Cory T Robertson

Learn More
OBJECTIVES This study examined the effect of age on the spinal mechanism post-activation depression (PD) and its relationship with postural sway. METHODS Two groups, young (n = 10, 25.2 +/- 5.2 yr) and elderly (n = 10, 74.6 +/- 6.3 yr) participated in this study. Soleus H-reflex amplitude (peak-to-peak EMG) was measured prior to and after a passive(More)
The factors that are responsible for the relationship between motoneuron excitability and muscle length may have both mechanical and/or neurophysiologic origins. The aim of the study was to investigate the changes in the level of presynaptic inhibition, as measured with a soleus H-reflex conditioning protocol, and muscle length. Ten healthy volunteers were(More)
Fluctuating asymmetry (FA), the small random deviations from perfect morphological symmetry that result during development, is ubiquitous throughout the animal kingdom. In many species, FA seems to play a role in mate choice, perhaps because it signals an individual's genetic quality and health. However, the relationship between an individual's FA and(More)
Spinal modulation of motoneuron excitability has been extensively investigated during various tasks in humans. Previous studies have revealed that balance tasks induce a decrease in Ia-motoneuron communication which has been attributed to increased levels of presynaptic inhibition (PI). Moreover, this depression in Ia-motoneuron connectivity takes place(More)
The H-max/M-max ratio has long been used to understand motoneuron excitability induced by the Ia fibers. However, we contend that when comparing young and elderly subjects, this measurement can be controversial. We compared the modulation of the soleus H-max and M-max at five different muscle lengths between elderly and young subjects. The young subjects(More)
  • 1