Cardiovascular responses to low‐frequency whole‐body acceleration

1981 ◽  
Vol 70 (S1) ◽  
pp. S36-S36
Author(s):  
C. Knapp ◽  
J. Evans ◽  
D. Randall ◽  
J. Marquis ◽  
A. Bhattacharya
Keyword(s):  
Low Frequency ◽  
Cardiovascular Responses ◽  
Whole Body ◽  
Body Acceleration

scholarly journals Acute Effects of Whole-Body Vibration on the Pain Level, Flexibility, and Cardiovascular Responses in Individuals With Metabolic Syndrome

Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581880213 ◽  
Author(s):  
D.C. Sá-Caputo ◽  
L.L. Paineiras-Domingos ◽  
Ricardo Oliveira ◽  
Mario F.T. Neves ◽  
Andrea Brandão ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Whole Body Vibration ◽  
Low Frequency ◽  
Cardiovascular Responses ◽  
Acute Effect ◽  
Whole Body ◽  
Control Group ◽  
Pain Level ◽  
Trunk Flexion ◽  
Body Vibration

The aim of the study was to assess the acute effect of whole-body vibration (WBV) exercise, with low frequency (5 Hz), on the pain level (PL), trunk flexibility, and cardiovascular responses (blood pressure [BP] and heart rate [HR]) in individuals with metabolic syndrome (MetS). Forty-four individuals were included in the study (control: 15) or in (WBV exercise: 29) groups. They were submitted to 3 bouts (1 minute each) of WBV exercise (5 Hz and peak-to-peak displacements of 2.5, 5.0, and 7.5 mm, corresponding to peak accelerations of 0.12, 0.25, and 0.35 g, respectively, sitting in a chair with the feet on the platform with knees flexed, followed by 1 minute of interset rest. The Control Group performed the same protocol, but the platform was turned off. The PL was measured through the visual analog pain scale, and the flexibility was measured through the anterior trunk flexion test. Significant improvements on PL ( P = .031) and flexibility ( P = .004) were found only in the WBV exercise group. The BP and HR remained at physiological levels. In conclusion, the WBV exercise would lead to physiological response decreasing PL and increasing flexibility as well as maintaining the cardiovascular responses in individuals with MetS.

Pressure Changes Induced by Whole Body Acceleration Shocks

1991 ◽  
Vol 113 (1) ◽  
pp. 27-29 ◽  
Author(s):  
E. Belardinelli ◽  
M. Ursino ◽  
G. Fabbri ◽  
A. Cevese ◽  
F. Schena
Keyword(s):  
Mathematical Model ◽  
Carotid Artery ◽  
Normal Pressure ◽  
Compressed Air ◽  
Whole Body ◽  
Body Acceleration ◽  
Vascular Bed ◽  
Pressure Changes ◽  
The Mathematical Model

In the present paper pressure changes induced by sudden body acceleration are studied “in vivo” on the dog and compared to the results obtainable with a recently developed mathematical model. A dog was fixed to a movable table, which was accelerated by a compressed air piston for less than 1 s. Acceleration was varied by changing the air pressure in the piston. Pressure was measured during the experiment at different points along the vascular bed. However, only data obtained in the carotid artery and abdominal aorta are presented here. The results demonstrated that impulse body accelerations cause significant pressure peaks in the vessel examined (about + 25 mmHg in the carotid artery with body acceleration of g/2). Moreover, pressure changes are rapidly damped, with a time constant of about 0.1s. From the present results it may be concluded that, according to the prediction of the mathematical model, body accelerations such as those occurring in normal life can induce pressure changes well beyond the normal pressure value.

Torsional vestibulo-ocular reflex during whole-body oscillation in the upright and the supine position: II. Responses in patients after vestibular neuritis

2004 ◽  
Vol 14 (4) ◽  
pp. 353-359
Author(s):  
A. Schmid-Priscoveanu ◽  
A.A. Kori ◽  
D. Straumann
Keyword(s):  
Supine Position ◽  
Semicircular Canal ◽  
Low Frequency ◽  
Phase Changes ◽  
Vestibular Neuritis ◽  
Whole Body ◽  
Healthy Human ◽  
Phase Lead ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex

In a recent study we demonstrated that otolith input modifies the torsional angular vestibulo-ocular reflex (torVOR) of healthy human subjects: Compared to turntable oscillations in supine position, oscillations in upright position increased the gain of torVOR by 0.1 and cancelled the phase lead originating from low-frequency semicircular canal signals. We asked whether these otolith-related changes of torVOR are still present in patients after vestibular neuritis (VN). Eight patients were sinusoidally oscillated about their naso-occipital axis in supine (canal-only stimulation) and upright (canal-and-otolith stimulation) position. Three-dimensional eye movements were recorded with dual search coils. The patients showed similar otolith-related gain and phase changes of the torVOR as healthy subjects: the gain increased by about 0.1 (p < 0.05) and the low-frequency phase lead from semicircular canal signals was abolished. These results indicate that otolith function after VN is still sufficient to interact with semicircular canal signals to optimize torsional gaze stabilization when the head is upright.

Optimal frequency of whole body vibration training for improving balance and physical performance in the older people with chronic stroke: A randomized controlled trial

2021 ◽  
pp. 026921552110505
Author(s):  
Ning Wei ◽  
Mengying Cai
Keyword(s):  
Older People ◽  
Physical Performance ◽  
High Frequency ◽  
Low Frequency ◽  
Chronic Stroke ◽  
Whole Body ◽  
Timed Up And Go ◽  
Stand Test ◽  
Sit To Stand ◽  
Frequency Group

Objective To explore the optimal frequency of whole-body vibration training for improving the balance and physical performance in older people with chronic stroke. Design a single-blind randomized controlled trial. Setting Two rehabilitation units in the Wuhan Brain Hospital in China. Participants A total of 78 seniors with chronic stroke. Interventions Low-frequency group (13 Hz), high-frequency group (26 Hz), and zero-frequency group (Standing on the vibration platform with 0 Hz) for 10 sessions of side-alternating WBV training. Main measures The timed-up-and-go test, five-repetition sit-to-stand test, 10-metre walking test, and Berg balance scale were assessed pre- and post-intervention. Results Significant time × group interaction effects in five-repetition sit-to-stand test (p = 0.014) and timed-up-and-go test at self-preferred speed (p = 0.028) were observed. The high-frequency group outperformed the zero-frequency group in both five-repetition sit-to-stand test (p = 0.039) and timed-up-and-go test at self-preferred speed (p = 0.024) after 10-sessions training. The low-frequency group displayed only a significant improvement in five-repetition sit-to-stand test after training (p = 0.028). No significant within- or between-group changes were observed in the Berg balance scale and walking speed (p > 0.05). No significant group-difference were found between low-frequency and high-frequency groups. No adverse events were reported during study. Conclusions Compared with 13 Hz, 26 Hz had no more benefits on balance and physical performance in older people with chronic stroke.

scholarly journals Lower Body Acceleration and Muscular Responses to Rotational and Vertical Whole-Body Vibration at Different Frequencies and Amplitudes

Dose-Response ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 155932581881994 ◽  
Author(s):  
Lisa N. Zaidell ◽  
Ross D. Pollock ◽  
Darren C. James ◽  
Joanna L. Bowtell ◽  
Di J. Newham ◽  
...  
Keyword(s):  
Whole Body Vibration ◽  
Whole Body ◽  
Lower Body ◽  
Body Acceleration ◽  
Body Vibration ◽  
Muscular Responses

scholarly journals Biases in the perception of self-motion during whole-body acceleration and deceleration

2013 ◽  
Vol 7 ◽  
Author(s):  
Luc Tremblay ◽  
Andrew Kennedy ◽  
Dany Paleressompoulle ◽  
Liliane Borel ◽  
Laurence Mouchnino ◽  
...  
Keyword(s):  
Whole Body ◽  
Body Acceleration ◽  
Acceleration And Deceleration ◽  
Perception Of Self ◽  
Self Motion

Whole body and hindlimb cardiovascular responses of the anesthetized dog during CO hypoxia

1984 ◽  
Vol 62 (7) ◽  
pp. 769-774 ◽  
Author(s):  
C. E. King ◽  
S. M. Cain ◽  
C. K. Chapler
Keyword(s):  
Carbon Monoxide ◽  
Blood Flow ◽  
Cardiac Output ◽  
Sympathetic Innervation ◽  
Cardiovascular Responses ◽  
The Body ◽  
Whole Body ◽  
Total Resistance ◽  
Intact Group ◽  
Anesthetized Dogs

To compare with earlier studies of anemic hypoxia obtained by hemodilution, O2 carring capacity was decreased by carbon monoxide (CO) hypoxia. Arterial O2 content was reduced either 50% (moderate CO) or 65% (severe CO). In two groups of anesthetized dogs (moderate and severe CO) hindlimb innervation remained intact while in a third group (moderate CO) the hindlimb was denervated. Measurements were obtained prior to and at 30 and 60 min of CO hypoxia. Cardiac output was elevated at 30 min of CO hypoxia in all groups (p < 0.01) and in the severe CO group at 60 min (p < 0.01). Hindlimb blood flow remained unchanged during CO hypoxia in the intact groups. In the denervated group, hindlimb blood flow was greater (p < 0.05) than that in the intact groups throughout the experiment. A decrease in mean arterial pressure (p < 0.01) in all groups was associated with a fall in total resistance (p < 0.01). Hindlimb resistance remained unchanged during moderate CO hypoxia in the intact group but increased (p < 0.05) in the denervated group. In the severe CO group hindlimb resistance was decreased (p < 0.05) at 60 min. The results indicate that the increase in cardiac output during CO hypoxia was directed to nonmuscle areas of the body and that intact sympathetic innervation was required to achieve this redistribution.

Cardiac autonomic function during hypothermia and its measurement repeatability

2019 ◽  
Vol 44 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Gary J. Hodges ◽  
Steven A.H. Ferguson ◽  
Stephen S. Cheung
Keyword(s):  
Heart Rate ◽  
Rectal Temperature ◽  
Mild Hypothermia ◽  
Core Body Temperature ◽  
Intraclass Correlation ◽  
Low Frequency ◽  
Whole Body ◽  
Body Cooling ◽  
Mean Square Difference ◽  
Whole Body Cooling

This study examined the effect of mild hypothermia (a 0.5 °C decrease in rectal temperature) on heart rate variability (HRV), with the identical hypothermia protocol performed twice and compared using intraclass correlation coefficient (r) analysis to study the repeatability. Twelve healthy males each completed 1 neutral (23 °C) and 2 cold (0 °C) trials. In the neutral trial, participants sat quietly for 30 min. In the cold trials, baseline data were obtained from a 5-min sample following 30 min of quiet sitting at 23 °C, followed by passive exposure to 0 °C; hypothermic measures were taken from a 5-min period immediately prior to rectal temperature decreasing by 0.5 °C. HRV was obtained from a 3-lead electrocardiogram. There were no differences (all p > 0.05) in baseline measures between the neutral and the 2 cold trials, suggesting no precooling anxiety related to the cold trials. Heart rate, together with HRV measures (i.e., root mean square difference of successive normal RR intervals, triangular interpolation of NN interval histogram, low-frequency oscillations (LF), and high-frequency oscillations (HF)), increased (all p < 0.05) with mild hypothermia and showed excellent reliability between the 2 cold trials (all r ≥ 0.81). In contrast, the LF/HF ratio decreased (p < 0.05) and had only fair reliability between the 2 cold trials (r = 0.551). In general, hypothermia led to increases in heart rate, together with most measures of HRV. Although it was counterintuitive that both sympathetic and vagal influences would increase simultaneously, these changes likely reflected increased stress from whole-body cooling, together with marked cardiovascular strain and sympathetic nervous system activity from shivering to defend core body temperature. An important methodological consideration for future studies is the consistent and repeatable HRV responses to hypothermia.

scholarly journals Effect of Low-Frequency Vibration on Muscle Response under Different Neurointact Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Chaofei Zhang ◽  
Wenjun Wang ◽  
Dennis Anderson ◽  
Sishu Guan ◽  
Guofa Li ◽  
...  
Keyword(s):  
Stretch Reflex ◽  
Muscle Force ◽  
Low Frequency ◽  
Quantitative Relationship ◽  
Length Change ◽  
Whole Body ◽  
Sprague Dawley ◽  
Nonlinear Hysteresis ◽  
Low Frequency Vibration ◽  
Gastrocnemius Muscles

Stretch reflex is an important factor that influences the biomechanical response of the human body under whole-body vibration. However, there is a lack of quantitative evaluation at lower frequencies. Thus, the aim of this study was to investigate the effects of vibration on the stretch reflex and, in particular, to explore the quantitative relationship between dynamic muscle responses and low-frequency vibrations. The gastrocnemius muscle of 45 Sprague-Dawley rats was dissected. Sinusoidal vibrations of five discrete frequencies (2~16 Hz) with peak-to-peak amplitudes of 1 mm were applied to the gastrocnemius muscles with 2 mm or 3 mm prelengthening. Variables including dynamic muscle force, vibration acceleration, and displacement were recorded in two conditions, with and without the stretch reflex. Results showed that the dynamic muscle forces decreased by 20% on average for the 2 mm prelengthening group after the stretch reflex was blocked and by 24% for the 3 mm prelengthening group. Statistical analysis indicated that the amplitude of dynamic muscle force in the “with stretch reflex” condition was significantly larger than that in the “without stretch reflex” condition (p<0.001). The tension-length curve was found to be a nonlinear hysteresis loop that changed with frequency. The phase difference between the dynamic muscle force and the length change was affected significantly by vibration frequency (p<0.01), and the minimum frequency was 4–8 Hz. Experimental results of this study could benefit musculoskeletal model by providing a theoretical support to build a stretch reflex model for low-frequency vibration.

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