Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lifting”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
PubMed1997

Morphological and biochemical evidence of muscle hyperplasia following weight-lifting exercise in rats.

We used a rat model of weight lifting to examine the serial biochemical and morphological changes following muscle fiber hyperplasia during 14 days of exercise. [3H]thymidine and [14C]leucine labeling were used to determine the serial changes in cellular mitotic activity and the level of amino acid uptake and myosin synthesis. Morphological changes were assessed with light and transmission electron microscopy, whereas proliferation of cells was evaluated immunohistochemically with 5-bromo-2'-deoxyuridine (BrdU). The intensity of the exercise and degree of muscle damage were monitored by serum creatine kinase (CK) activity. Damaged fibers were sparsely distributed, and a significant CK leakage was observed 30-60 min after exercise. Anti-BrdU-positive cells were observed in damaged fibers and at the periphery of undamaged fibers. Changes typical of muscle regeneration were observed; however, the formation of new fibers in the interstitial space was also evident. The mitotic activity also changed and reflected the appearance of anti-BrdU-positive cells and activated satellite cells. Amino acid uptake increased during the first week of exercise, probably reflecting muscle hypertrophy and synthesis of other noncontractile related proteins. The uptake also increased during the second week, probably due to hyperplasia, a finding also supported by electron microscopy. Our results suggest that one bout of weight-lifting exercise in untrained rats induced muscle hyperplasia following regeneration. The process of muscle hyperplasia was activated by muscle fiber damage in our model.

Animals↗
PubMed1992

Factors affecting blood pressure during heavy weight lifting and static contractions.

Brachial arterial pressure was directly recorded in 31 healthy male volunteers through protocols examining the effects of the Valsalva maneuver, muscle size and strength, contraction force, contraction type (concentric, isometric, eccentric), changes in joint angle, and muscle fatigue on the blood pressure response to resistance exercise. Weight lifting at the same relative intensity produced similar increases in blood pressure, regardless of individual differences in muscle size or strength. Concentric, isometric, or eccentric exercise at the same relative intensity caused similar increases despite differences in force production. In weight lifting, the greatest increase in blood pressure occurred at the joint angle corresponding to the weakest point in the strength curve and the least at the angle corresponding to the strongest point. Isometric contractions of the same relative intensity at different joint angles produced identical blood pressures despite differences in absolute force production. When subjects attempted to maintain a maximum isometric contraction for 45 s, the blood pressure increase remained the same despite a marked diminution in force. Thus the magnitude of the blood pressure response depends on the degree of effort or central command and not actual force production. A brief Valsalva maneuver, which exaggerates the increase in blood pressure, is unavoidable when desired force production exceeds approximately 80% maximum voluntary contraction.

Adult↗
PubMed1994

Relationships between energy expenditure and positive and negative mechanical work in repetitive lifting and lowering.

Determining the separate energy costs of the positive and negative mechanical work in repetitive lifting or lowering is quite complex, as a mixture of both work components will always be involved in the up- and downward motion of the lifter's body mass. In the current study, a new method was tested in which coefficients specifically related to the positive and negative work were estimated by multiple regression on a data set of weight-lifting and weight-lowering tasks. The energy cost was obtained from oxygen uptake measurements. The slopes of the regression lines for energy cost and mechanical work were steeper for positive than for negative work. The cost related to the negative work was approximately 0.3-0.5 times the cost of the positive work. This finding is well in line with data obtained directly from other isolated activities of either positive or negative work (e.g., ladder climbing vs. descending). However, the intercept values of the regression lines were not significantly different from zero or were even negative. This was most likely due to the metabolic energy not related to processes that yield mechanical work (e.g., isometric muscle actions) that was not constant among trials.

Adult↗
PubMed1998

Control of grasp stability when humans lift objects with different surface curvatures.

In previous investigations of the control of grasp stability, humans manipulated test objects with flat grasp surfaces. The surfaces of most objects that we handle in everyday activities, however, are curved. In the present study, we examined the influence of surface curvature on the fingertip forces used when humans lifted and held objects of various weights. Subjects grasped the test object between the thumb and the index finger. The matching pair of grasped surfaces were spherically curved with one of six different curvatures (concave with radius 20 or 40 mm; flat; convex with radius 20, 10, or 5 mm) and the object had one of five different weights ranging from 168 to 705 g. The grip force used by subjects (force along the axis between the 2 grasped surfaces) increased with increasing weight of the object but was modified inconsistently and incompletely by surface curvature. Similarly, the duration and rate of force generation, when the grip and load forces increased isometrically in the load phase before object lift-off, were not influenced by surface curvature. In contrast, surface curvature did affect the minimum grip forces required to prevent frictional slips (the slip force). The slip force was smaller for larger curvatures (both concave and convex) than for flatter surfaces. Therefore the force safety margin against slips (difference between the employed grip force and the slip force) was higher for the higher curvatures. We conclude that surface curvature has little influence on grip force regulation during this type of manipulation; the moderate changes in slip force resulting from changes in curvature are not fully compensated for by changes in grip force.

Adult↗
PubMed1997

Design of lifting gear for a plastination laboratory.

Conventional lifting gear based on steel components can be safely used in a laboratory where acetone is used provided that: (a) the circumstances under which significant amounts of acetone vapour will be present are known and can be controlled and (b) operating practices are imposed to prevent the use of the lifting gear at times when acetone vapour may be present in explosive concentrations.

Acetone↗
PubMedDate not supplied

An epidemiologic study of sports and weight lifting as possible risk factors for herniated lumbar and cervical discs. The Northeast Collaborative Group on Low Back Pain.

The associations between participation in several specific sports, use of free weights, and use of weight lifting equipment and herniated lumbar or cervical intervertebral discs were examined in a case-control epidemiologic study. Specific sports considered were baseball or softball, golf, bowling, swimming, diving, jogging, aerobics, and racquet sports. Included in the final analysis were 287 patients with lumbar disc herniation and 63 patients with cervical disc herniation, each matched by sex, source of care, and decade of age to 1 control who was free of disc herniation and other conditions of the back or neck. Results indicated that most sports are not associated with an increased risk of herniation, and may be protective. Relative risk estimates for the association between individual sports and lumbar or cervical herniation were generally less than or close to 1.0. There was, however, a weak positive association between bowling and herniation at both the lumbar and cervical regions of the spine. Use of weight lifting equipment was not associated with herniated lumbar or cervical disc, but a possible association was indicated between use of free weights and risk of cervical herniation (relative risk, 1.87; 95% confidence interval, 0.74 to 4.74).

Adult↗
PubMed1995

Effects of back support on intra-abdominal pressure and lumbar kinetics during heavy lifting.

Lumbosacral supports (LSSs) have been used to minimize the risk of lower back injuries. Theoretically, an LSS will raise intra-abdominal pressure (IAP) and reduce loads in the lower back region. This investigation compared three different LSSs with an unsupported condition. Nine males lifted a weighted box four times, once per condition, at 90% of their one-repetition maximum. Conditions were compared in terms of effects on IAP and its relieving force on L5-S1 kinetics. A multivariate analysis of covariance revealed no statistically significant differences among the three LSSs and the nonsupport conditions on the aforementioned dependent variables. This suggests that there is no difference among LSSs in terms of their biomechanical effects on the lower back region and that the use of any LSS does not necessarily afford more protection than a proper lift without one.

Abdomen↗
PubMed2003

Weight lifting belt use patterns among a population of health club members.

The purpose of this study was to identify patterns of weight belt use in a population of recreational weight trainers. We hypothesized that the majority of weight belt users utilized weight belts to reduce injury risk and/or improve performance while lifting submaximal loads. Three hundred fifty-two strength training health center members (189 men, 156 women, 7 gender not indicated) aged 20-72 years (36.5 +/- 10.5 years) completed a voluntary weight belt use survey. Overall, 27% (94/352) were weight belt users and 73% (258/352) were nonusers. Ninety percent (85/94) of belt users and 63% (55/88) of former belt users utilized belts to prevent injury, whereas 22% (21/94) of belt users and 28% (25/88) of former belt users utilized belts to improve performance. Many belt users were found to utilize belts during inappropriate situations such as lifting light loads or during exercises that do not typically stress the trunk musculature. Based on these findings we suggest that specific educational interventions be developed at health and fitness facilities to help provide a foundation for more informed decision-making regarding weight belt use.

Adult↗
PubMed2004

Comparison of Olympic vs. traditional power lifting training programs in football players.

Twenty members of an National Collegiate Athletic Association Division III collegiate football team were assigned to either an Olympic lifting (OL) group or power lifting (PL) group. Each group was matched by position and trained 4-days.wk(-1) for 15 weeks. Testing consisted of field tests to evaluate strength (1RM squat and bench press), 40-yard sprint, agility, vertical jump height (VJ), and vertical jump power (VJP). No significant pre- to posttraining differences were observed in 1RM bench press, 40-yard sprint, agility, VJ or in VJP in either group. Significant improvements were seen in 1RM squat in both the OL and PL groups. After log10-transformation, OL were observed to have a significantly greater improvement in Delta VJ than PL. Despite an 18% greater improvement in 1RM squat (p > 0.05), and a twofold greater improvement (p > 0.05) in 40-yard sprint time by OL, no further significant group differences were seen. Results suggest that OL can provide a significant advantage over PL in vertical jump performance changes.

Football↗
PubMed2006

Lighter or heavier than predicted: neural correlates of corrective mechanisms during erroneously programmed lifts.

A central concept in neuroscience is that the CNS signals the sensory discrepancy between the predicted and actual sensory consequences of action. It has been proposed that the cerebellum and parietal cortex are involved in this process. A discrepancy will trigger preprogrammed corrective responses and update the engaged sensorimotor memories. Here we use functional magnetic resonance imaging with an event-related design to investigate the neuronal correlates of such discrepancies. Healthy adults repeatedly lifted an object between their right index fingers and thumbs, and on some lifting trials, the weight of the object was unpredictably changed between light (230 g) and heavy (830 g). Regardless of whether the weight was heavier or lighter than predicted, activity was found in the right inferior parietal cortex (supramarginal gyrus). This suggests that this region is involved in the comparison of the predicted and actual sensory input and the updating of the sensorimotor memories. When the object was lighter or heavier than predicted, two different types of preprogrammed force corrections occurred. There was a slow force increase when the weight of the object was heavier than predicted. This corrective response was associated with activity in the left primary motor and somatosensory cortices. The fast termination of the excessive force when the object was lighter than predicted activated the right cerebellum. These findings show how the parietal cortex, cerebellum, and motor cortex are involved in the signaling of the discrepancy between predicated and actual sensory feedback and the associated corrective mechanisms.

Adult↗
PubMed1997

Assessing lumbar stabilization from point-light and normal video displays of manual lifting.

Routinely, physical therapists use visual observation to assess qualitatively a patient's performance. The literature, however, indicates that assessments of gait and lumbar stabilization from visual observation are at best only moderately reliable. Point-light video displays have been used to study the visual perception of human motion. The present purpose was to examine the reliability of assessments made by a physical therapist when viewing point light and normal video displays of subjects performing a lifting task. Three physical therapists assessed lumbar stabilization by viewing normal and point-light displays of 25 subjects who lifted an 8-lb. milkcrate from floor to waist height. Greater agreement of the therapists' ratings of lumbar stabilization was achieved on assessments made from point-light displays than on those made from normal displays. This finding suggests that the use of point-light displays may improve the reliability of qualitative assessments of performance on motor tasks.

Biomechanical Phenomena↗
PubMed1999

Vocal disinhibition (grunting) does not increase dead lift force in college athletes or nonathletes.

31 17-35 yr.-old men (15 college athletes and 16 nonathletes) performed three dead-lifts with and three without grunting, the order of which was randomly assigned. No differences were found across the grunting trials and grunting did not affect maximal force production. Grunting does not appear to increase maximum force production significantly during a large muscle group, force output activity (isometric dead lift).

Adolescent↗
PubMed2006

Diagnosis of a rare source of upper extremity symptoms in a healthy woman after weight lifting.

STUDY DESIGN: Resident's case problem. BACKGROUND: The popularity of weight training has increased dramatically during the past 20 years. With the increase in popularity of weight training, the rate of injury has also increased dramatically. The types of injuries range from benign to life threatening. DIAGNOSIS: The patient was a 21-year-old woman originally referred for pelvic pain who presented with new complaints of right upper extremity swelling, discomfort, and cyanosis after recently beginning a comprehensive weight-lifting program. Additional signs, including paresthesias decreased pulses, and venous distension, warranted a timely referral by the physical therapist bavk to the referring physician. DISCUSSION: The primary injury in this case report was hypothesized to have been induced by the recent start of a weight-lifting program, with no other significant contributing risk factors. A comprehensive examination by the physical therapist revealed clinical signs of an upper extremity deep vein thrombosis, leading to a same-day referral back to the referring physician. Further research, resulting in a clinical decision rule for upper extremity deep vein thrombosis or estimates of diagnostic accuracy of clinical signs and symptoms, would improve the diagnostic process.

Adult↗
PubMed1996

Injury caused by lifting: a study of the nurse's viewpoint.

This article reports the findings of a questionnaire survey of work-injured nurses. Thirty nurses reported back injury caused by lifting and nine causative factors were identified in significantly more than 20 per cent of accidents. The threshold of reported weight at which accidents began to happen was 50.9kg. Nurses were found to be particularly at risk when mobilising patients because walking accidents are not preventable by using non-lifting techniques. The findings suggest that nurses should be equipped with the appropriate levels of expertise in assisting patients with mobilising.

Biomechanical Phenomena↗
PubMed1999

Effect of changes in lordosis on mechanics of the lumbar spine-lumbar curvature in lifting.

Using a realistic nonlinear three-dimensional finite element model, biomechanics of the entire lumbar spine L1-S1, risk of tissue injury, and required local lumbar muscle exertion in extended and flexed postures are investigated under moderate to relatively large compression loads as great as 2800 N as the lumbar lordosis is altered from the undeformed value of -46 degrees by + 15 degrees in extension or by as much as 38 degrees in flexion. To prevent the instability of the passive structure in compression, the changes in segmental rotations are prescribed and the required sagittal/lateral moments at each level calculated. The effect of load distribution is considered by applying the whole compression on the L1 vertebra alone or among all vertebral levels with 90% or 80% of the compression on the L1 and the remaining evenly shared by the rest. The results are markedly affected by the postural changes and load distributions. The primary global displacement responses are stiffened in the presence of combined loads. The axial compression load substantially increases the intradiscal pressure, facet loads, and disc fiber strains. The large facet loads at the caudal L5-S1 level causes large differential sagittal rotations at vertebral posterior and anterior bony structures, resulting in large stresses in the pedicles and pars interarticularis. The contribution of the passive structures in carrying the load is influenced by the lumbar lordosis and compression load magnitude. Slight flattening of the lumbar spine under large compression reduces the maximum disc fiber strains and required equilibrating moments without adversely affecting the disc pressure and ligament forces. During lifting tasks, the passive spinal structures are protected by slight to moderate flattening in the lumbar curvature, whereas larger flexion angles impose significantly higher risk by increasing the disc pressure, disc anulus fiber strains, ligamentous forces, and facet forces. Changes in lordosis also markedly affect the stabilizing sagittal moments; the required moments diminish in small flexion angles, thus requiring smaller forces in local lumbar muscles. Thus, the lumbar posture during heavy lifting could be adjusted to minimize the required moments generated by lumbar muscle exertions and the risk of tissue injury.

Aged↗
PubMedDate not supplied

Royal Brisbane Hospital--no lifting 1998.

In August of 1997 the Royal Brisbane Hospital commenced working towards the implementation of a no-lift policy in line with the Queensland Nurses' Union No Lifting by the Year 2000 policy. This is a report on that implementation.

Humans↗
PubMed2005

The effectiveness of a comprehensive work hardening program as measured by lifting capacity, pain scales, and depression scores.

OBJECTIVE: The purpose of this pilot study was to examine the effectiveness of a four-week work rehabilitation program. METHOD: Investigators conducted a retrospective chart review of 312 clients participating in the Work Evaluation and Rehabilitation Clinic (WERC) Program from 1994-2000. Only 196 charts were sufficiently complete to be included in the study. Of these 196 prospective clients, 166 began the WERC program and 141 completed the program and were included in the database. Data were gathered from the initial history and evaluations conducted upon admission to the program and from the final evaluation conducted at the time of discharge. Demographic information was recorded. Data from the following assessments were collected: pre- and post-scores for subjective measures of pain using the Oswestry Back Pain Scale and a self-report of pain, the Beck Depression Inventory, the Waddell Sign, and pre- and post-scores of several physical performance tasks. RESULTS: Statistically significant post-test improvements were shown in all six outcome measures used in this study. A decrease in pain correlated with the Floor to Waist Lift test and with the Carrying An Object 20 Feet test. The percentage increase in Waddell's Sign correlated with a decrease in the Carrying An Object 20 Feet test. The Floor to Waist Lift test correlated with the Carrying an Object 20 Feet test. The Oswestry Test correlated with the Beck Depression Scale. There was no significant relationship found between diagnosis of back injury and Waddell's Sign, between either the Waddell's Sign and the Oswestry, or the Waddell's Sign and depression. A regression analysis revealed diagnosis, level of education, gender, and pre-injury work load as significant predictors of improvements made during the work program. CONCLUSION: The program was shown to be effective as measured by the post-test improvements in all 6 performance tests. Although more research is warranted into the effectiveness of treatment for clients with chronic pain, it appears that there is a relationship between pain and physical performance and pain and depression in clients completing a work hardening program.

Adult↗
PubMed2004

Weight lifting and type II aortic dissection. A case report.

The case of a 28-year-old previously healthy male with a 13-year history of weight lifting is described. The patient presented to the emergency department complaining of severe anterior chest pain beginning during a workout. Following transthoracic echocardiogram and computerized tomogram the diagnosis of an ascending aortic dissection was made. The patient was taken emergently for surgical repair of an incompetent aortic valve and type II aortic dissection. Histopathologic examination of the aorta showed cystic medial degeneration. This is the first reported case of a type II aortic dissection secondary to cystic medial degeneration and the hemodynamic stresses of weight lifting. Physicians should be aware of this potentially catastrophic entity in weight lifters.

Adult↗