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Bente R. Jensen, Line Hovgaard-Hansen and Katrine L. Cappelen

Running on a lower-body positive-pressure (LBPP) treadmill allows effects of weight support on leg muscle activation to be assessed systematically, and has the potential to facilitate rehabilitation and prevent overloading. The aim was to study the effect of running with weight support on leg muscle activation and to estimate relative knee and ankle joint forces. Runners performed 6-min running sessions at 2.22 m/s and 3.33 m/s, at 100%, 80%, 60%, 40%, and 20% body weight (BW). Surface electromyography, ground reaction force, and running characteristics were measured. Relative knee and ankle joint forces were estimated. Leg muscles responded differently to unweighting during running, reflecting different relative contribution to propulsion and antigravity forces. At 20% BW, knee extensor EMGpeak decreased to 22% at 2.22 m/s and 28% at 3.33 m/s of 100% BW values. Plantar flexors decreased to 52% and 58% at 20% BW, while activity of biceps femoris muscle remained unchanged. Unweighting with LBPP reduced estimated joint force significantly although less than proportional to the degree of weight support (ankle).It was concluded that leg muscle activation adapted to the new biomechanical environment, and the effect of unweighting on estimated knee force was more pronounced than on ankle force.

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Ui-Jae Hwang, Sung-Hoon Jung, Hyun-A Kim, Jun-Hee Kim and Oh-Yun Kwon

with EMS, which may produce a load insufficient to yield group differences. The analysis did not reveal a significant difference in the CSA of the RA or LAW between the groups, so we could not confirm that ST was superior to EMS for increasing the CSA of the RA and LAW; moreover, muscle activation was

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Kellie C. Huxel Bliven and Kelsey J. Picha

, several themes became apparent that we want to draw attention to as you read the articles. While studying muscle activation and strength has been persistent over time, the nature in which it is being studied has evolved. No longer are muscles being examined in isolation; rather primary and secondary

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Rosa M. Rodriguez, Ashley Marroquin and Nicole Cosby

; 15-min sessions for every 2 d in combination with standard physical therapy. Subjects were instructed to perceive muscle activation and joint tension, while imagining maximal isometric contraction of a full knee extension during 10 s, without overt movement. The intervention group received 10

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David Cruz-Díaz, Kyung-Min Kim, Fidel Hita-Contreras, Marco Bergamin, Agustin Aibar-Almazán and Antonio Martínez-Amat

even lead to an increased risk of osteoarthritis. 7 Chronic ankle instability may be associated with an altered muscle activation ratio, impaired proprioception, and neuromuscular control, which in turn could be linked to impairment in postural balance. 8 , 9 An alteration of the nervous system

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Zhen Zeng, Christoph Centner, Albert Gollhofer and Daniel König

when training with partial vascular occlusion. This is underpinned by the fact that both acute and chronic studies have demonstrated cuff pressure-dependent changes in electromyography amplitude. 10 – 12 Loenneke et al 11 and Fatela et al, 10 for instance, reported that muscle activation changes

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Kimmery Migel and Erik Wikstrom

the long-term effects (eg, accommodation) of taping and bracing on gait biomechanics. Historically, taping and bracing have been used in the acute phase of healing to protect injured tissues. Long-term taping and bracing are anecdotally criticized for potentially hindering muscle activation and

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Neil Armstrong

Editor, Dotan ( 22 ) argues that children are more limited than adults in their capacity to recruit and utilize higher threshold type II motor units and reviews the role of the child–adult differential muscle-activation hypothesis in explaining why children have faster V ˙ O 2 kinetics than adults. He

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Scott W. Cheatham, Kyle R. Stull, Mike Fantigrassi and Ian Montel

assessment . J Appl Biomech . 2015 ; 31 ( 4 ): 244 – 249 . PubMed doi:10.1123/jab.2014-0272 10.1123/jab.2014-0272 25838245 6. Macrum E , Bell DR , Boling M , Lewek M , Padua D . Effect of limiting ankle-dorsiflexion range of motion on lower extremity kinematics and muscle-activation patterns

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Tomomasa Nakamura, Yuriko Yoshida, Hiroshi Churei, Junya Aizawa, Kenji Hirohata, Takehiro Ohmi, Shunsuke Ohji, Toshiyuki Takahashi, Mitsuhiro Enomoto, Toshiaki Ueno and Kazuyoshi Yagishita

vertical ground reaction force during jump landing: a systematic review . J Athl Train . 2013 ; 48 ( 5 ): 685 – 695 . PubMed doi: 10.4085/1062-6050-48.3.02 24067153 29. Jamison ST , McNally MP , Schmitt LC , Chaudhari AM . The effects of core muscle activation on dynamic trunk position and