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Kazuhiro Ishimura and Shinji Sakurai

This study investigates the potential asymmetries between inside and outside legs in determinants of curved running speed. To test these asymmetries, a deterministic model of curved running speed was constructed based on components of step length and frequency, including the distances and times of different step phases, takeoff speed and angle, velocities in different directions, and relative height of the runner’s center of gravity. Eighteen athletes sprinted 60 m on the curved path of a 400-m track; trials were recorded using a motion-capture system. The variables were calculated following the deterministic model. The average speeds were identical between the 2 sides; however, the step length and frequency were asymmetric. In straight sprinting, there is a trade-off relationship between the step length and frequency; however, such a trade-off relationship was not observed in each step of curved sprinting in this study. Asymmetric vertical velocity at takeoff resulted in an asymmetric flight distance and time. The runners changed the running direction significantly during the outside foot stance because of the asymmetric centripetal force. Moreover, the outside leg had a larger tangential force and shorter stance time. These asymmetries between legs indicated the outside leg plays an important role in curved sprinting.

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Rachel L. Wright, Joseph W. Bevins, David Pratt, Catherine M. Sackley and Alan M. Wing

Asymmetry in weight-bearing is a common feature in poststroke hemiparesis, with the nonparetic lower limb being favored during quiet standing. 1 , 2 This weight-bearing asymmetry remains in more dynamic tasks such as swaying, 3 standing up from a chair, 4 and walking, 5 , 6 and a reduced

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Hitoshi Koda, Yoshihiro Kai, Shin Murata, Hironori Osugi, Kunihiko Anami, Takahiko Fukumoto and Hidetaka Imagita

Although the human body looks symmetric at first glance, the limbs have functional asymmetry, such as a dominant hand or leg ( Coren, Porac, & Duncan, 1979 ; Incel, Ceceli, Durukan, Erdem, & Yorgancioglu, 2002 ). Previous literature has defined laterality as “a side of the body being

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Victor Spiandor Beretta, Fabio Augusto Barbieri, Diego Orcioli-Silva, Paulo Cezar Rocha dos Santos, Lucas Simieli, Rodrigo Vitório and Lilian Teresa Bucken Gobbi

theoretical possibility is that, for some reason, one substantia nigra is more vulnerable than the other, and once the degenerative process starts, accelerated cell death occurs first on that side (see Djaldetti et al., 2006 for more details). The unilateral signs/symptoms of disease cause asymmetry in the

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Janina M. Prado-Rico and Marcos Duarte

the asymmetry of upright standing. For Borelli ( 1989 ), “standing alternately on one foot with the other loaded vertically is less fatiguing than standing on both feet simultaneously.” For Vierordt ( 1864 ), “body fluctuations are much lower when asymmetrically standing.” Hellebrandt ( Hellebrandt

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Paul J. Read, Jon L. Oliver, Gregory D. Myer, Mark B.A. De Ste Croix and Rhodri S. Lloyd

disruptions in motor control strategies underlie these periods of increased injury risk ( 2 , 30 , 38 ). Between-limb asymmetry in functional performance is a potential risk factor for male youth soccer players where preferred lower limb dominance is evident ( 11 ). This may be further confounded by

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Hanatsu Nagano, Rezaul K. Begg, William A. Sparrow and Simon Taylor

Although lower limb strength becomes asymmetrical with age, past studies of aging effects on gait biomechanics have usually analyzed only one limb. This experiment measured how aging and treadmill surface influenced both dominant and nondominant step parameters in older (mean 74.0 y) and young participants (mean 21.9 y). Step-cycle parameters were obtained from 3-dimensional position/time data during preferred-speed walking for 40 trials along a 10 m walkway and for 10 minutes of treadmill walking. Walking speed (young 1.23 m/s, older 1.24 m/s) and step velocity for the two age groups were similar in overground walking but older adults showed significantly slower walking speed (young 1.26 m/s, older 1.05 m/s) and step velocity on the treadmill due to reduced step length and prolonged step time. Older adults had shorter step length than young adults and both groups reduced step length on the treadmill. Step velocity and length of older adults’ dominant limb was asymmetrically larger. Older adults increased the proportion of double support in step time when treadmill walking. This adaptation combined with reduced step velocity and length may preserve balance. The results suggest that bilateral analyses should be employed to accurately describe asymmetric features of gait especially for older adults.

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Scott R. Brown, Matt Brughelli and Seth Lenetsky

potential assessment tool in detecting lower-extremity asymmetries. Although many studies ( Gstöttner et al., 2009 ; Huurnink, Fransz, Kingma, Hupperets, & van Dieën, 2014 ; Riemann & Davies, 2013 ) have examined leg preference during balance tasks, none have assessed rugby athletes, and mixed results

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Harsh H. Buddhadev, Daniel L. Crisafulli, David N. Suprak and Jun G. San Juan

asymmetry in power output has been observed in individuals with unilateral anterior cruciate ligament (ACL) deficiency during cycling. When pedaling at a fixed intensity, the normal ACL-intact limb increased its output by 44% to 50% to compensate for the reduced effort by the ACL-deficient leg. 11 Similar

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Silvia Cabral, Renan A. Resende, Adam C. Clansey, Kevin J. Deluzio, W. Scott Selbie and António P. Veloso

High levels of gait asymmetry are associated with many pathologies. Our long-term goal is to improve gait symmetry through real-time biofeedback of a symmetry index. Symmetry is often reported as a single metric or a collective signature of multiple discrete measures. While this is useful for assessment, incorporating multiple feedback metrics presents too much information for most subjects to use as visual feedback for gait retraining. The aim of this article was to develop a global gait asymmetry (GGA) score that could be used as a biofeedback metric for gait retraining and to test the effectiveness of the GGA for classifying artificially-induced asymmetry. Eighteen participants (11 males; age 26.9 y [SD = 7.7]; height 1.8 m [SD = 0.1]; body mass 72.7 kg [SD = 8.9]) walked on a treadmill in 3 symmetry conditions, induced by wearing custom-made sandals: a symmetric condition (identical sandals) and 2 asymmetric conditions (different sandals). The GGA score was calculated, based on several joint angles, and compared between conditions. Significant differences were found among all conditions (P < .001), meaning that the GGA score is sensitive to different levels of asymmetry, and may be useful for rehabilitation and assessment.