Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Torque”

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 937 records · Page 52Linked to original sources
PubMed1988

MR imaging artifacts, ferromagnetism, and magnetic torque of intravascular filters, stents, and coils.

Experiments were conducted in which various intravascular filters, stents, and coils were imaged using magnetic resonance (MR) spin-echo technique at 0.35 T. These devices were also evaluated for ferromagnetism (at 0.35, 1.5, and 4.7 T), magnetic torque (at 0.35 and 1.5 T), and magnetically induced migration within a plastic tube (at 0.35 and 1.5 T for the Greenfield filter [GF]). The stainless-steel GF was evaluated in vitro for its propensity to perforate canine inferior venae cavae (IVC). Magnetic force and torque at 1.5 T did not dislodge the GF or result in perforation of canine IVC by the GF. Beta-3 titanium alloy (used in a new percutaneous version of the GF) is apparently one of the best-suited metals for use with MR imaging because of its lack of ferromagnetism (up to 4.7 T) and absence of MR imaging artifacts (at 0.35 T). Devices composed of Elgiloy (Mobin-Uddin filter), nitinol, and MP32-N (Amplatz filter) alloys all created mild artifacts. Devices fashioned from 304 and 316L (GF and Palmaz stent) stainless-steel alloys created severe "black-hole" artifacts, with the 304 alloy devices also showing marked image distortion. Generally, the greater the ferromagnetism of a device, the greater its magnetic susceptibility artifact.

Filtration↗
PubMedDate not supplied

Measurement of upper extremity torque production and its relationship to throwing speed in the competitive athlete.

This study was conducted to establish whether or not a correlation exists between peak torque production of upper extremity (UE) musculature and throwing speed. Eleven professional baseball players were tested for upper extremity peak torque production using a Cybex II Isokinetic Dynamometer. Throwing speed was measured with a radar gun. Results of statistical analysis performed on the data indicate a correlation between shoulder adductors and throwing speed.

Arm↗
PubMedDate not supplied

Comparison of failure strength between metallic and absorbable interference screws. Influence of insertion torque, tunnel-bone block gap, bone mineral density, and interference.

Because of the good initial fixation strength of interference screws used in anterior cruciate ligament reconstruction, metal interference screws have become the standard method for fixation of bone-patellar tendon-bone grafts. To avoid some of the complications with metal screws, a bioabsorbable interference screw was developed. Data on fixation strength in older human cadavers indicate a similar failure strength between bioabsorbable and metal screws. We studied the failure mechanisms, insertion torques, and fixation strengths of absorbable and metal interference screws in cadaveric knees from young and middle-aged donors. With identical gap and screw size, the mean insertion torque for the metal screws (mean, 1.5 N-m; SD, 0.8) was significantly higher than for the absorbable screws (mean, 0.3 N-m; SD, 0.19). The mean failure load for the metal screws (mean 640 N; SD, 201) was also significantly higher than for the absorbable screws (mean, 418 N; SD, 118).

Absorption↗
PubMedDate not supplied

Activation of the rotator cuff in generating isometric shoulder rotation torque.

This study compared and quantified electromyographic muscle activation of the rotator cuff with the isometric torque generated by performing shoulder rotation in various positions. Twenty healthy volunteers were tested in 29 shoulder positions. Using a Cybex II dynamometer synchronously with electromyography, surface electrodes were placed over the pectoralis major muscle and three parts of the deltoid muscle. Intramuscular wire electrodes were inserted into the four rotator cuff muscles. We found that the greatest external rotation isometric force is generated in the frontal and scapular planes in the neutral or full internal rotation positions. The sagittal, dependent, and the scapular plane with 45 degrees of elevation in rotational positions of either full or half external rotation generated the greatest torques for internal rotation isometric force. The rotator cuff muscles generated greatest electromyographic activity in neutral to midrotational positions. The scapular plane with 90 degrees of shoulder elevation in neutral rotation best isolated the subscapularis muscle. The infraspinatus-teres minor muscles were isolated in the sagittal plane with 90 degrees of shoulder elevation in a half externally rotated position. We were unable to isolate the supraspinatus muscle in any of these tested positions. These positions are recommended for manual muscle testing and for strengthening these muscles.

Adult↗
PubMed1994

A study to compare the effects of simulated torquing forces on pre-adjusted orthodontic brackets.

The transmission of torquing forces between three types of preadjusted bracket was investigated. 0.022-inch Roth prescription 'A'-Company (stainless steel), Silkon (reinforced polycarbonate), and Allure III (polycrystalline ceramic) brackets were used. A selection of stainless steel archwires were chosen, 0.018 x 0.025, 0.019 x 0.025, and 0.021 x 0.025 inch. The brackets were torqued with respect to the archwire and force v. angular deflection was recorded on an Instron machine. The dimension of angular change was in part dependent on the ability of the bracket to elastically or plastically deform. There were no significant differences between bracket types with the 0.018 x 0.025-inch archwire. 'A'-Company brackets demonstrated a significantly lower resistance to loading compared to Silkon brackets in the 0.019 x 0.025-inch group. The greatest amount of distortion was seen in Silkon brackets with an 0.021 x 0.025-inch archwire. Allure III brackets demonstrated the greatest resistance to loading in all groups. As no apparent distortion under loading is seen in Allure III brackets, it is assumed that the load is largely transmitted to the tooth. Full thickness stainless steel rectangular wires should be avoided with these brackets, in order to prevent overloading.

Aluminum Oxide↗
PubMed1996

A controlled trial of amino acid therapy in amyotrophic lateral sclerosis: I. Clinical, functional, and maximum isometric torque data.

We conducted a two center, double-blind, placebo-controlled treatment trial with oral branched chain amino acids (BCAA) (L-leucine 12 g, L-isoleucine 8 g, and L-valine 6.4 g daily) or L-threonine (4 g daily) with pyridoxal phosphate (160 mg daily) for six months in patients with amyotrophic lateral sclerosis (ALS). The effect of treatment on disease progression was estimated every two months by recording clinical muscle strength, maximum isometric muscle torque in selected muscles, forced vital capacity (FVC), activities of daily living pertaining to the upper and lower limbs, and timed tasks. Ninety-five patients were randomized to receive BCAA (n = 31), L-threonine (n = 32), or placebo (n = 32), of whom 77 (81%) completed the trial. Mean weight loss in the placebo group was 1.1 kg and in the L-threonine group was 3.2 kg; the BCAA group gained 0.2 kg (p = 0.04). The estimated decline in FVC was about 2.5 times greater in the BCAA and L-threonine groups as compared to placebo (p = 0.03). Otherwise, no significant differences were found in the changes observed in clinical, functional, timed, or maximum torque measures among treatment groups. The amino acids were well tolerated. The results of our study failed to show a beneficial effect of BCAA or L-threonine treatment for six months on the disease course in ALS. The higher rate of loss of pulmonary function in patients treated with BCAA or L-threonine may have been due to chance, but an adverse effect of these amino acids cannot be ruled out.

Adult↗
PubMed1999

Body bending during fast-starts in fish can be explained in terms of muscle torque and hydrodynamic resistance

Fish fast-starts are rapid events caused by the simultaneous onset of muscle activity along one side of the body. Spine curvature and the strain and electromyographic activity in white muscle were measured for fast-starts in the common carp Cyprinus carpio. The first bend of the fast-start was powered by muscle on the concave side: muscle fibres on this side were activated and began shortening simultaneously between the length-specific longitudinal sites 0.3L and 0.56L, where L is total body length. However, there was an increasing delay in the timing of the first peak in body curvature and muscle strain along the length of the body. Modelling studies related the rate of body bending to the muscle torque and hydrodynamic resistance of the fish. The muscle torque produced on the spine was greatest in the central region of the trunk, and this acted against the moments of inertia of the fish mass and added mass of water. It was concluded that a wave of body bending can be generated as a result of the hydrodynamic resistance of the fish despite the initiation of that bending being simultaneous along the length of the body.

Journal Article↗
PubMed1985

Effect of attempted lifting speed on forces and torque exerted on the lumbar spine.

Factors affecting compressive and shear forces and torque at the L5/S1 vertebral joint were examined for nine different load/lifting-speed combinations during performances of a dynamic lifting task by 10 subjects. Loads were 40, 60, and 80% of each subject's maximum lifting capability. Target lifting times were 1.5, 3.5, and 7 s. A rigid link model of the human body was used to derive estimates of axial force, shear force, and torque acting at the L5/S1 vertebral joint from high-speed film data. Variables examined empirically were myoelectric activity at the fifth lumbar level of sacrospinalis and intra-abdominal pressure. The respective effects of load and attempted lifting time were assessed through two-factor ANOVA's and subsequent Scheffé tests. Heavier loads were found to result in significantly higher (P less than .001) values of mean compressive force, mean shear force, and maximum myoelectric activity. Faster target lifting times resulted in significantly higher mean and maximum values of all the variables quantified except intra-abdominal pressure.

Adult↗
PubMed1988

Effects of fatigue on activation profiles and relative torque contribution of elbow flexor synergists.

The purpose of this study was to examine changes in elbow flexion synergies as a result of fatigue. Subjects performed a series of five isometric contractions at 10% maximum voluntary contraction step intervals. Pre- and post-fatigue surface electromyograms for the muscles were rectified, integrated, normalized, a representative equation determined using the least-squares method, and the equations numerically differentiated. The differentiated curves represent the change of excitation (and therefore, change of isometric torque) with respect to the change in resultant torque (dIEMG/dT). Pre-fatigue synergy, as indicated by the dIEMG/dT, was characterized by both co-activation and trade-off patterns. The nature of the synergy was changed as a result of fatigue. This technique, focusing upon synergistic patterns, quantifies differences in excitation profiles in a manner not previously described.

Adult↗
PubMed1989

[Longitudinal evaluation of aerobic capacity determined by torque auto-controlled system with the feedback of photoelectric pulse].

We have previously developed a unique and simple procedure for assessing cardiorespiratory fitness. The present investigation was conducted to evaluate whether an aerobic index determined by torque auto-controlled system with the feedback of photoelectric pulse could sufficiently approximate the cardiorespiratory fitness represented by anaerobic threshold (AT) and maximal oxygen uptake (VO2max). Analysis of the cross-sectional data indicated that the aerobic score (AS: K (WR/Wt)/HR; where WR = mean work rate during 12-min cycling, Wt = weight, and HR = mean heart rate during 12-min cycling) determined by the torque auto-controlled system was significantly correlated with directly measured VO2/AT (r = 0.922, 76 males; r = 0.814, 34 females). Cross-validity of the predicted VO2max from the AS was significant and sufficiently high (r = 0.949, 31 males) for use in the general public. In addition, the effects of cycling or jogging training on the AS were longitudinally investigated on 17 females and 1 male. Major effects of the training were significant improvements in the AS, VO2max, and VO2/AT. Delta percentage change [(post-value - pre-value)/pre-value; delta %] in the AS was closely associated (r = 0.718, 8 females) with delta % in VO2/AT. It appears likely from the present investigation that information obtained through the use of our unique system (i.e., the AS) could provide considerably reliable estimate of cardiorespiratory fitness in both males and females.

Adult↗
PubMed1980

Does the 'torque test' measure cerebral dominance in adults?

The direction of drawing a circle, labeled the 'torque test' (Blau, 1977), was evaluated in 74 normal adults (age 14 to 44 yr.) as a predictor of both handedness and cerebral dominance on the dichotic listening test. The results indicate that torque is related to handedness but not to lateralization of language. We suggest that circle-drawing by adults is dependent more on the muscle mechanics of the hand than on cerebral dominance.

Adolescent↗
PubMed1981

Channel capacity for kinesthetic torque information.

A previous study (Russel & Marteniuk, 1974) used informational analysis of absolute judgments to investigate the capacity of the kinesthetic system to transmit information derived from torque cues. As perfect transmission was not obtained in that study, no firm statement regarding channel capacity could be made. Four experiments were conducted in which five subjects made judgments concerning in intensity of 2, 4, 6, and 8 categories, respectively, in an attempt to determine the channel capacity for torque. Information transfer for the four experiments was 1.00, 1.45, 1.60, and 1.67 bits, respectively. It is argued that the latter figure probably reflects the true capacity of the kinesthetic system rather than the 2.09 bits previously reported.

Adult↗
PubMed1991

The perception of torque pulses.

The reliability of perception of a series of torque pulses and the influence of practice on the perceptual threshold were assessed. Eleven subjects were tested. Analysis showed distinctive cumulative frequency curves with the threshold of perception ranging from 0.016 Nm to 0.049 Nm. The reliability of individual differences over 100 trials was .998 and, when the number of trials was reduced to 25, reliability was .992. There was little evidence of a practice effect. It was clear that individual differences in torque perception could be accurately measured.

Adult↗
PubMed1994

Test-retest reliability of eccentric peak torque values for shoulder medial and lateral rotation using the Biodex isokinetic dynamometer.

In order for the Biodex isokinetic dynamometer to be used in clinical research, it must be documented to be a reliable measurement tool. The purpose of this study was to determine eccentric peak torque test-retest reliability for glenohumeral medial and lateral rotator muscles using the Biodex isokinetic dynamometer. Eighteen healthy men and women volunteers ranging in ages from 18 to 30 who exhibited no prior history of glenohumeral injury were studied. The subjects were tested bilaterally for eccentric glenohumeral medial rotation (MR) and lateral rotation (LR) at 90 and 120 degrees/sec using 0 degrees of shoulder abduction so that the subject's arm was in contact with his or her trunk. Seven days following the initial test, a retest was administered using the identical protocol. Data collection of pretesting and posttesting was done using the IBM basic computer and the Biodex software program. Test data were analyzed using the intraclass correlation coefficient. The test-retest results indicated: dominant LR at 90 degrees/sec, r = 0.86, and at 120 degrees/sec, r = 0.83; dominant MR at 90 degrees/sec, r = 0.76, and at 120 degrees/sec, r = 0.77; nondominant LR at 90 degrees/sec, r = 0.76, and at 120 degrees/sec, r = 0.83; and nondominant MR at 90 degrees/sec, r = 0.75, and at 120 degrees/sec, r = 0.83. The results demonstrate the isokinetic eccentric mode of the Biodex dynamometer to be reliable for the test-retest measure of peak torque. These data may be used to support future clinical research of the eccentric isokinetic mode of the Biodex isokinetic dynamometer.

Adolescent↗
PubMed1994

The effects of 16 months of angle-specific isometric strengthening exercises in midrange on torque of the knee extensor muscles in osteoarthritis of the knee: a case study.

Although often advocated for arthritis rehabilitation, several studies conducted on healthy subjects have demonstrated conflicting results as to whether isometric strengthening exercises performed at one joint angle can result in strength gains at other angles. The objective of this study was to determine whether midrange strength training of the quadriceps surrounding an osteoarthritic knee would increase strength in this part of the range of motion as well at other knee angles. The midrange position was chosen because the subject, a 57-year-old female with a 2-year history of moderately severe osteoarthritis of the left knee, had greatest weakness in this position. The training occurred three times per week for 16 months using a resistance training program of three sets of two maximal isometric contractions at a knee angle of 60 degrees. The dependent variable of maximal isometric knee extensor torque was recorded on an isokinetic dynamometer at knee angles of 90, 60, and 30 degrees at 6 weeks, 1 year, and 16 months. These data demonstrated a progressive torque increase at all angles over the 16-month period, with a steeper slope at the training angle. Contrary to the specificity of training concept, angle-specific strengthening in midrange may be sufficient to strengthen the extensors surrounding an osteoarthritic knee through a wide range of motion. Mid-range isometric strengthening exercises might thus prove useful in the rehabilitation of patients with knee osteoarthritis who are unable to exercise their weakened quadriceps at other angles due to pain or swelling.

Exercise Therapy↗
PubMed1997

The isokinetic torque curve of shoulder instability in high school baseball pitchers.

Athletes with shoulder problems are commonly referred to orthopaedic and sports physical therapists for rehabilitation. Many of these problems include some form of shoulder instability. The purpose of this study was to generate an isokinetic torque curve that is representative of the shoulder impingement syndrome that may affect high school baseball pitchers. A sample of 241 subjects, each diagnosed with an impingement syndrome in the right shoulder, was tested using a Cybex II+ dynamometer configured to duplicate the orthopaedic loose-packed and plane of the scapula positions of the shoulder complex. The subjects were tested concentrically across five maximal repetitions of internal and external rotation at the speeds of 60, 120, 180, 240, and 300 degree/sec; graphic records were collected at 60 degrees/sec. Descriptively, testing revealed a distinct isokinetic torque curve for the impingement syndrome compared with the noninvolved shoulder. This information might serve as a useful complement to traditional clinical procedures for the diagnosis of the shoulder impingement syndrome.

Adolescent↗
PubMed1987

Laterality, torque and personality.

Evidence accumulating from a variety of methodological approaches suggests that unusual laterality is often a concomitant feature of emotional pathology. In the present study both torque and a multifaceted measure of laterality were examined with respect to personality variables measured by the 16 PF in a normal population. Interestingly, a pattern of emotionality for subjects with a more confused laterality was revealed in a normal population which is notably similar to reported aberrant personality factors and laterality in more pathological groups. The existence of a cohesive continuum of emotional expression in relation to confused laterality is suggested. In addition, both torque and the multifactored measure of laterality are critiqued as research measures and for their clinical potential.

Adolescent↗
PubMed1976

A comparison of plantar flexion torque with and without the triceps surae.

Torque generated about the ankle joints during maximum isometric contraction of the plantar flexor muscles was measured on a subject 4 months after unilateral excision of the entire triceps surae. Resulting torque output on the operated limb was 327 kg-cm, or 38 per cent of the 871 kg-cm total for the sound limb.

Biomechanical Phenomena↗