Search results for "VELOCITY"
showing 10 items of 881 documents
Training at maximal power in resisted sprinting: Optimal load determination methodology and pilot results in team sport athletes.
2018
Aims: In the current study we investigated the effects of resisted sprint training on sprinting performance and underlying mechanical parameters (force-velocity-power profile) based on two different training protocols: (i) loads that represented maximum power output (Lopt) and a 50% decrease in maximum unresisted sprinting velocity and (ii) lighter loads that represented a 10% decrease in maximum unresisted sprinting velocity, as drawn from previous research (L10). Methods: Soccer [n = 15 male] and rugby [n = 21; 9 male and 12 female] club-level athletes were individually assessed for horizontal force-velocity and load-velocity profiles using a battery of resisted sprints, sled or robotic r…
Regression of structural vascular changes in hypertensives after captopril treatment.
1992
In order to investigate whether hypertension-related structural vascular changes may be influenced by antihypertensive treatment, 10 patients were studied suffering from essential arterial hypertension, five males and five females, aged between 34 and 61 years (mean age: 46.9 +/- 8.13 years). All patients received a placebo for 1 week and then captopril, 75 mg b.i.d. for 3 months. After placebo and captopril treatments, the following parameters were evaluated: SBP, DBP, mean blood pressure (MBP), by the formula 1/3 (SBP + 2 x DBP) and basal and minimal vascular resistances, respectively obtained by the ratios MBP/rest flow and MBP/peak flow. Blood flows have been obtained by strain gauge pl…
Blood flow velocity waveforms of the fetal middle cerebral artery in a normal population: reference values from 18 weeks to 42 weeks of gestation
2002
The aim of this prospective cross-sectional study was to establish new Doppler reference curves for peak blood flow velocities (Vmax, Vmean, Vmin) and impedance indices (PI, RI) of the middle cerebral artery at 18-42 weeks of gestation by an automatic wave form analysis integrated into the ultrasound device. In 962 low-risk pregnancies, blood flow velocities were derived from the middle cerebral artery with pulsed color Doppler ultrasonography. Reference curves were constructed for the individual parameters based on a growth function from a four-parameter class of monotonic continuous functions according to the smallest square principle for maximum blood flow velocities, as well as on a pol…
Changes of sensory conduction velocity and refractory periods with decreasing tissue temperature in man.
1977
Changes with temperature of maximum sensory nerve conduction velocity as well as absolute and relative refractory periods were tested in 14 human subjects. Corresponding to previously published findings maximum conduction velocity decreased with cooling following a Q10 of +1.4. The absolute and relative refractory periods were increased by cooling, the Q10 being -3.1 and -3.35 respectively. There was a tendency showing a more pronounced temperature effect at low temperatures. The Q10 and the steepness of the regressionline changed at the level of 26.9 degrees C, but were significant for the relative refractory period only.
Evaluation of carpal tunnel syndrome in patients with polyneuropathy
1997
The difference between the median nerve latency to the second lumbrical muscle and the ulnar nerve latency to the second interosseous muscle (L-I DIFF) was tested in a prospective study to discriminate whether prolonged distal motor latency of the median nerve in patients with polyneuropathy (PNP) reflects an additional carpal tunnel syndrome (CTS). We investigated 92 patients (107 hands) with CTS, 30 patients (34 hands) with PNP, 22 patients (27 hands) with CTS and coexisting PNP (PNP+CTS), and 77 controls (87 hands). L-I DIFF was significantly prolonged in both the CTS and PNP+CTS patients as compared to PNP patients and controls. It proved to be the most specific test to differentiate be…
[Velocity perception for curved motion].
1996
This study examined the effect of direction change of tangential velocity on speed perception using a dot in curved motion. The PSE values were measured for four standard stimuli of different motion curvature. In Experiment 1, semicircular motion was a comparison stimulus. The result showed that the PSE values increased with increasing motion curvature. This implies that direction change of tangential velocity can affect its speed perception. However, in Experiment 2, the effect of direction change of tangential velocity was not clear when a comparison stimulus was replaced with linear motion. In Experiment 3, the motion curvature as a comparison stimulus was set near the threshold level of…
Bone and Muscle Development During Puberty in Girls: A Seven-Year Longitudinal Study
2009
The growth of lean mass precedes that of bone mass, suggesting that muscle plays an important role in the growth of bone. However, to date, no study has directly followed the growth of bone and muscle size through puberty and into adulthood. This study aimed to test the hypothesis that the growth of muscle size precedes that of bone size (width and length) and mass during puberty. Bone and muscle properties were measured using pQCT and DXA in 258 healthy girls at baseline (mean age, 11.2 yr) and 1-, 2-, 3-4- and 7-yr follow-up. Growth trends as a function of time relative to menarche were determined from prepuberty to early adulthood for tibial length (TL), total cross-sectional area (tCSA)…
Impaired refractory periods of peripheral sensory nerves in multiple sclerosis.
1978
Maximum conduction velocity and relative refractory period (RRP) of median nerve sensory fibers were studied in 36 patients diagnosed as having multiple sclerosis (MS) and in 31 controls. Maximum conduction velocity did not differ in the two groups, but the RRP was significantly prolonged in MS patients. Increased RRP is observed mainly when peripheral nerve myelin is abnormal or damaged. Our findings support the assumption that peripheral nerve myelinated fibers are usually involved in MS.
Sympathetic Vasomotor Response of the Radial Artery in Patients With Diabetic Foot Syndrome
2003
OBJECTIVE—Neurophysiological assessment of the peripheral autonomic system is characterized by various limitations. An alternative approach to laser Doppler and venous plethymography is the assessment of the sympathetic vasomotor response of the radial artery obtained by continuous wave Doppler sonography. Nomogram data have been established and demonstrate the temporary disappearance of diastolic flow after coughing or deep inspiration. RESEARCH DESIGN AND METHODS—We assessed the sympathetic vasomotor response in 25 patients (mean age 64 years, range 43–76) with diabetic foot syndrome. The Doppler data were correlated with nerve conduction studies of the median and peroneal nerve, the exte…
Endovascular Embolization of a Large High-Flow Splenic Arteriovenous Fistula and Aneurysm Using the Amplatzer Vascular Plug II.
2015
We describe the use of an Amplatzer Vascular Plug (AVP) II for embolizing a large high-flow splenic arteriovenous fistula and an aneurysm in a young patient. This patient presented to our center with persistent mild abdominal discomfort, 5 years after open splenectomy. Contrast-enhanced computed tomography angiography showed the presence of a fistula between the splenic arterial and splenic venous remnants and a resultant fusiform aneurysmal dilatation of the residual splenic vein. We decide to embolize the splenic artery with a 12-mm diameter AVP II with an oversizing by 70% of the vessel diameter. Celiac angiography performed 5 min postembolization revealed complete obliteration of the sp…