Spatial frequency thresholds for recognition were measured for binocular and monocular viewing conditions at two contrast levels (95% and 7%). Measurements were obtained at the fovea and at four different eccentric retinal locations. Each eccentric retinal location was 8 degrees from the fovea, one on the horizontal axis (180 degrees ), and the other three in the superior field on retinal axes ...

The ability of the vestibulo-ocular reflex (VOR) to alter the phase of the motor output relative to the sensory input is examined. Alert cats were trained for 2 h with 0.25 Hz sinusoidal horizontal vestibular and vertical optokinetic rotational stimuli. In each experiment the optokinetic training stimulus was phase shifted by 0 degree, +45 degrees, -45 degrees, or 90 degrees from the vestibular...

This study was supported in part by a grant from the Foundation for Physical Therapy, Inc. The purpose of this study was to compare the relationships among isometric, isotonic, and isokinetic concentric and eccentric quadriceps and hamstring forces and three components of athletic performance in college-aged, male athletes. Bilateral quadriceps and hamstring muscle torque were obtained (N = 39)...

Background: At present, there is no consensus on an appropriate treatment modality for intertrochanteric fractures in the elderly with background diseases. The aim of the present study was to compare treatment outcomes of intertrochanteric fractures reduced with dynamic hip screws (DHS) and bipolar hemiarthroplasty in elderly patients with background medical conditions. Methods: In this randomi...

We investigated in normal human subjects how semicircular canal and otolith signals interact in the estimation of the subjective visual vertical after constant velocity or constant acceleration roll tilt. In the constant velocity paradigm, subjects were rotated in darkness at +/-60 degrees/s for five complete cycles before being stopped in one of seven orientations ranging from 0 to +/-90 degre...

PURPOSE To establish a three-dimensional finite element model for orthodontic anchorage micro-implant,and to analyze the influence of different titled angles on the biomechanical characteristics of orthodontic anchorage implant-bone interface. METHODS ANSYS(Analysis System)finite element analysis software was used to perform the finite element modeling of the micro-implant with 7 different ti...

The authors have performed a retrospective study of 20 patients who underwent surgical treatment for kyphosis secondary to trauma (10 patients) or Scheuermann's disease (10 patients) between 1992 and 2000. The mean follow-up was 60 months (range, 32-90) and 59.5 months (range, 24-109) respectively. Radiological evaluation of Scheuermann kyphosis included assessment of thoracic kyphosis angle (T...

Visual detection of a line target differing in orientation from a background of lines may be achieved speedily and effortlessly. Such performance is assumed to occur early in vision and to involve filter mechanisms acting in parallel over the visual field. This study establishes orientational limits on this performance and analytically derives some generic properties of the underlying filters. ...

The influence of tubule orientation on the transition from fatigue to fatigue crack growth in human dentin was examined. Compact tension (CT) and rectangular beam specimens were prepared from the coronal dentin of molars with three unique tubule orientations (i.e., 0 degrees , 45 degrees and 90 degrees). The CT specimens (N=25) were used to characterize fatigue crack initiation and steady-state...