Doctoral theses
Current Record: 2194 of 2491
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Identifier |
000367093 |
Title |
Ανάπτυξη και αξιολόγηση μιας γενικευμένης διαγνωστικής μεθόδου στην ορθοπαιδική βασισμένη στην κινησιομετρία του ανθρώπινου σώματος |
Alternative Title |
Development and evaluation of a generalized diagnostic method in orthopedics based on kinesiology of human body |
Author
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Τζαγκαράκης,Γεώργιος Ν
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Thesis advisor
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Κατώνης, Παύλος
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Reviewer
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Καμπάνης, Νίκος
Κοντάκης, Γελωργιος
Βελεγράκης, Γεώργιος
Δουγαλής, Βασίλης
Τερσένοβ, Άλκης
Χλουβεράκης, Γρηγόρης
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Abstract |
Aim: Development and evaluation of a new method based on theory of
statistical entropy. The new method is going to permit an objective and
quantitative evaluation of the gait characteristics in patients with Lumbar
Spinal Stenosis (LSS) and will be useful for the evaluation of responses to
surgical treatment in these subjects. It will also permit an objective and
quantitative evaluation of the gait variability of patients with excessive Anterior
Cruciate Ligament (ACL) Rupture.
Methods: Oswestry Disability Questionnaire (ODQ) forms were completed. A
tri-axial accelerometer sensor was used for the gait measurement and
entropy algorithm was used for accelerometer data analysis. The
measurement device measured the approximate gait acceleration of the
centre of gravity (COG) of the subject body. All subjects were instructed to
walk along a 40 m straight hospital level walkway at a self-selected walking
speed.
Two groups participated at the first study. The experimental group consisted
of subjects diagnosed with spinal stenosis (n=35) and the control group
consisted of healthy subjects (n=35). The experimental group’s subjects were
diagnosed with spinal stenosis, without any other neuromuscular and
musculoskeletal pathology or injury, using Magnetic Resonance Imaging
(MRI) and Computerized Axial Tomography (CAT) scans. A t-test was used to
compare the entropy values between the two groups. A receiver operating
characteristic (ROC) analysis was used to assess the diagnostic value of the
method.
The objective of the second study was to assess the gait variability of lumbar
spinal stenosis (LSS) patients and to evaluate quantitatively its postoperative
progression. Twelve (12) subjects with LSS were measured before and after
surgery. Preoperative measurements were performed 2 days before surgery.
Postoperative measurements were performed 6 and 12 months after surgery.
Repeated measures analysis of variance (ANOVA) was used to test whether
there was a significant surgery effect on entropy at 6 and 12 months
postoperatively. In the case of a statistically significant finding, post hoc
Bonferroni adjusted tests were needed to pinpoint differences.
The objective of the third study was to compare the gait variability of patients
with excessive anterior cruciate ligament (ACL) deficiency (experimental
group) with that of healthy individuals (control group) using the proposed
method. The experimental group consisted of 20 men with an ACL tear and
the control group consisted of 20 healthy men without any neurological and/or
musculoskeletal pathology or injury. A receiver operating characteristic (ROC)
analysis was used to assess the diagnostic value of the method.
Results: For the first study, the ROC analysis estimated a 97.1% probability
for correct identification of patients (sensitivity) and an 80.0% probability for
correct identification of healthy subjects (specificity). According to ROC
analysis, the entropy index has a 97.6% probability for distinguishing between
patients with spinal stenosis and healthy subjects. The positive likelihood ratio
(PLR) was 4.86 and the negative likelihood ratio (NLR) was 0.21. The
Spearman correlation coefficient between entropy values and Oswestry
scores for the experimental group was 0.654.
In the second study, repeated measures ANOVA revealed that there was a
statistical significant surgery effect (p<0.001). The preoperative and
postoperative measurements of the LSS patients’ comparison indicated a
statistically significant decrease in entropy for each patient. Post hoc
Bonferroni adjusted tests yield that there was a statistically significant
reduction in gait variability postoperatively.
In the third study, the entropy index of the experimental group in the medio–
lateral axis, but not the anterior–posterior axis, was statistically significantly
higher (P<
0.0001) than that of the control group. For the medio–lateral axis,
the ROC analysis estimated a 90% probability for the correct identification of
patients (sensitivity) and an 85% probability for the correct identification of
healthy subjects (specificity). According to the ROC analysis, the entropy
index had a 95.6% probability for distinguishing between ACL patients and
healthy subjects. The positive likelihood ratio (PLR) was 6.0 and the negative
likelihood ratio (NLR) was 0.17. Thus, the LR values of gait variability
suggested that the method has strong diagnostic value for using the medio–
lateral axis data.
Conclusions: The proposed method permits an objective and quantitative
evaluation of the gait characteristics in patients with LSS and is useful for the
evaluation of responses to surgical treatment in these subjects. It also permits
objective and quantitative evaluation of the gait characteristics in patients with
ACL Rupture. The proposed method is also painless, low-cost, non-invasive,
requires no radiation or chemicals and the objective index that corresponds to
gait irregularity may be computed instantly.
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Language |
Greek |
Subject |
Accelerometry |
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Anterior cruciate ligament rupture |
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Biosignal analysis |
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Entropy |
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Gait variability |
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Musculoskeletal system |
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Postoperative estimation |
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Spine diseases |
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Ανάλυση βιοσήματος |
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Εντρόπια |
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Επιταχυνσιομετρία |
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Μεταβλητότητα βάδισης |
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Μετεγχειρητική εκτίμηση |
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Μυοσκελετικό σύστημα |
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Παθήσεις σπονδυλικής στήλης |
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Ρήξη πρόσθιου χιαστού συνδέσμου |
Issue date |
2010-07-20 |
Collection
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School/Department--School of Medicine--Department of Medicine--Doctoral theses
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Type of Work--Doctoral theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/c/f/3/metadata-dlib-46c62d27634522f62426aa31a78b0970_1308907397.tkl
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