Lower extremity joint kinetics and lumbar curvature during squat and stoop lifting

<p>Abstract</p> <p>Background</p> <p>In this study, kinematics and kinetics of the lower extremity joint and the lumbar lordosis during two different symmetrical lifting techniques(squat and stoop) were examined using the three-dimensional motion analysis.</p> <p>Methods</p> <p>Twenty-six young male volunteers were selected for the subjects in this study. While they lifted boxes weighing 5, 10 and 15 kg by both squat and stoop lifting techniques, their motions were captured and analyzed using the 3D motion analysis system which was synchronized with two forceplates and the electromyographic system. Joint kinematics was determined by the forty-three reflective markers which were attached on the anatomical locations based on the VICON Plug-in-Gait marker placement protocol. Joint kinetics was analyzed by using the inverse dynamics. Paired t-test and Kruskal-Wallis test was used to compare the differences of variables between two techniques, and among three different weights. Correlation coefficient was calculated to explain the role of lower limb joint motion in relation to the lumbar lordosis.</p> <p>Results</p> <p>There were not significant differences in maximum lumbar joint moments between two techniques. The hip and ankle contributed the most part of the support moment during squat lifting, and the knee flexion moment played an important role in stoop lifting. The hip, ankle and lumbar joints generated power and only the knee joint absorbed power in the squat lifting. The knee and ankle joints absorbed power, the hip and lumbar joints generated power in the stoop lifting. The bi-articular antagonist muscles' co-contraction around the knee joint during the squat lifting and the eccentric co-contraction of the gastrocnemius and the biceps femoris were found important for maintaining the straight leg during the stoop lifting. At the time of lordotic curvature appearance in the squat lifting, there were significant correlations in all three lower extremity joint moments with the lumbar joint. Differently, only the hip moment had significant correlation with the lumbar joint in the stoop lifting.</p> <p>Conclusion</p> <p>In conclusion, the knee extension which is prominent kinematics during the squat lifting was produced by the contributions of the kinetic factors from the hip and ankle joints(extensor moment and power generation) and the lumbar extension which is prominent kinematics during the stoop lifting could be produced by the contributions of the knee joint kinetic factors(flexor moment, power absorption, bi-articular muscle function).</p

Lower extremity joint kinetics and lumbar curvature during squat and stoop lifting

<p>Abstract</p> <p>Background</p> <p>In this study, kinematics and kinetics of the lower extremity joint and the lumbar lordosis during two different symmetrical lifting techniques(squat and stoop) were examined using the three-dimensional motion analysis.</p> <p>Methods</p> <p>Twenty-six young male volunteers were selected for the subjects in this study. While they lifted boxes weighing 5, 10 and 15 kg by both squat and stoop lifting techniques, their motions were captured and analyzed using the 3D motion analysis system which was synchronized with two forceplates and the electromyographic system. Joint kinematics was determined by the forty-three reflective markers which were attached on the anatomical locations based on the VICON Plug-in-Gait marker placement protocol. Joint kinetics was analyzed by using the inverse dynamics. Paired t-test and Kruskal-Wallis test was used to compare the differences of variables between two techniques, and among three different weights. Correlation coefficient was calculated to explain the role of lower limb joint motion in relation to the lumbar lordosis.</p> <p>Results</p> <p>There were not significant differences in maximum lumbar joint moments between two techniques. The hip and ankle contributed the most part of the support moment during squat lifting, and the knee flexion moment played an important role in stoop lifting. The hip, ankle and lumbar joints generated power and only the knee joint absorbed power in the squat lifting. The knee and ankle joints absorbed power, the hip and lumbar joints generated power in the stoop lifting. The bi-articular antagonist muscles' co-contraction around the knee joint during the squat lifting and the eccentric co-contraction of the gastrocnemius and the biceps femoris were found important for maintaining the straight leg during the stoop lifting. At the time of lordotic curvature appearance in the squat lifting, there were significant correlations in all three lower extremity joint moments with the lumbar joint. Differently, only the hip moment had significant correlation with the lumbar joint in the stoop lifting.</p> <p>Conclusion</p> <p>In conclusion, the knee extension which is prominent kinematics during the squat lifting was produced by the contributions of the kinetic factors from the hip and ankle joints(extensor moment and power generation) and the lumbar extension which is prominent kinematics during the stoop lifting could be produced by the contributions of the knee joint kinetic factors(flexor moment, power absorption, bi-articular muscle function).</p

Searching biomedical databases on complementary medicine: the use of controlled vocabulary among authors, indexers and investigators

BACKGROUND: The optimal retrieval of a literature search in biomedicine depends on the appropriate use of Medical Subject Headings (MeSH), descriptors and keywords among authors and indexers. We hypothesized that authors, investigators and indexers in four biomedical databases are not consistent in their use of terminology in Complementary and Alternative Medicine (CAM). METHODS: Based on a research question addressing the validity of spinal palpation for the diagnosis of neuromuscular dysfunction, we developed four search concepts with their respective controlled vocabulary and key terms. We calculated the frequency of MeSH, descriptors, and keywords used by authors in titles and abstracts in comparison to standard practices in semantic and analytic indexing in MEDLINE, MANTIS, CINAHL, and Web of Science. RESULTS: Multiple searches resulted in the final selection of 38 relevant studies that were indexed at least in one of the four selected databases. Of the four search concepts, validity showed the greatest inconsistency in terminology among authors, indexers and investigators. The use of spinal terms showed the greatest consistency. Of the 22 neuromuscular dysfunction terms provided by the investigators, 11 were not contained in the controlled vocabulary and six were never used by authors or indexers. Most authors did not seem familiar with the controlled vocabulary for validity in the area of neuromuscular dysfunction. Recently, standard glossaries have been developed to assist in the research development of manual medicine. CONCLUSIONS: Searching biomedical databases for CAM is challenging due to inconsistent use of controlled vocabulary and indexing procedures in different databases. A standard terminology should be used by investigators in conducting their search strategies and authors when writing titles, abstracts and submitting keywords for publications