Rhythmic Lower Leg Cuff Inflation Enhances Cardiovagal Reflex During Quiet Standing In Healthy Subjects

2011 ◽  
Vol 43 (Suppl 1) ◽  
pp. 658-659
Author(s):  
Kyuichi Niizeki ◽  
Takanori Tominaga ◽  
Kohnosuke Chiku ◽  
Megumi Nabuchi ◽  
Tadashi Saitoh ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Lower Leg ◽  
Quiet Standing ◽  
Cuff Inflation

Effects of lower-leg rhythmic cuff inflation on cardiovascular autonomic responses during quiet standing in healthy subjects

2011 ◽  
Vol 300 (5) ◽  
pp. H1923-H1929 ◽  
Author(s):  
Kyuichi Niizeki ◽  
Takanori Tominaga ◽  
Tadashi Saitoh ◽  
Izumi Nishidate ◽  
Tatsuhisa Takahashi ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Cuff Pressure ◽  
Venous Pressure ◽  
Lower Leg ◽  
Pulse Contour ◽  
Quiet Standing ◽  
Contour Method ◽  
Cuff Inflation ◽  
Muscle Pump ◽  
Pulse Contour Method

To determine the effects of muscle pump function on cardiac autonomic activity in response to quiet standing, we simulated the muscle pump effect by rhythmic lower-leg cuff inflation (RCI) with four cuff pressures of 0 (sham), 40, 80, and 120 mmHg at 5 cycles/min. The R-R interval (RRI) and beat-to-beat blood pressure (BP) were acquired in healthy subjects (6 males and 5 females, aged 21–24 yr). From the continuous BP measurement, stroke volume (SV) was calculated by a pulse-contour method. Using spectral and cross-spectral analysis, RRI and systolic BP variability as well as the gain of spontaneous cardiac baroreflex sensitivity (sBRS) were estimated for the low- and high-frequency (HF) bands. Compared with the sham condition, RCI with cuff pressures of 80 and 120 mmHg led to increases in the mean RRI ( P < 0.01) and HF power of RRI fluctuation ( P < 0.05 for 80 mmHg and P < 0.01 for 120 mmHg) during quiet standing. Reduction in SV during standing was suppressed, and the sBRS of the HF band for standing were increased by RCI for either cuff pressure ( P < 0.05 for 80 mmHg and P < 0.01 for 120 mmHg). However, at 40 mmHg RCI, these remained unchanged. These results suggest that, during standing, RCI of the lower leg increases cardiac vagal outflow when the cuff pressure is raised enough to oppose the hydrostatic-induced venous pressure in the calf.

The Amount and Temporal Structure of Center of Pressure Fluctuations During Quiet Standing in Patients With Chronic Low Back Pain

Motor Control ◽  
2020 ◽  
Vol 24 (1) ◽  
pp. 91-112
Author(s):  
Fatemeh Azadinia ◽  
Ismail Ebrahimi-Takamjani ◽  
Mojtaba Kamyab ◽  
Morteza Asgari ◽  
Mohamad Parnianpour
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Chronic Low Back Pain ◽  
Healthy Subjects ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Pressure Fluctuations ◽  
Quiet Standing ◽  
Low Back ◽  
Nonlinear Parameters

The characteristics of postural sway were assessed in quiet standing under three different postural task conditions in 14 patients with nonspecific chronic low back pain and 12 healthy subjects using linear and nonlinear center of pressure parameters. The linear parameters consisted of area, the mean total velocity, sway amplitude, the SD of velocity, and the phase plane portrait. The nonlinear parameters included the Lyapunov exponent, sample entropy, and the correlation dimension. The results showed that the amount of postural sway was higher in the patients with low back pain compared with the healthy subjects. Assessing the nonlinear parameters of the center of pressure showed a lower sample entropy and a higher correlation dimension in the patients with low back pain compared with the healthy subjects. The results of this study demonstrate the greater regularity and higher dimensionality of the center of pressure fluctuations in patients with nonspecific chronic low back pain, which suggests that these patients adopt different postural control strategies to maintain an upright stance.

The Effects of Uni- and Bilateral Fatigue on Postural and Power Tasks

2013 ◽  
Vol 29 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Paulo H. Marchetti ◽  
Maria I.V. Orselli ◽  
Marcos Duarte
Keyword(s):  
Lower Limb ◽  
Healthy Subjects ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Lower Limbs ◽  
Quiet Standing ◽  
Ground Reaction Forces ◽  
Before And After ◽  
Reaction Forces ◽  
The Mean

The aim of this study was to investigate the effects of unilateral and bilateral fatigue on both postural and power bipedal tasks. Ten healthy subjects performed two tasks: bipedal quiet standing and a maximal bipedal counter-movement jumping before and after unilateral (with either the dominant or nondominant lower limb) and bilateral (with both lower limbs) fatigue. We employed two force plates (one under each lower limb) to measure the ground reaction forces and center of pressure produced by subjects during the tasks. To quantify the postural sway during quiet standing, we calculated the resultant center of pressure (COP) speed and COP area of sway, as well as the mean weight distribution between lower limbs. To quantify the performance during the countermovement jumping, we calculated the jump height and the peak force of each lower limb. We observed that both unilateral and bilateral fatigue affected the performance of maximal voluntary jumping and standing tasks and that the effects of unilateral and bilateral fatigue were stronger in the dominant limb than in the nondominant limb during bipedal tasks. We conclude that unilateral neuromuscular fatigue affects both postural and power tasks negatively.

scholarly journals Leg pain in neuropathic postural tachycardia syndrome is associated with altered muscle membrane properties

2021 ◽  
Author(s):  
Belén Rodriguez ◽  
Karin Jost ◽  
Lotte Hardbo Larsen ◽  
Hatice Tankisi ◽  
Werner J. Z’Graggen
Keyword(s):  
Supine Position ◽  
Healthy Subjects ◽  
Body Position ◽  
Lower Leg ◽  
Membrane Properties ◽  
Leg Pain ◽  
Muscle Membrane ◽  
Postural Tachycardia Syndrome ◽  
Postural Tachycardia ◽  
Muscle Excitability

Abstract Purpose In neuropathic postural tachycardia syndrome, peripheral sympathetic dysfunction leads to excessive venous blood pooling during orthostasis. Up to 84% of patients report leg pain and weakness in the upright position. To explore possible pathophysiological processes underlying these symptoms, the present study examined muscle excitability depending on body position in patients with neuropathic postural tachycardia syndrome and healthy subjects. Methods In ten patients with neuropathic postural tachycardia syndrome and ten healthy subjects, muscle excitability measurements were performed repeatedly: in the supine position, during 10 min of head-up tilt and during 6 min thereafter. Additionally, lower leg circumference was measured and subjective leg pain levels were assessed. Results In patients with neuropathic postural tachycardia syndrome, muscle excitability was increased in the supine position, decreased progressively during tilt, continued to decrease after being returned to the supine position, and did not completely recover to baseline values after 6 min of supine rest. The reduction in muscle excitability during tilt was paralleled by an increase in lower leg circumference as well as leg pain levels. No such changes were observed in healthy subjects. Conclusions This study provides evidence for the occurrence of orthostatic changes in muscle excitability in patients with neuropathic postural tachycardia syndrome and that these may be associated with inadequate perfusion of the lower extremities. Insufficient perfusion as a consequence of blood stasis may cause misery perfusion of the muscles, which could explain the occurrence of orthostatic leg pain in neuropathic postural tachycardia syndrome.

Human soleus H-reflex excitability is decreased by dynamic head-and-body tilts

1999 ◽  
Vol 9 (5) ◽  
pp. 379-383
Author(s):  
Nicole Paquet ◽  
Christina W.Y. Hui-Chan
Keyword(s):  
Healthy Subjects ◽  
Stretch Reflex ◽  
H Reflex ◽  
Quiet Standing ◽  
Head Acceleration ◽  
Reflex Amplitude ◽  
Reflex Excitability ◽  
Dynamic Head ◽  
Reflex Arc

The modulation of soleus (SO) H-reflex excitability during dynamic whole head-and-body tilts (WHBT) was investigated in normal healthy subjects. Between 30 and 70 ms, and 151 and 190 ms after head acceleration onset, the H-reflex amplitude was smaller than during quiet standing by 7.6% ( p < 0.01) and 15.4% ( p = 0.06) respectively. This finding suggested that dynamic WHBT reduced the excitability of the predominantly monosynaptic stretch reflex arc in the majority of the subjects studied.

Exercise and conditioned pain modulation have different effects on cuff pressure pain tolerance in humans

2012 ◽  
Vol 3 (3) ◽  
pp. 190-190
Author(s):  
H.B. Madsen ◽  
G. Handberg ◽  
T. Graven-Nielsen
Keyword(s):  
Healthy Subjects ◽  
Pain Sensitivity ◽  
Biceps Brachii ◽  
Experimental Pain ◽  
Cold Pressor ◽  
Lower Leg ◽  
Pain Tolerance ◽  
Dominant Hand ◽  
Deep Tissue ◽  
Different Types

Abstract Background/aims Exercise and experimental pain is known to cause an acute decrease of the pain sensitivity. Assessment of pain inhibitory mechanisms is often done by paradigms of exercise and experimental pain in both healthy subjects and pain patients. It is currently unknown whether pain and different types of exercise has similar effects on pain sensitivity. The aim of the present study was to investigate the effects of experimental pain and different types of exercise on deep tissue pain tolerance in healthy subjects. Methods On two separate days fifty-four healthy subjects (23 females, 33.8 ± 15.0 years) were assigned in random order to cold pressor tests (ice water at 1–2°C; 120 s duration) for the dominant hand and foot, bicycling exercises (100 W and 200 W; 20 min duration), and isometric contraction exercises (30% and 60% of maximal voluntary contraction, MVC; 180 s duration) of the dominant quadriceps and biceps brachii muscles. Before, immediately after, and 10 min after cold pressor tests and exercises, pressure pain tolerance (PTT) were assessed with computerized cuff-algometry at the non-dominant lower-leg and upper arm. Subjects reaching maximum stimulation intensity at baseline were excluded from the analysis. PTTs were analysed with repeated measures ANOVA and multiple comparisons. Results Immediately and 10 min after the cold pressor test in the dominant hand and foot significantly increased PTTs were found at the non-dominant upper arm and lower leg (P < 0.05). Both intensities of dominant biceps brachii isometric contractions produced a significant increase in the PTT at the non-dominant lower leg immediately after and 10 min after contractions (P < 0.05). After the 30% dominant quadriceps isometric contraction the PTT at the non-dominant lower leg was significantly increased (P < 0.05). Conclusion Cold pressor pain produced a contralateral and extrasegmental increase in deep tissue pain tolerance. Isometric arm exercise produced an extrasegmental increase in pain tolerance, whereas isometric leg contractions produced a contralateral effect. Aerobic exercise had no effect on pain tolerance. Thus, exercise and pain related inhibitory effects were not comparable. Acknowledgment/disclosures H.B. Madsen was supported by grants from the philanthropic foundation TrygFonden (7-11-0990), The Danish Rheumatism Association 8R95-A1871), The Research Foundation of the Danish Physiotherapy Association and The Fund for Physiotherapy in Private Practice.

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