James P. Schmiedeler

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Models of human walking with moderate complexity have the potential to accurately capture both joint kinematics and whole body energetics, thereby offering more simultaneous information than very simple models and less computational cost than very complex models. This work examines four- and six-link planar biped models with knees and rigid circular feet.(More)
The relative motion of the brain with respect to the skull has been widely studied to investigate brain injury mechanisms under impacts, but the motion patterns are not yet thoroughly understood. This work analyzes brain motion patterns using the most recent and advanced experimental relative brain/skull motion data collected under low-severity impacts.(More)
Balance retraining is a critical part of rehabilitation for many individuals following neuro-trauma such as stroke. The WeHab system described in this paper is a low-cost rehabilitation instrument suite centered around the Nintendo Wii Balance Board that has the potential to enhance rehabilitation for patients with balance disorders. Using the WeHab system,(More)
In nature, quadrupedal mammals can run at high speeds over uneven terrain, turn sharply, jump obstacles, and stop suddenly. While these abilities are common features in biological locomotion, they represent remarkable feats from both an engineering and control perspective. Although some robots over the past several decades have been capable of dynamic(More)
The leading joint hypothesis (LJH), developed for planar arm reaching, proposes that the interaction torques experienced by the proximal joint are low compared to the corresponding muscle torques. The human central nervous system could potentially ignore these interaction torques at the proximal (leading) joint with little effect on the wrist trajectory,(More)
This paper presents a new definition of stable walking - that is not necessarily periodic - for a class of biped robots. The inspiration for the definition is the commonly-held notion of stable walking: the biped does not fall. To make the definition useful, an algorithm is given to verify if a given controller induces stable walking. Also given is a(More)
Seventy-nine young, healthy adults were led through static balance and weight-shifting activities in order to study the effects of visual feedback on balance. Based on their performance, the relative effects of various feedback properties were analyzed: (1) arrangement [direct center of pressure (CoP) vs. lateral weight distribution feedback], (2) numbers(More)
In modeling running gaits of biological and robotic quadrupeds, leg mass is often neglected. Analysis of the system angular momentum in a biological model and a robot model indicates that including leg mass is significant in capturing the roll motion in trotting and pacing. Leg mass has a more significant effect on the pitch motion in bounding and is most(More)