OBJECTIVE The present study assessed the reliability and validity of isokinetic dynamometry in the qualitative determination of the evolution of total knee arthroplasty. CASES 20 patients whose mean age was 71.35 years, undergoing knee arthroplasty, and 25 controls whose mean age was 71.36 years. METHOD Computerized isokinetic assessment of flexor and extensor muscles using a CYBEX 6000 dyn...

Subjects with chronic hemiplegia following stroke attempted to perform voluntary isometric, isokinetic, and free contractions of the extensor muscles of the metacarpophalangeal (MCP) joints. We recorded torque, metacarpophalangeal joint angle and velocity, and electromyographic (EMG) activity of the extrinsic extensors and flexors and the first dorsal interosseous (FDI). We found that voluntary...

OBJECTIVE To estimate jitter parameters in myasthenia gravis in stimulated frontalis and extensor digitorum muscles using the concentric needle electrode. METHODS Forty-two confirmed myasthenia gravis patients, being 22 males (aged 45.6±17.2 years-old) were studied. Jitter was expressed as the mean consecutive difference (MCD). RESULTS MCD in extensor digitorum was 61.6 µs (abnormal in 85.7...

An intersegmental reflex initiated by flexing a crayfish leg at the merocarpal joint was examined by recording reflex response latencies of cephalic, thoracic and abdominal muscles. The first response was an intrasegmental resistance reflex in the extensor muscle of the stimulated leg. Spread of the intersegmental reflex occurred in both cephalic and caudal directions. Activation of the cephali...

K channels regulate action potential duration and thereby force of skeletal muscles. Diaphragm differs from limb muscles in the dependence of contraction on extracellular Ca. We hypothesized that diaphragm also differs from limb muscles in the regulation of contraction by membranous K conductances. This was tested in vitro by assessing changes in isometric twitch force and kinetics in response ...

OBJECTIVE Only a few abdominal muscle exercises have been quantitatively evaluated on both a mat and exercise ball, but the benefits reported for the ball have been equivocally applied to all exercises. The purpose of this study is to evaluate differences in the biological response of muscle activation, lumbar spine posture, and loading variables for extensor exercises performed on 2 surfaces. ...

We discovered that the contemporary procedure for assessing voluntary activation of knee extensor muscles with transcranial magnetic stimulation (TMS) is invalid. TMS activates too few agonist quadriceps motoneurons and many antagonist hamstrings to estimate resting twitch accurately. A modified procedure, in which TMS-evoked superimposed twitches are considered together from femoral nerve stim...

The storage and recovery of elastic strain energy in muscles and tendons increases the economy of locomotion in running vertebrates. In this investigation, we compared the negative and positive external work produced at individual limb joints of running dogs to evaluate which muscle-tendon systems contribute to elastic storage and to determine the extent to which the external work of locomotion...

the aim of the present study was to investigate the effect of hiit run on pgc-1α gene expression in fast & slow twitch muscles of healthy male  rats. for this purpose, 12 male wistar rats divided into two groups: contorol (n=6) and exercise (n=6) , respectively. intense interval training was consists of five days and a total of eight weeks,  that was formed the three frequencies ( 90 to 100% vo...

The choice of activity to improve finger extension of post-CVA patients is based on untested assumptions and hypotheses. In this study, using electromyography of the extrinsic finger muscles and electrogoniometry of wrist and finger joints, the effects of five types of exercise on the finger extension of post-CVA patients were documented. Results indicated that resisted and rapid exercises recr...