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 1,045 records · Page 58Linked to original sources
PubMedDate not supplied

Reliability of torque range of motion: a preliminary study.

The clinical reliability of torque range of motion (TROM) has not been tested. This preliminary review was performed to determine the intra- and interrater reliability of TROM. The proximal interphalangeal joints of the index and middle fingers of 14 normal subjects, 56 digits, were tested by applying extension forces of 200 g, 400 g, 600 g, and 800 g. Data were collected using both the hand-held Haldex orthotic gauge with the dial goniometer (manual) and the cantilever-beam force transducer and electrogoniometer (digital) as testing instruments. The testing order of digits, sides, and devices was randomized and tested separately by three different test teams. Results of the analysis of variance showed a significant difference of the means between raters at all force levels (p < 0.0001) and between instruments at 600-g and 800-g forces (p < 0.01). The Pearson product-moment correlation coefficient test, used to test the consistency, resulted in moderate consistency of measures of intrarater reliability between trials, and between instruments used (digital and manual). Intraclass correlation coefficients (ICCs) were calculated with results that were nearly identical to those of the Pearson. Intrarater reliability was in more consistent agreement at the 600-g and 800-g levels. There was significantly high agreement between the tests of tester B, compared with moderate correlations of the tests of testers A and C.

Adult↗
PubMed2002

SEMG power spectrum changes during a sustained 50% Maximum Voluntary Isometric Torque do not depend upon the prior knowledge of the exercise duration.

Endurance time (Tlim) is a relevant indicator of muscular resistance to fatigue. It has been recently shown that SEMG changes computed during shorter periods (sub-maximal durations) than the whole test duration could serve to predict Tlim. The aim of the present study was to test whether the prior knowledge of the sub-maximal duration had any influence on Tlim prediction throughout SEMG changes. For this purpose, we compared myoelectric changes estimated over a 30-s isometric contraction whose duration was known by the subjects, to those changes measured during the first 30 s of a test prolonged until exhaustion. The effort intensity was set at 50% of the maximal voluntary isometric torque (MVIT). The myoelectric manifestations of muscle fatigue appeared to change in a similar way during both sessions for temporal and spectral analyses. In conclusion, the prior knowledge of the duration of sustained isometric contraction did not influence the motor unit recruitment strategy throughout surface EMG evaluation. These results confirmed that the use of SEMG changes computed over shorter periods than expected endurance time may be applied to investigate the capability of the initial rate of SEMG changes to predict muscle endurance capacity at 50%MVIT. This may be of particular interest for patient evaluation in the clinical field.

Adult↗
PubMed1999

Reproducibility of surface EMG variables and peak torque during three sets of ten dynamic contractions.

The interpretation of the electromyogram (EMG) of dynamic contractions might be difficult because the movement per se introduces additional factors that could affect its characteristics. There is a lack of studies concerning the reproducibility of surface EMG registrations during dynamic contractions. The aim was to investigate the during-the-day reproducibility (using intra-class correlation; ICC) of the peak torque (PT) and the EMG variables (without removing the electrodes) of dynamic contractions. Ten healthy subjects performed three sets of 10 dynamic maximum right-knee extensions with a one-hour interval in between, using an isokinetic dynamometer and the PT was determined. EMG signals were recorded from the right vastus lateralis, rectus femoris and vastus medialis muscles using surface electrodes and the mean frequency of the power spectrum (MNF [Hz]) and the signal amplitude (RMS [microV]), were computed. The ability to relax in-between the maximum extensions was calculated as a ratio of the RMS during the passive flexion phase and the RMS during the active extension phase of each contraction cycle: the signal amplitude ratio (SAR). Both PT (ICC = 0.99) and RMS (ICC = 0.83-0.98) had good reproducibility. The reproducibility of MNF was good for all muscles when the mean of contraction nos.: 1-10 was used. Vastus lateralis had the highest ICC among the three muscles. The reproducibility of SAR was generally poor (ICC < 0.60). The present study showed good reproducibility for common EMG variables (MNF and RMS) obtained during maximum isokinetic contractions.

Adult↗
PubMed1999

Two methods for the measurement of voluntary contraction torque in the biceps brachii muscle.

Appropriate measurement of maximal voluntary contraction force of a single limb muscle or of a muscle group is important in clinical and research situations. To measure muscle force, one segment of an isometric measuring brace is fixed to a support and force is applied to the other. The output of this arrangement is affected by additional contributions such as pushing or pulling with the whole body. This paper quantifies the differences between measurements of torque produced by the biceps brachii with the brace fixed versus those produced when the elbow joint was isolated by suspending the brace from cables. No statistically significant differences were found between MVC values observed with the two methods within subjects. However, a statistically significant difference in EMG fatigue indices was observed and attributed to a different sharing of force production among different muscles in the two conditions. We conclude that different brace arrangements may lead to the same maximal force but to different rates of myoelectric manifestations of muscle fatigue since the effort may be shared differently among the muscles of synergic or stabilizing groups.

Adult↗
PubMed2000

Torque variations during repeated passive isokinetic movements of the knee in subjects with Parkinson's disease and healthy control subjects.

The purpose of this study was to quantify response variations during isokinetic passive movements of the knee in subjects with Parkinson's disease. Parkinsonian patients demonstrated a greater decrease of resistive torque compared to healthy control subjects, particularly in tests at higher velocities and during knee flexion movements. Responses were influenced by electromyographic activity in stretched and shortened muscle groups and also by mechanical factors. The results indicate that repetition of movements needs to be taken into account when measuring hypertonia in parkinsonian subjects.

Journal Article↗
PubMed1995

A histomorphometric and removal torque study of screw-shaped titanium implants with three different surface topographies.

Screw-shaped implants with 3 different surface topographies, evidenced visually as well as numerically with an optical profilometer, were inserted in rabbit bone. After a healing period of 12 weeks, a statistically significant higher removal torque was needed to unscrew screws blasted with 25-microns TiO2 particles and screws blasted with 75-microns particles of AI2O3 compared with screws with a turned surface. The histomorphometric evaluation demonstrated a higher percentage of bone-to-metal contact for implants blasted with 25-microns particles of TiO2 compared with the as-machined implants. A greater surface area of bone in threads was found for the turned screws compared with screws blasted with 25-microns TiO2 particles. In the short-term follow-up, there was a better fixation of implants with an average surface roughness of 0.9-1.3-microns and with a homogeneous surface structure than of implants with an average surface roughness of 0.4 microns and with a clear direction of the surface pattern.

Aluminum Oxide↗
PubMed2006

Rib torque does not assist resting tidal expiration or most conversational speech expiration.

PURPOSE: This research note discusses a common misconception in speech science and speech-language pathology textbooks that rib torque (i.e., rotational stress) assists resting tidal expiration and conversational speech production. METHOD: The nature of this misconception is considered. CONCLUSION: An alternate conceptualization is offered that is consistent with knowledge from respiratory biomechanics.

Biomechanical Phenomena↗
PubMed1990

Maximal peak torque as a predictor of peak angular impulse and average power of thigh muscles--an isometric and isokinetic study.

The aim of this study was to determine whether isometric and isokinetic peak torque (PT) of hamstring and quadriceps muscles (speed of movement 0 degrees, 60 degrees, and 180 degrees/sec) is a valid predictor of peak angular impulse (PAI) and average power (AP) (180 degrees/sec) in 20 patients after an injury to the lateral collateral ligament (LCL) of the knee. At every test speed the Pearson product moment (r) and the Spearman rank (rs) correlation coefficients between the PT and PAI were highly significant for both muscle groups in the uninjured (r = .71-.96, rs = .76-.96) as well as in the injured (r = .70-.96, rs = .78-.98) knees. The results were the same between the PT and AP (uninjured knee: r = .83-.98, rs = .78-.95; injured knee; r = .64-.97, rs = .74-.96). In both knees and in both muscle groups the correlation coefficients increased towards the highest speed of the isokinetic movement, obviously since the PAI and AP were registered at that speed. In conclusion, concerning LCL insufficient or uninjured knees, the PAI or AP analysis may offer little additional information about thigh muscle function to that attained by more simple measurement, the PT analysis.

Adult↗
PubMed1989

Prospective study of concentric and eccentric leg muscle torques, flexibility, physical conditioning, and variation of injury rates during one season of amateur ice hockey.

Twenty-three male ice hockey players in a third division amateur ice hockey team were prospectively studied during the 1987-1988 season. O2 uptake, muscle flexibility, and isokinetic concentric and eccentric leg muscle strength were measured before and after the season. All injuries were recorded by one and the same physician attending all the games: 68 injuries occurred altogether but only six of these led to absence from training or matches. O2 uptake and muscle flexibility were unchanged during the season, but a significant drop of both concentric and eccentric quadriceps and hamstring torques occurred in spite of the fact that the team played two games and trained twice per week during the entire season. No correlation between the fall in muscle strength and the injury rate was found. Although many injuries occur in ice hockey, the majority are minor ones that do not lead to absence from playing.

Adult↗
PubMed1995

Decreased torque and electromyographic activity in the extensor thigh muscles in chondromalacia patellae.

The alterations in thigh muscle properties of chondromalacia patellae patients during isometric and dynamic endurance tests were studied using a variokinetic knee testing system linked to surface EMG. A total of 41 patients (chondromalacia group) with arthroscopically certified chondromalacia of the patella were studied. The control group consisted of 31 healthy adult volunteers with no history of knee pain or trauma. Peak torque values were 21% (p < 0.01) and force output values 25% (p < 0.05) lower on the symptomatic side of the chondromalacia group than in the control group. The decrease in the ratio between integrated EMG (IEMG) and measured force were found in all parts of the quadriceps femoris muscle in patients with chondromalacia of the patella in isometric extension. No change in the normalized IEMG levels of the thigh muscles were found between chondromalacia patients and controls in dynamic endurance test. The severity of the chondromalacia of the patella did not affect the level of electromyographic activation in thigh muscles. The ratio of normalized EMG levels of vastus medialis and vastus lateralis did not differ between the groups. The present study showed that chondromalacia patellae patients have reduced force and electromyographic activation levels of quadriceps femoris muscle. Especially, the explosive strength of the quadriceps femoris muscle is reduced.

Adolescent↗
PubMed2004

Calculations of helical twisting powers from intermolecular torques.

We present a Monte Carlo molecular simulation method that calculates the helical twisting power of a chiral molecule by sampling intermolecular torques. The approach is applied to an achiral nematic liquid crystalline system, composed of Gay-Berne particles, that is doped with chiral molecules. Calculations are presented for six chiral dopant molecules and the results show a good correlation with the sign and magnitude of experimentally determined helical twisting powers.

Computer Simulation↗
PubMed2006

Unifying kinetic approach to phoretic forces and torques onto moving and rotating convex particles.

We derive general expressions and present several examples for the phoretic forces and torques acting on a translationally moving and rotating convex tracer particle, usually a submicrosized aerosol particle, assumed to be small compared to the mean free path of the surrounding nonequilibrium gas. Point of departure is an expression of the stress tensor in terms of half-sphere integrals to be evaluated with the inhomogeneous velocity distribution function of the surrounding gas, more specifically, its approximation in terms of a finite number of moments. A worked out example covers Grad's 13 moment approximation in and out of the so-called hydrodynamic approximation. We implement an accommodation coefficient characterizing the collision process in order to derive the tracer particle's complete equations of motion in a form which offers the possibility for immediate numerical implementation, and the analytical exploration of the effect of particle shape and size on phoretic drift velocity. Explicit expressions for axisymmetric, spherical, cylindrical, and also cuboidal particles are presented, discussed, and successfully compared with the rarely available, previously treated special cases, thus supporting the unifying approach presented in this manuscript.

Journal Article↗
PubMed1997

Purification and characterization of blood group A-degrading isoforms of alpha-N-acetylgalactosaminidase from Ruminococcus torques strain IX-70.

To cleave blood group A immunodeterminants from erythrocytes (Hoskins, L. C., Larson, G., and Naff, G. B. (1995) Transfusion 35, 813-821), we purified and characterized alpha-N-acetylgalactosaminidase (EC 3.2.1.49) activity from culture supernatants of the human fecal bacterium Ruminococcus torques strain IX-70. Three isoforms separated during hydrophobic interaction chromatography. Hydroxyapatite chromatography further resolved the most hydrophilic, isoform I, into isoforms IA and IB. The most hydrophobic, isoform III, differed from IA and IB by a more acidic pH optimum, greater heat resistance, greater sensitivity to alkylating agents, and anomalous retardation during gel filtration chromatography. Isoform IB differed from IA and III in N-terminal amino acid sequence and in sensitivity to EDTA inhibition. Each cleaved nonreducing alpha(1-->3)-N-acetylgalactosamine residues from human blood group A and AB mucin glycoproteins, Forssman hapten, and blood group A lacto series glycolipids. The apparent molecular mass of denatured isoform subunits of IA, IB, and III-PII (158, 173, and 201 kDa, respectively) bore no integer relationship to the apparent molecular mass of the native isoforms (265, 417, and 530 kDa), but the latter bore a ratio of 1.96:3.09:3.93 to the weight-average apparent molecular mass of native IA (135 kDa), suggesting that the isoforms are multimers of a 135-kDa sequence. Isoforms IA and III-PII had an identical N-terminal amino acid sequence which showed homologies to the N-terminal sequence of sialidases produced by Bacteroides fragilis SBT3182, another commensal enteric bacterium.

ABO Blood-Group System↗
PubMed1997

The influence of gloves during maximum volitional torque exertion of supination.

This study focuses on the influence of friction between gloves and handle surface during maximum volitional torque exertion of supination (S-MVTE) and under both friction-controlled and regular friction conditions. Forty student subjects (20 males and 20 females) participated in this study. Five types of gloves (surgical, single cotton, double cotton, leather, and rubber), seven handle sizes (25.4, 31.8, 38.1, 44.5, 50.8, 57.2, and 63.5 mm in diameter) and two handle shapes (cylindrical and hexagonal) were evaluated to determine their combined influences on S-MVTE. The barehanded condition was also included for comparison. The results indicate that all the main effects were significant (P < 0.001). Under friction-controlled conditions (oiled surface handle), the S-MVTEs with gloves were found to be greater than the S-MVTEs of the gloveless, and the thicker the gloves, the greater the S-MVTE. On the other hand, under regular (unoiled) conditions, the S-MVTE was mainly affected by the friction between handle surface and gloves, although the interaction between gloves and handle shape was also a minor influence. A hexagonal handle produced, in all handle diameters, greater S-MVTE than a cylindrical handle. The mean S-MVTE under oiled conditions was about 53% of that of unoiled conditions. The mean S-MVTE of females was about 61% of that of males.

Adolescent↗
PubMed1990

Relationships between peak torque, peak angular impulse, and average power in the thigh muscles of subjects with knee damage.

The purpose of this study was to determine the relationship between the isometric and isokinetic peak torque (PT) (speed of movement 0, 60, and 180 deg/s) and the peak angular impulse (PAI) and average power (AP) of multiple contractions (180 deg/s) of the quadriceps and hamstrings in 29 patients with a chronic, complete deficiency of the medial collateral ligament (MCL) of the knee. At every test speed the Pearson product moment (r) and the Spearman rank (rs) correlation coefficients between the PT and PAI were highly significant for both muscle groups in the uninjured (r = .81-.97, rs = .77-.97) as well as in the MCL deficient (r = .77-.97, rs = .75-.95 knees. The results were the same between the PT and AP (uninjured knee: r = .83-.98, rs = .82-.98; MCL deficient knee: r = .78-.97, rs = .76-.97). In both knees and in both muscle groups the correlation coefficients increased toward the highest speed of the isokinetic movement, obviously because the PAI and AP were registered at that speed. In conclusion, concerning MCL deficient or uninjured knees the PAI or AP analysis may offer little additional information about thigh muscle function to that attained by more simple measurement, the PT analysis.

Adult↗
PubMed2001

Ankle dorsiflexor muscle performance in healthy young men and women: reliability of eccentric peak torque and work measurements.

The aims of this study were: (i) to assess the test-retest intrarater reliability of eccentric ankle dorsiflexor muscle performance in young healthy men and women using the Biodex dynamometer; and (ii) to examine different statistical indices for the interpretation of reliability. Thirty men and women (age 22.5 +/- 2.5 years, mean +/- S.D.) performed three maximal eccentric contractions at 30 degrees/second and 90 degrees/second, with 7-10 days between test sessions. Reliability was evaluated with three intraclass correlation coefficients (ICC1,1, ICC2,1 and ICC3,1), and was excellent for peak torque (ICC 0.90-0.96) and good to excellent for work (ICC 0.69-0.83), with no discernible differences among the three ICCs. Method errors, assessed by the standard error of the measurement (S.E.M.) and S.E.M.%, were low. The Bland & Altman graphs and analyses indicated no significant systematic bias in the data. In conclusion, measurements of eccentric ankle dorsiflexor muscle performance in young healthy individuals using the Biodex are highly reliable.

Adult↗
PubMed1990

Hand-held compared with isokinetic dynamometry for measurement of static knee extension torque (parallel reliability of dynamometers).

The purpose of this study was to compare measurements of static knee extension torque obtained using a hand-held dynamometer (HHD) and an isokinetic dynamometer (IKD). Twenty young healthy women performed two maximum knee extension efforts against each device. The two HHD measurements did not differ significantly and were highly reliable (intraclass correlation coefficient (ICC) = 0.945). The two IKD measurements did not differ significantly and were highly reliable (ICC = 0.932). The mean of the two HHD and two IKD measurements did not differ significantly. The inter-instrument reliability was fair (ICC = 0.797). Thus, under limited circumstances the instruments may be interchangeable. The less expensive and more portable HHD may be a practical alternative for the clinical measurement of muscle strength.

Adult↗