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PubMed1999

Laparoscopic splenectomy using a wall-lifting procedure.

A laparoscopic splenectomy using a hanger wall-lifting procedure is herein described. The patient is placed in the right lateral position. The left lower chest and left abdominal wall are then lifted by three wires in two directions, left laterally and vertical to the abdominal wall. The view of the operative field thus obtained is excellent. The lifting wires and bars do not hinder the movement of the forceps, since the angles of the instruments to approach the spleen are different from those of the wires. A laparoscopic splenectomy using this wall-lifting procedure avoids the usual complications associated with pneumoperitoneum while still being technically comparable to a procedure with pneumoperitoneum.

Humans↗
PubMed2005

Measuring photosynthetic parameters at a distance: laser induced fluorescence transient (LIFT) method for remote measurements of photosynthesis in terrestrial vegetation.

We have developed a laser induced fluorescence transient (LIFT) technique and instrumentation to remotely measure photosynthetic properties in terrestrial vegetation at a distance of up to 50 m. The LIFT method uses a 665 nm laser to project a collimated, 100 mm diameter excitation beam onto leaves of the targeted plant. Fluorescence emission at 690 nm is collected by a 250 mm reflective telescope and processed in real time to calculate the efficiency of photosynthetic light utilization, quantum efficiency of PS II, and the kinetics of photosynthetic electron transport. Operating with peak excitation power of 125 W m-2, and duty cycle of 10-50%, the instrument conforms to laser safety regulations. The LIFT instrument is controlled via an Internet connection, allowing it to operate from remote locations or platforms. Here we describe the theoretical basis of the LIFT methodology, and demonstrate its applications in remote measurements of photosynthetic properties in the canopy of cottonwood and oak trees, and in the rosette of Arabidopsis mutants.

Fluorescence↗
PubMed1971

Back muscle strength, lifting, and stooped working postures.

When lifting loads and working in a forward stooped position, the muscles of the back rather than the ligaments and bony structures of the spine should overcome the gravitational forces. Formulae, based on measurements of back muscle strength, for prediction of maximal loads to be lifted, and for the ability to sustain work in a stooped position, have been worked out and tested in practical situations. From tests with 50 male and female subjects the simplest prediction formulae for maximum loads were: max. load = 1.10 x isometric back muscle strength for men; and max. load = 0.95 x isometric back muscle strength - 8 kg for women. Some standard values for maximum lifts and permissible single and repeated lifts have been calculated for men and women separately and are given in Table 1. From tests with 65 rehabilitees it was found that the maximum isometric strength of the back muscles measured at shoulder height should exceed 2/3 of the body weight, if fatigue and/or pain in the back muscles is to be avoided during work in a standing stooped position.

Journal Article↗
PubMed1990

The relationship between isometric strength of Cantonese males and the US NIOSH guide for manual lifting.

A laboratory study was undertaken to assess the relationship between the maximal voluntary isometric strength (MVIS) of a group of Hong Kong Cantonese males and recommended limiting values for lifting proposed in the Work Practices Guide for Manual Lifting (NIOSH, 1981). Forty-one male subjects were required to apply a 'free-style' vertical 'lift' force to a horizontal bar located 150 mm from the ground. Forces were applied with the horizontal location of the midpoint of the ankles at 200, 400, 600 and 800 mm from the bar. The results were compared with the Maximal Permissible Limit (MPL) and the Action Limit (AL) values proposed in the NIOSH guide. The results showed that the mean MVIS of the Hong Kong subjects lay between the MPL and AL when the load was 200 mm and 400 mm from the ankles, but was significantly below the AL at 600 mm. At 800 mm more than half of the subjects were unable to apply any measurable positive vertical force. The compressive force at the L5/S1 disc of four subjects was estimated using a static biomechanical model. The relationship between the disc pressure and the force exerted was largely in accordance with NIOSH guide values. The results are discussed in terms of differences in subject population and lifting technique. Comments on the applicability of the NIOSH standards internationally, are also presented.

Journal Article↗
PubMed1993

Psychophysical modelling of lifting capacity of Chinese males using strength variables.

This study used the psychophysical approach to determine the maximum acceptable weight of lift (MAWL) for 12 young Chinese male subjects, and used strength variables as predictors to develop prediction models. Each subject performed 12 different lifting tasks involving three lifting heights and four lifting frequencies. The results showed that both the dynamic and static models developed in this study could predict the MAWL with a reasonable degree of accuracy. However, a comparison of the models revealed that the use of the dynamic model resulted in less PRESS (PRediction Error Sum of Squares) statistics and higher [Formula: see text] values than the static model. Isoinertial 1.83 m maximum strength (T1) and the isoinertial elbow-height strength, tested on an incremental weightlifting machine, were found to be the best screening test. This was different from a previous study that recommended T1 as the most promising single screening test for Occidentals.

Journal Article↗
PubMed1996

Gender differences in performance of a selection test using the incremental lifting machine.

The purpose of the study was twofold: (1) to examine any gender differences in the performance of a pre-employment selection test using the incremental lifting machine (ILM); and (2) to formulate recommendations regarding analyses of selection fairness in studies of pre-employment screening tests and devices. Data were collected in a series of studies designed to permit analyses of: (1) dynamic measures derived for a 1.8 m maximum ILM strength test; (2) relationships between ILM test scores and performance of a maximal box-lifting task using three different protocols; (3) the impact of anthropom trie measures on performance of both test and task; (4) prediction of actual task performance; and (5) accuracy of the ILM screening test for three different cut-off standards. Results revealed that females differed significantly from males in their performance of a 1.8 m maximum ILM strength test in terms of timing, displacement, velocity, acceleration, force and power. Maximum ILM scores attained by females were poorly correlated with maximum box-lifting scores, but they were significantly related to body weight. Also, regression analyses based on ILM scores and associated dynamic parameters accounted for twice as much variance in box-lifting scores for males than for females. Furthermore, the use of cut-off standards of 22.7 kg and 27.3 kg produced a percentage of false negative results for females (12% and 32% respectively), but not for males. Also, for the cut-off level of 27.3 kg, female selection rates were only 56% of the selection rates for males. Issues for future investigation are recommended.

Journal Article↗
PubMed1987

The relationship between trunk muscle electromyography and lifting moments in the sagittal and frontal planes.

In this study, we explore the relationship between moments in the frontal and sagittal planes, generated by a lifting task, vs the electromyographic (EMG) activity of right and left trunk muscle groups. In particular, we postulate that the functional dependence between erector spinae muscle activity and the applied lifting moments about the spine is as follows: the sum of left and right erector spinae processed EMG depends on the sagittal plane moment, and the difference of left and right erector spinae processed EMG depends on the frontal plane moment. A simple out-of-sagittal plane physical model, treating the lumbar spine as a two degree-of-freedom pivot point is discussed to justify these hypotheses. To validate this model, we collected surface EMG and lifting moment data for ten males performing a grid of frontal and sagittal plane lifting tasks. A digital RMS-to-DC algorithm was developed for processing raw EMG. For these tests, we measured EMG for the left and right erector spinae and for the left and right external oblique muscles. The processed EMG signals of the left and right erector spinae muscles are summed and differenced for comparison to the measured sagittal and frontal plane moments. A linear correlation (r2) of 0.96 was obtained for the sum of erector spinae EMG vs the sagittal plane moment; a corresponding value of r2 = 0.95 was obtained for the difference vs the frontal plane moment. No correlations (r2 less than 0.004) was found for the sagittal plane moment and the difference of the left and right erector spinae EMG, and the frontal plane moment and the sum of the left and right erector spinae EMG.

Back↗
PubMed1995

Hydrodynamic drag and lift forces on human hand/arm models.

Forces acting on the forearm and hand during swimming can be decomposed into drag forces and lift forces. In this study drag and lift forces were measured on two models of a human hand and forearm when towed in a towing tank. To compare the results of models with different size at different velocities force data were normalized to drag and lift coefficients (Cd and Ct). Influence of the orientation of the model with respect to the flow, velocity, size of the model and the relative contribution of the hand and forearm on Cd and Ct were studied. The orientation of the model with respect to the line of motion was varied by rotating the models around three axes, and quantified using the angle of pitch (AP: the angle between the hand plane and flow) and the sweep-back angle (SB: the orientation of the flow vector when projected on the hand plane). Cd was maximal when the palm of the hand is almost perpendicular to the flow (AP = 65 degrees, SB = 342 degrees). Ct shows maximal values at two different orientations: with the hand in a thumb-leading position, AP = 31 degrees, SB = 358 degrees, and with the hand in a little finger-leading position, AP = 48 degrees, SB = 193 degrees. The orientation of the hand was very critical in generating lift forces. By contrast, the influence of velocity and size of the model on the values of Cd and Ct was limited.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical Phenomena↗
PubMed1985

A comparison of shock avoidance learning in headless cockroaches in leg-lifting and lowering task.

Headless cockroaches were trained either to lift or to lower the prothoracic leg to avoid electric shocks. The learning process in both cases was very distinct. However, the learning performance in the lifting was better than in the lowering task. The reason for this poorer learning in the lowering task is due to the unconditioned leg raising movement of the animals to electric shocks. This unconditioned response affects the headless cockroaches avoid shocks in the lifting task by escape learning, whereas they avoid shocks in the lowering task by true avoidance learning. Injection of 30 microliter of Ringer's solution has no significant effect on the learning process in the lifting task. In the lowering task, however, Ringer's solution impairs the learning ability considerably. Crude extract of corpora cardiaca strongly inhibits the learning of both tasks.

Animals↗
PubMed1995

Moments at the L(5)/S(1) joint during asymmetrical lifting: effects of different load trajectories and initial load positions.

The purpose of this study was to examine the reaction moments at L(5)/S(1) about the three orthogonal orthopaedic axes on the trunk when performing asymmetrical lifting tasks under six experimental conditions. The first three conditions were three lifting modes referring to different load trajectories (diagonal, extension then twisting, twisting then extension). The next three conditions were three lifts referring to different initial load positions (90 degrees, 45 degrees, 0 degrees ). Ten male volunteers (mean age 23.4 years) participated in the study. The mass of the load was 11.6 kg and two shelves were used: a low shelf of 22 cm from which the load was removed and a high shelf of 80 cm onto which the load was laid down following the manoeuvre. A dynamic 3D multisegment model was used to compute spinal loadings. The maximum reaction moments generated at the joint for the three load trajectories and for the three initial load positions were approximately of the same magnitude. On the other hand, significant differences were observed in the trunk orientation when the maximal moment was generated. Symmetrical trunk positions appeared to be more advantageous because of the reduction in the capability of maximal extension force in asymmetric trunk posture. A possible alternative for avoiding excessive stress on the back in asymmetric trunk posture may be to keep the shoulders parallel to the ground. RELEVANCE: Three-dimensional studies of the resulting moments at L(5)/S(1) when performing lifting activities are not common, particularly when the tasks include muscular exertions in trunk flexion combined with either twisting or lateral bending. This type of analysis is particularly important since asymmetries have been identified as risk factors for low back disorders. The knowledge of reaction moments in relation to postures are essential to understand the mechanism of low back pain.

Journal Article↗
PubMedDate not supplied

The laryngeal lift: a method to facilitate endotracheal intubation.

STUDY OBJECTIVE: To assess the efficacy of the "laryngeal lift" maneuver in improving laryngoscopic visualization to facilitate endotracheal intubation. DESIGN: Blinded study. SETTING: Operating room at Meridia Huron Hospital. PATIENTS: 305 patients receiving general anesthesia for elective surgery requiring intubation. (Five patients were eliminated from the study because we elected to intubate these patients awake and sedated.) INTERVENTIONS: Following induction of anesthesia and paralysis with muscle relaxants, laryngoscopic views of each patient were evaluated by the laryngoscopist before and after the laryngeal lift was performed by an anesthesiologist assisting the laryngoscopist. Each patient served as his or her own control group. The anesthesiologist was blinded to the results obtained by the laryngoscopist. All Grade I laryngoscopic views were eliminated (198 patients). Five patients were eliminated on the basis of obesity or atlantoaxial subluxation. The laryngeal lift was performed on the remaining 102 patients, representing Grade II to Grade V laryngoscopic views. MEASUREMENTS AND MAIN RESULTS: A modification of the original classification of laryngoscopic views by Cormack and Lehane was used: Grade I = full view of glottis; Grade II = only posterior commissure visible; Grade III = arytenoids visible; Grade IV = epiglottis visible; Grade V = no glottic structure visible. In 98 of 102 cases (96%), the maneuver improved visualization by at least 1 grade. There was no evidence of change in the 4 remaining cases. CONCLUSIONS: The laryngeal lift should be part of the anesthesiologists' armamentarium in helping the laryngoscopist who is faced with Grades II, III, IV, and V laryngoscopic views to enhance visualization of the larynx and thus facilitate endotracheal intubation.

Anesthesia, General↗
PubMed2006

[Subperiosteal midface lifting].

Since 1990, when we had found the solutions about the oval of the face and the neck problems by the vertical lift, our whole attention was focused on the midface. We have been through the "cheek lift", high SMAS incision. We followed Oscar Ramirez and Richard Anderson in the subperiosteal undermining of the mid face under endoscopic control by a buccal and temporal incision. The actual technic made possible by Paul Tessier's work who initiated the subperiosteal undermining and Oscar Ramirez who initiated the endoscopy. The endoscopy allowed us to go through this technic, but now we don't use it anymore. We have to credit Thierry Besins who mixed these concepts alltogether to obtain a complete and effective technic. The idea is to move up the centrofacial structures and to secure them reliably because of the perioste strengh. This technic solve in an unparallel way, all the stigmata of the centrofacial aging; so, we have a scarless lifting. For the one who have a neck problem, we associate the deep vertical lift.

Humans↗
PubMed2006

Grip force regulation during pinch grip lifts under somatosensory guidance: comparison between people with stroke and healthy controls.

OBJECTIVES: To compare the timing and grip force application in a pinch grip task performed under somatosensory guidance in stroke and matched controls and to identify characteristics of impaired grip force regulation after stroke. DESIGN: Matched-pairs control group. SETTING: University research laboratory. PARTICIPANTS: Forty-five people with stroke who could pick up a pen lid using a pinch grip and actively participated in rehabilitation and 45 adults without neurologic conditions or musculoskeletal or skin impairments affecting the hand, matched for age, sex, and hand dominance. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Timing and magnitude of grip forces applied during pinch grip lift and hold. RESULTS: Prolonged time to grip and lift objects, and excessive grip force prior to commencing the lift occurred in approximately half of the contralesional (involved) hands of people with stroke. Fluctuating irregular forces and reduced adaptation of the grip safety margin were also observed. Excessive safety margins were not predominant after stroke. Extreme slowing and disorganized sequencing of the grip and lifting forces and difficulty maintaining a stable grip characterized severe dysfunction. CONCLUSIONS: Delayed grip formulation and variable grip force application are key characteristics of grip dysfunction after stroke.

Adult↗
PubMed2006

Assessment of the sinus lift operation by magnetic resonance imaging.

OBJECTIVES: Vertical bone loss in edentulous maxillary alveolar processes may necessitate a sinus lift before the placement of dental implants. We have measured and assessed maxillary sinuses meticulously before the operation and evaluated the postoperative results of the operation with magnetic resonance imaging (MRI). METHODS: Thirteen edentulous maxillary regions in eight patients were included in the study. The patients were examined 1 week before and 3 months after the sinus lift operations using a 1.5 T superconductive MR imager that gave oblique sagittal T2-weighted images with slices 2 mm thick without a gap. RESULTS: The images that were obtained 3 months after the sinus lift operations confirmed that vertical height had increased. CONCLUSION: We obtained high quality images without any artefacts during a short examination period with a high-resolution scanner. The results showed that it is possible to assess the maxillary sinus before the sinus lift and to evaluate the postoperative results using MRI accurately in three dimensions without the risk of radiation. This makes MRI a suitable alternative to computed tomography (CT).

Adult↗
PubMed2004

Differences in motor recruitment and resulting kinematics between low back pain patients and asymptomatic participants during lifting exertions.

BACKGROUND: Low back disorders are a prevalent problem in society today and may lead to chronic debilitating low back pain. Developing our understanding of temporal muscle and kinematic patterns during manual material handling tasks may provide insight for preventing the cascading series of events leading to chronic low back pain. METHODS: Sixty-two low back pain patients and 61 asymptomatic participants performed a variety of lifting exertions that varied in lift origin horizontal and vertical distance, lift asymmetry, and weight. Electromyographic activity of 10 trunk muscles as well as trunk and pelvic kinematics was recorded during each exertion. Differences in muscle activation and kinematic parameters were compared between low back pain patients and asymptomatic participants as a function of experimental conditions. FINDINGS: Both the left and right erector spinae activated significantly earlier and were on significantly longer in low back pain patients compared to asymptomatic participants. The horizontal and vertical location of the lift influenced the EMG and kinematic differences between the low back pain patients and asymptomatic participants. INTERPRETATION: These finding indicate that low back pain patients would be exposed to increase muscle activity resulting in higher spine loads for a greater length of time compared to asymptomatic participants. The longer exposure time to increased spine load may lead to greater risk of future low back injury and cascading events leading to debilitating low back pain. The longer muscle activation time suggests that low back pain patients have changed their motor program from an open to a closed loop system.

Adult↗
PubMed2006

Characterization of hind paw licking and lifting to noxious radiant heat in the rat with and without chronic inflammation.

The paw withdrawal latency to thermal radiant heat stimuli is a widely used nociceptive measure to study hyperalgesic mechanisms. In the present study, in addition to the paw withdrawal latency, two behavioral components of pain behaviors, paw licking and paw lifting have been characterized and quantified. The thermal stimuli were successively applied to the plantar surface of the rat hind paws and recorded the behavioral responses to each of the stimuli. Noxious radiant heat significantly increased the frequency of paw lifting behavior in naïve rats. On the other hand, the thermal stimuli significantly evoked the occurrence of paw licking behavior in inflamed paws and it was maintained at all time points of measurements. The paw withdrawal latency decreased in inflamed rats in comparison with control rats. These data informs that noxious radiant heat specifically evokes the frequency of paw lifting behavior in normal physiological condition, and paw licking behavior in a pathological inflammatory condition. These findings suggest that in addition to the measurement of PWL, scoring of paw licking and lifting behaviors will improve the sensitivity of this pain test.

Animals↗
PubMed2004

In situ lift-out using a FIB-SEM system.

An in situ 'lift-out' technique for preparing transmission electron microscopy specimens, which is performed using secondary electron imaging within the chamber of a focused ion beam-SEM system is presented. The main advantage of this in situ approach, relative to the ex situ lift-out technique, is that secondary electron imaging enables higher magnifications to be used than is possible with optical microscopy. This makes the lift-out procedure more controllable and thus increases the overall success rate especially for inexperienced users. The technique is also compared with another in situ lift-out approach, the 'wedge' technique.

Journal Article↗
PubMed2006

Subperiosteal midface lift with or without a hard palate mucosal graft for correction of lower eyelid retraction.

PURPOSE: To compare functional and surgical outcomes of a subperiosteal midface lift with and without the placement of a hard palate mucosal graft (HPMG) in patients with lower eyelid retraction. DESIGN: Retrospective, comparative, interventional case series. PARTICIPANTS: Thirty-four patients with lower eyelid retractions who underwent surgery at the Jules Stein Eye Institute in a 5-year period. METHODS: Medical record review of all patients who underwent surgery for lower eyelid retraction by a subperiosteal midface lift with or without an HPMG. Preoperative and postoperative digital photographs were taken in all patients. MAIN OUTCOME MEASURES: Change in margin reflex distance 2 (MRD2), measured from the pupillary margin to the upper margin of the lower eyelid; patient discomfort; and surgical complications. RESULTS: Thirty-four patients (20 female; mean age, 64 years) participated in the study; 11 underwent bilateral surgery, with overall 43 surgeries performed. Eighteen patients (42%) had lower eyelid retraction secondary to previous transcutaneous lower eyelid blepharoplasty. Postoperatively, patients attained a better lower eyelid position, with improvement of lower eyelid height of 1.4 mm (P<0.001, 1-sample t test). Patients operated using an HPMG (12 surgeries) achieved a greater reduction in MRD2 postoperatively as compared with patients operated by subperiosteal midface lift alone (31 surgeries; 2.2 mm vs. 1.1 mm, respectively; P = 0.02, Wilcoxon Mann-Whitney). One patient needed reoperation secondary to symptomatic lower eyelid retraction postoperatively. CONCLUSIONS: The subperiosteal midface lift is effective in correction of lower eyelid retraction of various causes. The use of an HPMG spacer may enhance surgical outcomes and results in a better lower eyelid position.

Adolescent↗