The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform
Christopher M Powers - One of the best experts on this subject based on the ideXlab platform.
-
patellar kinematics part i the influence of Vastus Muscle activity in subjects with and without patellofemoral pain
Physical Therapy, 2000Co-Authors: Christopher M PowersAbstract:Background and Purpose. Reduced motor unit activity of the Vastus medialis Muscle relative to the Vastus lateralis Muscle has been implicated as a cause of lateral patellar subluxation. The purpose of this study was to assess the influence of Vastus Muscle motor unit activity on patellar kinematics. Subjects. Twenty-three women (mean age=26.8 years, SD=8.5, range=14–46) with a diagnosis of patellofemoral pain and 12 women (mean age=29.1 years, SD=5.0, range=24–38) without patellofemoral pain participated. Only female subjects were studied because of potential biomechanical differences between sexes. Methods. Patellar kinematics (kinematic magnetic resonance imaging) and Vastus Muscle electromyographic (EMG) activity using indwelling electrodes were measured during resisted knee extension. Measurements of medial and lateral patellar displacement and tilt obtained from magnetic resonance images were correlated with normalized Vastus lateralis:Vastus medialis oblique Muscle and Vastus lateralis:Vastus medialis longus Muscle EMG ratios at 45, 36, 27, 18, 9, and 0 degrees of knee flexion using a stepwise regression procedure. Results. The Vastus lateralis:Vastus medialis longus Muscle EMG ratio contributed to the prediction of lateral patellar displacement at 27 degrees of knee flexion ( r =−.48), with increased Vastus medialis longus Muscle activity being associated with greater lateral patellar displacement. A similar inverse relationship was evident with lateral patellar tilt at 36, 27, 18, and 9 degrees of knee flexion. Conclusion and Discussion. These results suggest that increased motor unit activity of the Vastus medialis Muscle appears to be associated with abnormal patellar kinematics in women, but it is not necessarily a cause of abnormal patellar kinematics.
-
timing and intensity of Vastus Muscle activity during functional activities in subjects with and without patellofemoral pain
Physical Therapy, 1996Co-Authors: Christopher M Powers, Robert Landel, Jacquelin PerryAbstract:Background and Purpose. Differences in intensity and timing of Muscle activity between the Vastus medialis and Vastus lateralis Muscles have been hypothesized as contributing to lateral patellar tracking and patellofemoral pain (PFP). The purpose of this study was to ascertain whether there were differences in the activity of the Vastus Muscles that would be suggestive of patellar instability in subjects with PFP. Subjects. Twenty-six subjects with PFP and 19 subjects without PFP participated in the study. Methods. Fine-wire electromyography was used to record activity of the Vastus medialis oblique, Vastus medialis longus, Vastus lateralis, and Vastus intermedius Muscles during level walking, stair climbing, and walking on ramps. Knee motion was assessed using a six-camera motion analysis system. Results. No differences in onset or cessation of Muscle activity was found among the Vastus Muscles for either group, regardless of condition. Subjects with PFP demonstrated less activity of all Vastus Muscles for level walking and ramp walking than did subjects without PFP. Conclusions and Discussion. These results do not support the hypothesis that timing or intensity differences between the Vastus medialis and Vastus lateralis Muscles are associated with PFP.
Karl Swedberg - One of the best experts on this subject based on the ideXlab platform.
-
Angiotensin-converting enzyme gene expression in skeletal Muscle in patients with chronic heart failure*
Journal of Cardiac Failure, 1998Co-Authors: Maria Schaufelberger, Helmut Drexler, Elisabeth Schieffer, Karl SwedbergAbstract:Abstract Background: Skeletal Muscle factors may influence functional limitation in patients with heart failure. The renin-angiotensin system is activated in chronic heart failure. Treatment with angiotensin-converting enzyme (ACE) inhibitors improve symptoms and prognosis. The goal of this study was to quantify and localize skeletal Muscle ACE-mRNA in patients with chronic heart failure and in control subjects, and to elucidate skeletal Muscle fiber area and capillary density. Methods and Results: Biopsies from the lateral Vastus Muscle were taken from 9 patients before and after treatment with enalapril and in 10 control subjects. ACE-mRNA was quantified with reverse transcription polymerase chain reaction. Immunohistochemistry was used to localize ACE within skeletal Muscle. No difference in ACE-mRNA transcripts between patients and control subjects was detected, nor did ACE gene expression change after treatment with enalapril. The number of ACE-mRNA transcripts was related to Muscle fiber area, whereas an inverse relationship between the number of ACE transcripts and capillary density was found. ACE was detected in the endothelial cells of capillaries in skeletal Muscle. Conclusion: ACE is expressed in skeletal Muscle and is confined to endothelial cells. The close relationship between capillary density and number of ACE transcripts indicate that activation of the renin-angiotensin system has an impact on capillary growth.
-
Skeletal Muscle alterations in patients with chronic heart failure
European Heart Journal, 1997Co-Authors: Maria Schaufelberger, B. O. Eriksson, Gunnar Grimby, P. Held, Karl SwedbergAbstract:Aims To investigate skeletal Muscle in patients with chronic heart failure and controls, and relate skeletal Muscle variables to functional class, exercise capacity, central haemodynamics, Muscle strength and medical treatment. Methods Biopsy from the lateral Vastus Muscle was obtained in 43 patients and 20 controls. Right sided heart catheterization was performed in 19 patients and maximal exercise testing in 26 patients. In nine patients Muscle strength was measured. Patients had higher lactate levels, higher lactate dehydrogenase activity, and lower oxidative enzymes activity than controls. In patients, the percentage of type I fibres and capillarization were decreased while the percentage of type II B fibres were increased. Lactate dehydrogenase activity correlated with exercise capacity, Muscle strength and right atrial pressure. Digoxin-treated patients had significantly lower oxidative enzyme activity than patients without digoxin treatment. Conclusions Patients with chronic heart failure have several skeletal Muscle abnormalities. Central haemodynamics and medical treatment may, in addition to inactivity, be important in skeletal Muscle changes.
-
Skeletal Muscle changes in patients with chronic heart failure before and after treatment with enalapril.
European Heart Journal, 1996Co-Authors: Maria Schaufelberger, B. O. Eriksson, Gunnar Grimby, P. Held, Gull Andersson, Karl SwedbergAbstract:To evaluate if enalapril treatment can influence skeletal Muscle metabolism and histology weinvestigated 26 patients with congestive heart failure and 20 normal subjects. The patients were treated with enalapril for 3 months in addition to diuretics and digitalis. Biopsies from thelateral Vastus Muscle were taken before and after treatment. Citrate synthetase, 3-hydroxyacyl-CoA dehydrogenase and phosphorylase activities were significantly decreased in the patients compared with controls. The number of capillaries per fibre and the number of capillaries surrounding each fibre were significantly decreased among patients. After 3 months of enalapril treatment functional class improved significantly. The lactate dehydrogenase activity increased whereas the oxidative enzymes did not change significantly. The type II and II A fibre areas increased significantly after enalapril treatment. We conclude that patients with chronic heart failurehave decreased activity of oxidative enzymes and of phosphorylase in skeletal Muscle. They alsohave decreased capillarization in skeletal Muscle. These changes were not influenced by enalapril treatment. The increase in Muscle fibre area seen after enalapril treatment could be due to increased physical activity. The cause of increased Muscle lactate dehydrogenase activity afterenalapril treatment needs further investigation.
-
Skeletal Muscle fiber composition and capillarization in patients with chronic heart failure: Relation to exercise capacity and central hemodynamics
Journal of Cardiac Failure, 1995Co-Authors: Maria Schaufelberger, B. O. Eriksson, Gunnar Grimby, P. Held, Karl SwedbergAbstract:Abstract Patients with chronic heart failure have structural and metabolic changes in skeletal Muscle, which may be of importance for symptomatology. The origin of these changes are still unknown. The relationship between fiber composition and capillarization in skeletal Muscle with exercise capacity and central hemodynamic variables was examined. Biopsies from the lateral Vastus Muscle were taken in 12 patients with chronic heart failure. Samples from eight normal subjects served as control samples. All patients underwent maximal exercise tests. Central hemodynamic variables were measured during exercise in five patients. The patients had a higher percentage of type II B fibers ( P = .03) and fewer capillaries per fiber ( P = .02) than the controls subjects. VO 2 max correlated with the percentage of type I fibers, whereas the correlation with the type II A fibers was inverse. Cardiac index and pulmonary capillary wedge pressure at submaximal and maximal exercise were related to fiber type composition and relative fiber areas. Skeletal Muscle fiber type composition and capillarization was changed in patients with chronic heart failure. These changes might influence exercise capacity. There were relationships between central hemodynamic variables and skeletal Muscle changes. What the cause and effects were need further investigation.
Jacquelin Perry - One of the best experts on this subject based on the ideXlab platform.
-
timing and intensity of Vastus Muscle activity during functional activities in subjects with and without patellofemoral pain
Physical Therapy, 1996Co-Authors: Christopher M Powers, Robert Landel, Jacquelin PerryAbstract:Background and Purpose. Differences in intensity and timing of Muscle activity between the Vastus medialis and Vastus lateralis Muscles have been hypothesized as contributing to lateral patellar tracking and patellofemoral pain (PFP). The purpose of this study was to ascertain whether there were differences in the activity of the Vastus Muscles that would be suggestive of patellar instability in subjects with PFP. Subjects. Twenty-six subjects with PFP and 19 subjects without PFP participated in the study. Methods. Fine-wire electromyography was used to record activity of the Vastus medialis oblique, Vastus medialis longus, Vastus lateralis, and Vastus intermedius Muscles during level walking, stair climbing, and walking on ramps. Knee motion was assessed using a six-camera motion analysis system. Results. No differences in onset or cessation of Muscle activity was found among the Vastus Muscles for either group, regardless of condition. Subjects with PFP demonstrated less activity of all Vastus Muscles for level walking and ramp walking than did subjects without PFP. Conclusions and Discussion. These results do not support the hypothesis that timing or intensity differences between the Vastus medialis and Vastus lateralis Muscles are associated with PFP.
Maria Schaufelberger - One of the best experts on this subject based on the ideXlab platform.
-
Angiotensin-converting enzyme gene expression in skeletal Muscle in patients with chronic heart failure*
Journal of Cardiac Failure, 1998Co-Authors: Maria Schaufelberger, Helmut Drexler, Elisabeth Schieffer, Karl SwedbergAbstract:Abstract Background: Skeletal Muscle factors may influence functional limitation in patients with heart failure. The renin-angiotensin system is activated in chronic heart failure. Treatment with angiotensin-converting enzyme (ACE) inhibitors improve symptoms and prognosis. The goal of this study was to quantify and localize skeletal Muscle ACE-mRNA in patients with chronic heart failure and in control subjects, and to elucidate skeletal Muscle fiber area and capillary density. Methods and Results: Biopsies from the lateral Vastus Muscle were taken from 9 patients before and after treatment with enalapril and in 10 control subjects. ACE-mRNA was quantified with reverse transcription polymerase chain reaction. Immunohistochemistry was used to localize ACE within skeletal Muscle. No difference in ACE-mRNA transcripts between patients and control subjects was detected, nor did ACE gene expression change after treatment with enalapril. The number of ACE-mRNA transcripts was related to Muscle fiber area, whereas an inverse relationship between the number of ACE transcripts and capillary density was found. ACE was detected in the endothelial cells of capillaries in skeletal Muscle. Conclusion: ACE is expressed in skeletal Muscle and is confined to endothelial cells. The close relationship between capillary density and number of ACE transcripts indicate that activation of the renin-angiotensin system has an impact on capillary growth.
-
Skeletal Muscle alterations in patients with chronic heart failure
European Heart Journal, 1997Co-Authors: Maria Schaufelberger, B. O. Eriksson, Gunnar Grimby, P. Held, Karl SwedbergAbstract:Aims To investigate skeletal Muscle in patients with chronic heart failure and controls, and relate skeletal Muscle variables to functional class, exercise capacity, central haemodynamics, Muscle strength and medical treatment. Methods Biopsy from the lateral Vastus Muscle was obtained in 43 patients and 20 controls. Right sided heart catheterization was performed in 19 patients and maximal exercise testing in 26 patients. In nine patients Muscle strength was measured. Patients had higher lactate levels, higher lactate dehydrogenase activity, and lower oxidative enzymes activity than controls. In patients, the percentage of type I fibres and capillarization were decreased while the percentage of type II B fibres were increased. Lactate dehydrogenase activity correlated with exercise capacity, Muscle strength and right atrial pressure. Digoxin-treated patients had significantly lower oxidative enzyme activity than patients without digoxin treatment. Conclusions Patients with chronic heart failure have several skeletal Muscle abnormalities. Central haemodynamics and medical treatment may, in addition to inactivity, be important in skeletal Muscle changes.
-
Skeletal Muscle changes in patients with chronic heart failure before and after treatment with enalapril.
European Heart Journal, 1996Co-Authors: Maria Schaufelberger, B. O. Eriksson, Gunnar Grimby, P. Held, Gull Andersson, Karl SwedbergAbstract:To evaluate if enalapril treatment can influence skeletal Muscle metabolism and histology weinvestigated 26 patients with congestive heart failure and 20 normal subjects. The patients were treated with enalapril for 3 months in addition to diuretics and digitalis. Biopsies from thelateral Vastus Muscle were taken before and after treatment. Citrate synthetase, 3-hydroxyacyl-CoA dehydrogenase and phosphorylase activities were significantly decreased in the patients compared with controls. The number of capillaries per fibre and the number of capillaries surrounding each fibre were significantly decreased among patients. After 3 months of enalapril treatment functional class improved significantly. The lactate dehydrogenase activity increased whereas the oxidative enzymes did not change significantly. The type II and II A fibre areas increased significantly after enalapril treatment. We conclude that patients with chronic heart failurehave decreased activity of oxidative enzymes and of phosphorylase in skeletal Muscle. They alsohave decreased capillarization in skeletal Muscle. These changes were not influenced by enalapril treatment. The increase in Muscle fibre area seen after enalapril treatment could be due to increased physical activity. The cause of increased Muscle lactate dehydrogenase activity afterenalapril treatment needs further investigation.
-
Skeletal Muscle fiber composition and capillarization in patients with chronic heart failure: Relation to exercise capacity and central hemodynamics
Journal of Cardiac Failure, 1995Co-Authors: Maria Schaufelberger, B. O. Eriksson, Gunnar Grimby, P. Held, Karl SwedbergAbstract:Abstract Patients with chronic heart failure have structural and metabolic changes in skeletal Muscle, which may be of importance for symptomatology. The origin of these changes are still unknown. The relationship between fiber composition and capillarization in skeletal Muscle with exercise capacity and central hemodynamic variables was examined. Biopsies from the lateral Vastus Muscle were taken in 12 patients with chronic heart failure. Samples from eight normal subjects served as control samples. All patients underwent maximal exercise tests. Central hemodynamic variables were measured during exercise in five patients. The patients had a higher percentage of type II B fibers ( P = .03) and fewer capillaries per fiber ( P = .02) than the controls subjects. VO 2 max correlated with the percentage of type I fibers, whereas the correlation with the type II A fibers was inverse. Cardiac index and pulmonary capillary wedge pressure at submaximal and maximal exercise were related to fiber type composition and relative fiber areas. Skeletal Muscle fiber type composition and capillarization was changed in patients with chronic heart failure. These changes might influence exercise capacity. There were relationships between central hemodynamic variables and skeletal Muscle changes. What the cause and effects were need further investigation.
Hans Metelmann - One of the best experts on this subject based on the ideXlab platform.
-
Applications of the lateral Vastus Muscle flap
International Journal of Oral and Maxillofacial Surgery, 1992Co-Authors: K.-d. Wolff, Hans MetelmannAbstract:Abstract The lateral Vastus Muscle flap has the potential to become one of the most appropriate free flaps for reconstructive surgery in the oral maxillofacial area in selected cases. The flap is relatively easy to harvest and gives rise to little donor site morbidity. The quality of the large diameter vessels allows for relatively easy microsurgical anastomosis. Nerve anastomosis is possible, which makes it extremely suitable for tongue reconstruction.
-
Applications of the lateral Vastus Muscle flap Oncology
1992Co-Authors: K.-d. Wolff, Hans MetelmannAbstract:The lateral Vastus Muscle flap has the potential to become one of the most appropriate free flaps for reconstructive surgery in the oral maxillofacial area in selected cases. The flap is relatively easy to harvest and gives rise to little donor site morbidity. The quality of the large diameter vessels allows for relatively easy microsurgical anastomosis. Nerve anastomosis is possible, which makes it extremely suitable for tongue reconstruction. Zusammenfassung. Der Vastus lateralis-Lappen kann als myocutanes oder myo- fasciales Transplantat in der rekonstruktiven Mund-Kiefer-Gesichtschirugie an- gewendet werden und besonders fiir die Zungenrekonstruktion oder die Deckung perforierender Mundh6hlendefekte niitzlich sein. Die Lappenhebung ist tech- nisch einfach und hinterlfigt nur geringe Beeintr/ichtigungen an der Entnahmestel- le, der neurovascul/ire Stiel ist lang und kaliberstark.
