ORIGINAL ARTICLE: Tetraparesis resembling acute transverse myelitis in a captive chimpanzee (Pan troglodytes): long‐term care and recovery

Background A 24‐year‐old, male chimpanzee (Pan troglodytes) developed acute tetraparesis. Magnetic resonance imaging showed a diffuse T2‐weighted hyperintensive lesion, indicating inflammation at the C1–2 level. All infective, autoimmune, and vascular investigations were unremarkable. Results and Conclusions The chimpanzee’s condition most resembled acute transverse myelitis (ATM) in humans. The chimpanzee was in severe incapacitated neurological condition with bedridden status and required 24‐hour attention for 2 months followed by special care for over a year. Initially, corticosteroid therapy was performed, and his neurological symptoms improved to some extent; however, the general condition of the chimpanzee deteriorated in the first 6 months after onset. Pressure ulcers had developed at various areas on the animal’s body, as the bedridden status was protracted. Supportive therapy was continued, and the general condition, appetite, mobility, and pressure ulcers have slowly but synergistically recovered over the course of 2 years.     

Technical note: Chromosomal and mtDNA analysis of Oliver

Oliver is an African ape whose species identity has been debated in the popular media and by various scientists since the early 1970s. Although decisive morphological data has never been adduced on Oliver, many reports indicated that Oliver was morphologically unusual for a chimpanzee, particularly in his habitual bipedal posture. In addition, his diploid chromosome number was reported to be inconsistent with either human or chimpanzee, but instead intermediate between those species. We performed standard chromosomal studies which demonstrated that Oliver had the diploid number expected for a chimpanzee (2N = 48) and that the banding patterns of his chromosomes were typical for a chimpanzee and different from both humans and bonobos. We also sequenced a 312 bp region of his mitochondrial DNA D-loop region. Results indicated a high sequence homology to the Central African variety of chimpanzee, Pan troglodytes troglodytes. The highest percent homology was observed with a previously characterized specimen from Gabon, strongly suggesting that Oliver originated from this region. Am J Phys Anthropol 105:395–403, 1998. © 1998 Wiley-Liss, Inc.     

Activity of respiratory muscles in upright and recumbent humans

It is established that during tidal breathing the rib cage expands more than the abdomen in the upright posture, whereas the reverse is usually true in the supine posture. To explore the reasons for this, we studied nine normal subjects in the supine, standing, and sitting postures, measuring thoracoabdominal movement with magnetometers and respiratory muscle activity via integrated electromyograms. In eight of the subjects, gastric and esophageal pressures and diaphragmatic electromyograms via esophageal electrodes were also measured. In the upright postures, there was generally more phasic and tonic activity in the scalene, sternocleidomastoid, and parasternal intercostal muscles. The diaphragm showed more phasic (but not more tonic) activity in the upright postures, and the abdominal oblique muscle showed more tonic (but not phasic) activity in the standing posture. Relative to the esophageal pressure change with inspiration, the inspiratory gastric pressure change was greater in the upright than in the supine posture. We conclude that the increased rib cage motion characteristic of the upright posture owes to a combination of increased activation of rib cage inspiratory muscles plus greater activation of the diaphragm that, together with a stiffened abdomen, acts to move the rib cage more effectively.     

Human esophageal pressures and chest wall configuration in upright and head-down posture

Pressures were measured at two levels in the esophagus in 14 young healthy subjects performing slow inspiratory and expiratory vital capacity (VC) maneuvers in upright and head-down posture (180 degrees body tilt). In both postures, a gravitational pressure gradient was found, which increased very slightly with decreasing lung volumes (0.006 cmH2O X % VC-1 X cm descent-1) except for upright expiratory curves above 60% VC. The expiratory pressure gradient tended to be larger in head-down than in upright posture; however, during inspiration the opposite was true. In both postures the pressure change between 100 and 20% VC was smaller in the uppermost zone, which is consistent with the smaller changes in alveolar expansion in this zone. Also, in seven of the subjects, changes in cross-sectional area of the middle and lower part of the rib cage (HRC and LRC) and of the abdomen (ABD) were measured by respiratory inductive plethysmography in upright and head-down posture. The ratio of HRC motion to LRC motion was constant throughout the VC and did not change with posture, yet the ratio of ABD motion to mean RC motion changed with overall volume and was also larger in head-down than in upright posture. In conclusion, the changes in esophageal pressure gradient during slow VC maneuvers in head-down vs. upright posture were not related to (and thus not caused by) changes in chest wall configuration.     

The neutral posture of the cervical spine is not unique in human subjects

Cervical spine injuries often happen in dynamic environments (e.g., sports and motor vehicle crashes) where individuals may be moving their head and neck immediately prior to impact. This motion may reposition the cervical vertebrae in a way that is dissimilar to the upright resting posture that is often used as the initial position in cadaveric studies of catastrophic neck injury. Therefore our aim was to compare the “neutral” cervical alignment measured using fluoroscopy of 11 human subjects while resting in a neutral posture and as their neck passed through neutral during the four combinations of active flexion and extension movements in both an upright and inverted posture. Muscle activation patterns were also measured unilaterally using surface and indwelling electromyography in 8 muscles and then compared between the different conditions. Overall, the head posture, cervical spine alignment and muscle activation levels were significantly different while moving compared to resting upright. Compared to the resting upright condition, average head postures were 6–13° more extended, average vertebral angles varied from 11° more extended to 10° more flexed, and average muscle activation levels varied from unchanged to 10% MVC more active, although the exact differences varied with both direction of motion and orientation. These findings are important for ex vivo testing where the head and neck are statically positioned prior to impact – often in an upright neutral posture with negligible muscle forces – and suggest that current cadaveric head-first impact tests may not reflect many dynamic injury environments.     

Flat-out napping: The quantity and quality of sleep obtained in a seat during the daytime increase as the angle of recline of the seat increases

ABSTRACT

Some shiftwokers in the long-haul transportation industries (i.e. road, rail, sea, air) have the opportunity to sleep in on-board rest facilities during duty periods. These rest facilities are typically fitted with a seat with a maximum back angle to the vertical of 20°, 40°, or 90°. The aim of this study was to examine the impact of “back angle” on the quantity and quality of sleep obtained in a seat during a daytime nap. Six healthy adults (3 females aged 27.0 years and 3 males aged 22.7 years) each participated in three conditions. For each condition, participants had a 4-h sleep opportunity in a bed (02:00–06:00 h) followed by a 4-h sleep opportunity in a seat (13:00–17:00 h). The only difference between conditions was in the back angle of the seat to the vertical during the seat-based sleep periods: 20° (upright), 40° (reclined), and 90° (flat). Polysomnographic data were collected during all sleep episodes. For the seat-based sleep episodes, there was a significant effect of back angle on three of four measures of sleep quantity, i.e. total sleep time, slow-wave sleep, and rapid eye movement (REM) sleep, and three of four measures of sleep quality, i.e. latency to REM sleep, arousals, and stage shifts. In general, the quantity and quality of sleep obtained in the reclined and flat seats were better than those obtained in the upright seat. In particular, compared to the flat seat, the reclined seat resulted in similar amounts of total sleep and slow-wave sleep, but 37% less REM sleep; and the upright seat resulted in 29% less total sleep, 30% less slow-wave sleep, and 79% less REM sleep. There are two main mechanisms that may explain the results. First, it is difficult to maintain the head in a comfortable position for sleep when sitting upright, and this is likely exacerbated during REM sleep, when muscle tone is very low. Second, an upright posture increases sympathetic activity and decreases parasympathetic activity, resulting in a heightened level of physiological arousal.     

Biological rhythm and emotional and behavioral problems among schoolchildren in Southern Brazil

Emotional and behavioral problems have been considered an indicative of mental disorder in children. Mental health problems affect 10–20% of children and adolescents living in low-income and middle-income countries. Evidence suggests that disruptions in the biological rhythm may be a primary cause of emotional and behavioral changes, which affects several psychological functions and moods. Thus, this study aimed at verifying the association between biological rhythm and emotional and behavioral problems in schoolchildren living in Southern Brazil. This is a cross-sectional study with a school-based sample conducted between August 2015 and November 2016. The presence of emotional and behavioral problems in children was verified by the Strengths and Difficulties Questionnaire (SDQ), parents’ version. This is a 25-item assessment questionnaire used to screen mental health problems in children and adolescents (from 4 to 17 years of age) in the last 6 months. The Biological Rhythm Interview of Assessment in Neuropsychiatry-Kids (BRIAN-K) was used to measure the degree of biological rhythm disruption. The BRIAN-K consists of 20 items; from among these, 17 items are added to generate a quantitative measure, with greater scores indicating more biological rhythm disruption. The final score can also be divided into four subscales: sleep, social rhythm, eating pattern and overall activities. A total of 609 children responded to the assessment instruments. With regard to parents or primary caregiver, 596 completed the assessment and 13 (2%) were not located or refused to participate in the study. Thus, 596 dyads were included in the analysis. Children with emotional and behavioral problems presented higher scores in all domains of BRIAN-K: sleep, social, activity, eating pattern and total score (p < 0.001). The following variables remained associated with emotional and behavioral problems after adjusted analysis: BRIAN-K total score (p < 0.001) and all subscales sleep (p < 0.001), social (p < 0.001), activity (p < 0.001) and eating pattern (p < 0.001). Children with emotional and behavioral problems presented higher biological rhythm disruption when compared with children without emotional and behavioral problems. Our study emphasizes the importance of biological rhythm and its influence on emotional and behavioral problems in schoolchildren. Early detection of any biological rhythm disruption may enhance further assessment of any eventual emotional and behavioral problem and even a psychopathology.     

Lung function during and after prolonged head-down bed rest.

We determined the effects of prolonged head-down tilt bed rest (HDT) on lung mechanics and gas exchange. Six subjects were studied in supine and upright postures before (control), during [day 113 (D113)], and after (R + number of days of recovery) 120 days of HDT. Peak expiratory flow (PF) never differed between positions at any time and never differed from controls. Maximal midexpiratory flow (FEF(25-75%)) was lower in the supine than in the upright posture before HDT and was reduced in the supine posture by about 20% between baseline and D113, R + 0, and R + 3. The diffusing capacity for carbon monoxide corrected to a standardized alveolar volume (volume-corrected DL(CO)) was lower in the upright than in the supine posture and decreased in both postures by 20% between baseline and R + 0 and by 15% between baseline and R + 15. Pulmonary blood flow (Q(C)) increased from R + 0 to R + 3 by 20 (supine) and 35% (upright). As PF is mostly effort dependent, our data speak against major respiratory muscle deconditioning after 120 days of HDT. The decrease in FEF(25-75%) suggests a reduction in elastic recoil. Time courses of volume-corrected DL(CO) and Q(C) could be explained by a decrease in central blood volume during and immediately after HDT.     

Passive acoustic monitoring reveals group ranging and territory use: a case study of wild chimpanzees (<Emphasis Type="Italic">Pan troglodytes</Emphasis>)

Background

Assessing the range and territories of wild mammals traditionally requires years of data collection and often involves directly following individuals or using tracking devices. Indirect and non-invasive methods of monitoring wildlife have therefore emerged as attractive alternatives due to their ability to collect data at large spatiotemporal scales using standardized remote sensing technologies. Here, we investigate the use of two novel passive acoustic monitoring (PAM) systems used to capture long-distance sounds produced by the same species, wild chimpanzees (Pan troglodytes), living in two different habitats: forest (Taï, Côte d’Ivoire) and savanna-woodland (Issa valley, Tanzania).

Results

Using data collected independently at two field sites, we show that detections of chimpanzee sounds on autonomous recording devices were predicted by direct and indirect indices of chimpanzee presence. At Taï, the number of chimpanzee buttress drums detected on recording devices was positively influenced by the number of hours chimpanzees were seen ranging within a 1 km radius of a device. We observed a similar but weaker relationship within a 500 m radius. At Issa, the number of indirect chimpanzee observations positively predicted detections of chimpanzee loud calls on a recording device within a 500 m but not a 1 km radius. Moreover, using just seven months of PAM data, we could locate two known chimpanzee communities in Taï and observed monthly spatial variation in the center of activity for each group.

Conclusions

Our work shows PAM is a promising new tool for gathering information about the ranging behavior and habitat use of chimpanzees and can be easily adopted for other large territorial mammals, provided they produce long-distance acoustic signals that can be captured by autonomous recording devices (e.g., lions and wolves). With this study we hope to promote more interdisciplinary research in PAM to help overcome its challenges, particularly in data processing, to improve its wider application.

     

An ameliorative effect of recovery sleep on total sleep deprivation-induced neurodegeneration

Neurodegenerative changes following sleep deprivation (SD) result in debilitating behavioral and cognitive dysfunction. SD causes gradual cognitive impairment and later results in neurodegeneration. These changes are thought to be the consequences of cellular disorganization and degeneration in selected brain areas – the hippocampus, prefrontal cortex, amygdala, and hypothalamus. We investigated the histological changes in mice exposed to 6 days SD and to the effects of 2 days of recovery sleep in the brain regions listed above. Cytological changes, total viable cell count in hippocampal subregions, Bcl-2 expression, and degenerative changes like cell morphology and membrane integrity of neurons were evaluated. Results demonstrated that prolonged SD decreased the count of viable and healthy cells and caused a decrease in Bcl-2 positive cells and an increase in degenerated cells with pyknotic morphology, chromatolysis and darkly stained cytoplasm. Degenerative changes were ameliorated by 2 days of recovery sleep or rehabilitation after SD. Data suggest that chronic SD constitutes a severe threat to the brain and leads to neurodegeneration, while rehabilitation or recovery sleep ameliorates or protects the brain from neurodegenerative challenges.     

Bipedal behavior and the emergence of erect posture in man

Bipedal behavior is present to some degree in most of the higher primates. Field studies of living pongids have shown that an upright stance and various types and degrees of bipedal progression are not uncommon and are thus presumably advantageous. Bipedal behavior similar to that in living pongids could also have been, and probably was, present in pre-hominids. As the environment of the pre-hominids changed, the increased use of bipedalism was of survival value. That is, it was a behavioral response to environmental circumstances and not just a random event. Once bipedal behavior became habitual, it formed part of a pattern of natural selection which shaped a physical type adapted for erect, bipedal posture.     

Immunologic and prognostic factors associated with overall survival employing a poxviral-based PSA vaccine in metastatic castrate-resistant prostate cancer

A concurrent multicenter, randomized Phase II trial employing a recombinant poxviral vaccine provided evidence of enhanced median overall survival (OS) (p = 0.0061) in patients with metastatic castrate-resistant prostate cancer (mCRPC). The study reported here employed the identical vaccine in mCRPC to investigate the influence of GM-CSF with vaccine, and the influence of immunologic and prognostic factors on median OS. Thirty-two patients were vaccinated once with recombinant vaccinia containing the transgenes for prostate-specific antigen (PSA) and three costimulatory molecules. Patients received boosters with recombinant fowlpox containing the same four transgenes. Twelve of 32 patients showed declines in serum PSA post-vaccination and 2/12 showed decreases in index lesions. Median OS was 26.6 months (predicted median OS by the Halabi nomogram was 17.4 months). Patients with greater PSA-specific T-cell responses showed a trend (p = 0.055) toward enhanced survival. There was no difference in T-cell responses or survival in cohorts of patients receiving GM-CSF versus no GM-CSF. Patients with a Halabi predicted survival of <18 months (median predicted 12.3 months) had an actual median OS of 14.6 months, while those with a Halabi predicted survival of ≥18 months (median predicted survival 20.9 months) will meet or exceed 37.3 months, with 12/15 patients living longer than predicted (p = 0.035). Treg suppressive function was shown to decrease following vaccine in patients surviving longer than predicted, and increase in patients surviving less than predicted. This hypothesis-generating study provides evidence that patients with more indolent mCRPC (Halabi predicted survival ≥18 months) may best benefit from vaccine therapy.     

Savanna chimpanzee (<Emphasis Type="Italic">Pan troglodytes verus</Emphasis>) nesting ecology at Bagnomba (Kedougou,Senegal)

We studied the nesting behavior of the critically endangered West African chimpanzee (Pan troglodytes verus). We assumed that the nesting data stemmed from a single, unhabituated community at the Bagnomba hill site in the savanna-woodlands of southeastern Senegal. The aim of this study was to examine chimpanzees’ nesting habits in terms of the tree species utilized and sleeping nest heights. We recorded a total of 550 chimpanzee nests at Bagnomba between January 2015 and December 2015. The chimpanzees here made nests in particular tree species more often than others. The majority of nests (63%) were in two tree species: Diospyros mespiliformis and Pterocarpus erinaceus. The average height of nesting trees was 10.54 m (SD 3.91, range, 0.0–29.0 m) and average nest height was 7.90 m (SD 3.62, range, 0.0–25.0 m). The result of a linear regression analysis (r = 0.7874; n = 550; p < 0.05) is consistent with a preference for nesting at a particular height. Bagnomba chimpanzees rarely made ground nests (0.36% of nests), but the presence of any ground nesting was unexpected, given that at least one leopard (Panthera pardus) also occupied the hill. This knowledge will enable stakeholders involved in the protection of chimpanzees specifically and of biodiversity in general to better understand chimpanzee ecology and inform a conservation action plan in Senegal where the survival of this species is threatened.     

Effect of load position on muscle forces,internal loads and stability of the human spine in upright postures

A novel kinematics-based approach coupled with a non-linear finite element model was used to investigate the effect of changes in the load position and posture on muscle activity, internal loads and stability margin of the human spine in upright standing postures. In addition to 397 N gravity, external loads of 195 and 380 N were considered at different lever arms and heights. Muscle forces, internal loads and stability margin substantially increased as loads displaced anteriorly away from the body. Under same load magnitude and location, adopting a kyphotic posture as compared with a lordotic one increased muscle forces, internal loads and stability margin. An increase in the height of a load held at a fixed lever arm substantially diminished system stability thus requiring additional muscle activations to maintain the same margin of stability. Results suggest the importance of the load position and lumbar posture in spinal biomechanics during various manual material handling operations.     

Comparison of neutron organ and effective dose coefficients for PIMAL stylized phantom in bent postures in standard irradiation geometries

Neutron dose coefficients for standard irradiation geometries have been reported in International Commission on Radiological Protection (ICRP) Publication 116 for the ICRP Publication 110 adult reference phantoms. In the present work, organ and effective dose coefficients have been calculated for a receptor in both upright and articulated (bent) postures representing more realistic working postures exposed to a mono-energetic neutron radiation field. This work builds upon prior work by Dewji and co-workers comparing upright and bent postures for exposure to mono-energetic photon fields. Simulations were conducted using the Oak Ridge National Laboratory’s articulated stylized adult phantom, “Phantom wIth Moving Arms and Legs” (PIMAL) software package, and the Monte Carlo N-Particle (MCNP) version 6.1.1 radiation transport code. Organ doses were compared for the upright and bent (45° and 90°) phantom postures for neutron energies ranging from 1 × 10^??9 to 20 MeV for the ICRP Publication 116 external exposure geometries—antero-posterior (AP), postero-anterior (PA), and left and right lateral (LLAT, RLAT). Using both male and female phantoms, effective dose coefficients were computed using ICRP Publication 103 methodology. The resulting coefficients for articulated phantoms were compared to those of the upright phantom. Computed organ and effective dose coefficients are discussed as a function of neutron energy, phantom posture, and source irradiation geometry. For example, it is shown here that for the AP and PA irradiation geometries, the differences in the organ coefficients between the upright and bent posture become more pronounced with increasing bending angle. In the AP geometry, the brain dose coefficients are expectedly higher in the bent postures than in the upright posture, while all other organs have lower dose coefficients, with the thyroid showing the greatest difference. Overall, the effective dose estimated for the upright phantom is more conservative than that for the articulated phantom, which may have ramifications in the estimation or reconstruction of radiation doses.     

Effecten van geriatrische COPD-revalidatie op ziekenhuisopnames en inspanningstolerantie: een retrospectief observationele studie

Introduction

Frail COPD patients are frequently not accepted for regular pulmonary rehabilitation programs due to low physical condition and functional limitations. Rehabilitation programs in nursing homes for geriatric patients with COPD have been developed. The effects of such programs are largely unknown.

Aims

To assess the course of COPD-related hospital admissions and exercise tolerance in a cohort of frail COPD patients participating in geriatric COPD rehabilitation.

Methods

Retrospective observational study with a follow up of 12 months after discharge from rehabilitation. COPD related hospital admission days were measured in the year before and after participating rehabilitation. Exercise tolerance was measured by the six minute walk test (6MWT) at admission and at discharge from rehabilitation.

Results

Fifty-eight participants accomplished the rehabilitation program. Twelve patients died in the first year after discharge. The median number of hospital admission days in the year before participating rehabilitation was 21 (IQR 10–33). The first year after discharge this was decreased to a median of 6 (IQR 0–12). The 6MWT increased from 194 (SD 85) meters at admission to 274 (SD 95) meters at discharge (mean difference 80 m, SD 72; p < 0.05).

Conclusions

Geriatric COPD rehabilitation in a nursing home setting seems to reduce hospital admissions in frail COPD patients and to increase exercise tolerance.

     

Age class influence on the yield of edible fungi in a managed Mediterranean forest

Lack of information and difficulty in predicting wild edible sporocarp yields is blocking its integration in forest management. In the Mediterranean area, this nontimber forest product has increased its market value, consumption demand, and interest over the last decade. In this work, sampling year and stand age effects are analyzed in order to advance knowledge of edible fungi community structure, dynamics, and production. Weekly autumnal sporocarp monitoring was performed from 1997 to 2011 in a Pinus pinaster managed forest in central Spain. After applying a random stand age-stratified survey, 21 plots of 150 m² have been set with three per stand age class. The forest age classes have been defined as follows: 0–10 years, mixture of parent and regenerated trees, 11–20, 21–40, 41–60, 61–90, and over 90 years. A total of 153 species belonging to 56 genera were recorded, 55 of which are edible. The production of edible sporocarps was 19.8 kg ha^?1, representing 31 % of total production. Sporocarp production presents a sharp interannual variability with autumns 62 times more productive than others. The most abundant edible species in terms of fresh weight per hectare has been Lactarius deliciosus with 7.0 kg ha^?1. Edible fungi yields registered a significant decline in 10 years following regenerative cutting. The presence of parent trees significantly increases production with regard to the first class. The highest production of edible species occurs in the middle age, 41–60 years, and in the following classes, a decrease is produced. L. deliciosus production registered differences with age, manifesting in a high yield in young stands (11–20 years) and significant recovery in woodlands near to the cutting.     

Functional identity versus species richness: herbivory resistance in plant communities

The resistance of a plant community against herbivore attack may depend on plant species richness, with monocultures often much more severely affected than mixtures of plant species. Here, we used a plant–herbivore system to study the effects of selective herbivory on consumption resistance and recovery after herbivory in 81 experimental grassland plots. Communities were established from seed in 2002 and contained 1, 2, 4, 8, 16 or 60 plant species of 1, 2, 3 or 4 functional groups. In 2004, pairs of enclosure cages (1 m tall, 0.5 m diameter) were set up on all 81 plots. One randomly selected cage of each pair was stocked with 10 male and 10 female nymphs of the meadow grasshopper, Chorthippus parallelus. The grasshoppers fed for 2 months, and the vegetation was monitored over 1 year. Consumption resistance and recovery of vegetation were calculated as proportional changes in vegetation biomass. Overall, grasshopper herbivory averaged 6.8%. Herbivory resistance and recovery were influenced by plant functional group identity, but independent of plant species richness and number of functional groups. However, herbivory induced shifts in vegetation composition that depended on plant species richness. Grasshopper herbivory led to increases in herb cover at the expense of grasses. Herb cover increased more strongly in species-rich mixtures. We conclude that selective herbivory changes the functional composition of plant communities and that compositional changes due to selective herbivory depend on plant species richness.     

Evaluation of Novel EMG Biofeedback for Postural Correction During Computer Use

Postural correction is an effective rehabilitation technique used to treat chronic neck and shoulder pain, and is aimed toward reducing the load on the surrounding muscles by adopting a neutral posture. The objective of this investigation was to evaluate the effectiveness of real-time high-density surface EMG (HDsEMG) biofeedback for postural correction during typing. Twenty healthy participants performed a typing task with two forms of postural feedback: (1) verbal postural coaching and (2) verbal postural coaching plus HDsEMG biofeedback. The interface used activity from two HDsEMG arrays placed over the trapezius designed to shift trapezius muscle activity inferiorly. The center of gravity across both arrays was used to quantify the spatial distribution of trapezius activity. Planar angles taken from upper extremity reflective markers quantified cervicoscapular posture. During the biofeedback condition, trapezius muscle activity was located 12.74 ± 3.73 mm more inferior, the scapula was 2.58 ± 1.18° more adducted and 0.23 ± 0.24° more depressed in comparison to verbal postural coaching alone. The results demonstrate the short-term effectiveness of a real-time HDsEMG biofeedback intervention to achieve postural correction, and may be more effective at creating an inferior shift in trapezius muscle activity in comparison to verbal postural coaching alone.     

Greater sensitivity of the vestibulosympathetic reflex in the upright posture in humans.

Otolith organs have been shown to activate the sympathetic nervous system in the prone position by head-down rotation (HDR) in humans. To date, otolithic stimulation by HDR has not been comprehensively studied in the upright posture. The purpose of the present study was to determine whether otolithic stimulation increases muscle sympathetic nerve activity (MSNA) in the upright posture. It was hypothesized that stimulation of the otolith organs would increase MSNA in the upright posture, despite increased baseline sympathetic activation due to unloading of the baroreceptors. MSNA, arterial blood pressure, heart rate, and degree of head rotation were measured during HDR in 18 volunteers (23 +/- 1 yr) in different postures. Study 1 (n = 11) examined HDR in the prone and sitting positions and study 2 (n = 7) examined HDR in the prone and 60 degrees head-up tilt positions. Baseline MSNA was 8 +/- 4, 15 +/- 4, and 33 +/- 2 bursts/min for prone, sitting, and head-up tilt, respectively. HDR significantly increased MSNA in the prone (Delta4 +/- 1 and Delta105 +/- 37% for burst frequency and total activity, respectively), sitting (Delta5 +/- 1 and Delta43 +/- 12%), and head-up tilt (Delta7 +/- 1 and Delta110 +/- 41%; P < 0.05). Sensitivity of the vestibulosympathetic reflex (%DeltaMSNA/DeltaHDR; degree of head rotation) was significantly greater in the sitting and head-up tilt than prone position (prone = 74 +/- 22; sitting = 109 +/- 30; head-up tilt = 276 +/- 103; P < 0.05). These data indicate that stimulation of the otolith organs can mediate increases in MSNA in the upright posture and suggest a greater sensitivity of the vestibulosympathetic reflex in the upright posture in humans.