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At least 523 records · Page 29Linked to original sources
PubMed2001

Propofol action in both spinal cord and brain blunts electroencephalographic responses to noxious stimulation in goats.

STUDY OBJECTIVES: Anesthetics, including propofol, depress the electroencephalogram (EEG) and neuronal activity in the midbrain reticular formation (MRF). Because propofol has anesthetic effects in the spinal cord, we hypothesized that it would indirectly depress EEG and MRF neuronal responses to noxious stimulation in part by a spinal cord action. DESIGN: Six goats were anesthetized with isoflurane and the jugular veins and carotid arteries were isolated to permit cranial bypass and differential propofol delivery. A noxious mechanical stimulus was applied to the distal forelimb while recording bifrontal EEG and MRF single-unit activities. Propofol was separately administered to the cranial (0.08 +/- 0.06 mg/kg) and torso circulations (4 mg/kg) and the noxious stimulus applied at 1,5, 10, and 15 min after each injection. SETTING: N/A. PATIENTS OR PARTICIPANTS: N/A. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Noxious stimulation decreased total power (TP) from 96 +/- 33, microV2/Hz to 38 +/- 20microV2/Hz, (mean +/- SD) and increased spectral edge frequency (SEF) from 10 +/- 3 Hz to 19 +/- 5 Hz (p<0.01). Propofol administered to the torso prevented stimulus-evoked changes in TP (121+/- 80 microV2/Hz, 121 +/- 74 microV2/Hz, 114 +/- 74 microV2/Hz at 1,5, and 10 min respectively, p<0.01 compared to control evoked response) and SEF (11 +/- 6Hz, 9 +/- 2Hz, 10 +/- 6Hz, and 12 +/- 5Hz at 1, 5, 10 and 15 min, respectively, p<0.001 compared to control evoked response). Propofol administered to the cranial circulation significantly blunted the EEG and MRF response, while torso-administered propofol had slight effects on MRF responses. CONCLUSIONS: Propofol blunted the EEG response to noxious stimulation in part via a subcortical action.

Analgesics↗
PubMed2000

Isoflurane action in the spinal cord blunts electroencephalographic and thalamic-reticular formation responses to noxious stimulation in goats.

BACKGROUND: Isoflurane depresses the electroencephalographic (EEG) activity and exerts part of its anesthetic effect in the spinal cord. The authors hypothesized that isoflurane would indirectly depress the EEG and subcortical response to noxious stimulation in part by a spinal cord action. METHODS: Depth electrodes were inserted into the midbrain reticular formation (MRF) and thalamus of six of seven isoflurane-anesthetized goats, and needle-electrodes were placed into the skull periosteum. In five of seven goats, an MRF microelectrode recorded single-unit activity. The jugular veins and carotid arteries were isolated to permit cranial bypass and differential isoflurane delivery. A noxious mechanical stimulus (1 min) was applied to a forelimb dewclaw at each of two cranial-torso isoflurane combinations: 1.1+/-0.3%-1.2+/-0.3% and 1.1+/-0.3-0.3+/-0.1% (mean +/- SD). RESULTS: When cranial-torso isoflurane was 1.1-1.2%, the noxious stimulus did not alter the EEG. When torso isoflurane was decreased to 0.3%, the noxious stimulus activated the MRF, thalamic, and bifrontal-hemispheric regions (decreased high-amplitude, low-frequency power). For all channels combined, total (-33+/-15%), delta(-51+/-22%), theta (-33+/-19%), and alpha (-26+/-16%) power decreased after the noxious stimulus (P<0.05); beta power was unchanged. The MRF unit responses to the noxious stimulus were significantly higher when the spinal cord isoflurane concentration was 0.3% (1,286+/-1,317 impulses/min) as compared with 1.2% (489+/-437 impulses/min, P<0.05). CONCLUSIONS: Isoflurane blunted the EEG and MRF-thalamic response to noxious stimulation in part via an action in the spinal cord.

Anesthetics, Inhalation↗
PubMed2000

A preliminary report on the effect of measured strength training in adolescent idiopathic scoliosis.

The authors studied 12 adolescent patients with scoliosis (10 girls and 2 boys) who were 11 to 16 years old and had curvatures ranging from 20 degrees to 60 degrees. Seven were right thoracic curves and five were thoracolumbar with double curves. When tested on the MedX Torso Rotation Machine, both sides were unequal in their torso rotation strength all patients. Myoelectric activity was asymmetric in both sides and in abdominal and paraspinal muscles of all patients. These asymmetries were corrected completely with torso rotation, which was associated with significant strength gains. Strength gains ranged from 12% to 40%. A 16-year-old girl with a 60 degree lumbar curve progressed and had surgery. None of the remaining patients progressed, and 4 of the 12 had decreases in their curvatures from 20 degrees to 28 degrees. None of the patients used braces during this study.

Adolescent↗
PubMed1997

The biomechanics of cervical spine injury and implications for injury prevention.

Most catastrophic cervical spinal injuries occur as a result of head impacts in which the head stops and the neck is forced to stop the moving torso. In these situations the neck is sufficiently fragile that injuries have been reported at velocities as low as 3.1 m/s with only a fraction of the mass of the torso loading the cervical spine. Cervical spinal injury occurs in less than 20 ms following head impact, explaining the absence of a relationship between clinically reported head motions and the cervical spinal injury mechanism. In contrast, the forces acting on the spine at the time of injury are able to explain the injury mechanism and form a rational basis for classification of vertebral fractures and dislocations. Fortunately, most head impacts do not result in cervical spine injuries. Analysis of the biomechanical and clinical literature shows that the flexibility of the cervical spine frequently allows the head and neck to flex or extend out of the path of the torso and escape injury. Accordingly, constraints which restrict the motion of the neck can increase the risk for cervical spine injury. These observations serve as a foundation on which injury prevention strategies, including coaching, helmets, and padding, may be evaluated.

Athletic Injuries↗
PubMed1997

Stabilizing properties of the halo apparatus.

STUDY DESIGN: A cadaveric cervical spine specimen fixed between a fiberglass torso and a plastic skull was used as a model to determine the effect of halo structural parameters on motion at a lesion simulated at C5-C6. In a second part, nine commercially available halo devices were compared. OBJECTIVES: To define the contributions of the various components of the halo apparatus to reducing motion in an injured cervical spine and to compare the stability offered by a sample of commercially available halo devices. Controversy exists concerning the ability of the halo apparatus to stabilize the injured cervical spine. SUMMARY OF BACKGROUND DATA: The halo apparatus has been shown to be the most effective nonsurgical method for stabilizing the fractured spine. Nonetheless, several clinical studies have demonstrated that unacceptably large motions can occur at the injured spinal segment stabilized with a halo apparatus. METHODS: Each cadaveric cervical spine was mounted onto a fiberglass torso and a rigid plastic skull was attached to the base of the occiput. A posterior ligamentous lesion was created between C5 and C6. The halo ring was fitted to the skull and a vest to the torso. Loads were applied to the skull in flexion, extension, and lateral bending, and relative angulation between C5 and C6 was measured with electroinclinometers. In the first part, the effect of parameters such as vest tightness, vest-thorax friction, vest deformation, and connecting bar rigidity on spinal angulation were measured using one vest. In the second part, the stability offered by each of nine commercially available halo devices was compared. RESULTS: Increasing chest strap tightness and decreasing vest deformation reduced angulation at the spinal lesion. Once connecting bar joints were tightened to 25% of their recommended torque, increased tightening or adding additional bars had no effect on rigidity. Although specific vests permitted significantly greater motion in specific directions, no vest allowed greater angulation consistently in all loading planes. CONCLUSIONS: Increasing vest tightness, decreasing the deformability of the vest, and ensuring a good fit can reduce motion in the fractured spine. Most commercially available halo vests provide similar mechanical stability to the injured cervical spine.

Biomechanical Phenomena↗
PubMed1999

Congenital scoliosis with posterior spinal arthrodesis T2-L3 at age 3 years with 41-year follow-up. A case report.

STUDY DESIGN: A case report. OBJECTIVES: To document the long-term effects of early fusion for progressive congenital scoliosis. SUMMARY OF BACKGROUND DATA: There is concern about fusion at an early age causing torso shortening and possible crankshaft phenomenon. METHODS: A review of medical and radiologic records. RESULTS: A 3-year old girl with progressive congenital scoliosis had posterior spinal arthrodesis in 1955. A pseudarthrosis was repaired at age 4, and at age 8 she had an osteotomy of the fusion mass because of bending of the fusion mass. In a follow-up 41 years after fusion, she has no back pain and no history of pulmonary problems. Despite the long fusion at a young age, her torso-to-leg ratio was remarkably good. The thoracic lordosis had improved to a normal thoracic kyphosis. CONCLUSION: Early arthrodesis was life saving and caused no long-term problems. Because significant spinal growth has occurred by age 3, no adverse effects on torso-leg ratio with an early long arthrodesis, and in addition the crankshaft phenomenon is rare in congenital scoliosis.

Child, Preschool↗
PubMed2004

Suffocation in motor vehicle crashes.

Because death from suffocation in traffic fatalities has not been well described, we delineated the clinical, circumstantial, and autopsy findings associated with suffocation in a series of motor vehicle crashes. Medical examiner case files from a 5-year period were reviewed. Scene investigation, autopsy, toxicology, and first-responder reports were examined. Crash descriptions were reviewed, including vehicle type, mechanism of crash, response time, restraint use, occupant ejection, and victim position in cabins of vehicles. Mechanisms of suffocation, including torso compression, inversion, neck flexion, facial occlusion, and blood aspiration, were determined for each case. The files were searched for factors relevant to the diagnosis of suffocation, namely, cerebral concussion, alcohol intoxication, obesity, petechiae, lung weights as a proxy for livor, natural disease, and impact wounds. Twenty-nine traffic fatality cases were identified in which suffocation caused death. In 26, suffocation mechanisms were solely responsible for death. In 3, death was caused by suffocation in combination with other mechanisms. Twenty-five subjects were occupants of vehicles with cabins and 4 were motorcycle riders. The most common mechanism of suffocation was torso compression. Most subjects had either multiple mechanisms of suffocation or a single mechanism acting in concert with concussion or alcohol intoxication. Concussion and intoxication were common, with one or both present in 20 subjects, including all of those with blood aspiration. Petechiae were frequent but were found consistently only among those with inversion. Cutaneous chest petechiae were associated with inversion and torso compression. Lung weights were highest among those with blood aspiration and lowest among those with inversion. Body mass index was highest among those with inversion, suggesting that obesity could be a risk factor for this mechanism.

Accidents, Traffic↗
PubMed2004

Single-staged total body lift after massive weight loss.

This is a retrospective clinical report of a single-staged total body lift in 8 massive weight loss patients. While the combination of circumferential abdominoplasty, a modified lower body lift, and medial thighplasty adequately treats the lower torso and thighs, the residual skin laxity in the upper torso and breasts leaves an incomplete result. Hence, a 2-stage total body lift was designed. The second stage, called the upper body lift, removes epigastric and midback rolls of skin, adjusts the inframammary fold, and reshapes the breast or corrects gynecomastia, leaving behind a near circumferential transverse scar partially hidden by the breasts. In selected patients, a complete torso correction, the total body lift, was done in a single stage. Four to 31 months later, 7 of the 8 patients were satisfied. One male with ultrasonic-assisted lipoplasty and a lateral skin excision found the chest skin too loose. Blood transfusions ranged from none to 4 units. The operations range from 7 to 12 hours of general anesthesia. Hospital stays were from 3 to 4 days. The complications included 3 resolved seromas, 2 minor wound infections due to fat and skin necrosis, and 1 minor skin dehiscence. One patient was readmitted to the hospital due to hypoalbuminemia and generalized edema. Scar revisions and liposuction are scheduled for 2 patients. Single stage total body lift is effective and safe in selected patients after massive weight loss when performed by a plastic surgeon and team experienced in body contouring surgery.

Adult↗
PubMed2003

Efficacy of hypertonic saline dextran fluid resuscitation for patients with hypotension from penetrating trauma.

BACKGROUND: The purpose of this study was to assess whether the administration of hypertonic saline dextran (HSD) was detrimental when administered to patients who were hypotensive because of penetrating injuries to the torso. The administration of HSD causes an immediate and sustained increase in blood pressure that could contribute to an increase in bleeding in the presence of uncontrolled hemorrhage. We prospectively designed a series of questions to be addressed by a meta-analysis of individual patient data using a computerized data file and case report forms from a multicenter study of HSD. METHODS: The investigators were "blind" as to the treatment the patient received. Patients (n = 230) with penetrating injuries to the torso were studied as to survival until discharge. The patients were administered 250 mL of HSD or normal saline (standard of care [SOC]) as the initial fluid therapy. RESULTS: Of the 120 patients treated with HSD, 82.5% survived compared with 75.5% for 110 SOC patients (p = 0.19). Sixty-eight percent (n = 157) of these patients required surgery. HSD treatment (n = 84) in this population improved survival, 84.5% compared with 67.1% with SOC (n = 73) (p = 0.01). HSD resulted in an increase in blood pressure and a reduction in hematocrit, with no differences noted in fluid requirements or indices of clotting. CONCLUSION: For patients with penetrating injuries to the torso that result in hypotension, initial fluid resuscitation with HSD is beneficial in improving survival, especially if surgery is subsequently required.

Adult↗
PubMed1989

Ocular vergence under natural conditions. I. Continuous changes of target distance along the median plane.

Horizontal binocular eye movements of four subjects were recorded with the scleral sensor coil--revolving magnetic field technique while they fixated a natural target, whose distance was varied in a normally illuminated room. The distance of the target relative to the head of the subject was changed in three ways: (a) the target was moved manually by the experimenter; (b) the target was moved manually by the subject; (c) the target remained stationary while the subject moved his upper torso towards and away from the target. The rate of change of target distance was varied systematically in four levels, ranging from 'slow' to 'very fast', corresponding to changes in target vergence from about 10 degrees s-1 to about 100 degrees s-1. The dynamics of ocular vergence with regard to delay and speed were, under all three conditions, considerably better than could be expected from the literature on ocular vergence induced by disparity and/or blur. When 'very fast' changes in the distance of the target were made, subjects achieved maximum vergence speeds of up to about 100 degrees s-1. Delays of these fast vergence responses were generally smaller than 125 ms. Negative delays, i.e. ocular vergence leading the change in target distance, were observed. The eyes led the target (i.e. predicted target motion) by about 90 ms on average, when the subject used his hand to move the target. Vergence tracking was almost perfect when changes in distance were produced by moving the upper torso. In this condition, the eye led the target by about 5 ms. In the 'slow' and 'medium' conditions (stimulus speeds about 10-40 degrees s-1) tracking was accurate to within 1-2 degrees, irrespective of the way in which the target was moved. In the 'fast' and 'very fast' conditions (stimulus speeds about 40-100 degrees s-1), the accuracy of vergence tracking was better for self-induced than for experimenter-induced target displacements, and accuracy was best during voluntary movements of the upper torso. In the last case, ocular vergence speed was within about 10% of the rate of change of the vergence angle formed by the eyes and the stationary target. The dynamics of convergent and divergent vergence responses varied considerably. These variations were idiosyncratic. They were consistent within, but not between, subjects. Ocular vergence associated with attempted fixation of an imagined target, changing distance in darkness, could only be made by two of the four subjects.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed2002

Human female attractiveness: waveform analysis of body shape.

Two putative cues to female physical attractiveness are body mass index (BMI) and shape (particularly the waist-hip ratio or WHR). To determine the relative importance of these cues we asked 23 male and 23 female undergraduates to rate a set of 60 pictures of real women's bodies in front-view for attractiveness. In our set of images, the relative ranges of BMI and WHR favoured WHR. We based these ranges on a sample of 457 women. We did not limit the WHR range, although we kept the BMI range to 0.5 s.d. either side of the sample means. As a result, WHR averaged 1.65 s.d. either side of its sample mean. However, even with these advantages, WHR was less important than BMI as a predictor of attractiveness ratings for bodies. BMI is far more strongly correlated with ratings of attractiveness than WHR (BMI approximately 0.5, WHR approximately 0.2). To further explore the relative importance of BMI and WHR, we deliberately chose a subset of these images that demonstrated an inverse correlation of BMI and WHR (i.e. a group in which as images get heavier they also become more curvaceous). If WHR is the most important determinant of attractiveness, then the more curvaceous (but higher BMI) images should be judged most attractive. However, if BMI is a better predictor, then the opposite should be true. We found that the more curvaceous (but higher BMI) images were judged least attractive, thereby inverting the expected rating pattern. This strongly suggests that viewers' judgements were influenced more by BMI than WHR. Finally, it is possible that body shape is an important cue to attractiveness, but that simple ratios (such as WHR) are not adequately capturing it. Therefore, we treated the outline of the torso as a waveform and carried out a set of waveform analyses on it to allow us to quantify body shape and correlate it with attractiveness. The waveform analyses address the complexity of the whole torso shape, and reveal innate properties of the torso shape and not shape elements based on prior decisions about arbitrary physical features. Our analyses decompose the waveform into objective quantified elements whose importance in predicting attractiveness can then be tested. All of the components that were good descriptors of body shape were weakly correlated with attractiveness. Our results suggest that BMI is a stronger predictor of attractiveness than WHR.

Adult↗
PubMed1994

Forward and inverse problems of electrocardiography: modeling and recovery of epicardial potentials in humans.

To assess the accuracy of solutions to the inverse problem of electrocardiography in man, epicardial potentials computed from thoracic potential distributions were compared to potentials measured directly over the surface of the heart during arrhythmia surgery. Three-dimensional finite element models of the thorax with different mesh resolutions and conductivity inhomogeneities were constructed from serial computerized tomography scans of a patient. These torso models were used to compute transfer matrices relating the epicardial potentials to the thoracic potentials. Potential distributions over the torso and the ventricles were measured with 63 leads in the same patient whose anatomical data was used to construct the torso models. To solve the inverse problem, different methods based on Tykhonov regularization or regularization- truncation were applied. The recovered epicardial potential distributions closely resembled the epicardial potential distributions measured early during ventricular preexcitation, but not the more complex distributions measured later during the QRS complex. Several problems encountered as the validation process is applied in man are also discussed.

Electrocardiography↗
PubMed1997

Regional regularization of the electrocardiographic inverse problem: a model study using spherical geometry.

This study examines the use of a new regularization scheme, called regional regularization, for solving the electrocardiographic inverse problem. Previous work has shown that different time frames in the cardiac cycle require varying degrees of regularization. This reflects differences in potential magnitudes, gradients, signal-to-noise ratio (SNR), and locations of electrical activity. One might expect, therefore, that a single regularization parameter and a uniform level of regularization may also be insufficient for a single potential map of a single time frame because in one map there are regions of high and low potentials and potential gradients. Regional regularization is a class of methods that subdivides a given potential map into functional "regions" based on the spatial characteristics of the potential ("spatial frequencies"). These individual regions are regularized separately and recombined into a complete map. This paper examines the hypothesis that such regionally regularized maps are more accurate than if all regions were taken together and solved with an averaged level of regularization. In a homogeneous concentric spheres model, Legendre polynomials are used to decompose a torso potential map into a set of submaps, each with a different degree of spatial variation. The original torso map is contaminated with data noise, or geometrical error or both, and regional regularization improves the epicardial potential reconstruction by up to 25% [relative error (RE)]. Regional regularization also improves the reconstructed location of peaks. A practical goal is to extend the application of this method to the realistic torso geometry, but because Legendre decomposition is limited to geometries with spherical symmetry, other methods of map decomposition must be found. Singular value decomposition (SVD) is used to decompose the maps into component parts. Its individual submaps also have different levels of spatial variation; moreover, it is generalizable to any vector, does not require spherical symmetry, and is extremely efficient numerically. Using SVD decomposition for regional regularization, significant improvement was achieved in the map quality in the presence of data noise.

Artifacts↗
PubMed1999

Is accurate recording of the ECG surface Laplacian feasible?

Experimental and model studies were performed to measure the electrocardiographic surface Laplacian using a rectangular finite difference approximation. The experimental approach used ten normal subjects with two sites on the torso. Electrode spacing was 2 cm. The surface Laplacian is theoretically independent of rotation of the electrode array. The data showed considerable variation with rotation. Model studies employed a realistic 23-dipole source. A spherical volume conductor showed invariance with rotation, as anticipated theoretically. A realistic torso, however, showed variation with rotation, although not as severe as that measured. A separate experimental study considered the signal-to-noise ratio (SNR) for the surface Laplacian. The average SNR was 3.3 and 2.5 at the two sites. These results raise serious questions about the practical ability to measure the surface Laplacian on the torso.

Adult↗
PubMed1987

Cooling different body surfaces during upper and lower body exercise.

The effect of varying the body surface area being cooled by a liquid microclimate system was evaluated during exercise heat-stress conditions. Six male subjects performed a total of six exercise (O2 uptake = 1.2 l/min) tests in a hot environment (ambient temperature = 38 degrees C, relative humidity = 30%) while dressed in clothing having low moisture permeability and high insulation. Each subject completed two upper body exercise (U; arm crank) tests: 1) with only the torso surface (T) cooled; and 2) with the surfaces of both the torso and upper arms (TA) cooled [coolant temperature at the inlet (Ti) was 20 degrees C for all upper body tests]. Each subject also completed four lower body exercise (L; walking) tests: 1) with only the T cooled (Ti = 20 degrees C); 2) with only the T cooled (Ti = 26 degrees C); 3) with torso, upper arm, and thigh surface (TAT) cooled (Ti = 20 degrees C); and 4) with TAT cooled (Ti = 26 degrees C). During U exercise, TA cooling had no effects compared with cooling only T. During L exercise, sweat rates, heart rates, and rectal temperature (Tre) changes were less with TAT cooling compared with cooling only the T. Altering Ti had no effect on Tre changes, but higher heart rates were observed with 26 than with 20 degrees C. These data indicate that cooling arms during upper body exercise provides no thermoregulatory advantage, although cooling the thigh surfaces during lower body exercise does provide an advantage.

Adult↗
PubMed2006

A control system for a flexible spine belly-dancing humanoid.

Recently, there has been a lot of interest in building anthropomorphic robots. Research on humanoid robotics has focused on the control of manipulators and walking machines. The contributions of the torso towards ordinary movements (such as walking, dancing, attracting mates, and maintaining balance) have been neglected by almost all humanoid robotic researchers. We believe that the next generation of humanoid robots will incorporate a flexible spine in the torso. To meet the challenge of controlling this kind of high-degree-of-freedom robot, a new control architecture is necessary. Inspired by the rhythmic movements commonly exhibited in lamprey locomotion as well as belly dancing, we designed a controller for a simulated belly-dancing robot using the lamprey central pattern generator. Experimental results show that the proposed lamprey central pattern generator module could potentially generate plausible output patterns, which could be used for all the possible spine motions with minimized control parameters. For instance, in the case of planar spine motions, only three input parameters are required. Using our controller, the simulated robot is able to perform complex torso movements commonly seen in belly dancing as well. Our work suggests that the proposed controller can potentially be a suitable controller for a high-degree-of-freedom, flexible spine humanoid robot. Furthermore, it allows us to gain a better understanding of belly dancing by synthesis.

Animals↗
PubMed1995

A simulation study on magnetic source imaging with a realistic model of the entire human heart.

A computer model study on magnetic source imaging from magnetocardiographic data is presented using a cellular automaton model of the entire human heart in the so-called forward problem. A homogeneous boundary element (BE) torso is built up from real magnetic resonance imaging (MRI) cross-sections. The heart model, which has a realistic anatomical shape, is positioned inside the BE torso. In the forward problem the spread of excitation is simulated by applying a modified Huygen's propagation principle. The magnetocardiogram (MCG) and electrocardiogram (ECG) can then be computed following the bidomain theory. From the simulated MCG data, pseudo primary current dipole (PPCD) estimation within the electrically active tissue is performed. The reconstruction space is defined as a surface in the middle of the atrial and ventricular myocardium and septum. The observation space consists of two mutually perpendicular planes closely above the torso surface on the frontal and the left lateral side, respectively. An iterative minimum-norm approach is applied in order to reconstruct PPCD distributions. The errors in PPCD estimation arising from noisy data and regularization algorithms are investigated in more detail.

Computer Simulation↗
PubMed1998

Trunk muscle use during pulling tasks: effects of a lifting belt and footing conditions.

Pulling tasks require the torso to act as a rigid link in order to facilitate the force transmission between the ground and the hands. In this study, we tested the hypothesis that a lifting belt increases the rigidity of the torso, thereby increasing pulling strength or reducing trunk muscle forces, or both, as pulling tasks are performed. Twelve volunteers performed maximal and submaximal isometric pulling exertions; the latter were performed on nonslippery and slippery surfaces. Electromyographic data from 8 trunk muscles, trunk kinematic data, and ground reaction forces were sampled during each exertion. Results indicated that the lifting belt had no effect during maximal exertions on the maximal pull forces generated or the muscle recruitment levels, irrespective of the pulling posture. The lifting belt did not affect the EMG data obtained during the submaximal (40% of maximum) exertions, even when participants pulled on a slippery surface. However, the slippery surface increased the coactivation within the trunk musculature, perhaps stiffening the torso in the event of a slip. The absence of a statistical interaction effect between the lifting belt and the footing condition (slipperiness) indicates that the belt did not alter the coactivation pattern and hence was not relied upon by the participants as a protective mechanism. The data presented here will assist those who must make decisions regarding lifting-belt use and those who train individuals in manual materials handling techniques.

Adult↗