The Experts below are selected from a list of 181194 Experts worldwide ranked by ideXlab platform
Robert A Gaunt - One of the best experts on this subject based on the ideXlab platform.
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the effect of wrist Posture on extrinsic finger muscle activity during single joint movements
Scientific Reports, 2020Co-Authors: Carl R Beringer, Misagh Mansouri, Lee E Fisher, Jennifer L Collinger, Michael C Munin, Michael L Boninger, Robert A GauntAbstract:Wrist Posture impacts the muscle lengths and moment arms of the extrinsic finger muscles that cross the wrist. As a result, the electromyographic (EMG) activity associated with digit movement at different wrist Postures must also change. We sought to quantify the Posture-dependence of extrinsic finger muscle activity using bipolar fine-wire electrodes inserted into the extrinsic finger muscles of able-bodied subjects during unrestricted wrist and finger movements across the entire range of motion. EMG activity of all the recorded finger muscles were significantly different (p < 0.05, ANOVA) when performing the same digit movement in five different wrist Postures. Depending on the wrist Posture, EMG activity changed by up to 70% in individual finger muscles for the same movement, with the highest levels of activity observed in finger extensors when the wrist was extended. Similarly, finger flexors were most active when the wrist was flexed. For the finger flexors, EMG variations with wrist Posture were most prominent for index finger muscles, while the EMG activity of all finger extensor muscles were modulated in a similar way across all digits. In addition to comprehensively quantifying the effect of wrist Posture on extrinsic finger EMG activity in able-bodied subjects, these results may contribute to designing control algorithms for myoelectric prosthetic hands in the future.
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the effect of wrist Posture on extrinsic finger muscle activity during single joint movements
bioRxiv, 2019Co-Authors: Carl R Beringer, Misagh Mansouri, Lee E Fisher, Jennifer L Collinger, Michael C Munin, Michael L Boninger, Robert A GauntAbstract:Wrist Posture impacts the muscle lengths and moment arms of the extrinsic finger muscles that cross the wrist. As a result, the electromyographic (EMG) activity associated with digit movement at different wrist Postures may also change. Therefore, we sought to quantify the Posture-dependence of extrinsic finger muscle activity. Fine-wire bipolar electrodes were inserted in the extrinsic hand muscles of able-bodied subjects to record EMG activity during wrist and finger movements in various Postures. EMG activity of all the recorded finger muscles were significantly different (p
David M Antle - One of the best experts on this subject based on the ideXlab platform.
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lower limb blood flow and mean arterial pressure during standing and seated work implications for workplace Posture recommendations
Preventive medicine reports, 2018Co-Authors: David M Antle, Lauren Cormier, Megan Findlay, Linda Miller, Julie N CoteAbstract:Sit-stand workstations are a popular workplace intervention. Organizations often require a medical professional's guidance for implementation. Therefore, it is important to understand potential negative outcomes associated with standing work, such as lower limb discomfort and peripheral vascular issues. The objective of this study was to compare changes in lower limb discomfort, blood pressure and blood flow accumulation during a light-load repetitive upper limb work task accomplished from seated and standing Postures. At the Jewish Rehabilitation Hospital (Laval, Quebec, Canada), 16 participants were outfitted with Laser Doppler Flow (LDF) electrodes to measure blood flow in the lower limb, and a sphygmomanometer to measure lower limb mean arterial blood pressure (MAP). Participants completed simulated work over 34 min in standing and seated conditions. Repeated measures ANOVAs (Posture x Time) were used to assess the differences. There were significant effects for both Posture (p = 0.003) and Time (p = 0.007) for LDF-measured of blood flow accumulation in the soleus and the foot, with a mean increase of 77% blood flow over time in the standing Posture, when compared to seated work. There was a significant 'Posture × Time' (p = 0.0034) interaction effect and a significant Posture (p = 0.0001) effect for MAP, with higher values in the standing Posture by a mean of 37.2 mmHg. Posture had a significant effect (p < 0.001) on lower limb discomfort, with standing Posture reporting higher levels. These results suggest that recommendations for using static standing work Postures should be tempered, and physicians' guidance on workstation changes should consider the impacts on the lower limb.
Carl R Beringer - One of the best experts on this subject based on the ideXlab platform.
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the effect of wrist Posture on extrinsic finger muscle activity during single joint movements
Scientific Reports, 2020Co-Authors: Carl R Beringer, Misagh Mansouri, Lee E Fisher, Jennifer L Collinger, Michael C Munin, Michael L Boninger, Robert A GauntAbstract:Wrist Posture impacts the muscle lengths and moment arms of the extrinsic finger muscles that cross the wrist. As a result, the electromyographic (EMG) activity associated with digit movement at different wrist Postures must also change. We sought to quantify the Posture-dependence of extrinsic finger muscle activity using bipolar fine-wire electrodes inserted into the extrinsic finger muscles of able-bodied subjects during unrestricted wrist and finger movements across the entire range of motion. EMG activity of all the recorded finger muscles were significantly different (p < 0.05, ANOVA) when performing the same digit movement in five different wrist Postures. Depending on the wrist Posture, EMG activity changed by up to 70% in individual finger muscles for the same movement, with the highest levels of activity observed in finger extensors when the wrist was extended. Similarly, finger flexors were most active when the wrist was flexed. For the finger flexors, EMG variations with wrist Posture were most prominent for index finger muscles, while the EMG activity of all finger extensor muscles were modulated in a similar way across all digits. In addition to comprehensively quantifying the effect of wrist Posture on extrinsic finger EMG activity in able-bodied subjects, these results may contribute to designing control algorithms for myoelectric prosthetic hands in the future.
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the effect of wrist Posture on extrinsic finger muscle activity during single joint movements
bioRxiv, 2019Co-Authors: Carl R Beringer, Misagh Mansouri, Lee E Fisher, Jennifer L Collinger, Michael C Munin, Michael L Boninger, Robert A GauntAbstract:Wrist Posture impacts the muscle lengths and moment arms of the extrinsic finger muscles that cross the wrist. As a result, the electromyographic (EMG) activity associated with digit movement at different wrist Postures may also change. Therefore, we sought to quantify the Posture-dependence of extrinsic finger muscle activity. Fine-wire bipolar electrodes were inserted in the extrinsic hand muscles of able-bodied subjects to record EMG activity during wrist and finger movements in various Postures. EMG activity of all the recorded finger muscles were significantly different (p
Julie N Cote - One of the best experts on this subject based on the ideXlab platform.
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lower limb blood flow and mean arterial pressure during standing and seated work implications for workplace Posture recommendations
Preventive medicine reports, 2018Co-Authors: David M Antle, Lauren Cormier, Megan Findlay, Linda Miller, Julie N CoteAbstract:Sit-stand workstations are a popular workplace intervention. Organizations often require a medical professional's guidance for implementation. Therefore, it is important to understand potential negative outcomes associated with standing work, such as lower limb discomfort and peripheral vascular issues. The objective of this study was to compare changes in lower limb discomfort, blood pressure and blood flow accumulation during a light-load repetitive upper limb work task accomplished from seated and standing Postures. At the Jewish Rehabilitation Hospital (Laval, Quebec, Canada), 16 participants were outfitted with Laser Doppler Flow (LDF) electrodes to measure blood flow in the lower limb, and a sphygmomanometer to measure lower limb mean arterial blood pressure (MAP). Participants completed simulated work over 34 min in standing and seated conditions. Repeated measures ANOVAs (Posture x Time) were used to assess the differences. There were significant effects for both Posture (p = 0.003) and Time (p = 0.007) for LDF-measured of blood flow accumulation in the soleus and the foot, with a mean increase of 77% blood flow over time in the standing Posture, when compared to seated work. There was a significant 'Posture × Time' (p = 0.0034) interaction effect and a significant Posture (p = 0.0001) effect for MAP, with higher values in the standing Posture by a mean of 37.2 mmHg. Posture had a significant effect (p < 0.001) on lower limb discomfort, with standing Posture reporting higher levels. These results suggest that recommendations for using static standing work Postures should be tempered, and physicians' guidance on workstation changes should consider the impacts on the lower limb.
Peter Osullivan - One of the best experts on this subject based on the ideXlab platform.
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the influence of different sitting Postures on head neck Posture and muscle activity
Manual Therapy, 2010Co-Authors: J P Caneiro, Peter Osullivan, Angus Burnett, Avi Barach, David Oneil, Orjan Tveit, Karolina OlafsdottirAbstract:Abstract To date the influence that specific sitting Posture has on the head/neck Posture and cervico-thoracic muscle activity has been insufficiently investigated. Therefore the aim of this study was to investigate whether three different thoraco-lumbar sitting Postures affect head/neck Posture and cervico-thoracic muscle activity. Twenty (10 men, 10 women) asymptomatic subjects were placed in 3 standardized thoraco-lumbar sitting Postures (lumbo-pelvic, thoracic upright and slump) to investigate their influence on cervico-thoracic muscle activity and head/neck Posture. There were significant differences in lumbar and thoracic curvatures in the 3 different sitting Postures ( P P P =0.001). Thoracic upright sitting showed increased muscle activity of thoracic erector spinae (TES) compared to slump and lumbo-pelvic Postures ( P =0.015). Upper trapezius (UT) demonstrated no significant difference in muscle activation in the 3 sitting Postures ( P
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the influence of different sitting Postures on head neck Posture and muscle activity
Manual Therapy, 2010Co-Authors: J P Caneiro, Peter Osullivan, Angus Burnett, Avi Barach, David Oneil, Orjan Tveit, Karolina OlafsdottirAbstract:To date the influence that specific sitting Posture has on the head/neck Posture and cervico-thoracic muscle activity has been insufficiently investigated. Therefore the aim of this study was to investigate whether three different thoraco-lumbar sitting Postures affect head/neck Posture and cervico-thoracic muscle activity. Twenty (10 men, 10 women) asymptomatic subjects were placed in 3 standardized thoraco-lumbar sitting Postures (lumbo-pelvic, thoracic upright and slump) to investigate their influence on cervico-thoracic muscle activity and head/neck Posture. There were significant differences in lumbar and thoracic curvatures in the 3 different sitting Postures (P<0.002). Slump sitting was associated with greater head/neck flexion, anterior translation of the head (P<0.001) and increased muscle activity of cervical erector spinae (CES) compared to thoracic and lumbo-pelvic sitting (P=0.001). Thoracic upright sitting showed increased muscle activity of thoracic erector spinae (TES) compared to slump and lumbo-pelvic Postures (P=0.015). Upper trapezius (UT) demonstrated no significant difference in muscle activation in the 3 sitting Postures (P<0.991). This study demonstrates that different sitting Postures affect head/neck Posture and cervico-thoracic muscle activity. It highlights the potential importance of thoraco-lumbar spine postural adjustment when training head/neck Posture.
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classification of sagittal thoraco lumbo pelvic alignment of the adolescent spine in standing and its relationship to low back pain
Spine, 2008Co-Authors: Anne Smith, Peter Osullivan, Leon StrakerAbstract:STUDY DESIGN: A prospective study of the sagittal standing Posture of 766 adolescents. OBJECTIVE: To determine whether Posture subgroups based on photographic assessment are similar to those used clinically and to previous, radiographically determined subgroups of sagittal standing Posture, and whether identified subgroups are associated with measures of spinal pain. SUMMARY OF BACKGROUND DATA: Relatively little research has been performed toward a classification of subjects according to sagittal spinal alignment. Clinical descriptions of different standing Posture classifications have been reported, and recently confirmed in a radiographic study. There is limited epidemiological data available to support the belief that specific standing Postures are associated with back pain, despite plausible mechanisms. As Posture assessment using radiographic methods are limited in large population studies, successful characterization of Posture using 2-dimensional photographic images will enable epidemiological research of the association between Posture types and spinal pain. METHODS.: Three angular measures of thoraco-lumbo-pelvic alignment were calculated from lateral standing photographs of subjects with retro-reflective markers placed on bony landmarks. Subgroups of sagittal thoracolumbar Posture were determined by cluster analysis of these 3 angular measures. Back pain experience was assessed by questionnaire. The associations between Posture subgroups and spinal pain variables were evaluated using logistic regression. RESULTS: Postural subtypes identified by cluster analysis closely corresponded to those subtypes identified previously by analysis of radiographic spinal images in adults and to those described clinically. Significant associations between Posture subgroups and weight, height, body mass index, and gender were identified. Those adolescents classified as having non-neutral Postures when compared with those classified as having a neutral Posture demonstrated higher odds for all measures of back pain, with 7 of 15 analyses being statistically significant. CONCLUSION: Meaningful classifications exist for adolescent sagittal thoraco-lumbo-pelvic alignment, and these can be determined successfully from sagittal photographs. More neutral thoraco-lumbo-pelvic Postures are associated with less back pain.
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the relationship beween Posture and back muscle endurance in industrial workers with flexion related low back pain
Manual Therapy, 2006Co-Authors: Peter Osullivan, Tim Mitchell, Paul Bulich, Robert Waller, Johan HolteAbstract:This preliminary cross-sectional study was undertaken to determine if there were measurable relationships between Posture, back muscle endurance and low back pain (LBP) in industrial workers with a reported history of flexion strain injury and flexion pain provocation. Clinical reports state that subjects with flexion pain disorders of the lumbar spine commonly adopt passive flexed Postures such as slump sitting and present with associated dysfunction of the spinal postural stabilising musculature. However, to date there is little empirical evidence to support that patients with back pain, Posture their spines differently than pain-free subjects. Subjects included 21 healthy industrial workers and 24 industrial workers with flexion-provoked LBP. Lifestyle information, lumbo-pelvic Posture in sitting, standing and lifting, and back muscle endurance were measured. LBP subjects had significantly reduced back muscle endurance (P < 0.01). LBP subjects sat with less hip flexion, (P = 0.05), suggesting increased posterior pelvic tilt in sitting. LBP subjects Postured their spines significantly closer to their end of range lumbar flexion in 'usual' sitting than the healthy controls (P < 0.05). Correlations between increased time spent sitting, physical inactivity and poorer back muscle endurance were also identified. There were no significant differences found between the groups for the standing and lifting Posture measures. These preliminary results support that a relationship may exist between flexed spinal Postures, reduced back muscle endurance, physical inactivity and LBP in subjects with a history of flexion injury and pain.
