The effects of body weight on the soleus H-reflex modulation during standing

Jeon, Hye Seon; Yi, Chung Hwi

doi:10.1016/j.jelekin.2010.11.002

Cited by 12 publications

(15 citation statements)

References 24 publications

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“…This finding is consistent with results from studies showing no modulation of soleus H-reflex to the level of body-weight loading during quiet standing (Ali and Sabbahi, 2000; Field-Fote et al, 2000; Phadke et al, 2006), but different from soleus H-reflex amplitude during a sitting or prone-lying position (Hayashi et al, 1992; Koceja et al, 1993; Angulo-Kinzler et al, 1998; Ali and Sabbahi, 2000; Kawashima et al, 2003; Nakazawa et al, 2004; Hwang et al, 2011). A reduction of the H-reflex amplitude during standing may be attributed to inhibitory effects derived from supra-spinal systems due to a change in body orientation, rather than absolute body-weight load (Hayashi et al, 1992; Mynark and Koceja, 1997; Phadke et al, 2006).…”

Section: Discussionsupporting

confidence: 90%

“…Limb load is an important mechanical stimulus that induces a sensory feedback volley to control body dynamics during both static standing and walking (Andersen and Sinkjaer, 1999; Petersen et al, 1999; Trimble et al, 2001; Faist et al, 2006; Phadke et al, 2006; Huang et al, 2009; Knikou et al, 2009a, b). Although several studies suggest that skin and knee joint receptors modulate the alpha motor neuron pool during upright weight bearing tasks, the results remain wide-ranging (Ali and Sabbahi, 2000; Field-Fote et al, 2000; Kawashima et al, 2003; Nakazawa et al, 2004; Phadke et al, 2006; Hwang et al, 2011). Specifically, some authors report a systematic decrease in motor neuron excitability in response to increments of body-weight loads (Kawashima et al, 2003; Nakazawa et al, 2004; Hwang et al, 2011); whereas others report no effect of body-weight load (Ali and Sabbahi, 2000; Field-Fote et al, 2000; Phadke et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

“…Although several studies suggest that skin and knee joint receptors modulate the alpha motor neuron pool during upright weight bearing tasks, the results remain wide-ranging (Ali and Sabbahi, 2000; Field-Fote et al, 2000; Kawashima et al, 2003; Nakazawa et al, 2004; Phadke et al, 2006; Hwang et al, 2011). Specifically, some authors report a systematic decrease in motor neuron excitability in response to increments of body-weight loads (Kawashima et al, 2003; Nakazawa et al, 2004; Hwang et al, 2011); whereas others report no effect of body-weight load (Ali and Sabbahi, 2000; Field-Fote et al, 2000; Phadke et al, 2006). During weight bearing tasks, supra spinal systems are active at various levels (Iles and Pisini, 1992a, b; Lowrey and Bent, 2009).…”

Section: Introductionmentioning

confidence: 99%

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Limb segment load inhibits post activation depression of soleus H-reflex in humans

Tseng

Shields

2012

Clinical Neurophysiology

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Objective We investigated the effect of various doses of limb segment load on soleus H-reflex amplitude and post activation depression in healthy individuals. We also explored the influence of limb segment load on spinal circuitry in one individual with chronic SCI. Methods 28 healthy adults and one SCI subject received compressive loads applied to the top of their knee at varied doses of load (10%, 25%, and 50% of the body weight). Soleus H-reflexes were measured before (baseline) and during the loading phase. Results There were no significant differences in H-reflex amplitudes during the 50 % BW load-on phase as compared to either baseline session or the load-off phase. However, the post activation depression was decreased over 9% (p < 0.05) during the load-on phase compared to the load-off phase and scaled according to load (50%>25%>10%). The post activation depression ratio also appears less responsive to varying loads after chronic SCI. Conclusions Limb segment load decreases post-activation depression in humans. These findings suggest that the mechanism associated with post activation depression is modulated by limb segment load, and may be influenced by spinal reorganization after SCI. Significance Future studies will determine if various levels of spasticity modulate the response of limb segment load on post activation depression in those with acute and chronic SCI.

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Section: Discussionsupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Limb segment load inhibits post activation depression of soleus H-reflex in humans

Tseng

Shields

2012

Clinical Neurophysiology

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“…Our study may be underpowered and prone to type II error. The use of the H-reflex in order to explore walking has inherent practical challenges of using the appropriate intensity of stimulus, timing of the stimulus (Simonsen et al, 2013), protocol (Mynark, 2005), and control of the amount of body weight (Hwang et al, 2011); however, we used techniques with established reliability (Simonsen and Dyhre-Poulsen, 2011; König et al, 2013). Nevertheless the H-reflex has been shown to be effective in exploring the normal response to postural threat, and perhaps by measuring the reflex in mid stance changes at heel strike or other areas of the gait cycle were missed (Krauss and Misiaszek, 2007).…”

Section: Discussionmentioning

confidence: 99%

Associations between prefrontal cortex activation and H-reflex modulation during dual task gait

Meester¹,

Al-Yahya²,

Dawes³

et al. 2014

Front. Hum. Neurosci.

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Walking, although a largely automatic process, is controlled by the cortex and the spinal cord with corrective reflexes modulated through integration of neural signals from central and peripheral inputs at supraspinal level throughout the gait cycle. In this study we used an additional cognitive task to interfere with the automatic processing during walking in order to explore the neural mechanisms involved in healthy young adults. Participants were asked to walk on a treadmill at two speeds, both with and without additional cognitive load. We evaluated the impact of speed and cognitive load by analyzing activity of the prefrontal cortex (PFC) using functional Near-Infrared Spectroscopy (fNIRS) alongside spinal cord reflex activity measured by soleus H-reflex amplitude and gait changes obtained by using an inertial measuring unit. Repeated measures ANOVA revealed that fNIRS Oxy-Hb concentrations significantly increased in the PFC with dual task (walking while performing a cognitive task) compared to a single task (walking only; p < 0.05). PFC activity was unaffected by increases of walking speed. H-reflex amplitude and gait variables did not change in response to either dual task or increases in walking speed. When walking under additional cognitive load participants adapted by using greater activity in the PFC, but this adaptation did not detrimentally affect H-reflex amplitude or gait variables. Our findings suggest that in a healthy young population central mechanisms (PFC) are activated in response to cognitive loads but that H-reflex activity and gait performance can successfully be maintained. This study provides insights into the mechanisms behind healthy individuals safely performing dual task walking.

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“…Vibration caused an 83% reduction in the Hoffmann reflex (H-reflex), but limb load facilitated segmental excitability (decreased H-reflex post activation depression) [35,77]. Likewise, direct vibration over a muscle tendon increased pre-synaptic inhibition of the H-reflex [78-82] and loading (standing) reduces H-reflex post activation depression [83-85]. Recent research has shown that deficiencies in postural control were associated with brain activity during localized vibration of the foot [86].…”

Section: Discussionmentioning

confidence: 99%

Potential regenerative rehabilitation technology: implications of mechanical stimuli to tissue health

McHenry

Shields

2014

BMC Res Notes

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BackgroundMechanical loads induced through muscle contraction, vibration, or compressive forces are thought to modulate tissue plasticity. With the emergence of regenerative medicine, there is a need to understand the optimal mechanical environment (vibration, load, or muscle force) that promotes cellular health. To our knowledge no mechanical system has been proposed to deliver these isolated mechanical stimuli in human tissue. We present the design, performance, and utilization of a new technology that may be used to study localized mechanical stimuli on human tissues. A servo-controlled vibration and limb loading system were developed and integrated into a single instrument to deliver vibration, compression, or muscle contractile loads to a single limb (tibia) in humans. The accuracy, repeatability, transmissibility, and safety of the mechanical delivery system were evaluated on eight individuals with spinal cord injury (SCI).FindingsThe limb loading system was linear, repeatable, and accurate to less than 5, 1, and 1 percent of full scale, respectively, and transmissibility was excellent. The between session tests on individuals with spinal cord injury (SCI) showed high intra-class correlations (>0.9).ConclusionsAll tests supported that therapeutic loads can be delivered to a lower limb (tibia) in a safe, accurate, and measureable manner. Future collaborations between engineers and cellular physiologists will be important as research programs strive to determine the optimal mechanical environment for developing cells and tissues in humans.

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The effects of body weight on the soleus H-reflex modulation during standing

Cited by 12 publications

References 24 publications

Limb segment load inhibits post activation depression of soleus H-reflex in humans

Limb segment load inhibits post activation depression of soleus H-reflex in humans

Associations between prefrontal cortex activation and H-reflex modulation during dual task gait

Potential regenerative rehabilitation technology: implications of mechanical stimuli to tissue health

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