PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “REFLEX, TENDON”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources
PubMed1979

[Quantitative measurement of the tendon reflexes. A study on Achilles tendon reflex (author's transl)].

Quantitative analyses of tendon reflexes were performed for the purpose of clinical application. Tendon tap was marked with a WNS-5D semiconductor load cell inserted in the hammer to measure tapping force. Achilles tendon reflex (ATR) was measured with a LAS-0.1 displacement transducer in kneeling position on the chair. In ATR, six factors, i.e. duration of reaction time, the height of the wave, the time from the hammer tap to the top of the wave, the maximum speed of contraction, the time from the hammer tap to the maximum speed and half relaxation time, were analyzed. Correlation between these six factors were discussed. From the analyses of these factors, half relaxation time may serve as the best indicator of clinical status among the factors obtained by analysis of ATR.

Achilles Tendon↗
PubMedDate not supplied

Age and sex dependency of the Achilles tendon reflex.

Achilles tendon reflex time was measured in normal subjects (1,837 females and 7,937 males). Values of half relaxation time showed a clear dependency on both age and sex. The reflex becomes slower with advancing age and was consistently slower in females. The results redefine the normal range of the Achilles tendon reflex. Regression lines of relaxation time on age were fitted for each sex separately. Lines representing linear regression, log-linear regression or quadratic regression were inferior to those described by linear splines. The gradual increase of Achilles tendon relaxation time with age was not due to unrecognized hypothyroidism or peripheral neuropathy. It is suggested that one cause of the progressive increment is diminution of sympathetic tone with age, and changes in the muscles themselves may also contribute.

Achilles Tendon↗
PubMed1999

System identification of tendon reflex dynamics.

Patellar tendon reflexes were evaluated in 12 healthy adult subjects using several measures of the reflex responses and of the system input-output relationship. A hand-held instrumented hammer was used to tap the patellar tendon and to elicit the reflex response. Tendon reflex dynamics were estimated using the recorded tapping force (as input) and the quadriceps muscle electromyogram and knee joint extension torque signals (as output). A dome-shaped rubber pad was mounted onto the most sensitive spot on the patellar tendon, where it served as a tapping target, and helped to reduce the reflex variability significantly (p < 0.01). The input-output properties of the system relating the reflex torque to the tapping force were characterized using several measures: the tendon reflex gain (Gtr), contraction rate (Rc), and half-relaxation rate (Rhr). Reflex loop delay (t(d)) was estimated using the delay from the onset of tapping force to the onset of reflex torque. We determined that these system parameters provided significantly more repeatable and consistent characterization of tendon reflexes than did reflexive torque or EMG signals alone (p < 0.025). The input-output relationship relating the EMG signals of the stretched muscle to the tapping force was also identified to help characterize neuromuscular dynamics of tendon reflexes. The observed sensitivity and consistency of the reflex system measures suggest that with appropriate simplification of the instrumentation, these methods may prove useful in routine clinical practice, and may allow more precise quantification of the tendon jerk than is currently feasible with standard clinical tests.

Adult↗
PubMed1977

Conditioning of H reflex by a preceding subthreshold tendon reflex stimulus.

The soleus H reflex excitability cycle has been studied using, as conditioning stimulus, a mechanical tap, subthreshold for the tendon reflex, which was applied either on the Achilles tendon, the short biceps tendon, or the quadriceps tendon. In all cases there was an early facilitation followed by a longlasting inhibition of the test H reflex. The same results were obtained in patients with a complete spinal cord section. Wherever the site of the conditioning stimulation, these modifications disappeared after ischaemia of the leg. It is concluded that the effects observed are due to the activation by the tendon tap of the Ia nerve fibres from the soleus muscle, and that the longlasting inhibition is probably due to a transmitter depletion.

Adult↗
PubMed1982

Measurement of the Achilles tendon reflex for the diagnosis of lumbosacral root compression syndromes.

The Hoffmann reflex and the Achilles tendon reflex were measured in a group of 194 subjects suspected of having a lumbosacral root compression syndrome. The Achilles tendon reflex was elicited manually with a metal hammer. There was a high correlation between the H-M interval and the Achilles tendon reflex-M interval. The usefulness of the Achilles tendon reflex was evaluated in a selected sub-group of 61 patients with proven L5 or S1 root compression. Neither the H-reflex nor the Achilles tendon reflex appeared to be of any value in detecting L5 root compression. Both the H-reflex and the Achilles tendon reflex proved to be useful for diagnosis of S1 root compression syndromes, the latter being the more sensitive method.

Achilles Tendon↗
PubMedDate not supplied

[Reflex studies of the patellar tendon reflex in patients with varus gonarthrosis].

We discuss the role of the neuromuscular system following biomechanical circumstances for the development of osteoarthritis of the knee joint. We examined in 58 patients suffering from osteoarthritis with varus deformity and 22 healthy people the latency and velocity of the patellar tendon reflex. We found with increasing age and by osteoarthritis of the knees shorter reflex latencies, that we see as disintegration of motor system.

Electromyography↗
PubMed1990

Reliability of the clinical and electromyographic examination of tendon reflexes.

The reliability of clinical examination of the tendon reflexes was examined by studying inter-observer agreement. Twenty patients were examined by three neurologists. The briskness of the tendon reflexes in arms and legs was scored on a nine-point scale. In 28% of the 160 examined reflexes the observations disagreed 2 scale units or more. Disagreement on the presence of asymmetry occurred in 45% of the 80 reflex pairs. In 15% one observer judged a reflex pair to be symmetrical while another observer found asymmetry of at least 2 scale units. In a second experiment clinical observation of apparently asymmetrical quadriceps reflexes was compared with measurement by surface electromyography. A significant, semi-logarithmic relationship was found between clinical scores and measured reflex amplitudes. Measured reflex asymmetry always agreed with clinical asymmetry, and the magnitudes of right-left amplitude differences were correlated with the magnitude of clinically observed asymmetry. The bedside examination of tendon reflexes is subject to considerable inter-observer disagreement.

Adult↗
PubMed2002

Erb and Westphal: simultaneous discovery of the deep tendon reflexes.

Although the deep tendon reflexes (DTRs) were first introduced simultaneously into the medical literature by Erb and Westphal (1875), there is some evidence that the knee jerk response was well known to laymen prior to that time. Erb wrote that while he was not calling attention to anything new, he realized the utility of the phenomenon in diagnosing certain disease states. Erb viewed the phenomenon more clearly as a true reflex arc, whereas Westphal interpreted it as a local muscle phenomenon. By 1885, the maneuver was used in Europe and across the Atlantic in America. By then, the DTRs had become one of the cardinal features of the neurological examination.

History, 19th Century↗
PubMed1978

Deep tendon reflex in Eaton-Lambert syndrome.

The mechanism of absent or decreased deep tendon reflex in Eaton-Lambert syndrome was studied. There was no evidence suggestive of the presence of a neuropathy. On the other hand, a brief (about 10 seconds) maximal voluntary contraction made the absent deep tendon reflexes elicitable, which suggests that the block of neuromuscular transmission in Eaton-Lambert syndrome is responsible for the absent or decreased deep tendon reflex. Such enhancement of the decreased deep tendon reflex in Eaton-Lambert syndrome might be helpful in differentiating neuropathy and Eaton-Lambert syndrome.

Bronchial Neoplasms↗
PubMed1975

Obesity and thyroid function. 2. The effect of prolonged caloric restriction on Achilles tendon reflex values.

The results obtained are indicative of changes in thyroid function during prolonged caloric restriction. Achilles tendon reflex values were studied in obese individuals under reducing treatment. More pronounced weight loss during the first three months was associated with a shortening of Achilles tendon reflex values, or its values remained unchanged. From the sixth month on a growing percentage of obese patients in our group displayed prolongation of Achilles tendon reflex values coupled with a decrease in weight showed a statistically significant prolongation of Achilles tendon reflex values. Thyreoglobulin given at this stage normalised Achilles tendon values and reinduced weight decrease.

Achilles Tendon↗
PubMed1989

Early-onset cerebellar ataxia with retained tendon reflexes.

The authors report a clinical review of 16 childhood cases with early-onset cerebellar ataxia with retained tendon reflexes. The preservation of tendon reflexes distinguishes this disorder from Friedreich's ataxia. The mean age of onset of symptoms was 7.1 years. The main presenting symptom was abnormal gait (100%). Ataxia of gait and limbs and normal or increased tendon reflexes were found in all cases. This disorder is associated with dysarthria, pyramidal signs in the limbs, and in some instances, sensory loss. Other important differences from Friedreich's ataxia are absence of optic atrophy, diabetes mellitus, cardiomyopathy and severe skeletal deformity. Sensory nerve conduction was found to be normal, excluding one case. This finding constitutes another aspect of the syndrome different from Freidreich's ataxia. CT scans were normal in 2 of the 4 cases. The remaining two cases showed cerebellar atrophy. Inheritance is probably autosomal recessive in the majority of cases.

Adolescent↗
PubMed1988

Conditioned patellar tendon reflexes in sprint- and endurance-trained athletes.

Tendon reflex characteristics were examined in endurance-trained, sprint-trained, and control subjects (10 SS/group) using a conditioned patellar tendon reflex (PTR) paradigm. Paired PTRs were administered using inter-tap intervals of 0, 25, 50, 75, 150, and 300 ms, with the left leg reflex elicited first, followed by a right leg PTR. A force transducer secured at the ankle was used to measure peak force, time to peak force, and reflex latency. In the unilateral condition, significant differences (P less than 0.05) existed between athletic groups, with the sprint-trained athletes exhibiting greater peak force, faster time to peak force, and faster reflex latency than the endurance athletes. Significant differences (P less than 0.05) also existed for the conditioned reflex. There was a slight depression in reflex parameters in the untrained and sprint-trained groups up to an interval of 50 ms. At later intervals (greater than 50 ms), a marked enhancement occurred in all groups for all dependent measures studied. This longer latency excitatory effect persisted until the 150 ms interval. These differences in both simple and conditioned reflexes in individuals trained for endurance and sprint activities may reflect inherent differences in muscle-tendon stiffness or neural organization.

Adult↗
PubMed1973

Achilles tendon reflex in accidental hypothermia and hypothermic myxoedema.

The photomotogram (P.M.G.) of the Achilles tendon reflex was studied in 26 patients with hypothermia (rectal temperature 33.3 degrees C or less), 10 of whom also had myxoedema (serum protein bound iodine 2.8 mug/100 ml or less). No reflex could be elicited in eight (31%) of these patients, including three of those with myxoedema. Hypothermia increases both the contraction and the relaxation times of the reflex, the relaxation phase being particularly prolonged in those with myxoedema. In those patients from whom the reflex was elicited the ratio of the contraction time to the "half-relaxation time" in the P.M.G. was less than unity in six of the seven with myxoedema, and considerably greater than unity in eight of the 11 (73%) who were euthyroid. Thus, analysis of the Achilles tendon reflex P.M.G. correctly predicted the thyroid status in 14 of the 18 hypothermic patients in whom the Achilles tendon reflex was present (78%). The wider use of this rapid test of thyroid function would allow a more rational use of thyroid hormones in hypothermic patients and so lead to a better assessment of their value.

Achilles Tendon↗