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Michael S. Cherry, Sridhar Kota, Aaron Young and Daniel P. Ferris

Although there have been many lower limb robotic exoskeletons that have been tested for human walking, few devices have been tested for assisting running. It is possible that a pseudo-passive elastic exoskeleton could benefit human running without the addition of electrical motors due to the spring-like behavior of the human leg. We developed an elastic lower limb exoskeleton that added stiffness in parallel with the entire lower limb. Six healthy, young subjects ran on a treadmill at 2.3 m/s with and without the exoskeleton. Although the exoskeleton was designed to provide ~50% of normal leg stiffness during running, it only provided 24% of leg stiffness during testing. The difference in added leg stiffness was primarily due to soft tissue compression and harness compliance decreasing exoskeleton displacement during stance. As a result, the exoskeleton only supported about 7% of the peak vertical ground reaction force. There was a significant increase in metabolic cost when running with the exoskeleton compared with running without the exoskeleton (ANOVA, P < .01). We conclude that 2 major roadblocks to designing successful lower limb robotic exoskeletons for human running are human-machine interface compliance and the extra lower limb inertia from the exoskeleton.

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Lewis J. Vizard, Gareth Peden and Maximilian M. Wdowski

Key Points ▸ Lower-limb kinematic and kinetic asymmetries may transfer between dynamic movements. ▸ Individual-level asymmetries present in lower-limb kinematics and kinetics during sprint running and countermovement jumps. Rugby Union is an intermittent contact sport that exposes players to short

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Christopher Kevin Wong, Lizbeth Conway, Grant Fleming, Caitlin Gopie, Dara Liebeskind and Stephen Xue

Clinical Scenario People with musculoskeletal lower quarter dysfunction, whether knee pain, hip arthritis, or low-back pain, can present with lower-limb muscle weakness. Exercise to strengthen weakened muscles is a rehabilitation staple: early strength gains observed in the first 2 weeks have been

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Nicola Giovanelli, Filippo Vaccari, Mirco Floreani, Enrico Rejc, Jasmine Copetti, Marco Garra, Lea Biasutti and Stefano Lazzer

maintained during the effort. 17 In turn, our research group has also observed that Cr is affected by muscle power of lower limb extensors. 17 Hence, the primary objective of this study was to evaluate the effects of SMFR treatment on Cr. In addition, we evaluated the effects of SMFR on lower limbs’ muscle

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Harsh H. Buddhadev and Philip E. Martin

older participants. They concluded that the coactivation of antagonists helps explain the greater energy expenditure of walking typically observed in older adults. With respect to cycling, most research on energy expenditure and lower limb electromyography (EMG) has focused on younger adults. Numerous

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Karen L. Perell, Robert J. Gregor and A.M. Erika Scremin

Biomechanical analysis of the generalized muscle moment and power patterns involved in cycling provides information regarding coordination within each limb. The purpose of this study was to compare individual joint kinetics, bilaterally, in subjects who had experienced cerebrovascular accidents (CVAs). Two-dimensional cinematography and force pedal data in a linked-segment model were used to study 8 ambulatory subjects while they rode a recumbent bicycle. The involved lower limb was defined as the lower limb with the greatest deficits, whereas the contralateral lower limb was defined as the lower limb opposite the involved lower limb and ipsilateral to the lesion site. The contralateral lower limbs of subjects with CVAs demonstrated patterns similar to those reported for nondisabled cyclists on an upright bicycle except for a bimodal hip power generation pattern that was possibly due to compensation for a lack of involved lower limb power generation. There were two critical findings of this study: Single-joint power generation patterns during the power phase indicated that either the hip or the knee, but not both joints, generated power in the involved lower limb, and asymmetrical differences between lower limbs appeared significant at the ankle alone.

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Jessica Ferreira, André Bebiano, Daniel Raro, João Martins and Anabela G. Silva

). Before each test, participants performed 2 training trials (one with the dominant and one with the nondominant limb). Then, each test was repeated 3 times for each lower limb and the mean value was used for statistical analysis. Figure 2 —Representation of the measurements for the three hop tests: single

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Willemijn M.J. van Rooij, H.J.G. van den Berg-Emons, Herwin L.D. Horemans, Malou H.J. Fanchamps, Fred A. de Laat and Johannes B.J. Bussmann

-Emons, 2013 ; Lord et al., 2011 ). For people with a physical disability, such as lower-limb amputation, it is more difficult to perform regular daily activities, and therefore they are at extra risk for unfavorable physical behavior. People with a lower-limb amputation are an important patient group within

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Sarah Deans, Alison Kirk, Anthony McGarry and David Rowe

). Amputation is the surgical removal of all or part of a limb or extremity such as an arm, leg, foot, hand, toe, or finger. Major lower limb amputation refers to any amputation performed above the level of the ankle. Congenital absence describes all or part of a limb/extremity missing due to disease or

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AmirAli Jafarnezhadgero, Morteza Madadi-Shad, Christopher McCrum and Kiros Karamanidis

Human lower limbs contribute to locomotion in multiple ways; acting as springs, as force absorbing dampers, or as actuators ( Brown, O’Donovan, Hasselquist, Corner, & Schiffman, 2016 ; Raynor, Yi, Abernethy, & Jong, 2002 ). The progression of ground reaction forces (GRF) through the lower limbs