Background: Forward head posture is one of the most prevalent abnormal postures in patients with neck disorders. The aim of this study was to evaluate the effects of forward head posture on gait ground reaction force characteristics in children. Methods: Twelve children with forward head posture (age: 11.8±1.3 years) and sixteen healthy control children (...

In human walking, each transition to a new stance limb requires redirection of the center of mass (COM) velocity from one inverted pendulum arc to the next. While this can be accomplished with either negative collision work by the leading limb, positive push-off work by the trailing limb, or some combination of the two, physics-based models of step-to-step transitions predict that total positiv...

Certain peptides such as dynorphin A [dynA-(1-13)] enhance the release of antigenic peptides bound to class II MHC molecules at neutral pH. This enhanced release has been termed push off. Previous work has shown that the antigenic pigeon cytochrome c peptide PCC-(89-104) has at least two conformational isomers when bound to the class II MHC protein I-Ek. We have accordingly studied the push off...

1 Introduction The ankle delivers about half of the total mechanical work during walking. Lower-limb amputees using conventional passive-elastic prostheses experience 20 to 30% higher metabolic cost than able-bodied individuals, perhaps because these prostheses do not provide net positive work during the course of a step [1]. To address this problem, companies are developing battery-powered pro...

Passive prosthetic feet lack active plantarflexion and push-off power resulting in gait deviations and compensations by individuals with transtibial amputation (TTA) during slope ascent. We sought to determine the effect of active ankle plantarflexion and push-off power provided by a powered prosthetic ankle-foot (PWR) on lower extremity compensations in individuals with unilateral TTA as they ...

Larger terrestrial animals tend to support their weight with more upright limbs. This makes structural sense, reducing the loading on muscles and bones, which is disproportionately challenging in larger animals. However, it does not account for why smaller animals are more crouched; instead, they could enjoy relatively more slender supporting structures or higher safety factors. Here, an altern...

The purpose of this experiment is to explore the variables that affect the efficiency of a swimmer in the streamline position. There are various factors that affect the drag of a swimmer such as: the type of suit, wearing a cap or not, and the depth of the push off. The hydrophobicity of a fast suit and a regular suit was measured to show which one will be the most effective in the water. The c...

Rapid unloading and a peak in power output of the ankle joint have been widely observed during push-off in human walking. Model-based studies hypothesize that this push-off causes redirection of the body center of mass just before touch-down of the leading leg. Other research suggests that work done by the ankle extensors provides kinetic energy for the initiation of swing. Also, muscle work is...