The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform
Krzysztof A Tomaszewski - One of the best experts on this subject based on the ideXlab platform.
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Cervical rib prevalence and its association with thoracic outlet syndrome a meta analysis of 141 studies with surgical considerations
World Neurosurgery, 2017Co-Authors: Brandon Michael Henry, Jens Vikse, Beatrice Sanna, Dominik Taterra, Martyna Gomulska, Przemyslaw A Pekala, Shane R Tubbs, Krzysztof A TomaszewskiAbstract:Background Cervical ribs (CR) are supernumerary ribs that arise from the Seventh Cervical Vertebra. In the presence of CR, the boundaries of the interscalene triangle can be further constricted and result in neurovascular compression and thoracic outlet syndrome (TOS). The aim of our study was to provide a comprehensive evidence-based assessment of CR prevalence and their association with TOS as well as surgical approach to excision of CR and surgical patients' characteristics. Methods A thorough search of major electronic databases was conducted to identify any relevant studies. Data on the prevalence, laterality, and side of CR were extracted from the eligible studies for both healthy individuals and patients with TOS. Data on the type of TOS and surgical approach to excision of CR were extracted as well. Results A total of 141 studies (n = 77,924 participants) were included into the meta-analysis. CR was significantly more prevalent in patients with TOS than in healthy individuals, with pooled prevalence estimates of 29.5% and 1.1%, respectively. More than half of the patients had unilateral CR in both the healthy and the TOS group. The analysis showed that 51.3% of the symptomatic patients with CR had vascular TOS, and 48.7% had neurogenic TOS. Most CR were surgically excised in women using a supraclavicular approach. Conclusions CR ribs are frequent findings in patients with TOS. We recommended counseling asymptomatic patients with incidentally discovered CR on the symptoms of TOS, so that if symptoms develop, the patients can undergo prompt and appropriate workup and treatment.
Lars Arendtnielsen - One of the best experts on this subject based on the ideXlab platform.
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standardising surface electromyogram recordings for assessment of activity and fatigue in the human upper trapezius muscle
European Journal of Applied Physiology, 2002Co-Authors: Dario Farina, Thomas Gravennielsen, Pascal Madeleine, Roberto Merletti, Lars ArendtnielsenAbstract:The objectives of this work were to determine optimal surface electromyogram (EMG) electrode locations, and inter-electrode distance (IED), when assessing activity and fatigue in the human upper trapezius muscle. Surface EMG signals were recorded from the upper trapezius muscle of 11 healthy male subjects using a linear array of 16 surface electrodes. Five arm positions were investigated (arms at the side of the body, 45° and 90° flexion, 45° and 90° abduction). Fatiguing (1 kg hand load held for 3 min) and non-fatiguing (no load, 0.5 kg and 1 kg hand load held for 3 s) contractions were made. The variabilities of the average rectified value, root mean square, mean and median power spectral frequency and slope over time of these parameters as functions of electrode location and IED (from 5 mm over a range of 35 mm in steps of 5 mm) were quantitatively evaluated. A criterion for selecting the optimal electrode position was applied. This criterion indicated an optimal location measured from the acromion (38% of the distance from the lateral edge of acromion to the spine of the Seventh Cervical Vertebra) which was statistically the same for all the EMG descriptors, arm positions and IED investigated. Finally, it was found that both EMG variables and indexes of muscle fatigue depended on IED which should thus be properly standardised. On the basis of the sensitivity of the EMG descriptors to electrode location and cross-talk reduction, an IED of 20 mm is suggested when a global analysis of activity in the upper trapezius muscle is made using a single pair of electrodes. This study emphasises that a surface EMG analysis of the upper trapezius muscle, following a proper placement of the electrodes and selection of IED, can give reliable indications of muscle activity and fatigue. Data on the myoelectric manifestations of muscle fatigue of the upper trapezius muscle are provided for the optimal electrode location.
Arthur Spaepen - One of the best experts on this subject based on the ideXlab platform.
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influence of electrode position on changes in electromyograph parameters of the upper trapezius muscle during submaximal sustained contractions
European Journal of Applied Physiology, 1997Co-Authors: Veerle Hermans, Arthur SpaepenAbstract:The purpose of the present study was to evaluate whether differences could be found in the changes in mean power frequency (MPF) and root-mean-square (rms) due to electrode positions on the upper trapezius muscle during a sustained submaximal task. A group of 25 healthy subjects performed a continuous forward flexion of the right arm at 20% of their maximal voluntary contraction (MVC). Three pairs of bipolar surface electrodes were positioned on a straight line between the spine of the Seventh Cervical Vertebra (C7) and the lateral edge of the acromion. The fourth pair (the caudal position) was placed 2 cm below the midpoint of this line. The analysis of variance revealed significant differences between the electrode positions during the short 20% MVC and during MVC (P ≤ 0.01). Furthermore, lower rms values were found when the electrodes were placed symmetrically around the midpoint of the reference line, which confirms previous studies. A statistical model has been developed to discriminate additionally the very small changes in the electromyogram parameters due to electrode position during the sustained 20% MVC. It was found that the slope coefficients of rms and MPF were significantly different from 0 (P ≤ 0.01), although to a lesser degree for rms and more clearly for MPF of the caudal position (P ≤ 0.05). Furthermore, significant differences were found between several combinations of the uppermost electrodes and the caudal position (P ≤ 0.01). From this study, it is concluded that it is important to evaluate several electrode positions on the upper trapezius muscle to be able to represent the behaviour of this muscle accurately during a sustained contraction.
Hirofumi Suemori - One of the best experts on this subject based on the ideXlab platform.
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targeted disruption in the mouse hoxc 4 locus results in axial skeleton homeosis and malformation of the xiphoid process
Developmental Biology, 1996Co-Authors: Hironao Saegusa, Naoki Takahashi, Shigeru Noguchi, Hirofumi SuemoriAbstract:Hoxc-4 is a mouse homeobox gene located at the 3' end of the HoxC cluster. Of the HoxC genes, Hoxc-4 is expressed in the most anterior regions of the central nervous system and preVertebral column. To investigate its role in mouse development, we have generated Hoxc-4 mutant mice by gene targeting. Mice homozygous for the Hoxc-4 mutation are viable and fertile. Analysis of the skeletal system of homozygous mutants revealed various abnormalities in the Cervical and thoracic regions. The most frequent abnormality was a partial posterior homeotic transformation of the Seventh Cervical Vertebra. Less frequently, anterior transformations of the third and eighth thoracic Vertebrae were observed. Furthermore, the xiphoid process of the sternum was malformed such that it had an aperture or a fissure. Although Hoxc-4 is expressed abundantly in the central nervous system, no obvious defects were observed. These results suggest that Hoxc-4 is required for specifying Cervical and thoracic Vertebral identity.
Brandon Michael Henry - One of the best experts on this subject based on the ideXlab platform.
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Cervical rib prevalence and its association with thoracic outlet syndrome a meta analysis of 141 studies with surgical considerations
World Neurosurgery, 2017Co-Authors: Brandon Michael Henry, Jens Vikse, Beatrice Sanna, Dominik Taterra, Martyna Gomulska, Przemyslaw A Pekala, Shane R Tubbs, Krzysztof A TomaszewskiAbstract:Background Cervical ribs (CR) are supernumerary ribs that arise from the Seventh Cervical Vertebra. In the presence of CR, the boundaries of the interscalene triangle can be further constricted and result in neurovascular compression and thoracic outlet syndrome (TOS). The aim of our study was to provide a comprehensive evidence-based assessment of CR prevalence and their association with TOS as well as surgical approach to excision of CR and surgical patients' characteristics. Methods A thorough search of major electronic databases was conducted to identify any relevant studies. Data on the prevalence, laterality, and side of CR were extracted from the eligible studies for both healthy individuals and patients with TOS. Data on the type of TOS and surgical approach to excision of CR were extracted as well. Results A total of 141 studies (n = 77,924 participants) were included into the meta-analysis. CR was significantly more prevalent in patients with TOS than in healthy individuals, with pooled prevalence estimates of 29.5% and 1.1%, respectively. More than half of the patients had unilateral CR in both the healthy and the TOS group. The analysis showed that 51.3% of the symptomatic patients with CR had vascular TOS, and 48.7% had neurogenic TOS. Most CR were surgically excised in women using a supraclavicular approach. Conclusions CR ribs are frequent findings in patients with TOS. We recommended counseling asymptomatic patients with incidentally discovered CR on the symptoms of TOS, so that if symptoms develop, the patients can undergo prompt and appropriate workup and treatment.