metaphor of 'spillover' to help imagine a work's persistence beyond performance (and related considerations of annotation and archive), and proposes that the idea of stewardship helps to recognize the limited role of the director/choreographer in how performance is transmitted through time. This is an Accepted Manuscript of an article published by Taylor & Francis in Performance Research on 26 November 2015 available online: http://www.tandfonline.com/10.1080/13528165.2015.111106

Por que não estávamos prontos para o coronavírus?

This paper by David Quammen, author of the recommended book Spillover. Animal infections and the next human pandemic, makes a brief synthesis of the latest research on epizootic diseases, caused by viruses that jump from other animal species to the human species, and is a sort of addendum to the epilogue of the Spanish version, entitled “We were the ones who created the coronavirus epidemic”. In this paper Quammen argues that U.S. has fared worse than other countries not because it lacked information or funding but because it failed to learn the lessons of the last outbreaks.Este artículo de David Quammen, autor del recomendable libro Contagio. La evolución de las pandemias, hace una breve síntesis de las últimas investigaciones sobre las enfermedades epizoóticas, causadas por virus que saltan de otras especies animales a la especie humana, y es una especie de adenda al epílogo de la versión en castellano, titulado “Fuimos nosotros quienes creamos la epidemia del coronavirus”.En este artículo Quammen argumenta que a Estados Unidos le ha ido peor que a otros países, no porque haya carecido de información o de financiación, sino porque no aprendió las lecciones de los últimos brotes.Este artigo é de David Quammen, autor do livro recomendado Spillover. Infecções animais e a próxima pandemia humana, faz uma breve síntese das últimas pesquisas sobre doenças epizoóticas, causadas por vírus que saltam de outras espécies animais para a espécie humana, e é uma espécie de adendo ao epílogo da versão espanhola, intitulada “ Fomos nós que criamos a epidemia do coronavírus ”. Neste artigo, Quammen argumenta que se saiu pior do que outros países, não por falta de informação ou financiamento, mas porque não aprendeu as lições do último surtos

A Functional Agility Short-Term Fatigue Protocol Changes Lower Extremity Mechanics

The purpose of this study was to evaluate the effects of a functional agility fatigue protocol on lower extremity biomechanics between two unanticipated tasks (stop-jump and sidestep). The subjects consisted of fifteen female collegiate soccer athletes (19 ± 0.7 years, 1.67 ± 0.1 m, 61.7± 8 kg) free of lower extremity injury. Participants performed five trials of stop-jump and sidestep tasks. A functional short-term agility protocol was performed, and immediately following participants repeated the unanticipated running tasks. Lower extremity kinematic and kinetic values were obtained pre and post fatigue. Repeated measures analyses of variance were conducted for each dependent variable with an alpha level set at 0.05. Knee position post-fatigue had increased knee internal rotation (11.4 ± 7.5 degrees vs. 7.9 ± 6.5 degrees p = 0.011) than pre-fatigue, and a decreased knee flexion angle (-36.6 ± 6.2 degrees vs. -40.0 ± 6.3 degrees, p = 0.003), as well as hip position post-fatigue had decreased hip flexion angle (35.5 ± 8.7 degrees vs. 43.2 ± 9.5 degrees, p = 0.002). A quick functional fatigue protocol altered lower extremity mechanics of Division I collegiate soccer athletes during landing tasks. Proper mechanics should be emphasized from the beginning of practice/game to aid in potentially minimizing the effects of fatigue in lower extremity mechanics

Two Different Fatigue Protocols and Lower Extremity Motion Patterns During a Stop-Jump Task

Context: Altered neuromuscular control strategies during fatigue probably contribute to the increased incidence of non-contact anterior cruciate ligament injuries in female athletes. Objective: To determine biomechanical differences between 2 fatigue protocols (slow linear oxidative fatigue protocol [SLO-FP] and functional agility short-term fatigue protocol [FAST-FP]) when performing a running-stop-jump task. Design: Controlled laboratory study. Setting: Laboratory. Patients or Other Participants: A convenience sample of 15 female soccer players (age = 19.2 ± 0.8 years, height = 1.67± 0.05m, mass = 61.7 + 8.1 kg) without injury participated. Intervention(s): Five successful trials of a running–stop-jump task were obtained prefatigue and postfatigue during the 2 protocols. For the SLO-FP, a peak oxygen consumption (V˙o2peak) test was conducted before the fatigue protocol. Five minutes after the conclusion of the V˙o2peak test, participants started the fatigue protocol by performing a 30-minute interval run. The FAST-FP consisted of 4 sets of a functional circuit. Repeated 2 (fatigue protocol) × 2 (time) analyses of variance were conducted to assess differences between the 2 protocols and time (prefatigue, postfatigue). Main Outcome Measure(s): Kinematic and kinetic measures of the hip and knee were obtained at different times while participants performed both protocols during prefatigue and postfatigue. Results: Internal adduction moment at initial contact (IC) was greater during FAST-FP (0.064 ± 0.09 Nm/kgm) than SLO-FP (0.024±0.06 Nm/kgm) (F1,14 = 5.610, P= .03). At IC, participants had less hip flexion postfatigue (44.7°±8.1°) than prefatigue (50.1°± 9.5°) (F1,14 = 16.229, P= .001). At peak vertical ground reaction force, participants had less hip flexion postfatigue (44.7°± 8.4°) than prefatigue (50.4°± 10.3°) (F1,14 = 17.026, P=.001). At peak vertical ground reaction force, participants had less knee flexion postfatigue (−35.9°± 6.5°) than prefatigue (−38.8°± 5.03°) (F1,14 = 11.537, P= .001). Conclusions: Our results demonstrated a more erect landing posture due to a decrease in hip and knee flexion angles in the postfatigue condition. The changes were similar between protocols; however, the FAST-FP was a clinically applicable 5-minute protocol, whereas the SLO-FP lasted approximately 45 minutes

Why weren’t we ready for the coronavirus?

Este artículo de David Quammen, autor del recomendable libro Contagio. La evolución de las pandemias, hace una breve síntesis de las últimas investigaciones sobre las enfermedades epizoóticas, causadas por virus que saltan de otras especies animales a la especie humana, y es una especie de adenda al epílogo de la versión en castellano, titulado “Fuimos nosotros quienes creamos la epidemia del coronavirus”.En este artículo Quammen argumenta que a Estados Unidos le ha ido peor que a otros países, no porque haya carecido de información o de financiación, sino porque no aprendió las lecciones de los últimos brotes.This paper by David Quammen, author of the recommended book Spillover. Animal infections and the next human pandemic, makes a brief synthesis of the latest research on epizootic diseases, caused by viruses that jump from other animal species to the human species, and is a sort of addendum to the epilogue of the Spanish version, entitled “We were the ones who created the coronavirus epidemic”. In this paper Quammen argues that U.S. has fared worse than other countries not because it lacked information or funding but because it failed to learn the lessons of the last outbreaks