Trunk instability during sitting is a major problem following neuromuscular injuries such as stroke and spinal cord injury. In order to develop new strategies for alleviating this problem, a better understanding of the intrinsic contributions of the healthy trunk to sitting control is needed. As such, this study set out to propose and validate a novel methodology for determining multidirectiona...

Lateral constriction (transverse elastic constraint) of rod controls its apparent (longitudinal) stiffness and can even make it negative. (The total energy system + device remains positive.) The depends upon moduli the material modulus relating lateral normal stress strain components. Apparent negative arrest wave propagation along rod. This opens a way to design hybrid materials consisting sti...

We used a robotic device to test the idea that impedance control involves a process of learning or adaptation that is acquired over time and permits the voluntary control of the pattern of stiffness at the hand. The tests were conducted in statics. Subjects were trained over the course of 3 successive days to resist the effects of one of three different kinds of mechanical loads: single axis lo...

BACKGROUND To date, there has been no adequate biomechanical model that would allow a quantitative comparison in terms of stability/stiffness between a corpectomy with the posterior column preserved and a total spondylectomy with the posterior column sacrificed. The objective of this study was to perform a biomechanical comparison of 360° stabilizations for corpectomy and total spondylectomy, u...

Flexible pins eliminate the need for straddle mounting, and therefore enable the maximum possible number of planets to be used for any particular epicyclic ratio of power transmission systems. Having more planet gears will significantly increase the input torque density. In this type of design, the pin stiffness and position tolerances are important parameters as they affect the dynamic perform...

Pile foundations are relatively vulnerable to lateral loads. During liquefaction-induced lateral spreading, this vulnerability is particularly conspicuous due to a loss of strength and stiffness in the liquefied soil. A nonlinear effective stress analysis incorporating an elastoplastic constitutive model based on Finite Difference Method (FLAC2D program) was used to numerically simulate shake t...

Sonomicrometrics of in vivo axial strain of muscle has shown that the swimming fish body bends like a homogenous, continuous beam in all species except tuna. This simple beam-like behavior is surprising because the underlying tendon structure, muscle structure and behavior are complex. Given this incongruence, our goal was to understand the mechanical role of various myoseptal tendons. We model...

BACKGROUND Several physiological and pathological conditions in daily life cause sustained static bending or torsion loads on the spine resulting in creep of spinal segments. The objective of this study was to determine the effects of creep and recovery on the range of motion, neutral zone, and neutral zone stiffness of thoracolumbar multi-level spinal segments in flexion, extension, lateral be...

UNLABELLED The purpose of this cadaver study about the ACL graft was to compare a "Lateral Tibial Tunnel" (LTT) and a "classic, anteroMedial Tibial Tunnel" (MTT), as to fixation strength and mode of failure. Ten pairs of fresh frozen human proximal tibias were used. In one of both tibias a classic anteromedial tunnel was used, versus a lateral tibial tunnel in the contralateral knee. Autologous...

Experience with thirty-eight Asian children and adolescents who presented with either stiffness of the knee, genu recurvatum, habitual dislocation of the patella or congenital lateral dislocation of the patella showed that all those disorders were manifestations of contracture of the extensor mechanism, which fell into two groups according to the components involved. In Group I the main compone...