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C Haid

Publications and source records attributed to C Haid.

At least 37 records · Page 2Linked to original sources
PubMed1997

Muscular adaptation and strength during the early phase of eccentric training: influence of the training frequency.

We investigated the effects of different training frequencies on maximum isometric voluntary contraction (MVC) force and plasma concentrations of muscle proteins during the early phase of eccentric training. MVC and plasma concentrations of creatine kinase (CK) and slow-twitch skeletal (cardiac beta-type) myosin heavy chain (MHC) fragments were measured before and 4 and 7 d after performing the first and last training task. Training tasks, which comprised 70 high-force eccentric contractions involving the thigh muscles (single leg), were performed under supervision in three groups (A, B, C) at the beginning and at the end of the study period (7 wk). In addition, groups A (N = 10) and B (N = 10) trained during the study period starting 1 wk after the first training task. Group A performed one training task once a week for 5 wk and group B (N = 10) twice a week for 2 wk and three times a week during the subsequent 3 wk. In all three groups the first training task resulted in delayed CK and MHC peaks and decrements in MVC, which were comparable (P > 0.05). Only training regimen B resulted in a significant increase in the MVC. Compared with the first training task training regimens, A and B significantly (P < 0.01) reduced the increase in serum muscle protein and muscle function impairment. The responses to the last training task did not differ significantly between groups A and B. In group C the responses after the second training task did not differ significantly from those observed after the first task. Our results suggest that, compared with group A, additional eccentric exercise in group B is the essential basis for the increase in muscle strength during the early phase of eccentric training without further benefits for muscular adaptation. In group C we found no muscular adaptation.

Adaptation, Physiological↗
PubMed1996

Comparison between single-screw and triangulated, double-screw fixation in anterior spine surgery. A biomechanical test.

STUDY DESIGN: The advantage to fixation strength of triangulated, double-screw fixation compared with that of single-screw instrumentation in anterior spine surgery was evaluated by in vitro testing. OBJECTIVES: To compare the fixation strength of single-screw instrumentation with ventral derotation spondylodesis screws with the fixation strength of triangulated, double-screw instrumentation with Cotrel-Dubousset-Hopf screws. Resistance against pull-out load and against load perpendicular to the axis of the screws was evaluated. To avoid the bias caused by different screw design, the pull-out strength of single screws of both devices was compared first. SUMMARY OF BACKGROUND DATA: To the authors' knowledge, no study comparing anterior single with triangulated screws has been published. METHODS: A pull-out test was performed when one vertebra in each spine specimen was instrumented with a ventral derotation spondylodesis screw, one with an isolated Cotrel-Dubousset-Hopf screws, and one with two triangulated, Cotrel-Dubousset-Hopf screws linked by a Cotrel-Dubousset-Hopf block. Load perpendicular to the axis of the screw was applied on the bone-device interface after instrumentation of further specimens with ventral derotation spondylodesis and triangulated, Cotrel-Dubousset-Hopf devices. RESULTS: Use of isolated Cotrel-Dubousset-Hopf screws compared with ventral derotation spondylodesis screws showed no significant differences in pull-out strength. The use of triangulated, double-screw fixation with Cotrel-Dubousset-Hopf screws led to a significant 79% increase in resistance against pull-out and a 73% increase in resistance against load perpendicular to the screw axis compared with the resistance produced using ventral derotation spondylodesis single-screw instrumentation. CONCLUSION: In anterior surgery, fixation of the vertebra-device interface can be improved considerably by application of two triangulated screws.

Aged↗
PubMed1996

The contribution of anulus fibers to torque resistance.

STUDY DESIGN: Anulus fibers of the intervertebral disc oriented in one direction were dissected, and oppositely directed fibers were left intact as a result of a newly developed dissection method. Motion segments were dissected by this way, and motion segments after bilateral facetectomy were loaded in torsion and compared with each other. OBJECTIVES: To assess the contribution of facets and anulus fibers to torque resistance. SUMMARY OF BACKGROUND DATA: Mathematical models predict that torsional stress is transmitted only to those collagene fibers of the anulus that are angled in the direction of the applied torque. Torsion and forward bending or torsion and compression are likely to cause anulus damage. No experimental study that we are aware of has confirmed that anulus fibers are the main structure to resist against torque. METHODS: Pure axial rotation moments were applied on 12 lumbar motion segments. The six components of motion were recorded. Six motion segments were investigated intact after dissection of anulus fibers directed in one direction and after additional bilateral facetectomy. In six motion segments, bilateral facetectomy was performed before anulus dissection. RESULTS: With the application of an axial rotation moment of 8.5 Nm to the left, axial rotation increased 2 degrees after dissection of disc fibers in one direction, and 1.2 degrees after bilateral facetectomy (P = 0.002). In the opposite direction, there were no differences. After both injuries, axial rotation was 7.6 degrees to the left (direction of fiber dissection) and -3.3 degrees to the right (P = 0.0005). CONCLUSION: In lumbar motion segments without degeneration, anulus fibers restrict axial rotation more than the facets.

Adult↗
PubMed1996

Biomechanical properties of the human tibia: fracture behavior and morphology.

Standardized biomechanical dynamic load tests were performed to obtain fundamental information on the fracture behavior and morphology of the human tibia. After preparation, the specimens (n = 32) were loaded to breakage by ventral (one side alternately), dorsal, medial or lateral loading on a servo-hydraulic testing machine (Walter und Bai, Löhningen, Switzerland). Primary and secondary fracture lines and fissures were marked differently on the three surfaces of the tibia specimens. They were then videoscanned and digitized on a flatbed scanner to give two-dimensional fracture-line images. Load limits were 2475 to 12,206 Newton. The study revealed both direct fracture patterns with the fracture lines originating from the opposite site of impact, and indirect fracture patterns originating from the distal third of the specimens. Direct fractures occurred in 46% of the specimens after ventral loading, in 80% after medial or lateral loading, and in 100% after dorsal loading. Ventral, medial or lateral loading frequently produced direct wedge fractures of the Messerer type. Dorsal loading resulted in different direct patterns characterized by transverse fractures with longitudinal fissures at the impact site of the loading stamp. Direct transverse fractures also often showed a wedge-shaped pattern due to additional fissures. These were, however, identifiable only after maceration of the specimens and should receive closer attention in forensic practice.

Adolescent↗
PubMed1996

The possibility of creating lordosis and correcting scoliosis simultaneously after partial disc removal. Balance lines of lumbar motion segments.

STUDY DESIGN: The feasibility of correcting scoliosis and creating lordosis simultaneously in the thoracolumbar and lumbar spine by anterior instrumentation was investigated by in vitro testing. OBJECTIVES: To evaluate the vertebral zones in which a compressive load applied in a motion segment creates side bending and lordosis in intact motion segments and after partial disc removal. SUMMARY OF BACKGROUND DATA: Most investigators have observed a kyphogenic effect of anterior scoliosis instrumentation and recommended dorsal placement of screws and the use of wedge grafts, although wedge grafts were not used routinely by all surgeons. METHODS: Zones of lordosization and side bending were determined by evaluation of balance lines between extension-flexion and side bending, respectively, by axial loading on ligamentous human motion segments with intact discs and after partial disc removal. RESULTS: In lumbar motion segments with intact discs, it is possible to achieve ipsilateral side bending and lordosization by anterior instrumentation. After partial disc removal, the balance line between extension and flexion runs through the ipsilateral pedicle, and, therefore, a compressive load between the vertebral bodies always creates kyphosis. CONCLUSIONS: After partial disc removal, it is not possible to create lordosis and correction of scoliosis simultaneously by ipsilateral anterior instrumentation without the use of intervertebral wedge grafts.

Adult↗
PubMed1996

Axial rotation measurement of scoliotic vertebrae by means of computed tomography scans.

STUDY DESIGN: This study evaluated the preconditions for exact axial rotation measurement and the possibility for other parameters to measure axial rotation and mechanical torsion. OBJECTIVES: Quality criteria for axial rotation measurement in computed tomography scans are not established yet. Criteria should be found to improve axial rotation measurement. SUMMARY OF BACKGROUND DATA: To the authors' knowledge, no systematic analysis of the errors of axial rotation measurement based on computed tomography scans has been performed. METHODS: Axial rotation was measured in 259 computed tomography scans of 11 cadaveric vertebrae from scoliotic specimens. The sagittal axial rotation measurement angle of Aaro and Dahlborn and a new rotation parameter were measured with a pencil and ruler. Five landmarks were digitized and consequently five axial rotation parameters were computed. The influence of insufficient visualization of bony landmarks, mechanical torsion of the vertebra itself, and oblique position of the vertebra was evaluated. RESULTS: Accuracy is considerably improved in central computed tomography scans (same distance to the top and bottom of the vertebral body) due to good visualization of landmarks and reduction of effects of mechanical torsion. The oblique vertebral position causes more errors. One mechanical torsion parameter with sufficient reliability is identified. CONCLUSION: The sagittal axial rotation measurement method of Aaro and Dahlborn is superior to other techniques of measurement. It can be improved considerably if computed tomography scans fulfill certain quality criteria.

Anthropometry↗
PubMed1996

[Determination of back shape in median sagittal plane using an inclination sensory].

The measurement and assessment of the shape of the human back is in the process of becoming an important area of research. Various measuring techniques have already been developed, including moiré topography, stereoscopic photography and raster stereography. These have been employed in the evaluation of scoliosis, kyphosis, funnel chest and other pathological conditions of the spine. These systems are very complicated (and expensive) since they involve a three-dimensional analysis of the shape of the back. For preventive medical purposes, however, evaluation of the spine in the median sagittal plane alone often suffices. In this study, the inclinations of the back along the spine were measured, and it has been shown that these measurements can be used to reconstruct the shape of the back.

Anthropometry↗
PubMed1995

Light concentric exercise and heavy eccentric muscle loading: effects on CK, MRI and markers of inflammation.

The consequences of a single bout of heavy eccentric exercise with and without repeated concentric exercises on MRI images, serum CK levels and markers of inflammation were studied. Two groups (ECC and ECCON), each consisting of 18 male volunteers, performed 70 eccentic contractions of the quadriceps femoris muscle. The study group (ECCON) performed additional concentric contractions on a dynamometer (Cybex II+) one day before and two hours, 1, 2, 3, 6 and 9 days after eccentric loading. Serum levels of creatine kinase (CK) were examined as a function of time, and correlated with measurements of magnetic resonance imaging (MRI) of the involved muscle groups. T2-weighted images of the thigh muscles were studied. Serum C-reactive protein, complement factors C3c and C4, haptoglobin and transferrin were measured as markers of inflammation. Additional concentric contractions (ECCON group) significantly increased CK, compared to the ECC group. However, it has no apparent effect on MRI signal intensity changes, which were of equal magnitude in the loaded vastus intermedius and deep parts of the vastus lateralis in both groups. Likewise, the serum markers of inflammation of the exercised muscles appeared to be absent. Based on MRI-images, additional concentric contractions had no statistically significant effect on muscle damage and breakdown of connective tissue. The five-fold increase in CK in the ECCON group could be a reflection of "massaging out" of the CK from the muscles into the circulation by additional concentric exercises. However, it could also be an indication for a superior sensitivity of assessing muscle fiber damage in comparison to the MRI.

Adult↗
PubMed1995

Rapid adaptation to eccentric exercise-induced muscle damage.

This study examined eccentric exercise-induced muscle damage and rapid adaptation. Twenty-two male subjects performed 70 eccentric actions with the knee extensors. Group A (n = 11) and group B (n = 11) repeated the same exercise 4 and 13 days after the initial bout, respectively. Criterion measures included muscle soreness, muscle force generation (vertical jump height on a Kistler platform), and plasma levels of creatine kinase (CK), slow-twitch skeletal (cardiac beta-type) myosin heavy chains (MHC), and cardiac troponin I. Subjects were tested pre-exercise and up to day 4 following each bout. The initial exercise resulted in an increase in CK and MHC, a decrement in muscle force, and delayed onset muscle soreness in all participants. CK and MHC release correlated closely (rho = 0.73, p = 0.0001), both did not correlate with the decrement in muscle force generation after exercise. Because cardiac troponin I could not be detected in all samples, which excluded a protein release from the heart (cardiac beta-type MHC), this finding provides evidence for a injury of slow-twitch skeletal muscle fibers in response to eccentric contractions. Repetition of the initial eccentric exercise bout after 13 days (group B) did not cause muscle soreness, a decrement in muscle reaction force with vertical jump or significant changes in plasma MHC and CK concentrations, whereas in case of repetition after 4 days (group A) only the significant increases in CK and MHC were abolished. The decrement in reaction force with vertical jump did not differ significantly from that after the initial exercise session, but perceived muscle soreness was less pronounced.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1992

Effects of exercise on plasma myosin heavy chain fragments and MRI of skeletal muscle.

The effects of a single series of high-force eccentric contractions involving the quadriceps muscle group (single leg) on plasma concentrations of muscle proteins were examined as a function of time, in the context of measurements of torque production and magnetic resonance imaging (MRI) of the involved muscle groups. Plasma concentrations of slow-twitch skeletal (cardiac beta-type) myosin heavy chain (MHC) fragments, myoglobin, creatine kinase (CK), and cardiac troponin T were measured in blood samples of six healthy male volunteers before and 2 h after 70 eccentric contractions of the quadriceps femoris muscle. Screenings were conducted 1, 2, 3, 6, 9, and 13 days later. To visualize muscle injury, MRI of the loaded and unloaded thighs was performed 3, 6, and 9 days after the eccentric exercise bout. Force generation of the knee extensors was monitored on a dynamometer (Cybex II+) parallel to blood sampling. Exercise resulted in a biphasic myoglobin release profile, delayed CK and MHC peaks. Increased MHC fragment concentrations of slow skeletal muscle myosin occurred in late samples of all participants, which indicated a degradation of slow skeletal muscle myosin. Because cardiac troponin T was within the normal range in all samples, which excluded a protein release from the heart (cardiac beta-type MHC), this finding provides evidence for an injury of slow-twitch skeletal muscle fibers in response to eccentric contractions. Muscle action revealed delayed reversible increases in MRI signal intensities on T2-weighted images of the loaded vastus intermedius and deep parts of the vastus lateralis. We attributed MRI signal changes due to edema in part to slow skeletal muscle fiber injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Breast sonography with high-frequency short-focusing transducers].

Since 1984 two high-frequency short-focussed linear transducers have been used for breast sonography at Innsbruck University Gynaecological Clinic. In the study reported here 121 patients with pathologic change in the breast were examined. A significant improvement in diagnosis was achieved: on the one hand because of the improved resolution and distinction of the lesions, and on the other because of the manageability of the transducers and the individually adjustable breast compression. Both perforation of the physiological mammary strata as well as clearly distinguishable tumor ends without echoproof halos were considered reliable indicators of the malignancy of the respective changes.

Abscess↗
PubMed1985

[Improved early diagnosis of intrauterine pregnancy using an ultrasonic vaginal sonde].

The presented vaginal sonde can be brought up to the investigated tissue at minimal distance and the patient can be sonographed without special preparation (e.g. the uncomfortable and time consuming filling of the bladder). Besides the more feasible organization for the physician the method allows early diagnosis of intrauterine pregnancy and therefore the exclusion of ectopic pregnancy in patients suffering from sterility.

Abdomen↗