42 research outputs found
If only they knew! A nonâinferiority randomized controlled trial comparing deceptive and openâlabel placebo in healthy individuals
BackgroundPlacebo use is widespread in clinical practice. However, they are most often administered deceptively rather than openly. It is often suggested that openâlabel placebos (OLP) are less effective than deceptive placebos (DP). This study aimed to compare the use of DP and OLP treatments to reduce pain in healthy volunteers.MethodsWe conducted a nonâinferiority, parallel, randomized, controlled trial, which also included a nested crossâover noâtreatment condition. This study was conducted at a university clinic in France.ResultsWe included 60 subjects and the main result shows that the OLP was not inferior to the DP by a margin of 10âmm. The mean difference between both groups regarding intensity of pain was 0.7âmm with a 95% compatibility interval (95% CI) of ]ââ; 5.4], and 97.5% CI of ]ââ; 6.3]. Secondary outcomes require cautious interpretation of the effect of placebo versus no treatment due to a timeâtreatment interaction.ConclusionThe study indicates that OLP may perform just as well as DP and could provide support for the use of OLP as an ethical alternative to DP when they are to be used in a clinical setting. If only patients knew about the placebo nature of some treatments they are receiving, unnecessary lies could be avoided while maintaining similar placebo effects.SignificanceThis study is the first to show nonâinferiority of placebos administered honestly, also called OLP, compared to DP in reducing pain. This suggests that OLP could be as effective as their deceptive counterparts while having the ethical advantage of not being required to lie. If deception is not a necessary condition for efficacy, OLP should be preferred over DP
Re-weighting of somatosensory inputs from the foot and the ankle for controlling posture during quiet standing following trunk extensor muscles fatigue
The present study focused on the effects of trunk extensor muscles fatigue on
postural control during quiet standing under different somatosensory conditions
from the foot and the ankle. With this aim, 20 young healthy adults were asked
to stand as immobile as possible in two conditions of No fatigue and Fatigue of
trunk extensor muscles. In Experiment 1 (n = 10), somatosensation from the foot
and the ankle was degraded by standing on a foam surface. In Experiment 2 (n =
10), somatosensation from the foot and ankle was facilitated through the
increased cutaneous feedback at the foot and ankle provided by strips of
athletic tape applied across both ankle joints. The centre of foot pressure
displacements (CoP) were recorded using a force platform. The results showed
that (1) trunk extensor muscles fatigue increased CoP displacements under
normal somatosensatory conditions (Experiment 1 and Experiment 2), (2) this
destabilizing effect was exacerbated when somatosensation from the foot and the
ankle was degraded (Experiment 1), and (3) this destabilizing effect was
mitigated when somatosensation from the foot and the ankle was facilitated
(Experiment 2). Altogether, the present findings evidenced re-weighting of
sensory cues for controlling posture during quiet standing following trunk
extensor muscles fatigue by increasing the reliance on the somatosensory inputs
from the foot and the ankle. This could have implications in clinical and
rehabilitative areas
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
Differential postural effects of plantar-flexor muscles fatigue under normal, altered and improved vestibular and neck somatosensory conditions
The aim of the present study was to assess the effects of plantar-flexor
muscles fatigue on postural control during quiet standing under normal, altered
and improved vestibular and neck somatosensory conditions. To address this
objective, young male university students were asked to stand upright as still
as possible with their eyes closed in two conditions of No Fatigue and Fatigue
of the plantar-flexor muscles. In Experiment 1 (n=15), the postural task was
executed in two Neutral head and Head tilted backward postures, recognized to
degrade vestibular and neck somatosensory information. In Experiment 2 (n=15),
the postural task was executed in two conditions of No tactile and Tactile
stimulation of the neck provided by the application of strips of adhesive
bandage to the skin over and around the neck. Centre of foot pressure
displacements were recorded using a force platform. Results showed that (1) the
Fatigue condition yielded increased CoP displacements relative to the No
Fatigue condition (Experiment 1 and Experiment 2), (2) this destabilizing
effect was more accentuated in the Head tilted backward posture than Neutral
head posture (Experiment 1) and (3) this destabilizing effect was less
accentuated in the condition of Tactile stimulation than that of No tactile
stimulation of the neck (Experiment 2). In the context of the multisensory
control of balance, these results suggest an increased reliance on vestibular
and neck somatosensory information for controlling posture during quiet
standing in condition of altered ankle neuromuscular function
Can a Plantar Pressure-Based Tongue-Placed Electrotactile Biofeedback Improve Postural Control Under Altered Vestibular and Neck Proprioceptive Conditions?
We investigated the effects of a plantar pressure-based tongue-placed
electrotactile biofeedback on postural control during quiet standing under
normal and altered vestibular and neck proprioceptive conditions. To achieve
this goal, fourteen young healthy adults were asked to stand upright as
immobile as possible with their eyes closed in two Neutral and Extended head
postures and two conditions of No-biofeedback and Biofeedback. The underlying
principle of the biofeedback consisted of providing supplementary information
related to foot sole pressure distribution through a wireless embedded
tongue-placed tactile output device. Centre of foot pressure (CoP)
displacements were recorded using a plantar pressure data acquisition system.
Results showed that (1) the Extended head posture yielded increased CoP
displacements relative to the Neutral head posture in the No-biofeedback
condition, with a greater effect along the anteroposterior than mediolateral
axis, whereas (2) no significant difference between the two Neutral and
Extended head postures was observed in the Biofeedback condition. The present
findings suggested that the availability of the plantar pressure-based
tongue-placed electrotactile biofeedback allowed the subjects to suppress the
destabilizing effect induced by the disruption of vestibular and neck
proprioceptive inputs associated with the head extended posture. These results
are discussed according to the sensory re-weighting hypothesis, whereby the
central nervous system would dynamically and selectively adjust the relative
contributions of sensory inputs (i.e., the sensory weights) to maintain upright
stance depending on the sensory contexts and the neuromuscular constraints
acting on the subject
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
Consequences of lower extremity and trunk muscle fatigue on balance and functional tasks in older people: A systematic literature review
<p>Abstract</p> <p>Background</p> <p>Muscle fatigue reduces muscle strength and balance control in young people. It is not clear whether fatigue resistance seen in older persons leads to different effects. In order to understand whether muscle fatigue may increase fall risk in older persons, a systematic literature review aimed to summarize knowledge on the effects of lower extremity and trunk muscle fatigue on balance and functional tasks in older people was performed.</p> <p>Methods</p> <p>Studies were identified with searches of the PUBMED and SCOPUS data bases.</p> <p>Papers describing effects of lower extremity or trunk muscle fatigue protocols on balance or functional tasks in older people were included. Studies were compared with regards to study population characteristics, fatigue protocol, and balance and functional task outcomes.</p> <p>Results</p> <p>Seven out of 266 studies met the inclusion criteria. Primary findings were: fatigue via resistance exercises to lower limb and trunk muscles induces postural instability during quiet standing; induced hip, knee and ankle muscle fatigue impairs functional reach, reduces the speed and power of sit-to-stand repetitions, and produces less stable and more variable walking patterns; effects of age on degree of fatigue and rate of recovery from fatigue are inconsistent across studies, with these disparities likely due to differences in the fatigue protocols, study populations and outcome measures.</p> <p>Conclusion</p> <p>Taken together, the findings suggest that balance and functional task performance are impaired with fatigue. Future studies should assess whether fatigue is related to increased risk of falling and whether exercise interventions may decrease fatigue effects.</p
Comparison of balance assessment modalities in emergency department elders: a pilot cross-sectional observational study
<p>Abstract</p> <p>Background</p> <p>More than one-third of US adults 65 and over fall every year. These falls may cause serious injury including substantial long-term morbidity (due declines in activities of daily living) and death. The emergency department (ED) visit represents an opportunity for identifying high risk elders and potentially instituting falls-related interventions. The unique characteristic of the ED environment and patient population necessitate that risk-assessment modalities be validated in this specific setting. In order to better identify elders at risk of falls, we examined the relationship between patient-provided history of falling and two testing modalities (a balance plate system and the timed up-and-go [TUG] test) in elder emergency department (ED) patients.</p> <p>Methods</p> <p>We conducted a cross-sectional observational study of patients â„ 60 years old being discharged from the ED. Patient history of falls in the past week, month, 6 months, and year was obtained. Balance plate center of pressure excursion (COP) measurements and TUG testing times were recorded. COP was recorded under four conditions: normal stability eyes open (NSEO) and closed (NSEC), and perturbed stability eyes open and closed. Correlation between TUG and COP scores was measured. Univariate logistic regression was used to identify the relationship between patient-provided falls history and the two testing modalities. Proportions, likelihood ratios, and receiver-operating-characteristic (ROC) curves for prediction of previous falls were reported.</p> <p>Results</p> <p>Fifty-three subjects were enrolled, 11% had fallen in the previous week and 42% in the previous year. There was no correlation between TUG and any balance plate measurements. In logistic regression, neither testing modality was associated with prior history of falls (<it>p </it>> 0.05 for all time periods). Balance plate NSEO and NSEC testing cutoffs could be identified which were 83% sensitive and had a negative likelihood ratio (LR-) of 0.3 for falls in the past week. TUG testing was not useful for falls in the past week, but performed best for more distant falls in the past month, 6 months, or year. TUG cutoffs with sensitivity over 80% and LR(-) of 0.17-0.32 could be identified for these time periods.</p> <p>Conclusion</p> <p>Over 40% of community-dwelling elder ED patients report a fall within the past year. Balance plate and TUG testing were feasibly conducted in an ED setting. There is no relationship between scores on balance plate and TUG testing in these patients. In regression analysis, neither modality was significantly associated with patient provided history of falls. These modalities should not be adopted for screening purposes in elders in the ED setting without validation in future studies or as part of multi-factorial risk assessment.</p