Biomedical subjects

Y Karni

Publications and source records attributed to Y Karni.

4 recordsLinked to original sources

PubMed1995

Blood lactate concentration following exercise: effects of heat exposure and of active recovery in heat-acclimatized subjects.

The purpose of this study was to examine the effect of ambient heat on the decrease in blood lactate concentration ([LA]bl) during passive and during active recovery. Ten trained men performed six 1-min bouts of exercise at 100% VO2peak on a cycle ergometer, with 1-min rest between the bouts. Each subject exercised twice in thermoneutral (22 degrees C, 40% RH, TN), and twice in hot (35 degrees C, 30% RH, H) conditions. Exercise was followed by either 40 min of passive recovery (sitting) or by 20 min active recovery (cycling at 35% VO2peak) and 20 min passive recovery, named thereafter, 'active recovery'. Capillary blood lactate was measured before, 1 min after, and every 5 min during recovery. Heart rate (HR), rectal and skin temperatures (Tre, Tsk) were monitored continuously. VO2 was measured prior to exercise, during the last exercise bout, the first 10 min of recovery, and periodically thereafter. Post-exercise [LA]bl was similar in all treatments (13.5 +/- 1.8, 13.0 +/- 1.3, 14.8 +/- 4.1, 13.3 +/- 2.6 mmol.l-1 for TN-active, TN-passive, H-active and H-passive, respectively). [LA]bl was significantly lower during active, compared to passive recovery in both, TN and H conditions. Environmental heart did not independently affect [LA]bl during passive or active recovery. Exercise resulted in an elevation in Tre in all treatments, with a significantly higher Tre during active recovery in H compared to the other sessions. Likewise, no differences in HR and in VO2 were observed between H and TN conditions during active nor during passive recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗

PubMed1990

Laboratory testing of muscle function in the management of neuromuscular disease.

A laboratory was set up to assess muscle weakness and physical disability in patients with peripheral neuromuscular diseases. Muscle strength was mainly measured with a hand held dynamometer and results were expressed in relationship to a "guideline" range for sex: disability was expressed in terms of ordinal data with a performance score and as interval data with simple timed tests. Of 17 patients with polymyositis on immunosuppressive medication followed for a mean of 2.9 years (range 1.1 - 4.7 years) only eight became stronger one of whom died. Assessment of weakness (the major impairment), disability, body weight, creatine kinase and the patient's subjective view of their state were essential to obtaining a clear view of progress.

Adult↗

PubMed1987

Shoulder abduction fatiguability.

Shoulder abduction fatiguability has been measured using a hand held myometer in normal subjects and patients with peripheral neuromuscular diseases. An index of fatiguability was based on the decline in force over a series of ten maximum voluntary contractions performed in under a minute. The technique was repeatable and well tolerated. Patients with myasthenia, mitochondrial myopathy and motor neuron disease tended to show excess fatiguability independent of muscle strength. Serial measurements demonstrated alterations in fatiguability but not necessarily strength, associated with changes in symptoms.

Adult↗

PubMed1983

The measurement of muscle strength in patients with peripheral neuromuscular disorders.

The variability of voluntary isometric strength measurements has been assessed in normal subjects and patients with peripheral neuromuscular disorders. Knee extensor strength was measured in a muscle testing chair 13 times over 5 months in each of six normal subjects: coefficients of variation (CV) ranged from 4.5 to 14.0% (mean 8.5%) for individual legs in different subjects. Paired measurements of the strength of several clinically weak muscle groups were made 1-4 days apart in 20 patients using both a handheld dynamometer and the muscle chair technique: the test/retest correlation was high (r = 0.97, p less than 0.001). Visual biofeedback did not affect the strength recorded in most cases. Each of five patients had the strength of six or seven clinically weak muscle groups measured by five examiners within a 24 hour period: the CV for the five examiners ranged from 3.6-27.3% (mean 12.8%). A single examiner measuring the same groups on five occasions in three patients obtained a mean CV of 8.9%. Sources of variation are analysed and it is concluded that, with certain precautions, voluntary strength measurements offer a simple, reliable and acceptable method for monitoring change in patients.

Adolescent↗