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 487 records · Page 27Linked to original sources
PubMed1996

Fixation strength of interference screw fixation in bovine, young human, and elderly human cadaver knees: influence of insertion torque, tunnel-bone block gap, and interference.

A failure analysis of interference screw fixation was performed to test the hypothesis that bovine and/or elderly human cadavers are appropriate models for bone-patellar tendon-bone anterior cruciate ligament (ACL) reconstruction fixation studies. Failure mode is an important criterion for validating experimental models. The bovine, young human, and elderly human failure loads were 799 +/- 261 N, 655 +/- 186 N, and 382 +/- 118 N, respectively, and the failure modes were 75%, 69%, and 30% tissue failures, respectively. The similarities between the bovine and young human models in failure loads and failure modes indicate that bovine models are appropriate for ACL reconstruction fixation studies. The statistically significant differences between the young human and elderly human models in failure loads and failure modes indicate that elderly human cadavers are not an appropriate model for ACL reconstruction fixation studies. The differences in failure modes are consistent with previous studies using elderly human cadavers in which the predominant failure mode was bone block pullout. The tissue failures observed in the bovine and young human models contradict previous studies suggesting fixation strength is the weakest link in bone-patellar tendon-bone ACL reconstruction. Results of linear regression modeling showed statistically significant correlations between insertion torque and failure load (R2 = 0.44, P < 0.0001) and interference (defined as the screw outer thread diameter minus the tunnel-bone block gap) and insertion torque (R2 = 0.18, P = 0.003) when data from all models was combined. Results for the bovine model multiple regression showed a statistically significant regression of insertion torque (linear) and interference (quadritic) versus failure load (R2 = 0.56, P = 0.02). Regression slopes for screw diameter (P = 0.52) and gap size (P = 1.00) were not statistically significant. These results indicate that insertion torque and interference are independent predictors of failure load and should be included in future interference screw studies in addition to bone block dimensions, tunnel size, gap size, and screw diameter. Clinicians may consider using insertion torque and interference as indicators of postoperative graft fixation regarding rehabilitation decisions.

Adult↗
PubMed1993

Effect of taping the patella on concentric and eccentric torque and EMG of knee extensor and flexor muscles in patients with patellofemoral pain syndrome.

The acute effect of patella taping on torque and electromyographic (EMG) activity in maximal voluntary concentric and eccentric action of the knee extensor and flexor muscles in patients with patellofemoral pain syndrome was studied in 48 patients (62 knees). The patients (28 female, 20 male) were tested concentrically and eccentrically on a Kin-Com dynamometer with simultaneous EMG recording with the patella untaped and medially or laterally taped. Patients with clinically normal patellar mobility did not improve their quadriceps performance by taping of the patella; after medial taping they decreased their muscle torque during concentric work at 60 degrees/s (P < 0.05) and eccentric work at 180 degrees/s (P < 0.05). After lateral taping they decreased their muscle torque during concentric work at 60 degrees/s (P < 0.05) and eccentric work at both 60 degrees/s (P < 0.01) and 180 degrees/s (P < 0.05). Moreover, these patients also decreased their agonist EMG activity during concentric work at 60 degrees/s (P < 0.05) and 180 degrees/s (P < 0.05) and their antagonist EMG activity during eccentric work at 60 degrees/s (P < 0.01). Patients with a clinical lateral patellar hypermobility increased their knee extensor torque after medial taping at 60 degrees/s during both eccentric work (P < 0.01) and concentric work (P < 0.05). The greatest improvement in quadriceps performance, however, was in patients with a clinical medial patellar hypermobility. They increased their knee extensor torque after lateral taping during eccentric work at both 60 degrees/s (P < 0.001) and 180 degrees/s (P < 0.001) and during concentric work at 60 degrees/s (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2000

Human hip and knee torque accommodations to anterior cruciate ligament dysfunction.

It has been postulated that the adaptations of lower extremity function exhibited by anterior cruciate ligament (ACL) deficient and post-ACL surgical patients represent early accommodations to the loss of ACL function after injury so that excessive anterior displacement of the tibia is prevented. Prior studies have suggested that compensation patterns in ACL deficient and post-ACL surgical subjects may affect joint moments of the knee as well as the hip. However, the variance in knee and hip forces between ACL deficient, post-surgical ACL and uninjured groups has not been clearly elucidated. The purpose of this study was to assess hip:knee extensor torque ratios relative to anterior tibia shear in pre-surgical-ACL deficient, post-surgical and uninjured subjects. Measurements of hip and knee joint moments and anterior tibia shear were recorded from 45 injured and uninjured subjects (21 men, 24 women) during lower extremity, variable resistance exercise. Anterior tibia shear was computed by decomposing joint moments and reaction forces according to a model derived from cadaver knee dissections and radiography, in combination, to estimate the tibio-femoral compressive and shear forces generated by the patellar tendon at various angles throughout the knee joint range. Three groups of subjects were studied: recently injured ACL deficient pre-surgical subjects who were scheduled for immediate surgery (PRE; n = 15); postsurgical subjects who had undergone ACL reconstructive surgery at least 1 year prior to testing (POST; n = 15); and uninjured controls (CON; n = 15). All PRE and POST subjects had a normal contralateral limb. Tests were conducted under six conditions: 1 and 1.5 Hz cadence and maximal speed at 33% and 50% one repetition maximum resistance. The results revealed that the hip:knee ratios were significantly greater for the post-ACL surgical group than the PRE and CON groups (P<0.01; P<0.03). There were significant negative correlations between the hip extensor:knee extensor torque ratios and maximal anterior tibia shear across all groups. The hip:knee extensor torque ratio increased with decreased anterior tibia shear in all groups with significant correlations ranging from -0.55 to -0.88 (P<0.01) for the injured limbs of PRE and POST groups, and -0.64 to -0.78; (P<0.01) for the CON group. The highest overall correlations were found for the post-surgical subjects. The results revealed that anterior tibia shear declined significantly with speed (P<0.01) in all groups. However, the converse was true for the hip:knee extensor torque ratio across speeds. The ratio increased significantly with speed (P<0.001) for all groups at the 33% and 50% resistances. The results suggest (1) that post-ACL surgical subjects appear to accommodate to ACL substitution by using hip extensors to a significantly greater extent than the uninjured controls in closed-chain lower extremity exercise; (2) that the hip:knee extensor torque ratio is significantly related to the magnitude of anterior tibia shear; and (3) that the anterior tibia shear is significantly reduced as speed increases in closed-chain lower extremity exercise.

Adaptation, Physiological↗
PubMed1993

Torque reaction in angled nutrunners.

In the process of tightening a joint, the angled nutrunner acts on the operator with a torque reaction in the final stages of the tightening sequence. In the following series of experiments, the torque reaction of a machine acting on various joints is studied. A distinctive feature of the torque reaction is that the handle of the angled nutrunner causes a rapid displacement. The amplitude and time aspect of this displacement depend on the stiffness of the joint (whether it is hard or soft), and the movement of the handle depends on how the operator is holding it. How the operator responds to the torque reaction depends upon, among other things, the displacement amplitude as well as the torque level of the machine. Because of this, the displacement amplitude can be used as a measure of the operator's discomfort.

Journal Article↗
PubMed1975

Precentral unit activity following torque pulse injections into elbow movements.

(1) Precentral neural activity was studied in relation to transient load changes on self-paced elbow movements. Four Cebus monkeys were trained to turn a freely moving handle back and forth between two targets by alternating self-paced elbow flexions and extensions. Torque pulses (of 10 or 100 msec) injected randomly to load or unload the movements stretched or slackened the appropiate prime movers: biceps or triceps. Perturbed movements oscillated at about 5.5 Hz but were completed successfully in about the same time as unperturbed movements. (2) Torque pulses evoked distinct "early" responses with latencies of 20-40 msec in 134 out of 153 precenteral neurons. Oppositely directed torque pulses evoked reciprocal (i.e. increased or decreased) early responses in 61 neurons, and uniform responses in 27 neurons. (3) Early responses were followed by "late" responses with peaks succeeding one another at about 5.5 Hz in 111 neurons, but another 16 exhibited late responses only. (4) Timing of both early and late cortical responses was tightly coupled to peripheral changes. Early responses were timed by the initial torque-induced passive elbow jerk. Timing of late responses was best related to subsequent peak decelerations of accelerations. Intensity of the early but not of all late precentral responses was tightly coupled to peripheral events. (5) Torque pulses that impeded flexions or extensions evoked spinal stretch reflexes in biceps or triceps with EMG latencies of about 15 msec, leading to an acceleration peak about 25 msec later. A second EMG burst followed the first in about 30 msec. The second burst occurred about 20 msec after onset of the early precentral response, which is thought to have caused it, as well as a second acceleration peak that was seen about 60 msec after precentral response (for flexion load pulses). Peaks of late precentral responses were followed by acceleration peaks within about 70 msec. (6) An interaction akin to the spinal stretch reflex is thus revealed between elbow perturbations, early responses of precentral neurons and subsequent elbow movements: discharges of neurons that usually fire in relation to an intended movement can be altered by sudden load changes so that the neurons tend to reduce mismatch between intended and actual movements (cortical load compensation), created by the perturbation. An analagous interaction may also occur with late cortical responses.

Adaptation, Physiological↗
PubMed1985

Behavior of single motor units of human tibialis anterior muscle during voluntary shortening contraction under constant load torque.

The recruitment and discharge frequency of motor units during voluntary shortening contraction with constant load torque were studied in tibialis anterior muscle of 10 human subjects trained to dorsiflex the tibiopedal joint as linearly as possible from 30 degrees plantar flexion from the neutral position (tibiopedal joint angle, 90 degrees) by 20 degrees in 1, 2, 3, 5, 8, and 10 s. A constant load torque of 0, 5, 10, 20, and 25% of maximum voluntary torque of the muscle was applied. When speed of shortening contraction was constant there was considerable degree of constancy in the muscle length at which individual motor units were recruited. However, the recruitment order was not rigidly fixed among the units whose length range of recruitment overlapped. When the contraction was performed faster the units were recruited earlier. The discharge frequencies of the motor units changed little with a given ramp shortening of the muscle. There were also few changes in frequency among different contraction speeds. With increasing load torque to the muscle, the discharge frequency increased slightly at a rate of 1 to 2 Hz by increase of the load. The results suggest that the speed of shortening was coded by recruitment of motor units and that discharge frequency did not play any major role when a muscle was shortened under constant load torque.

Adolescent↗
PubMed1994

Shaping static elbow torque-angle relationships by spinal cord circuits: a theoretical study.

Static torque-angle relationships (invariant characteristics) as measured by Feldman [Feldman A. G. (1980) Neuroscience 5, 81-90] at the human elbow joint for constant descending excitatory drive have a monotonic convex shape determining joint angle-dependent stiffness. In contrast, for constant activation of elbow flexors, the torque increases, peaks and decreases again with increasing angle because of related moment arm alterations [Hasan Z. and Enoka R. M. (1985) Expl Brain Res. 59, 441-450]. Conversion of such constant-excitation torque-angle shapes into an invariant characteristic might result from action of the stretch reflex which adds excitation with increasing joint angle. To test whether a simple linear model of the stretch reflex could convert constant excitation torque-angle relationships into invariant characteristics, the following assumptions were made. (1) Muscle fibre length increases linearly with joint angle. (2) Reflex muscle excitation (electromyogram) is linearly related to muscle (fibre) length. With these assumptions, invariant characteristic shape cannot be derived from constant excitation torque-angle relationships because it would be sigmoid at low and nearly straight at large joint angles, whilst real flexor invariant characteristics are more convex at large than small angles. It is suggested that recurrent inhibition via Renshaw cells contributes to bend the invariant characteristics into their right shape. Renshaw cells show a nonlinear saturating dependence on motor axon input rate and amount of excitation, i.e. number of active axon collateral synapses. These relationships can contribute to shape motoneuron output so as to yield convex invariant characteristics. Whilst it is not quite clear whether the gain of recurrent inhibition from and to skeleto-motoneurons is high enough to co-determine the invariant characteristic shape significantly, recurrent inhibition of Ia inhibitory interneurons mediating reciprocal inhibition between antagonists is supposed to be quite strong and may influence joint stiffness by interacting with reciprocal inhibition. The arguments presented here extend those of Feldman and co-workers concerning the role of recurrent inhibition and in addition provide a possible explanation for the functional role of mutual inhibition between Renshaw cells. Together with reflex feedback, recurrent inhibition thus contributes to fine-regulate force output and joint stiffness. To account for this cooperation and to make another step towards a general theory of spinal cord circuits, major traits of a new concept are briefly outlined.

Biomechanical Phenomena↗
PubMed2006

The influence of pulleys on the quantitative characteristics of medial rectus muscle recessions: the torque vector model.

PURPOSE: To develop a new pulley-based torque vector mathematical model for medial rectus muscle recessions and compare it based on known clinical characteristics, to the currently accepted nonpulley length-tension model. METHODS: The following quantitative characteristics of the results of bilateral medial rectus muscle recessions were chosen for study to see whether the new torque vector model or the classic length-tension model would better predict these characteristics: (1) larger bilateral medial rectus muscle recessions produce more effect per millimeter, with the dose-response curve approximating an exponential shape; (2) the exact location of the preplaced medial rectus muscle suture prior to muscle disinsertion in recessions has minimal effect on the postoperative ocular alignment; and (3) medial rectus muscle recessions of more than eight mm are likely to produce an early consecutive exotropia. RESULTS: Based on the documented location of the medial rectus muscle pulley, the change in the torque vector per millimeter of medial rectus muscle recession was calculated and shown to have an exponential shape. For all three of the quantitative characteristics chosen, the torque vector model appears to better predict the results of medial rectus muscle recessions when compared with the length-tension model. CONCLUSIONS: Many quantitative characteristics of medial rectus muscle recessions are better explained by the torque vector model, instead of the classical length-tension model, and support the presence, location, and function of the medial rectus muscle pulley. This new understanding of ocular motility mechanics may influence surgical technique and introduce new surgical considerations for correction of ocular motility disorders.

Humans↗
PubMed2003

A comparison of eccentric isokinetic torque production and velocity of knee flexion angle during step down in patellofemoral pain syndrome patients and unaffected subjects.

OBJECTIVE: To determine knee angular velocity changes during stair descent and slow velocity eccentric isokinetic quadriceps contraction, in normal controls and patellofemoral pain syndrome patients. DESIGN: Isokinetic and kinematic analysis of the performance of patellofemoral pain syndrome patients and matched normal controls. BACKGROUND: In the presence of increased patellofemoral joint stresses, patellofemoral pain syndrome patients have been shown to adopt compensatory strategies to minimise joint loading and therefore pain. One of the compensatory strategies reported, is that of the break phenomena, which results in a change quadriceps torque production. METHODS: Twenty female patients with patellofemoral pain syndrome and 20 asymptomatic matched controls participated in the study. All subjects had their isokinetic eccentric and concentric quadriceps torque assessed at 30 degrees/second and 2-dimensional video data taken when descending from a step. Variations in knee angular velocity and torque curves were then identified. RESULTS: None of the subjects demonstrated a break on isokinetic concentric quadriceps contraction. Of the patellofemoral pain syndrome patients, 50% (10 out of 20) had a break in eccentric torque curve on testing, compared with 15% (3 out of 20) of the controls. Abnormal curve perturbation was demonstrated to occur in none of the controls isokinetically, but 20% (4 out 20) of the patellofemoral pain syndrome patients had perturbations in their torque curves. On stair decent a break was seen in 60% (12 out of 20) of the patellofemoral pain syndrome patients and 15% (3 out of 20) of the control subjects on analysis of the knee angular velocity. Twenty percent (4 out of 20) of the patellofemoral pain syndrome patients and 10% (2 out of 20) of the controls had abnormal curve perturbation on analysis of their stair descent. CONCLUSIONS: The implications are that there appears to be a relationship between patellofemoral pain syndrome and control of eccentric quadriceps contraction. This relationship is possibly related to joint and soft tissue loading not just the degree of pain, with the break being a saving reflex to prevent further stress. RELEVANCE: Exercise to rehabilitate the quadriceps in patellofemoral pain syndrome should be chosen with regard to joint loading and range of movement as well as velocity of contraction, in order to facilitate quadriceps activation as opposed to inhibiting it.

Aged↗
PubMed1994

In vitro torque-deformation characteristics of orthodontic polycarbonate brackets.

The purpose of this study was to investigate the torque-deformation characteristics of the following four types of polycarbonate brackets: (1) pure polycarbonate, PPC (anterior Miura, RMO, Denver, Colo.), (2) ceramic reinforced polycarbonate, CRPC (Silkon bracket, American, Sheboygan, Wis.), (3) metal slot reinforced polycarbonate, MRPC (Plastic bracket, Tella Tech, Miami, Fla.), and (4) metal slot and ceramic reinforced polycarbonate, MCRPC (Spirit, Ormco, Glendora, Calif.). A stainless steel bracket, (Mini Diamond, Ormco, Glendora, Calif.), was used as a control. Ten brackets of each type were tested. Each bracket was bonded to a porcelain tooth and engaged in a torquemeter. The tooth-bracket assembly was made stationary by embedding it in die stone. Torsion was applied to the bracket at 4 degrees per minute and the resultant torque (grams.centimeters) and deformation (degree) were measured. For optimum labiolingual tooth movement for a maxillary incisor at 175 grams . centimeters, the amount of angular deflection necessary for the different polycarbonate brackets was the following: (a) 15 degrees for MRPC, (b) 17 degrees for MRPC, (c) 24 degrees for CRPC, and (d) > 30 degrees for PPC. The amount of deformation at this deflection was the least for MRCP followed by MCRPC, CRCP, and PPC. When compared with the stainless steel bracket, all polycarbonate brackets showed significantly (p < 0.0001) higher deformation and lower torque. Within the polycarbonate group, there was a significant difference (p < 0.0001) between each bracket for both measurements. The MRPC produced the highest torque and lowest deformation values followed by the MCRPC, CRCP, and PPC. It appears that only the metal slot reinforced brackets are clinically capable of torquing teeth sufficiently.

Analysis of Variance↗
PubMed2001

Spasticity versus strength in cerebral palsy: relationships among involuntary resistance, voluntary torque, and motor function.

Despite the lack of consensus of the role of spasticity in the observed motor disability in cerebral palsy (CP), alleviation of spasticity remains a primary focus in the clinical management of these patients. The purposes of this study were to: (1) quantify voluntary torque and passive resistance across speeds in the hamstrings and quadriceps muscle groups with respect to the presence of stretch responses and/or passive muscle stiffness in patients with CP compared to age-related children without disability, and (2) relate these parameters to each other and to functional performance, as measured by the Gross Motor Function Measure (GMFM), in CP. Included were 23 subjects with CP, sub-grouped by the presence or absence of stretch responses as determined by electromyography, and 9 subjects without CP. Results indicated that peak torque was considerably greater in the comparison group than for each of the CP groups and resistance was greater in the CP group with spasticity compared to the nonspastic CP group in both muscles at all speeds. Stiffness differed between the spastic CP group and the comparison group only for the quadriceps at the fastest speed. Higher passive resistance torque and stiffness were correlated with decreased voluntary torque, particularly for the antagonists, and with lower GMFM scores. In conclusion, strength and motor function are related to the magnitude of resistance torque and stiffness in CP, although the small amount of variance explained reinforces the multidimensional nature of this disorder, and the challenges inherent in managing it.

Analysis of Variance↗
PubMed1989

The effect of velocity-specific strength training on peak torque and anaerobic rowing power.

This study investigated the effect of low- and high-velocity resistance training on isokinetic peak torque and anaerobic power output. Eighteen male varsity oarsmen were blocked on peak knee extension torque at 3.14 rad s-1 and assigned to a high-velocity resistance training group (HVR), a low-velocity resistance training group (LVR) or a control group. Subjects trained four times a week for 5 weeks. Each training session included three circuits of 12 stations using variable-resistance hydraulic equipment. The HVR training significantly improved peak torque (P less than 0.05) in knee extension and flexion at 2.61, 3.14, 3.66 and 4.19 rad s-1. The LVR training produced significant improvements (P less than 0.05) in peak torque for knee extension and flexion at 0.52, 1.05, 1.57 and 2.61 rad s-1. High positive correlations were found between peak torque and anaerobic power outputs for all groups. However, no significant changes occurred in 15 s power output, average 90 s power output or peak blood lactate in either training group. These results indicate that velocity-specific strength training does not necessarily improve anaerobic power output in a different exercise mode despite the high positive correlation between isokinetic strength and anaerobic power output.

Adult↗
PubMed2000

Direct pelletization in a rotary processor controlled by torque measurements. I. Influence of process variables.

The aim of this study was to elucidate the feasibility of using torque measurement to control the end point of a wet pelletization process in a rotary processor at varying levels of friction plate rotation speed, air gap pressure difference, and batch size. A 1:1 mixture of lactose monohydrate (200 mesh) and microcrystalline cellulose (PH-101) was granulated into pellets in an instrumented laboratory scale rotary processor using water as aqueous binder liquid. A full factorial designed study was performed to investigate the influence of the friction plate rotation speed (600 and 1200 rpm), the air gap pressure difference (1 and 3 kPa), the torque increase (0.4 and 0.8 N.m) and the batch size (500 and 1000 g) on the pellet properties. All pellets produced were round and showed a narrow size distribution. The geometric mean diameter varied from 400 to 1900 microns with a good reproducibility. Increasing the batch size and the rotation speed led to smaller pellets, whereas a higher torque produced larger pellets. This study showed that the process can be controlled by means of the torque increase because it was possible to produce pellets of a reproducible size by stopping the liquid addition at a certain torque level.

Drug Compounding↗
PubMed1978

Isometric torque of the finger extensors at the metacarpophalangeal joints.

A pilot study was undertaken to evaluate the isometric torque produced at the metacarpophalangeal joint during finger extension. Fifteen women with normal right hands, aged 21 to 29 years, participated. Each subject was tested for maximal force of isometric extension at the metacarpophalangeal joint angles of 0, 30, and 60 degrees on each of the four fingers. Torque was computed by multiplying the recorded tension and measured length of the proximal phalanx (lever arm). The mean torque for the long finger was significantly greater than the average torque for each of the other three fingers. The mean torque at the joint angle of 60 degrees was significantly greater than at 0 degrees but not at 30 degrees. Reasons for the findings are discussed.

Adult↗
PubMed1984

Effect of trunk stabilization on quadriceps femoris muscle torque.

The purpose of this study was to determine if differences exist in angle-specific torque, torque-velocity relationships, and power-velocity relationships of the quadriceps femoris muscle group when the trunk was and was not stabilized and the starting position was varied. We calculated isokinetic torques from seven adult men while the trunk was and was not stabilized for nine combinations of velocity of movement 0, 30, and 105 degrees/sec) and starting position (40, 60, and 100 degrees of knee flexion). The results suggest that peak angle-specific torques and instantaneous power are greater when the trunk is stabilized, the increase in the trunk-stabilized torque and power was greater at the higher velocity and for the larger ranges of motion, and the testing movement should not begin beyond 30 degrees of the angle of interest.

Adult↗
PubMed1986

Decreased isometric knee flexion torque with hip extension in hemiparetic patients.

I measured the 90-degree isometric knee flexion torque of 12 hemiparetic patients while they performed unilateral knee flexion in sitting and supine positions. The measurements were taken to clarify why hemiparetic patients have difficulty flexing their involved knees when their involved hip is extended. The patients generated more torque in the sitting position than in the supine position and more torque on their nonparetic side than on their paretic side. The ratio of supine-to-sitting knee flexion torque did not differ significantly between sides. This finding suggests that hemiparetic patients do not have relatively greater difficulty generating knee flexion torque on their involved side with the hip extended than with the hip flexed. Recommendations for assessment and treatment are made with this finding in mind.

Adult↗
PubMed1986

Effect of resisted knee flexion on knee extension torque.

We tested the principle of "reversal of antagonists" by measuring the effect of resisted knee flexion on subsequent peak knee extension torque at velocities of 60 degrees/sec and 120 degrees/sec using an isokinetic dynamometer. We determined peak knee extension torques from torque curves produced during knee extension that was performed reciprocally with either passive or maximum voluntary resisted knee flexion. We used a crossover design so that all 18 healthy adult subjects performed knee extension reciprocally with both passive and resisted knee flexion. Paired means t tests revealed no statistically significant difference between the peak knee extension torques produced under the two knee flexion conditions either at 60 degrees/sec or 120 degrees/sec. We, therefore, concluded that resisted knee flexion does not augment peak knee extension torque under our conditions of testing. The concept of reversal of antagonists was not supported. Antagonistic muscle functioning, therefore, may be irrelevant to agonist isokinetic testing and training in neurologically healthy persons.

Adult↗
PubMed1990

Validity of knee flexion and extension peak torque prediction models.

The primary purpose of this study was to test the validity of predictive models relating isokinetic knee torque production to anthropometric and demographic variables. Subjects were 23 healthy female and 15 healthy male volunteers between the ages of 10 and 77 years. We measured subjects' peak knee flexion and extension torque production at two angular velocities. For each torque dependent variable, we calculated a Pearson product-moment correlation coefficient between the measured torque values and the values obtained with prediction equations. The difference between the squared value of the correlation coefficients and the regression multiple R2 values obtained for an original group of 134 subjects ranged between .05 and .10 for the torque dependent variables. The results indicate the validity of the regression models at the level specified by the multiple regression R2 values. Clinicians can use the prediction equations presented in this article to establish rehabilitation goals for patients and can estimate the error involved in applying each prediction equation.

Adolescent↗