27 research outputs found
Influence of the moving fluoroscope on gait patterns
<div><p>Video-fluoroscopic analysis can provide important insights for the evaluation of outcome and functionality after total knee arthroplasty, allowing the in vivo assessment of tibiofemoral kinematics without soft tissue artefacts. To enable measurement of the knee throughout activities of daily living such as gait, robotic systems like the moving fluoroscope have been developed that follow the knee movement and maintain the joint in front of the image intensifier. Since it is unclear whether walking while being accompanied by moving fluoroscope affects normal gait, the objective of this study was to investigate its influence on gait characteristics in healthy subjects. In addition, the impact of the motors’ noise was analysed.</p><p>By means of skin markers analysis (VICON MX system, Oxford Metrics Group, UK) and simultaneous measurement of ground reaction forces (Kistler force plates, Kistler, Switzerland), gait characteristics when walking with and without the moving fluoroscope as well as with and without ear protectors in combination with the moving fluoroscope, were obtained in young (n = 10, 24.5y ± 3.0y) and elderly (n = 9, 61.6y ± 5.3y) subjects during level gait and stair descent. Walking with the moving fluoroscope significantly decreased gait velocity in level gait and stair descent over the respective movement without the fluoroscope. Statistical analysis, including gait velocity as a covariate, resulted in no differences on the ground reaction force parameters. However, some kinematic parameters (ankle, knee and hip ranges of motion, minimal knee angle in late stance phase, maximal knee angles in stance and swing phase) seemed to be modified by the presence of the moving fluoroscope, but statistical comparison was limited due to velocity differences between the conditions. Wearing ear protectors to avoid the influence of motor sound during walking with the moving fluoroscope caused no significant difference.</p><p>Walking with the moving fluoroscope has been shown to decrease gait velocity and small alterations in kinematic parameters were observed. Therefore, gait and movement alterations due to the moving fluoroscope cannot completely be excluded. However, based on the absence of differences in ground reaction force parameters (when adjusted for velocity within ANCOVA), as well as based on the comparable shape of the angular curves to the slow control condition, it can be concluded that changes in gait when walking with the moving fluoroscope are small, especially in comparison to natural slow walking. In order to allow assessment of joint replacement with the moving fluoroscope, including an understanding of the effects of joint pain, clinical analyses can only be compared to gait activities showing similarly reduced velocities. Importantly, the reduced gait speeds observed in this study are similar to those observed after total knee arthroplasty, suggesting that analyses in such subjects are appropriate. However, the moving fluoroscope would likely need to be optimized in order to detect natural gait characteristics at the higher gait velocities of healthy young subjects.</p><p>The moving fluoroscope can be applied for comparisons between groups measured with the moving fluoroscope, but care should be taken when comparing data to subjects walking at self-selected speed without the moving fluoroscope.</p></div
Vertical ground reaction forces.
<p>Mean and standard deviation of vertical ground reaction forces (F<sub>z</sub>) in level gait for young (A) and elderly (B) subjects as well as in stair descent for young (C) and elderly (D) subjects for the conditions control 1, control 2, FluMo and FluMo intervention.</p
Knee flexion and vertical ground reaction force for the slow in comparison to the FluMo and the control 1 conditions.
<p>The grey areas represent the range between the mean plus/minus standard deviation of the vertical ground reaction forces (A, B) and knee flexion (C, D) for young (A, C) and elderly (B, D) subjects for the conditions control 1 and FluMo in level gait. The black lines represent the mean of the two slow gait trials for each subject.</p
Knee flexion.
<p>Mean and standard deviations of knee flexion in level gait for young (A) and elderly (B) subjects, as well as in stair descent for young (C) and elderly (D) subjects, for the conditions control 1, control 2, FluMo and FluMo intervention.</p
Range of lumbar (a/b) and thoracic (c/d) curvature angle of the subjects, calculated using the vertebral bodies (black) and the skin markers (hatched).
<p>The range was defined from the upright to the flexed (a/c) and to the extended positions (c/d).</p
Average experimental strain patterns of the virtual PCL bundles during passive and active knee flexion.
<p>Included articles in this graph: Studies on passive flexion [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref019" target="_blank">19</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref022" target="_blank">22</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref024" target="_blank">24</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref025" target="_blank">25</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref027" target="_blank">27</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref029" target="_blank">29</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref051" target="_blank">51</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref060" target="_blank">60</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref061" target="_blank">61</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref073" target="_blank">73</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref082" target="_blank">82</a>] and studies on forward lunge [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref014" target="_blank">14</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref030" target="_blank">30</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref033" target="_blank">33</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167106#pone.0167106.ref057" target="_blank">57</a>].</p
Scatter diagram of the lumbar (a) and thoracic curvature angle (b) in the upright (circle), flexed (triangle) and extended positions (star).
<p>The x-axis represents the values calculated from the markers, and the y-axis from the vertebral bodies. The crosses show the open MRI's measurement uncertainty of the curvature angles calculated from the markers (x-axis) and calculated from the vertebral bodies (y-axis).</p