Whether early hominins were adept tree climbers is unclear. Although some researchers have argued that bipedality maladapts the hominin skeleton for climbing, others have argued that early hominin fossils display an amalgamation of features consistent with both locomotor strategies. Although chimpanzees have featured prominently in these arguments, there are no published data on the kinematics ...

INTRODUCTION The motion of the distal syndesmosis correlates highly with the instability, while an accurate kinematic description of the distal tibiofibular joint during normal gait has not previously been presented. MATERIAL AND METHODS Sixteen healthy syndesmoses of sixteen living subjects (8 male and 8 female) were studied during stance phase of the normal gait. Data of CT scanning were co...

This article shows that time derivatives of twists and wrenches are indeed screws, in contrast to many classical kinematicians’ believe. Furthermore, it is proven that the “centripetal screw,” as well as the momentum of a rigid body together with all its derivatives, are also screws, and that a rigid body’s dynamics can be geometrically expressed as a screw equation. The paper relies on a somew...

A recently developed spatial operator algebra for manipulator modeling, control, and trajectory design is discussed. The elements of this algebra are linear operators whose domain and range spaces consist of forces, moments, velocities, and accelerations. The effect of these operators is equivalent to a spatial recursion along the span of a manipulator. Inversion of operators can be efficiently...

Variable geometry trusses are composed, in general, of unit cells which can be modeled as bars connected by spherical joints. Under mild conditions, it has been shown that the only feasible cells are topologically equivalent to bipyramids. Unfortunately, using standard formulations, the closed-form position analysis of bipyramids is not a trivial task. Actually, it has only been achieved for bi...

The various precipitation types formed within winter storms (such as snow, wet snow and freezing rain) often lead to very hazardous weather conditions. These types of precipitation often occur during the passage of a warm front as a warm air mass ascends over a cold air mass. To address this issue further, we used a one-dimensional kinematic cloud model to simulate this gentle ascent (≤10 cm/s)...

the direct way to access the petrophysical property of hydrocarbon reservoir is based on well data but due to its high cost, the seismic data has been used to obtain these parameters. for this purpose, many different methods are available and each has its own advantages and limitations. from these methods the seismic inversion is the best tool to study the reservoir characterization. the outcom...

this paper presents the kinematic analysis and the development of a 4-degree-of-freedom serial-parallel mechanism for large commercial vehicle driving simulators. the degrees of freedom are selected according to the target maneuvers and the structure of human motion perception organs. several kinematic properties of parallel part of the mechanism under study are investigated, including the inve...

conclusions zebris movement analysis system is a highly reliable instrument for the measurement of gait parameters at different speeds in healthy athletes and those after acl reconstruction surgery. this implies its use in the assessment and treatment process of gait deficits in such a clinically important population. background reconstruction surgery is one of the treatment methods after an an...