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At least 649 records · Page 36Linked to original sources

PubMed2006

Effect of different upright sitting postures on spinal-pelvic curvature and trunk muscle activation in a pain-free population.

STUDY DESIGN: A normative within-subjects single-group study. OBJECTIVE: To compare spinal-pelvic curvature and trunk muscle activation in 2 upright sitting postures ("thoracic" and "lumbo-pelvic") and slump sitting in a pain-free population. SUMMARY OF BACKGROUND DATA: Clinical observations suggest that both upright and slump sitting postures can exacerbate low back pain. Little research has investigated the effects of different upright sitting postures on trunk muscle activation. METHODS: Spinal-pelvic curvature and surface electromyography of 6 trunk muscles were measured bilaterally in 2 upright (thoracic and lumbo-pelvic) sitting postures and slump sitting in 22 subjects. RESULTS: Thoracic, compared to lumbo-pelvic, upright sitting showed significantly greater thoracic extension (P < 0.001), with significantly less lumbar extension (P < 0.001) and anterior pelvic tilt (P = 0.03). Furthermore, there was significantly less superficial lumbar multifidus (P < 0.001) and internal oblique (P = 0.03) activity, with significantly higher thoracic erector spinae (P < 0.001) and external oblique (P = 0.04) activity in thoracic upright sitting. There was no significant difference in superficial lumbar multifidus activity between thoracic upright and slump sitting. CONCLUSIONS: Different upright sitting postures resulted in altered trunk muscle activation. Thoracic when compared to lumbo-pelvic upright sitting involved less coactivation of the local spinal muscles, with greater coactivation of the global muscles. These results highlight the importance of postural training specificity when the aim is to activate the lumbo-pelvic stabilizing muscles in subjects with back pain.

Adult↗

PubMed2005

Giant congenital melanocytic nevi of the trunk and an algorithm for treatment.

Giant congenital melanocytic nevi (CMN) are rare, congenital, disfiguring lesions with a risk of degeneration to malignant melanoma. Giant CMN are associated with an increased risk of malignant degeneration. In a minority of cases, patients with giant CMN may have associated neurocutaneous melanosis with leptomeningeal involvement. Giant CMN of the trunk pose difficult diagnostic and reconstructive problems requiring complex multistage treatment. For high-risk cases, diagnostic evaluation in the form of neuro-imaging is an essential component of the planning phase. Although nonsurgical options for the treatment of giant CMN have been advocated, these modalities may decrease the burden of nevus cells but do not result in complete removal of these cells. The ability to monitor nevus cells that remain after nonsurgical management of giant CMN remains questionable. These nonsurgical options include dermabrasion, laser ablation, and chemical peel. In contrast, direct excision of the nevus is the mainstay of treatment of nonsurgical management of giant CMN. There are numerous surgical options to resurface the resultant cutaneous defect after excision of the nevus. The simplest of these options consists of serial excision and direct closure of the defect in stages. However, if the defect cannot be closed by direct cutaneous advancement, other options for wound resurfacing include split- or full-thickness skin graft, tissue expansion, and free tissue transfer. Tissue expansion should be viewed as a category of treatment options because expanders can be used to create an expanded full-thickness skin graft, local expanded flaps adjacent to the lesion, or expansion of a free tissue donor site. Given the diversity of reconstructive options that use tissue expansion, these techniques have evolved as the primary treatment method for giant CMN of the trunk. The authors outline an approach to the evaluation of giant CMN of the trunk, review the risks of melanoma and of neurocutaneous melanosis, describe their preferred treatment regimen, and offer a treatment algorithm for giant CMN of the trunk.

Algorithms↗

PubMedDate not supplied

Prevalence of trunk abnormalities in eleven-year-old schoolchildren in Rotterdam, The Netherlands.

The prevalence of trunk abnormalities was studied in 4,915 children aged 11 years (2,528 boys, 2,387 girls); 33% of the children were of non-Dutch origin. The following measurements were recorded: height, weight, signs of puberty, and menarche. Trunk abnormality was assessed in the erect child (asymmetry of shoulders, waistline, imbalance of the trunk, scoliosis, lordosis, kyphosis, swayback, and flexibility) and by the forward bending test (rib hump or lumbar prominence, persistence of scoliosis, kyphosis, deviant lateral aspect); 85.9% of boys and 81.3% of girls were symmetric, and abnormal forward bending test was noted in 7.1% of boys and 10.6% of girls. In non-Dutch girls, trunk abnormalities were more prevalent.

Anthropometry↗

PubMed2004

The effects of trunk stimulation on bimanual seated workspace.

This study explores the effects of functional electrical stimulation (FES) of the lumbar trunk extensors on the seated posture and bimanual workspace of subjects with spinal cord injury (SCI). Four subjects with motor complete SCI with implanted intramuscular stimulating electrodes to activate the lumbar erector spinae were studied. The positions of markers on the pelvis, trunk, and hands were monitored by a motion capture system during bimanual reaching maneuvers. To define three-dimensional functional workspace boundaries, subjects swept their hands through the extremes of their range of motion without losing balance while sitting. To characterize forward reach, subjects reached to targets in the sagittal plane while carrying various masses with and without FES. Reaching trials were rated on the seven-point usability rating scale to determine effort and subject preference and change in pelvic angle with stimulation was monitored. There was a consistent change in the seated posture with FES in all subjects that resulted in significant forward or upward (6.85 cm +/- 2.15 cm) shifts in the workspace. Workspace volumes increased for two of the four subjects tested. FES caused significant anterior rotation of the pelvis to restore a more natural lumbar curve without a backrest (19.81 degrees +/- 8.75 degrees). With a backrest, the change in posture with FES allowed individuals with SCI to reach further in the sagittal plane and carry heavier masses by shifting the trunk, allowing increased elbow extension, or a combination of the two mechanisms. Reaching with FES was consistently preferred over reaching without FES. This preliminary study is encouraging for future research on trunk stability and reaching ability with FES.

Adult↗

PubMed1992

Rationale and technique for replacement of the ascending aorta, arch, and distal aorta using a modified elephant trunk procedure.

Replacement of the aortic arch during repair of either extensive aortic aneurysmal disease or aortic dissection can be a major undertaking. Borst introduced an "elephant trunk" technique whereby a tubular aortic graft prosthesis was inserted into the distal aorta while repairing the ascending aorta and aortic arch. The distal elephant trunk prosthesis was then used for a second stage operation that involved replacement of sections of the distal aorta. Since then, a few problems have been encountered with the standard elephant trunk procedure and this has led to a modification of the elephant trunk technique, which enables a more accurate and secure distal aortic arch anastomosis to be performed. Using the standard technique described by Borst, the surgeon has to suture in the groove between the tubular graft and the aortic wall, which can increase the risk that torsion on the suture needle will tear the aortic wall resulting in aortic rupture. Indeed, this complication has been noted in the postoperative period when performing the standard technique. Subsequently, the technique was modified with inversion of the graft in itself, placement of the graft in the descending aorta, and performance of the distal anastomosis using a technique similar to that described by Griepp. This has improved the ease of performing the procedure and the results of the technique such that a better than 90% survival rate can be expected for the first and the second stage repairs.

Anastomosis, Surgical↗

PubMed1989

Trunk asymmetry and scoliosis, Anthropometric measurements in prepuberal school children.

A total of 1060 children (515 girls, 545 boys) were examined for screening of trunk asymmetry ans scoliosis at an average age of 10.8 years. The physical examination consisted of height, sitting height, total arm length and leg length inequality determinations and moiré topography. Trunk asymmetry was measured by forward bending test and a posteroanterior standing radiograph of the spine was taken of those 188 (17.7%) children who had a trunk hump greater than or equal to 6 mm. Only 20.1% of the children were found to be exactly symmetric in the forward bending test, 47.3% had a right-sided hump and 32.6% had a left-side hump. Humps of 6 mm or more were significantly (p = 0.03) more prevalent among girls (21.7%) than boys (16.3%). Moré fringe asymmetry was provided to be common: only 9% of the material was totally symmetric, two thirds has asymmetry of less than or equal to 1 fringe, 26.6% has asymmetry greater than 1 and less than or equal or 2 and 5.4% greater than 2. The prevalence of scoliosis (trunk hump greater than or equal to 6 mm and Cobb angle less than or equal to 10 degree) was 4.1%. The majority (72.1%) of the curves were left convex.

Anthropometry↗

PubMedDate not supplied

Ultrasonographic imaging of the vagosympathetic trunk in the dog.

The purpose of this study was to evaluate the applicability of ultrasonographic imaging of the vagosympathetic trunk in the dog. Cervical ultrasound was performed in 30 healthy dogs. In all 30 dogs the vagosympathetic trunk was detected as a hypoechoic structure in the carotid sheath, adhering the dorsomedial surface of the common carotid artery. The echotexture of the nerve was heterogeneous with anechoic areas separated by hypoechoic bands. A scanner equipped with a 5 to 8 MHz linear array probe was used for imaging and measurements. The diameter of the vagosympathetic trunk ranged from 0.59 to 2.48 mm varying in correlation to the body weight. In summary, ultrasonography is a helpful noninvasive method to image and evaluate the cervical vagosympathetic trunk in the dog.

Animals↗

PubMed1987

Fast voluntary trunk flexion movements in standing: motor patterns.

The electromyographical (EMG) activity was studied during voluntary flexion movements of the trunk in erect standing man. The movements were performed at maximal velocity with successively increasing amplitude to cover the whole range of motion. The EMG activity was recorded from agonist-antagonist pairs of muscles at the ankle, knee, hip and trunk. The angular displacements at the corresponding joints were recorded using a Selspot optoelectronic system. The duration of initiating activity in prime movers (rectus abdominis and rectus femoris) as well as time to onset of activity in muscles braking the primary movement (erector spinae, gluteus maximus and hamstrings) were highly correlated with amplitude, duration, peak velocity and time to peak velocity of the movement (r = 0.59-0.91). The corresponding correlations for peak acceleration and deceleration of the movement were low (r = 0.03-0.38), indicating that acceleration and deceleration of a movement was not coded in the temporal aspects of the EMG. Onset of activity in rectus abdominis and rectus femoris as well as an early appearing burst of activity in vastus lateralis were invariant in relation to start of movement over the whole movement range. In the initial phase of a fast trunk flexion, activity in tibialis anterior appeared successively earlier with increasing movement amplitude. This resulted in a changed order of activation for the muscles from proximal to distal (rectus abdominis first) to distal to proximal (tibialis anterior first). Two different forms of associated postural adjustments are present during a fast trunk flexion, one early fast knee flexion and a later slower angle extension. Prior to knee flexion, no activity was recorded from muscles flexing at the knee implying that some other force must create a flexing torque around the knee. It is suggested that activity in rectus abdominis initiating the primary movement also initiates knee flexion through the upward pulling of pelvis. This would be possible since rectus femoris stabilizes the pelvis in relation to the leg, allowing the force in rectus abdominis to be transmitted below the hip joint and act extending around the ankle joint. However, when tibialis anterior is activated it stabilizes the shank which in turn will cause a knee flexion controlled by a lengthening contraction in vastus lateralis. During the subsequent ankle extension activity appears in lateral gastrocnemius and soleus causing the associated postural adjustment at the ankle. It can be concluded that activation of postural muscles prior to prime mover muscles is not always necessary.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed2003

Dynamics of the head-neck complex in response to the trunk horizontal vibration: modeling and identification.

Although many studies exist concerning the influence of seat vibration on the head in the seated human body, the dynamic response of the head-neck complex (HNC) to the trunk vibration has not been well investigated. Little quantitative knowledge exists about viscoelastic parameters of the neck. In this study, the dynamics of the HNC is identified when it is exposed to the trunk horizontal (fore-and-aft) vibration. The frequency response functions between the HNC angular velocity and the trunk horizontal acceleration, corresponding to four volunteers, are obtained in the frequency range of 0.5 Hz to 10 Hz. A fourth-order mathematical model, derived by considering a double-inverted-pendulum model for the HNC, is designed to simulate the dynamic response of the HNC to the trunk horizontal vibration. The frequency domain identification method is used to determine the coefficients of the mathematical model of the HNC. Good agreement has been obtained between experimental and simulation results. This indicates that the system, similar to the designed fourth-order model, has mainly two resonance frequencies. The viscoelastic parameters of the neck, including the spring and damping coefficients, are then obtained by use of the optimization method.

Acceleration↗

PubMed1988

The mechanical role of the trunk and lower extremities in a seated weight-moving task in the sagittal plane.

A two-dimensional, sagittally-symmetric biomechanical model was developed to analyze the joint moments required to stabilize the trunk in a seated, dynamic, weight-moving task. Kinematic and reaction force data were measured while subjects moved a hand-held weight (0-4 kgf) at shoulder level to and fro at 1 Hz. These data were then used for model input and validation purposes. A second, simpler model was used to simulate how joint loads varied with weight held, trunk inclination, and movement frequency. The results for this seated task demonstrate a) significant trunk, hip, knee, and ankle joint moments (37, 13, 4, 13 percent of maximum strength values, respectively) were required, b) considerable intersubject differences in mean joint moments (more than 66 percent) were found, which primarily were due to subtle differences in body segment kinematics and lower extremities use, and c) the important role of the lower extremities in stabilizing the trunk in the seated posture.

Adult↗

PubMed2005

Establishment of a protocol to test fatigue of the trunk muscles.

BACKGROUND: Muscle fatigue has high relevance in human performance yet little research has evaluated how it should be assessed. OBJECTIVE: To perform a pilot study to identify suitable methods of generating and assessing fatigue of the trunk flexor and extensor muscles. METHODS: Sixteen university rugby players (mean (SEM) age 21.9 (0.2) years) were recruited and subjected to four protocols (A, B, C, D), separated by a week to allow recovery, with peak torque being recorded during each test: A, isokinetic measurements before and after fatigue, with a 10 repetition isokinetic fatigue period; B, isokinetic measurements before and after fatigue with a 45 second isometric fatigue period; C, isometric measurements before and after fatigue with a 10 repetition isokinetic fatigue period; D, isometric measurements before and after fatigue with a 45 second isometric fatigue period. All were conducted during flexion and extension of the trunk on the Cybex Norm Isokinetic Dynamometer trunk flexion-extension unit. RESULTS: All subjects completed all four protocols. Fatigue induction appeared more effective in flexion than extension. Significant differences in mean peak torque before and after fatigue were seen in protocols A, B, and D in flexion and only in protocol D for extension. In flexion, protocol D produced the greatest fatigue, peak torque being 16.2% less after than before fatigue, suggesting greatest sensitivity. CONCLUSIONS: Protocol D, which incorporates isometric testing and fatigue protocols, appears to be able to produce fatigue most effectively, and therefore may provide the most valid assessment of fatigue in the trunk flexor and extensor muscles.

Adult↗

PubMed2006

Hearts with concordant ventriculoarterial connections but parallel arterial trunks.

OBJECTIVES: To determine the characteristic morphological features of hearts with concordant ventriculoarterial connections and parallel arterial trunks, and to provide unequivocally a method to describe their anatomy. DESIGN, METHODS AND PATIENTS: The entire cardiac database and cardiac pathological archive at the Hospital for Sick Children, Toronto, Ontario, Canada, was interrogated to identify all patients with concordant ventriculoarterial connections and parallel arterial trunks. The clinical records, autopsy reports and actual cardiac specimens of those who underwent autopsy, were reviewed. RESULTS: 8 cases meeting our criteria were identified. The infundibular anatomy was variable, including four hearts with bilateral infundibulums, three with subpulmonary infundibulums and one with bilaterally absent infundibulums. Considerable variability was also found in the type of atrial arrangement, along with the morphology of the atrioventricular junctions. The most common findings were the usual atrial arrangement (n = 5), left juxtaposition of the right atrial appendages (n = 3), an atrial septal defect (n = 6), univentricular atrioventricular connection (n = 5), ventricular septal defect (n = 8) and pulmonary obstruction (n = 4). In addition, five specimens had either a single coronary artery or two coronary arteries arising from the anticipated right coronary aortic sinus. CONCLUSIONS: Concordant ventriculoarterial connections with parallel arterial trunks can be found in a variety of segmental combinations. An accurate diagnosis of these rare hearts can be achieved by detailed analysis of not only the ventriculoarterial connections but also the infundibular anatomy and the spatial relationship of the arterial trunks. Particular attention to the coronary arteries is warranted.

Aorta↗

PubMed1976

Longitudinal extension of the pulmonary trunk during breathing in young rabbits: a possible factor in elastin fragmentation.

Corrosion casts of the pulmonary trunk and major branches of the pulmonary arteries of 39 rabbits were made from a silicone polymer. In half of the rabbits the casts were made with the lungs expanded and half with the lungs collapsed. The length of various segments of the casts were measured from magnified photographs. It was found that in rabbits less than 23 days old the pulmonary trunk is significantly longer when the lungs are expanded than when they are collapsed. This suggests that a repeated longitudinal extension of the vessel occurs during breathing. This effect disappears after 30 days of age, possibly because of elastin fragmentation. Between the ages of 23 and 30 days the growth in length and diameter of the pulmonary trunk undergoes a rapid acceleration. This may also be the result of elastin fragmentation. Whereas it may be that repeated longitudinal stress in the pulmonary trunk during breathing causes elastin in its media to fragment, one cannot exclude the possibility that other factors such as growth are responsible.

Aging↗

PubMed2003

Spatial distribution and morphological characteristics of the trunk lateral line neuromasts of the sea bass (Dicentrarchus labrax, L.; Teleostei, Serranidae).

The morphology and spatial distribution of the different types of neuromasts encountered on the trunk lateral line of the sea bass (Dicentrarchus labrax) were examined using scanning electron microscopy. The sea bass trunk lateral line exhibits a complete straight pattern. In their basic features, the two types of neuromasts present, canal and superficial, resemble what has been described in other fishes. They are similar in their general cellular organization but differ in sizes, and shapes, as well as in the densities and lengths of their hair bundles. However, the sea bass trunk lateral line distinguishes itself in several ways. For instance, the pores of the canal segments are partially obstructed due to the overlap of scales throughout the trunk. Moreover, based on the density and length of the hair bundles, two distinct areas, central and peripheral, could be distinguished within the maculae of canal neuromasts. Their cupulae are also peculiar as they possess two wing-like extensions and that their central core appears to be organized in layers instead of columns. In addition, the superficial neuromasts, up to 6 per scale, are either round or elliptical and seem to be distributed serendipitously. Finally, within the maculae of both types of neuromasts, a significant number of hair bundles do not follow the two-directional polarity pattern usually described. Although some hypotheses are proposed, the influence of these characteristics in terms of signal encoding and fish behavior is yet to be understood.

Animals↗

PubMed1976

Anatomical study of the cervical sympathetic trunk and ganglia in the albino rat (Mus norvegicus albinus).

Nine adult albino rats of both sexes were studied. 16 sympathetic trunks and ganglia were dissected in detail in eight rats. The right and left superior cervical ganglion and the sympathetic trunk below the ganglion were removed from an additional rat. The cell bodies of these ganglia and the axons of the trunks were counted with the aid of light and electron microscopy. Considering the number and location of ganglia and patterns of branching, the rat's cervical sympathetic nervous system compares closely with man's. There appears to be a relationship between body size and myelination of preganglionic neurons in the cervical sympathetic trunks, with smaller animals having the least number of myelinated fibers.

Animals↗

PubMed1981

Early development of postganglionic sympathetic trunk neurons in the chick embryo.

The main object of this investigation was to determine at which embryonic age the axonal endings of the first outgrowing sympathetic trunk neurons reach the shank musculature of the chick embryo. Horseradish peroxidase was injected in the shank musculature at different embryonic ages. Labelling of the sympathetic trunk perikarya was considered as evidence for the presence of sympathetic axonal endings in the injected area of the shank musculature. The earliest labellings were found at 8 days of incubation in the sympathetic ganglia attributed to the ischiadic plexus. The comparison of the subsequent developmental stages of sympathetic trunk neurons with the developmental stages of motoneurons, primary spinal sensory neurons and postganglionic ciliary neurons showed that the sympathetic trunk neurons are the last to establish contacts with their targets in the periphery.

Animals↗

PubMed1998

Sox4-deficiency syndrome in mice is an animal model for common trunk.

Embryonic mice lacking functional Sox4 transcription factor die from cardiac failure at embryonic day (ED) 14. Heart morphogenesis in these embryos was analyzed in hematoxylin-azophlochsin or immunohistochemically stained, 3-dimensionally reconstructed serial sections between ED12 and ED14. Although Sox4 is expressed in the endocardially derived tissue of both the outflow tract and atrioventricular canal, Sox4-deficient hearts only suffer from defective transformation of the endocardial ridges into semilunar valves and from lack of fusion of these ridges, usually resulting in common trunk, although the least affected hearts should be classified as having a large infundibular septal defect. The more serious cases are, in addition, characterized by an abnormal number and position of the semilunar valve-leaflet anlagen, a configuration of the ridges typical for transposition of the great arteries (with linear rather than spiral course of both ridges and posterior position of the pulmonary trunk at the level of the valve), and variable size of the aorta relative to the pulmonary trunk. The coronary arteries always originated from the aorta, irrespective of its position relative to the pulmonary trunk. The restriction of the malformations to the arterial pole implies that the interaction between the endocardially derived tissue of the outflow tract and the neural crest-derived myofibroblasts determines proper development of the arterial pole.

Actins↗

PubMedDate not supplied

Orientation of stapedial nerve fibers in the facial nerve trunk.

By staining with toluidine blue and vital staining with methylene blue, the topographical orientation of the stapedial nerve fibers in the facial nerve trunk was visualized in adult guinea pigs. The stapedial nerve with its perineural sheath emerges from the facial nerve trunk in the posteromedial aspect of the upper part of the vertical portion. Toward the horizontal portion, the stapedial nerve fibers gradually ramify, lose their investments, and intermingle with other nerve fibers inside the facial nerve trunk. In the labyrinthine portion, the stapedial nerve fibers are distributed diffusely near the surface along the posterior, medial, and anterior margins of the facial nerve trunk. These findings lead to the conclusion that the stapedial nerve fibers of guinea pigs do not form a single funiculus throughout the intratemporal course of the facial nerve.

Animals↗