36 research outputs found
Données isoenzymatiques pour onze souches boliviennes de Trypanosoma cruzi : interprétation génétique et calcul de distances
How a plantar pressure-based, tongue-placed tactile biofeedback modifies postural control mechanisms during quiet standing
The purpose of the present study was to determine the effects of a plantar
pressure-based, tongue-placed tactile biofeedback on postural control
mechanisms during quiet standing. To this aim, sixteen young healthy adults
were asked to stand as immobile as possible with their eyes closed in two
conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP)
displacements, recorded using a force platform, were used to compute the
horizontal displacements of the vertical projection the centre of gravity
(CoGh) and those of the difference between the CoP and the vertical projection
of the CoG (CoP-CoGv). Altogether, the present findings suggest that the main
way the plantar pressure-based, tongue-placed tactile biofeedback improves
postural control during quiet standing is via both a reduction of the
correction thresholds and an increased efficiency of the corrective mechanism
involving the CoGh displacements
Sensori-motor adaptation to knee osteoarthritis during stepping-down before and after total knee replacement
BACKGROUND: Stepping-down is preceded by a shift of the center of mass towards the supporting side and forward. The ability to control both balance and lower limb movement was investigated in knee osteoarthritis patients before and after surgery. It was hypothesized that pain rather than knee joint mobility affects the coordination between balance and movement control. METHODS: The experiment was performed with 25 adult individuals. Eleven were osteoarthritic patients with damage restricted to one lower limb (8 right leg and 3 left leg). Subjects were recruited within two weeks before total knee replacement by the same orthopedic surgeon using the same prosthesis and technics of surgery. Osteoarthritic patients were tested before total knee replacement (pre-surgery session) and then, 9 of the 11 patients were tested one year after the surgery when re-educative training was completed (post-surgery session). 14 adult individuals (men: n = 7 and women: n = 7) were tested as the control group. RESULTS: The way in which the center of mass shift forward and toward the supporting side is initiated (timing and amplitude) did not vary within patients before and after surgery. In addition knee joint range of motion of the leading leg remained close to normal before and after surgery. However, the relative timing between both postural and movement phases was modified for the osteoarthritis supporting leg (unusual strategy for stepping-down) before surgery. The "coordinated" control of balance and movement turned to be a "sequential" mode of control; once the body weight transfer has been completed, the movement onset is triggered. This strategy could be aimed at shortening the duration-time supporting on the painful limb. However no such compensatory response was observed. CONCLUSION: The change in the strategy used when supporting on the arthritis and painful limb could result from the action of nociceptors that lead to increased proprioceptor thresholds, thus gating the proprioceptive inputs that may be the critical afferents in controlling the timing of the coordination between balance and movement initiation control
Experimental neck muscle pain impairs standing balance in humans
Impaired postural control has been reported in patients with chronic neck
pain of both traumatic and non-traumatic etiologies, but whether painful
stimulation of neck muscle per se can affect balance control during quiet
standing in humans remains unclear. The purpose of the present experiment was
thus to investigate the effect of experimental neck muscle pain on standing
balance in young healthy adults. To achieve this goal, 16 male university
students were asked to stand upright as still as possible on a force platform
with their eyes closed in two conditions of No pain and Pain of the neck
muscles elicited by experimental painful electrical stimulation. Postural
control and postural performance were assessed by the displacements of the
center of foot pressure (CoP) and of the center of mass (CoM), respectively.
The results showed increased CoP and CoM displacements variance, range, mean
velocity, and mean and median frequencies in the Pain relative to the No pain
condition. The present findings emphasize the destabilizing effect of
experimental neck muscle pain per se, and more largely stress the importance of
intact neck neuromuscular function on standing balance
Intrusive versus domiciliated triatomines and the challenge of adapting vector control practices against Chagas disease
Direct identification of Trypanosoma cruzi naturel clones in vectors and mammalian hosts by polymerase chain reaction amplification
Direct identification of Trypanosoma cruzi naturel clones in vectors and mammalian hosts by polymerase chain reaction amplification
Photograph of people outdoors at a picnic table covered with food, drinks, and a cowboy hat. Two women (one of whom has a purse) sit to the left. Harry S. Truman turns to look at a man wearing a cowboy hat and holding a guitar. Sam Rayburn has his arm around a woman and looks toward Truman. Another woman sits to the right. Lyndon Johnson is standing over Truman
Bioenergetic studies in residents at high altitude (2,850 m) with asymptomatic Chagas' disease
Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe