Roy Müller

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In locomotion, humans have to deal with irregularities of the ground, i.e., pathways covered with stones, grass, or roots. When they encounter ground with changes in terrain height they seem to use spring-mass dynamics to help passively stabilize their locomotory trajectory. With increasing step heights humans reduce their leg stiffness, but it is as of yet(More)
In locomotion, humans have to deal with changes in ground level like pavement or stairs. When they encounter uneven ground with changes in terrain height, they reduce their angle of attack and leg stiffness on a step. This strategy was found for the single step upward movement. However, are these adjustments the result of a general strategy? In our study we(More)
In locomotion, humans have to deal with irregularities in the ground. When they encounter uneven terrain with changes in vertical height, they adjust the geometry of their legs. Recent investigations have shown that the preactivation of the gastrocnemius muscle (GM) correlates with the ankle angle at touchdown, but it is as of yet unclear why these(More)
In this study we explore the hypothesis that estimates of failure loads in the thoracic spine by lumbar dual energy X-ray absorptiometry (DXA) are compromised of skeletal heterogeneity throughout the spine and artifacts of spinal DXA. We studied the correlation between mechanical failure loads of thoracic and lumbar vertebrae, and that of in situ vs. ex(More)
While running on uneven ground, humans are able to negotiate visible but also camouflaged changes in ground level. Previous studies have shown that the leg kinematics before touch down change with ground level. The present study experimentally investigated the contributions of visual perception (visual feedback), proprioceptive feedback and feed-forward(More)
Motion systems must cope with internal and external disturbances affecting the envisioned movement program. In science responses to disturbances are used to characterize system properties. Recently, evidence has been collected that self-stability due to the mechanical response of a system can greatly contribute to safe guarding proper operation of the(More)
While running, humans are able to negotiate varied and sometimes unpredictable changes in ground level (e.g. roots, hills, stones or high grass hiding terrain). It seems that this ability can be attributed to a correct setting of the mechanical system. In situations where the human runners become aware of a perturbation in ground level, they adjust their(More)
Pronograde trunk orientation in small birds causes prominent intra-limb asymmetries in the leg function. As yet, it is not clear whether these asymmetries induced by the trunk reflect general constraints on the leg function regardless of the specific leg architecture or size of the species. To address this, we instruct twelve participants to walk at a(More)
As an alternative to walking and running, humans are able to skip. However, adult humans avoid it. This fact seems to be related to the higher energetic costs associated with skipping. Still, children, some birds, lemurs and lizards use skipping gaits during daily locomotion. We combined experimental data on humans with numerical simulations to test whether(More)