Πέμπτη 9 Φεβρουαρίου 2017

Iranian Voice Quality of Life Profile (IVQLP): Factor Analysis

Publication date: Available online 9 February 2017
Source:Journal of Voice
Author(s): Ali Dehqan, Fariba Yadegari, Ronald C. Scherer, Ali Asgari, Payman Dabirmoghadam
ObjectivesAn important domain in health-related quality of life evaluations is quality of life perceptions due to having a voice disorder. The objective of this study was to examine the factor structure of the Iranian Voice Quality of Life Profile (IVQLP) based on Exploratory Factor Analysis and confirmatory factor analysis.MethodsThe study sample consisted of 280 patients (174 males and 106 females) diagnosed with MTD, benign organic disorders such as polyps and nodules, and unilateral vocal fold paralysis and cancer. To evaluate the different dimensions of the IVQLP, a principal component analysis (PCA) was conducted. Confirmatory factor analysis (CFA) was used to investigate the fitting of extracted dimensions and construct validity of the IVQLP.ResultsThe results showed that the IVQLP has a 4-factor structure. The first factor has 17 items and refers to Emotions. The second factor has 12 items and refers to Individual/Social Relations. The third factor with 6 items refers to Occupation, and the forth with 5 items relates to Psychosomatic characteristics.ConclusionsThe conclusion of this study is that the concept of quality of life in Iranian patients with voice disorders is somewhat different from that of Western patients. This difference can be seen in. the large number of items related to an Emotional factor and the identification of a Psychosomatic factor.



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Stapes displacement and intracochlear pressure in response to very high level, low frequency sounds

Publication date: Available online 9 February 2017
Source:Hearing Research
Author(s): Nathaniel T. Greene, Herman A. Jenkins, Daniel J. Tollin, James R. Easter
The stapes is held in the oval window by the stapedial annular ligament (SAL), which restricts total peak-to-peak displacement of the stapes. Previous studies have suggested that for moderate (<130 dB SPL) sound levels intracochlear pressure (PIC), measured at the base of the cochlea far from the basilar membrane, increases directly proportionally with stapes displacement (DStap), thus a current model of impulse noise exposure (the Auditory Hazard Assessment Algorithm for Humans, or AHAAH) predicts that peak PIC will vary linearly with DStap up to some saturation point. However, no direct tests of DStap, or of the relationship with PIC during such motion, have been performed during acoustic stimulation of the human ear. In order to examine the relationship between DStap and PIC to very high level sounds, measurements of DStap and PIC were made in cadaveric human temporal bones. Specimens were prepared by mastoidectomy and extended facial recess to expose the ossicular chain. Measurements of PIC were made in scala vestibuli (PSV) and scala tympani (PST), along with the SPL in the external auditory canal (PEAC), concurrently with laser Doppler vibrometry (LDV) measurements of stapes velocity (VStap). Stimuli were moderate (∼100 dB SPL) to very high level (up to ∼170 dB SPL), low frequency tones (20–2560 Hz). Both DStap and PSV increased proportionally with sound pressure level in the ear canal up to approximately ∼150 dB SPL, above which both DStap and PSV showed a distinct deviation from proportionality with PEAC. Both DStap and PSV approached saturation: DStap at a value exceeding 150 μm, which is substantially higher than has been reported for small mammals, while PSV showed substantial frequency dependence in the saturation point. The relationship between PSV and DStap remained constant, and cochlear input impedance did not vary across the levels tested, consistent with prior measurements at lower sound levels. These results suggest that PSV sound pressure holds constant relationship with DStap, described by the cochlear input impedance, at these, but perhaps not higher, stimulation levels. Additionally, these results indicate that the AHAAH model, which was developed using results from small animals, underestimates the sound pressure levels in the cochlea in response to high level sound stimulation, and must be revised.



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Stapes displacement and intracochlear pressure in response to very high level, low frequency sounds

Publication date: Available online 9 February 2017
Source:Hearing Research
Author(s): Nathaniel T. Greene, Herman A. Jenkins, Daniel J. Tollin, James R. Easter
The stapes is held in the oval window by the stapedial annular ligament (SAL), which restricts total peak-to-peak displacement of the stapes. Previous studies have suggested that for moderate (<130 dB SPL) sound levels intracochlear pressure (PIC), measured at the base of the cochlea far from the basilar membrane, increases directly proportionally with stapes displacement (DStap), thus a current model of impulse noise exposure (the Auditory Hazard Assessment Algorithm for Humans, or AHAAH) predicts that peak PIC will vary linearly with DStap up to some saturation point. However, no direct tests of DStap, or of the relationship with PIC during such motion, have been performed during acoustic stimulation of the human ear. In order to examine the relationship between DStap and PIC to very high level sounds, measurements of DStap and PIC were made in cadaveric human temporal bones. Specimens were prepared by mastoidectomy and extended facial recess to expose the ossicular chain. Measurements of PIC were made in scala vestibuli (PSV) and scala tympani (PST), along with the SPL in the external auditory canal (PEAC), concurrently with laser Doppler vibrometry (LDV) measurements of stapes velocity (VStap). Stimuli were moderate (∼100 dB SPL) to very high level (up to ∼170 dB SPL), low frequency tones (20–2560 Hz). Both DStap and PSV increased proportionally with sound pressure level in the ear canal up to approximately ∼150 dB SPL, above which both DStap and PSV showed a distinct deviation from proportionality with PEAC. Both DStap and PSV approached saturation: DStap at a value exceeding 150 μm, which is substantially higher than has been reported for small mammals, while PSV showed substantial frequency dependence in the saturation point. The relationship between PSV and DStap remained constant, and cochlear input impedance did not vary across the levels tested, consistent with prior measurements at lower sound levels. These results suggest that PSV sound pressure holds constant relationship with DStap, described by the cochlear input impedance, at these, but perhaps not higher, stimulation levels. Additionally, these results indicate that the AHAAH model, which was developed using results from small animals, underestimates the sound pressure levels in the cochlea in response to high level sound stimulation, and must be revised.



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Stapes displacement and intracochlear pressure in response to very high level, low frequency sounds

Publication date: Available online 9 February 2017
Source:Hearing Research
Author(s): Nathaniel T. Greene, Herman A. Jenkins, Daniel J. Tollin, James R. Easter
The stapes is held in the oval window by the stapedial annular ligament (SAL), which restricts total peak-to-peak displacement of the stapes. Previous studies have suggested that for moderate (<130 dB SPL) sound levels intracochlear pressure (PIC), measured at the base of the cochlea far from the basilar membrane, increases directly proportionally with stapes displacement (DStap), thus a current model of impulse noise exposure (the Auditory Hazard Assessment Algorithm for Humans, or AHAAH) predicts that peak PIC will vary linearly with DStap up to some saturation point. However, no direct tests of DStap, or of the relationship with PIC during such motion, have been performed during acoustic stimulation of the human ear. In order to examine the relationship between DStap and PIC to very high level sounds, measurements of DStap and PIC were made in cadaveric human temporal bones. Specimens were prepared by mastoidectomy and extended facial recess to expose the ossicular chain. Measurements of PIC were made in scala vestibuli (PSV) and scala tympani (PST), along with the SPL in the external auditory canal (PEAC), concurrently with laser Doppler vibrometry (LDV) measurements of stapes velocity (VStap). Stimuli were moderate (∼100 dB SPL) to very high level (up to ∼170 dB SPL), low frequency tones (20–2560 Hz). Both DStap and PSV increased proportionally with sound pressure level in the ear canal up to approximately ∼150 dB SPL, above which both DStap and PSV showed a distinct deviation from proportionality with PEAC. Both DStap and PSV approached saturation: DStap at a value exceeding 150 μm, which is substantially higher than has been reported for small mammals, while PSV showed substantial frequency dependence in the saturation point. The relationship between PSV and DStap remained constant, and cochlear input impedance did not vary across the levels tested, consistent with prior measurements at lower sound levels. These results suggest that PSV sound pressure holds constant relationship with DStap, described by the cochlear input impedance, at these, but perhaps not higher, stimulation levels. Additionally, these results indicate that the AHAAH model, which was developed using results from small animals, underestimates the sound pressure levels in the cochlea in response to high level sound stimulation, and must be revised.



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Polymorphisms of heat shock protein 70 genes (HSPA1A, HSPA1B and HSPA1L) and susceptibility of noise-induced hearing loss in a Chinese population: A case-control study

by Yanhong Li, Shanfa Yu, Guizhen Gu, Guoshun Chen, Yuxin Zheng, Jie Jiao, Wenhui Zhou, Hui Wu, Zengrui Zhang, Huanling Zhang, Lihua He, Qiuyue Yang, Xiangrong Xu

Noise-induced hearing loss (NIHL) is the second-most frequent form of sensorineural hearing loss. When exposed to the same noise, some workers develop NIHL while others do not, suggesting that NIHL may be associated with genetic factors. To explore the relationship between single nucleotide polymorphisms (SNPs) in heat shock protein 70 (HSP70) genes (HSPA1A, HSPA1B and HSPA1L) and susceptibility to NIHL in Han Chinese workers exposed to noise, a case-control association study was carried out with 286 hearing loss cases and 286 matched with gender, age, type of work, and exposure time, drawn from a population of 3790 noise-exposed workers. Four SNPs were selected and genotyped. Subsequently, the effects of the alleles and genotypes of the three HSP70 genes (HSPA1A, HSPA1B and HSPA1L) on NIHL were analyzed by using a conditional logistic regression. A generalized multiple dimensionality reduction (GMDR) was applied to further detect an interaction between the four SNPs. Compared with the combined genotypes CC/TC, carriers of the TT genotype of rs2763979 appeared to show greater susceptibility to NIHL (P = 0.042, adjusted OR = 1.731, 95% CI 1.021–2.935). A significant interaction between rs2763979 and CNE was found (P = 0.029), and a significant association was found between TT of s2763979 and NIHL (P = 0.024, adjusted OR = 5.694, 95%CI 1.256-25.817) in the 96 dB (A)≤CNE

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Reducing interaction in simultaneous paired stimulation with CI

by Dirk Vellinga, Saskia Bruijn, Jeroen J. Briaire, Randy K. Kalkman, Johan H. M. Frijns

In this study simultaneous paired stimulation of electrodes in cochlear implants is investigated by psychophysical experiments in 8 post-lingually deaf subjects (and one extra subject who only participated in part of the experiments). Simultaneous and sequential monopolar stimulation modes are used as references and are compared to channel interaction compensation, partial tripolar stimulation and a novel sequential stimulation strategy named phased array compensation. Psychophysical experiments are performed to investigate both the loudness integration during paired stimulation at the main electrodes as well as the interaction with the electrode contact located halfway between the stimulating pair. The study shows that simultaneous monopolar stimulation has more loudness integration on the main electrodes and more interaction in between the electrodes than sequential stimulation. Channel interaction compensation works to reduce the loudness integration at the main electrodes, but does not reduce the interaction in between the electrodes caused by paired stimulation. Partial tripolar stimulation uses much more current to reach the needed loudness, but shows the same interaction in between the electrodes as sequential monopolar stimulation. In phased array compensation we have used the individual impedance matrix of each subject to calculate the current needed on each electrode to exactly match the stimulation voltage along the array to that of sequential stimulation. The results show that the interaction in between the electrodes is the same as monopolar stimulation. The strategy uses less current than partial tripolar stimulation, but more than monopolar stimulation. In conclusion, the paper shows that paired stimulation is possible if the interaction is compensated.

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Internet-based peer support for Ménière's disease: a summary of web-based data collection, impact evaluation, and user evaluation

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Internet-based peer support for Ménière's disease: a summary of web-based data collection, impact evaluation, and user evaluation

.


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Internet-based peer support for Ménière's disease: a summary of web-based data collection, impact evaluation, and user evaluation

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The effects of cochlear implantation on vestibular function in 1-4 years old children.

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The effects of cochlear implantation on vestibular function in 1-4 years old children.

Int J Pediatr Otorhinolaryngol. 2017 Mar;94:100-103

Authors: Ajalloueyan M, Saeedi M, Sadeghi M, Zamiri Abdollahi F

Abstract
OBJECTIVES: Although cochlear implants offer an effective hearing restoration option in children with severe to profound hearing loss, concern continues to exist regarding the possible effects of cochlear implantation on the vestibular system and balance.
METHODS: In a prospective cohort study, 27 children with bilateral profound hearing loss (all candidates for cochlear implantation) were evaluated for their vestibular function before and after cochlear implantation. Vestibular evaluations consisted of Vestibular Evoked Myogenic Potentials, caloric testing and the Head-Impulse Test.
RESULTS: Mean age at the time of cochlear implantation was 27.19 months. Without considering vestibular evaluation results, one of the ears was selected for surgery. Vestibular tests after surgery were not indicative of any statistically significant change in vestibular system or balance.
CONCLUSION: This limited data shows that cochlear implantation did not impair the vestibular system of these patients. By the results of our study we may conclude that round window implantation does not have any disturbing impact on vestibular function in children. The generalization of this result needs further research.

PMID: 28166997 [PubMed - in process]



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The effects of cochlear implantation on vestibular function in 1-4 years old children.

Related Articles

The effects of cochlear implantation on vestibular function in 1-4 years old children.

Int J Pediatr Otorhinolaryngol. 2017 Mar;94:100-103

Authors: Ajalloueyan M, Saeedi M, Sadeghi M, Zamiri Abdollahi F

Abstract
OBJECTIVES: Although cochlear implants offer an effective hearing restoration option in children with severe to profound hearing loss, concern continues to exist regarding the possible effects of cochlear implantation on the vestibular system and balance.
METHODS: In a prospective cohort study, 27 children with bilateral profound hearing loss (all candidates for cochlear implantation) were evaluated for their vestibular function before and after cochlear implantation. Vestibular evaluations consisted of Vestibular Evoked Myogenic Potentials, caloric testing and the Head-Impulse Test.
RESULTS: Mean age at the time of cochlear implantation was 27.19 months. Without considering vestibular evaluation results, one of the ears was selected for surgery. Vestibular tests after surgery were not indicative of any statistically significant change in vestibular system or balance.
CONCLUSION: This limited data shows that cochlear implantation did not impair the vestibular system of these patients. By the results of our study we may conclude that round window implantation does not have any disturbing impact on vestibular function in children. The generalization of this result needs further research.

PMID: 28166997 [PubMed - in process]



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An example of the utility of genomic analysis for fast and accurate clinical diagnosis of complex rare phenotypes.

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An example of the utility of genomic analysis for fast and accurate clinical diagnosis of complex rare phenotypes.

Orphanet J Rare Dis. 2017 Feb 07;12(1):24

Authors: Le Quesne Stabej P, James C, Ocaka L, Tekman M, Grunewald S, Clement E, Stanescu HC, Kleta R, Morrogh D, Calder A, Williams HJ, Bitner-Glindzicz M

Abstract
BACKGROUND: We describe molecular diagnosis in a complex consanguineous family: four offspring presented with combinations of three distinctive phenotypes; non-syndromic hearing loss (NSHL), an unusual skeletal phenotype comprising multiple fractures, cranial abnormalities and diaphyseal expansion, and significant developmental delay with microcephaly. We performed Chromosomal Microarray Analysis on the offspring with either the skeletal or developmental delay phenotypes, and linkage analysis and whole exome sequencing (WES) on all four children, parents and maternal aunt.
RESULTS: Chromosomal microarray and FISH analysis identified a de novo unbalanced translocation as a cause of the microcephaly and severe developmental delay. WES identified a NSHL-causing splice variant in an autosomal recessive deafness gene PDZD7 which resided in a linkage region and affected three of the children. In the two children diagnosed with an unusual skeletal phenotype, WES eventually disclosed a heterozygous COL1A1 variant which affects C-propetide cleavage site of COL1. The variant was inherited from an apparently unaffected mosaic father in an autosomal dominant fashion. After the discovery of the COL1A1 variant, the skeletal phenotype was diagnosed as a high bone mass form of osteogenesis imperfecta.
CONCLUSIONS: Next generation sequencing offers an unbiased approach to molecular genetic diagnosis in highly heterogeneous and poorly characterised disorders and enables early diagnosis as well as detection of mosaicism.

PMID: 28173822 [PubMed - in process]



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SLC52A2 [p.P141T] and SLC52A3 [p.N21S] causing Brown-Vialetto-Van Laere Syndrome in an Indian patient: First genetically proven case with mutations in two riboflavin transporters.

http:--linkinghub.elsevier.com-ihub-imag Related Articles

SLC52A2 [p.P141T] and SLC52A3 [p.N21S] causing Brown-Vialetto-Van Laere Syndrome in an Indian patient: First genetically proven case with mutations in two riboflavin transporters.

Clin Chim Acta. 2016 Nov 01;462:210-214

Authors: Udhayabanu T, Subramanian VS, Teafatiller T, Gowda VK, Raghavan VS, Varalakshmi P, Said HM, Ashokkumar B

Abstract
BACKGROUND: Brown-Vialetto-Van Laere Syndrome (BVVLS), a rare neurological disorder characterized by bulbar palsies and sensorineural deafness, is mainly associated with defective riboflavin transporters encoded by the SLC52A2 and SLC52A3 genes.
METHODS: Here we present a 16-year-old BVVLS patient belonging to a five generation consanguineous family from Indian ethnicity with two homozygous missense mutations viz., c.421C>A [p.P141T] in SLC52A2 and c.62A>G [p.N21S] in SLC52A3.
RESULTS: Functional characterization based on (3)H-riboflavin uptake assay and live-cell confocal imaging revealed that the effect of mutation c.421C>A [p.P141T] identified in SLC52A2 had a slight reduction in riboflavin uptake; on the other hand, the c.62A>G [p.N21S] identified in SLC52A3 showed a drastic reduction in riboflavin uptake, which appeared to be due to impaired trafficking and membrane targeting of the hRFVT-3 protein.
CONCLUSIONS: This is the first report presenting mutations in both riboflavin transporters hRFVT-2 and hRFVT-3 in the same BVVLS patient. Also, c.62A>G [p.N21S] in SLC52A3 appears to contribute more to the disease phenotype in this patient than c.421C>A [p.P141T] in SLC52A2.

PMID: 27702554 [PubMed - indexed for MEDLINE]



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Minimum number of days required for a reliable estimate of daily step count and energy expenditure, in people with MS who walk unaided

Publication date: Available online 8 February 2017
Source:Gait & Posture
Author(s): Michelle Norris, Ross Anderson, Robert W. Motl, Sara Hayes, Susan Coote
Background and purposeThe purpose of this study was to examine the minimum number of days needed to reliably estimate daily step count and energy expenditure (EE), in people with multiple sclerosis (MS) who walked unaided.MethodsSeven days of activity monitor data were collected for 26 participants with MS (age=44.5±11.9years; time since diagnosis=6.5±6.2years; Patient Determined Disease Steps=≤3). Mean daily step count and mean daily EE (kcal) were calculated for all combinations of days (127 combinations), and compared to the respective 7-day mean daily step count or mean daily EE using intra-class correlations (ICC), the Generalizability Theory and Bland-Altman.ResultsFor step count, ICC values of 0.94–0.98 and a G-coefficient of 0.81 indicate a minimum of any random 2-day combination is required to reliably calculate mean daily step count. For EE, ICC values of 0.96–0.99 and a G-coefficient of 0.83 indicate a minimum of any random 4-day combination is required to reliably calculate mean daily EE. For Bland-Altman analyses all combinations of days, bar single day combinations, resulted in a mean bias within ±10%, when expressed as a percentage of the 7-day mean daily step count or mean daily EE.ConclusionsA minimum of 2days for step count and 4days for EE, regardless of day type, is needed to reliably estimate daily step count and daily EE, in people with MS who walk unaided.



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Comparison of body’s center of mass motion relative to center of pressure between treadmill and over-ground walking

Publication date: Available online 9 February 2017
Source:Gait & Posture
Author(s): Hsuan-Lun Lu, Tung-Wu Lu, Hsiu-Chen Lin, Wing P. Chan
Treadmills have been used in rehabilitation settings to provide convenient protocols and continuous monitoring of movement over multiple cycles at well-controlled speeds for gait and balance training. However, the potential differences in the movement control may affect the translation of the training outcomes to real life over-ground walking (OW). The similarities and differences in the balance control between treadmill walking (TW) and OW have largely been unexplored. The current study bridged the gap by comparing the motions of the body’s center of mass (COM) relative to the center of pressure (COP) between TW and OW, in terms of the COM-COP inclination angle (IA) and its rate of change (RCIA). The movement of the COM and COP separately were quite different between OW and TW, but when describing the COM motion relative to the COP, the COM motions became similar qualitatively with similar butterfly patterns. However, significantly increased peak values in themediolateral RCIA and greater ranges of mediolateral IA were found during TW (p<0.004). In the sagittal plane, the posterior velocity of the belt led to an anterior RCIA (posterior RCIA in OW) with increasing anterior IA during early double-limb support phase, and reduced posterior RCIA (p<0.009) with an increased anterior IA (p<0.001) during the remainder of the phase. These differences between TW and OW may have to be taken into account in future designs of strategies to optimize the translation of treadmill gait training outcomes into real life over-ground walking.



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Effects of toe-out and toe-in gait with varying walking speeds on knee joint mechanics and lower limb energetics

Publication date: March 2017
Source:Gait & Posture, Volume 53
Author(s): Soobia Saad Khan, Saad Jawaid Khan, Juliana Usman
Toe-out/-in gait has been prescribed in reducing knee joint load to medial knee osteoarthritis patients. This study focused on the effects of toe-out/-in at different walking speeds on first peak knee adduction moment (fKAM), second peak KAM (sKAM), knee adduction angular impulse (KAAI), net mechanical work by lower limb as well as joint-level contribution to the total limb work during level walking.Gait analysis of 20 healthy young adults was done walking at pre-defined normal (1.18m/s), slow (0.85m/s) and fast (1.43m/s) walking speeds with straight-toe (natural), toe-out (15°>natural) and toe-in (15°<natural). Repeated measure ANOVA (p<0.05) with post-hoc Tukey’s test was applied for statistical analysis.Toe-out gait increased fKAM at all walking speeds (highest at normal speed) while toe-in gait reduced fKAM at all speeds (highest at fast walking speed). Toeing-in reduced KAAI at all speeds while toeing-out affected KAAI only at normal speed. Increasing walking speed generally increased fKAM for all foot positions, but it did not affect sKAM considerably. Slowing down the speed, increased KAAI significantly at all foot positions except for toe-in. At slow walking speed, hip and knee joints were found to be major energy contributors for toe-in and toe-out respectively. At higher walking speeds, these contributions were switched. The ankle joint remained unaffected by changing walking speeds and foot progression angles.Toe-out/-in gait modifications affected knee joint kinetics and lower limb energetics at all walking speeds. However, their effects were inconsistent at different speeds. Therefore, walking speed should be taken into account when prescribing toe-out/-in gait.



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Stability against backward balance loss: age-related modifications following slip-like perturbations of multiple amplitudes

Publication date: Available online 9 February 2017
Source:Gait & Posture
Author(s): Dario Martelli, Federica Aprigliano, Peppino Tropea, Guido Pasquini, Silvestro Micera, Vito Monaco
Falls are one of the most serious problems in the elderly. Although previous studies clearly link the increased risk of falls with ageing, the mechanisms responsible for the modifications of reactive motor behaviours in response to external perturbations are not yet fully understood. This study investigated how the stability against backward balance loss is affected by aging and intensity of perturbations. The Margin of Stability (MoS) was estimated while eight young and eight elderly adults managed three slip-like perturbations of different intensities while walking at the same normalized speed. A compensatory step was necessary to regain stability. The forward swing phase of the trailing leg was rapidly interrupted and reversed in direction. Results have shown that ageing significantly affects the time required to select the most appropriate biomechanical response: even if the characteristic of the backward step was similar between groups, elderly subjects took more time to reverse the movement of their swinging limb, thus achieving a less efficient action to counteract the backward balance loss (lower MoS both during and at the end of the early compensatory reaction). In addition, young and elderly subjects scaled their reactions with respect to the perturbations intensity in a similar way by increasing the length of their backward step, thus revealing a context-dependent tuning of the biomechanical response that was not affected by aging. These behavioural features can be helpful in identifying the causes of increased fall risk among the elderly in order to define more suited intervention in fall prevention programs.



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Increased postural sway in persons with multiple sclerosis during short-term exposure to warm ambient temperatures

Publication date: Available online 8 February 2017
Source:Gait & Posture
Author(s): Paula Y.S. Poh, Amy N. Adams, Mu Huang, Dustin R. Allen, Scott L. Davis, Anna S. Tseng, Craig G. Crandall
BackgroundMultiple sclerosis (MS) is a neurological disease marked by demyelination and axonal loss. Individuals with MS experience increases in clinical signs and symptoms during heat exposure.Objective: To test the hypothesis that moderate heat exposure adversely affects postural sway in individuals with MS.MethodsTen individuals with relapsing-remitting MS (50±8y) and nine controls (47±10y) were examined under a Thermal and a Time Control trial. Following a 30min thermoneutral baseline (25°C, 30% relative humidity (RH)), stand tests randomized with eyes open and closed, was performed. For Thermal, subjects were first exposed to 60min of heating (40°C, 30%RH) followed by 60min of cooling (20°C, 30%RH). For Time Control, subjects remained in a thermoneutral environment throughout. Stand tests were repeated at consistent times in both trials.ResultsNo difference in skin and core temperatures between groups were observed for any trial (P >0.05). During heating, postural sway was higher in MS relative to control subjects (eyes open, P=0.03; eyes closed, P=0.011). No differences in postural sway, regardless of eye status, were observed during the Time Control trial for either group (P >0.05).ConclusionThese data demonstrate that exposure to a moderate heating environment increases postural sway in patients with MS.



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Minimum number of days required for a reliable estimate of daily step count and energy expenditure, in people with MS who walk unaided

Publication date: Available online 8 February 2017
Source:Gait & Posture
Author(s): Michelle Norris, Ross Anderson, Robert W. Motl, Sara Hayes, Susan Coote
Background and purposeThe purpose of this study was to examine the minimum number of days needed to reliably estimate daily step count and energy expenditure (EE), in people with multiple sclerosis (MS) who walked unaided.MethodsSeven days of activity monitor data were collected for 26 participants with MS (age=44.5±11.9years; time since diagnosis=6.5±6.2years; Patient Determined Disease Steps=≤3). Mean daily step count and mean daily EE (kcal) were calculated for all combinations of days (127 combinations), and compared to the respective 7-day mean daily step count or mean daily EE using intra-class correlations (ICC), the Generalizability Theory and Bland-Altman.ResultsFor step count, ICC values of 0.94–0.98 and a G-coefficient of 0.81 indicate a minimum of any random 2-day combination is required to reliably calculate mean daily step count. For EE, ICC values of 0.96–0.99 and a G-coefficient of 0.83 indicate a minimum of any random 4-day combination is required to reliably calculate mean daily EE. For Bland-Altman analyses all combinations of days, bar single day combinations, resulted in a mean bias within ±10%, when expressed as a percentage of the 7-day mean daily step count or mean daily EE.ConclusionsA minimum of 2days for step count and 4days for EE, regardless of day type, is needed to reliably estimate daily step count and daily EE, in people with MS who walk unaided.



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Comparison of body’s center of mass motion relative to center of pressure between treadmill and over-ground walking

Publication date: Available online 9 February 2017
Source:Gait & Posture
Author(s): Hsuan-Lun Lu, Tung-Wu Lu, Hsiu-Chen Lin, Wing P. Chan
Treadmills have been used in rehabilitation settings to provide convenient protocols and continuous monitoring of movement over multiple cycles at well-controlled speeds for gait and balance training. However, the potential differences in the movement control may affect the translation of the training outcomes to real life over-ground walking (OW). The similarities and differences in the balance control between treadmill walking (TW) and OW have largely been unexplored. The current study bridged the gap by comparing the motions of the body’s center of mass (COM) relative to the center of pressure (COP) between TW and OW, in terms of the COM-COP inclination angle (IA) and its rate of change (RCIA). The movement of the COM and COP separately were quite different between OW and TW, but when describing the COM motion relative to the COP, the COM motions became similar qualitatively with similar butterfly patterns. However, significantly increased peak values in themediolateral RCIA and greater ranges of mediolateral IA were found during TW (p<0.004). In the sagittal plane, the posterior velocity of the belt led to an anterior RCIA (posterior RCIA in OW) with increasing anterior IA during early double-limb support phase, and reduced posterior RCIA (p<0.009) with an increased anterior IA (p<0.001) during the remainder of the phase. These differences between TW and OW may have to be taken into account in future designs of strategies to optimize the translation of treadmill gait training outcomes into real life over-ground walking.



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Effects of toe-out and toe-in gait with varying walking speeds on knee joint mechanics and lower limb energetics

Publication date: March 2017
Source:Gait & Posture, Volume 53
Author(s): Soobia Saad Khan, Saad Jawaid Khan, Juliana Usman
Toe-out/-in gait has been prescribed in reducing knee joint load to medial knee osteoarthritis patients. This study focused on the effects of toe-out/-in at different walking speeds on first peak knee adduction moment (fKAM), second peak KAM (sKAM), knee adduction angular impulse (KAAI), net mechanical work by lower limb as well as joint-level contribution to the total limb work during level walking.Gait analysis of 20 healthy young adults was done walking at pre-defined normal (1.18m/s), slow (0.85m/s) and fast (1.43m/s) walking speeds with straight-toe (natural), toe-out (15°>natural) and toe-in (15°<natural). Repeated measure ANOVA (p<0.05) with post-hoc Tukey’s test was applied for statistical analysis.Toe-out gait increased fKAM at all walking speeds (highest at normal speed) while toe-in gait reduced fKAM at all speeds (highest at fast walking speed). Toeing-in reduced KAAI at all speeds while toeing-out affected KAAI only at normal speed. Increasing walking speed generally increased fKAM for all foot positions, but it did not affect sKAM considerably. Slowing down the speed, increased KAAI significantly at all foot positions except for toe-in. At slow walking speed, hip and knee joints were found to be major energy contributors for toe-in and toe-out respectively. At higher walking speeds, these contributions were switched. The ankle joint remained unaffected by changing walking speeds and foot progression angles.Toe-out/-in gait modifications affected knee joint kinetics and lower limb energetics at all walking speeds. However, their effects were inconsistent at different speeds. Therefore, walking speed should be taken into account when prescribing toe-out/-in gait.



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Stability against backward balance loss: age-related modifications following slip-like perturbations of multiple amplitudes

Publication date: Available online 9 February 2017
Source:Gait & Posture
Author(s): Dario Martelli, Federica Aprigliano, Peppino Tropea, Guido Pasquini, Silvestro Micera, Vito Monaco
Falls are one of the most serious problems in the elderly. Although previous studies clearly link the increased risk of falls with ageing, the mechanisms responsible for the modifications of reactive motor behaviours in response to external perturbations are not yet fully understood. This study investigated how the stability against backward balance loss is affected by aging and intensity of perturbations. The Margin of Stability (MoS) was estimated while eight young and eight elderly adults managed three slip-like perturbations of different intensities while walking at the same normalized speed. A compensatory step was necessary to regain stability. The forward swing phase of the trailing leg was rapidly interrupted and reversed in direction. Results have shown that ageing significantly affects the time required to select the most appropriate biomechanical response: even if the characteristic of the backward step was similar between groups, elderly subjects took more time to reverse the movement of their swinging limb, thus achieving a less efficient action to counteract the backward balance loss (lower MoS both during and at the end of the early compensatory reaction). In addition, young and elderly subjects scaled their reactions with respect to the perturbations intensity in a similar way by increasing the length of their backward step, thus revealing a context-dependent tuning of the biomechanical response that was not affected by aging. These behavioural features can be helpful in identifying the causes of increased fall risk among the elderly in order to define more suited intervention in fall prevention programs.



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Increased postural sway in persons with multiple sclerosis during short-term exposure to warm ambient temperatures

Publication date: Available online 8 February 2017
Source:Gait & Posture
Author(s): Paula Y.S. Poh, Amy N. Adams, Mu Huang, Dustin R. Allen, Scott L. Davis, Anna S. Tseng, Craig G. Crandall
BackgroundMultiple sclerosis (MS) is a neurological disease marked by demyelination and axonal loss. Individuals with MS experience increases in clinical signs and symptoms during heat exposure.Objective: To test the hypothesis that moderate heat exposure adversely affects postural sway in individuals with MS.MethodsTen individuals with relapsing-remitting MS (50±8y) and nine controls (47±10y) were examined under a Thermal and a Time Control trial. Following a 30min thermoneutral baseline (25°C, 30% relative humidity (RH)), stand tests randomized with eyes open and closed, was performed. For Thermal, subjects were first exposed to 60min of heating (40°C, 30%RH) followed by 60min of cooling (20°C, 30%RH). For Time Control, subjects remained in a thermoneutral environment throughout. Stand tests were repeated at consistent times in both trials.ResultsNo difference in skin and core temperatures between groups were observed for any trial (P >0.05). During heating, postural sway was higher in MS relative to control subjects (eyes open, P=0.03; eyes closed, P=0.011). No differences in postural sway, regardless of eye status, were observed during the Time Control trial for either group (P >0.05).ConclusionThese data demonstrate that exposure to a moderate heating environment increases postural sway in patients with MS.



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Minimum number of days required for a reliable estimate of daily step count and energy expenditure, in people with MS who walk unaided

Publication date: Available online 8 February 2017
Source:Gait & Posture
Author(s): Michelle Norris, Ross Anderson, Robert W. Motl, Sara Hayes, Susan Coote
Background and purposeThe purpose of this study was to examine the minimum number of days needed to reliably estimate daily step count and energy expenditure (EE), in people with multiple sclerosis (MS) who walked unaided.MethodsSeven days of activity monitor data were collected for 26 participants with MS (age=44.5±11.9years; time since diagnosis=6.5±6.2years; Patient Determined Disease Steps=≤3). Mean daily step count and mean daily EE (kcal) were calculated for all combinations of days (127 combinations), and compared to the respective 7-day mean daily step count or mean daily EE using intra-class correlations (ICC), the Generalizability Theory and Bland-Altman.ResultsFor step count, ICC values of 0.94–0.98 and a G-coefficient of 0.81 indicate a minimum of any random 2-day combination is required to reliably calculate mean daily step count. For EE, ICC values of 0.96–0.99 and a G-coefficient of 0.83 indicate a minimum of any random 4-day combination is required to reliably calculate mean daily EE. For Bland-Altman analyses all combinations of days, bar single day combinations, resulted in a mean bias within ±10%, when expressed as a percentage of the 7-day mean daily step count or mean daily EE.ConclusionsA minimum of 2days for step count and 4days for EE, regardless of day type, is needed to reliably estimate daily step count and daily EE, in people with MS who walk unaided.



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Comparison of body’s center of mass motion relative to center of pressure between treadmill and over-ground walking

Publication date: Available online 9 February 2017
Source:Gait & Posture
Author(s): Hsuan-Lun Lu, Tung-Wu Lu, Hsiu-Chen Lin, Wing P. Chan
Treadmills have been used in rehabilitation settings to provide convenient protocols and continuous monitoring of movement over multiple cycles at well-controlled speeds for gait and balance training. However, the potential differences in the movement control may affect the translation of the training outcomes to real life over-ground walking (OW). The similarities and differences in the balance control between treadmill walking (TW) and OW have largely been unexplored. The current study bridged the gap by comparing the motions of the body’s center of mass (COM) relative to the center of pressure (COP) between TW and OW, in terms of the COM-COP inclination angle (IA) and its rate of change (RCIA). The movement of the COM and COP separately were quite different between OW and TW, but when describing the COM motion relative to the COP, the COM motions became similar qualitatively with similar butterfly patterns. However, significantly increased peak values in themediolateral RCIA and greater ranges of mediolateral IA were found during TW (p<0.004). In the sagittal plane, the posterior velocity of the belt led to an anterior RCIA (posterior RCIA in OW) with increasing anterior IA during early double-limb support phase, and reduced posterior RCIA (p<0.009) with an increased anterior IA (p<0.001) during the remainder of the phase. These differences between TW and OW may have to be taken into account in future designs of strategies to optimize the translation of treadmill gait training outcomes into real life over-ground walking.



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Effects of toe-out and toe-in gait with varying walking speeds on knee joint mechanics and lower limb energetics

Publication date: March 2017
Source:Gait & Posture, Volume 53
Author(s): Soobia Saad Khan, Saad Jawaid Khan, Juliana Usman
Toe-out/-in gait has been prescribed in reducing knee joint load to medial knee osteoarthritis patients. This study focused on the effects of toe-out/-in at different walking speeds on first peak knee adduction moment (fKAM), second peak KAM (sKAM), knee adduction angular impulse (KAAI), net mechanical work by lower limb as well as joint-level contribution to the total limb work during level walking.Gait analysis of 20 healthy young adults was done walking at pre-defined normal (1.18m/s), slow (0.85m/s) and fast (1.43m/s) walking speeds with straight-toe (natural), toe-out (15°>natural) and toe-in (15°<natural). Repeated measure ANOVA (p<0.05) with post-hoc Tukey’s test was applied for statistical analysis.Toe-out gait increased fKAM at all walking speeds (highest at normal speed) while toe-in gait reduced fKAM at all speeds (highest at fast walking speed). Toeing-in reduced KAAI at all speeds while toeing-out affected KAAI only at normal speed. Increasing walking speed generally increased fKAM for all foot positions, but it did not affect sKAM considerably. Slowing down the speed, increased KAAI significantly at all foot positions except for toe-in. At slow walking speed, hip and knee joints were found to be major energy contributors for toe-in and toe-out respectively. At higher walking speeds, these contributions were switched. The ankle joint remained unaffected by changing walking speeds and foot progression angles.Toe-out/-in gait modifications affected knee joint kinetics and lower limb energetics at all walking speeds. However, their effects were inconsistent at different speeds. Therefore, walking speed should be taken into account when prescribing toe-out/-in gait.



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Stability against backward balance loss: age-related modifications following slip-like perturbations of multiple amplitudes

Publication date: Available online 9 February 2017
Source:Gait & Posture
Author(s): Dario Martelli, Federica Aprigliano, Peppino Tropea, Guido Pasquini, Silvestro Micera, Vito Monaco
Falls are one of the most serious problems in the elderly. Although previous studies clearly link the increased risk of falls with ageing, the mechanisms responsible for the modifications of reactive motor behaviours in response to external perturbations are not yet fully understood. This study investigated how the stability against backward balance loss is affected by aging and intensity of perturbations. The Margin of Stability (MoS) was estimated while eight young and eight elderly adults managed three slip-like perturbations of different intensities while walking at the same normalized speed. A compensatory step was necessary to regain stability. The forward swing phase of the trailing leg was rapidly interrupted and reversed in direction. Results have shown that ageing significantly affects the time required to select the most appropriate biomechanical response: even if the characteristic of the backward step was similar between groups, elderly subjects took more time to reverse the movement of their swinging limb, thus achieving a less efficient action to counteract the backward balance loss (lower MoS both during and at the end of the early compensatory reaction). In addition, young and elderly subjects scaled their reactions with respect to the perturbations intensity in a similar way by increasing the length of their backward step, thus revealing a context-dependent tuning of the biomechanical response that was not affected by aging. These behavioural features can be helpful in identifying the causes of increased fall risk among the elderly in order to define more suited intervention in fall prevention programs.



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Increased postural sway in persons with multiple sclerosis during short-term exposure to warm ambient temperatures

Publication date: Available online 8 February 2017
Source:Gait & Posture
Author(s): Paula Y.S. Poh, Amy N. Adams, Mu Huang, Dustin R. Allen, Scott L. Davis, Anna S. Tseng, Craig G. Crandall
BackgroundMultiple sclerosis (MS) is a neurological disease marked by demyelination and axonal loss. Individuals with MS experience increases in clinical signs and symptoms during heat exposure.Objective: To test the hypothesis that moderate heat exposure adversely affects postural sway in individuals with MS.MethodsTen individuals with relapsing-remitting MS (50±8y) and nine controls (47±10y) were examined under a Thermal and a Time Control trial. Following a 30min thermoneutral baseline (25°C, 30% relative humidity (RH)), stand tests randomized with eyes open and closed, was performed. For Thermal, subjects were first exposed to 60min of heating (40°C, 30%RH) followed by 60min of cooling (20°C, 30%RH). For Time Control, subjects remained in a thermoneutral environment throughout. Stand tests were repeated at consistent times in both trials.ResultsNo difference in skin and core temperatures between groups were observed for any trial (P >0.05). During heating, postural sway was higher in MS relative to control subjects (eyes open, P=0.03; eyes closed, P=0.011). No differences in postural sway, regardless of eye status, were observed during the Time Control trial for either group (P >0.05).ConclusionThese data demonstrate that exposure to a moderate heating environment increases postural sway in patients with MS.



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Effect of ear canal pressure and age on wideband absorbance in young infants

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Analysis of audiometric notch as a noise-induced hearing loss phenotype in US youth: data from the National Health And Nutrition Examination Survey, 2005–2010

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Effect of ear canal pressure and age on wideband absorbance in young infants

.


from #Audiology via ola Kala on Inoreader http://ift.tt/2lucm3B
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Analysis of audiometric notch as a noise-induced hearing loss phenotype in US youth: data from the National Health And Nutrition Examination Survey, 2005–2010

.


from #Audiology via ola Kala on Inoreader http://ift.tt/2k6dixQ
via IFTTT

Effect of ear canal pressure and age on wideband absorbance in young infants

.


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via IFTTT

Analysis of audiometric notch as a noise-induced hearing loss phenotype in US youth: data from the National Health And Nutrition Examination Survey, 2005–2010

.


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