Search Results

You are looking at 1 - 10 of 187 items for :

  • "fixations" x
  • Refine by Access: All Content x
Clear All
Restricted access

Melissa Hunfalvay and Nicholas Murray

, & Williams, 1999 ), cognition ( Williams & Grant, 1999 ), and long-term memory ( Reina et al., 2004 ). Past researchers have found that experts compared with novices have fewer fixations of longer duration (e.g.,  Perez, Mendez, Manzano, & Collado, 2013 ; Piras, Pierantozzi, & Squatrito, 2014 ), which

Open access

Scott Benson Street, Matthew Rawlins, and Jason Miller

FiberWire ® . This provides physiologic stabilization of the ankle mortise and reduces the need for a second procedure to remove the hardware. 2 Focused Clinical Question In patients suffering from ankle syndesmosis injuries, is the Tightrope ™ ankle syndesmosis fixation system more effective than

Restricted access

Cédrick T. Bonnet

In the literature on postural control, many investigators have studied the movements of the body in one or several tasks and used the fixation task to provide baseline data to better understand their results (e.g.,  Kapteyn et al., 1983 ; Raymakers, Samson, & Verhaar, 2005 ). In this fixation task

Open access

Hannah W. Tucker, Emily R. Tobin, and Matthew F. Moran

use during SLH. 6 Using a trunk-mounted accelerometer via double-sided tape (DST), Williams et al 6 reported that a measure of postural sway to quantify hop landing balance had moderate-to-excellent reliability. 6 The integrity of fixation between accelerometer and body influences the measurement

Restricted access

Jason Flindall, Scott Sinnett, and Alan Kingstone

players make fewer fixations than nonexperts ( Helsen and Pauwels, 1993 ; cf. Williams and Davids, 1998 ; Williams et al., 2002 ). Highly skilled golfers fixate on the ball throughout the putting motion, whereas golfers with lower levels of skill tend to track the putter head only up until ball contact

Restricted access

Cameron Coates, Priya Goeser, Camille Coates-Clark, and Mark Jenkins

The objectives of this work were to explore a methodology that combines static and dynamic finite element (FE) analysis, linear elastic fracture mechanics (LEFM) and experimental methods to investigate a worst-case scenario in which a previously damaged bone plate system is subjected to an impact load. Cadaver ulnas with and without midshaft dynamic compression plates are subjected to a static three-point bend test and loaded such that subcritical crack growth occurs as predicted by a hybrid method that couples LEFM and static FE. The plated and unplated bones are then unloaded and subsequently subjected to a midshaft transverse impact test. A dynamic strain-based FE model is also developed to model the midshaft transverse impact test. The average value of the impact energy required for failure was observed to be 10.53% greater for the plated set. There appears to be a trade-off between impact damage and impact resistance when ulnas are supported by fixation devices. Predictions from the dynamic FE model are shown to corroborate inferences from the experimental approach.

Restricted access

Oscar Martel, Juan F. Cárdenes, Gerardo Garcés, and José A. Carta

Anterior cruciate ligament (ACL) reconstruction is one of the most important aspects of knee surgery. For this purpose, several fixation devices have been developed, although the interference screw is the most frequently used. The most typical biomechanical test of these devices consists of placing them in a testing machine and subjecting them to a pull-out test. However, insufficient attention has been paid to the influence of the displacement test rate on the mechanical properties of the fixation system. The aim of this study is to compare the influence of the crosshead rate in the biomechanical test of two different devices for the fixation of ACL tendon grafts. One hundred in vitro tests were performed using porcine tibiae and bovine tendons. The fixation devices used were (1) an interference screw and (2) a new expansion device. All ACL reconstructions were subjected to pull-out test to failure. Five crosshead rates were employed in a range from 30 mm/min to 4000 mm/min. Statistical analyses of the results show that, for the two devices, the rate has a significant effect on both maximum force and stiffness. Moreover, the new expansion device showed lesser dependency on the crosshead rate than the interference screw.

Restricted access

Melissa R. Taylor, Erin E. Sutton, Wiebke S. Diestelkamp, and Kimberly Edginton Bigelow

The goal of this study was to examine the effects of 3 factors and their interactions on posturography: a period of time to become accustomed to the force platform before the initiation of data collection, presence of a visual fixation point, and participant talking during testing. The postural stability of 30 young adults and 30 older adults was evaluated to determine whether any observed effects were confounded with age. Analysis of variance techniques were used to test all possible combinations of the 3 factors. We hypothesized that all 3 factors would significantly affect postural stability. For both participant groups, the results suggest that a period of time to become accustomed to the force platform before the initiation of data collection and a visual fixation point significantly affect postural control measures, while brief participant talking does not. Despite this, no significant interactions existed suggesting that the effects of these factors, which may occur in clinical testing, do not depend on each other. Our results suggest that inconsistencies in posturography testing methods have the potential to significantly affect the results of posturography, underscoring the importance of developing a standardized testing methodology.

Restricted access

David Brown, Kyle Sanders, Drew Farrar, Joshua Newton, Adam J. Thompson, and Andrew T. Doyle

Restricted access

David O. Draper, J. Chris Castel, and Dawn Castel