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Search Results: 1 - 10 of 325966 matches for " Jill S. Higginson "
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Differences in Plantar Flexor Fascicle Length and Pennation Angle between Healthy and Poststroke Individuals and Implications for Poststroke Plantar Flexor Force Contributions
John W. Ramsay,Thomas S. Buchanan,Jill S. Higginson
Stroke Research and Treatment , 2014, DOI: 10.1155/2014/919486
Abstract: Poststroke plantar flexor muscle weakness has been attributed to muscle atrophy and impaired activation, which cannot collectively explain the limitations in force-generating capability of the entire muscle group. It is of interest whether changes in poststroke plantar flexor muscle fascicle length and pennation angle influence the individual force-generating capability and whether plantar flexor weakness is due to uniform changes in individual muscle force contributions. Fascicle lengths and pennation angles for the soleus, medial, and lateral gastrocnemius were measured using ultrasound and compared between ten hemiparetic poststroke subjects and ten healthy controls. Physiological cross-sectional areas and force contributions to poststroke plantar flexor torque were estimated for each muscle. No statistical differences were observed for any muscle fascicle lengths or for the lateral gastrocnemius and soleus pennation angles between paretic, nonparetic, and healthy limbs. There was a significant decrease ( ) in the paretic medial gastrocnemius pennation angle compared to both nonparetic and healthy limbs. Physiological cross-sectional areas and force contributions were smaller on the paretic side. Additionally, bilateral muscle contributions to plantar flexor torque remained the same. While the architecture of each individual plantar flexor muscle is affected differently after stroke, the relative contribution of each muscle remains the same. 1. Introduction Stroke is a leading cause of long-term adult disability in the United States. It has been reported that approximately 795,000 American adults are affected by a stroke each year and that the prevalence of stroke will increase by an estimated 25% by 2030 [1]. Muscle weakness contralateral to the brain lesion, or hemiparesis, is the most common impairment following stroke [2, 3] and is evident by a decrease in maximal voluntary strength on the paretic limb compared to the nonparetic limb [4, 5]. A combination of muscular and neurological impairments is believed to contribute to poststroke hemiparesis [6]. Since the force-generating capacity of a muscle is dependent on amount of impairment, some recent studies have identified the extent to which these changes occur after stroke. Using magnetic resonance imaging, Ramsay et al. [7] observed muscle atrophy in twelve out of fifteen lower extremity muscles. They found an overall decrease in contractile tissue of 20% in the shank area and 24% in the thigh. Similarly, Klein et al. [8] also observed muscle atrophy in the plantar flexor muscles but
Poststroke Muscle Architectural Parameters of the Tibialis Anterior and the Potential Implications for Rehabilitation of Foot Drop
John W. Ramsay,Molly A. Wessel,Thomas S. Buchanan,Jill S. Higginson
Stroke Research and Treatment , 2014, DOI: 10.1155/2014/948475
Abstract: Poststroke dorsiflexor weakness and paretic limb foot drop increase the risk of stumbling and falling and decrease overall functional mobility. It is of interest whether dorsiflexor muscle weakness is primarily neurological in origin or whether morphological differences also contribute to the impairment. Ten poststroke hemiparetic individuals were imaged bilaterally using noninvasive medical imaging techniques. Magnetic resonance imaging was used to identify changes in tibialis anterior muscle volume and muscle belly length. Ultrasonography was used to measure fascicle length and pennation angle in a neutral position. We found no clinically meaningful bilateral differences in any architectural parameter across all subjects, which indicates that these subjects have the muscular capacity to dorsiflex their foot. Therefore, poststroke dorsiflexor weakness is primarily neural in origin and likely due to muscle activation failure or increased spasticity of the plantar flexors. The current finding suggests that electrical stimulation methods or additional neuromuscular retraining may be more beneficial than targeting muscle strength (i.e., increasing muscle mass). 1. Introduction In the United States alone, about 795,000 people suffer from a new or recurrent stroke each year [1]. Stroke survivors often suffer from hemiparesis or muscle weakness on one side of the body. Foot drop commonly occurs from muscle weakness in the paretic leg and manifests itself as a decrease in dorsiflexion range of motion [2]. For many poststroke survivors, paretic limb foot drop increases the risk of stumbling and falling and decreases functional mobility [2]. It is unclear whether dorsiflexor weakness is solely due to neurological impairment following stroke or whether changes in the muscle architecture are additional contributing factors. Muscle fascicle length and pennation angle (i.e., the angle in which the fascicles insert themselves into the aponeuroses of the muscle) are two architectural parameters that can influence how a muscle generates force. Varying these two parameters can alter the functional ability of a muscle, including range of motion and total force production [3]. Therefore, changes in fascicle length or pennation angle may contribute to post-stroke dorsiflexor weakness [4]. Medical imaging techniques (e.g., ultrasonography and magnetic resonance imaging) are often used to study muscle architecture in vivo in healthy populations and patients with neurological disorders [5–11]. However, little is known about poststroke muscle architectural changes. In the
Changes in Predicted Muscle Coordination with Subject-Specific Muscle Parameters for Individuals after Stroke
Brian A. Knarr,Darcy S. Reisman,Stuart A. Binder-Macleod,Jill S. Higginson
Stroke Research and Treatment , 2014, DOI: 10.1155/2014/321747
Abstract: Muscle weakness is commonly seen in individuals after stroke, characterized by lower forces during a maximal volitional contraction. Accurate quantification of muscle weakness is paramount when evaluating individual performance and response to after stroke rehabilitation. The objective of this study was to examine the effect of subject-specific muscle force and activation deficits on predicted muscle coordination when using musculoskeletal models for individuals after stroke. Maximum force generating ability and central activation ratio of the paretic plantar flexors, dorsiflexors, and quadriceps muscle groups were obtained using burst superimposition for four individuals after stroke with a range of walking speeds. Two models were created per subject: one with generic and one with subject-specific activation and maximum isometric force parameters. The inclusion of subject-specific muscle data resulted in changes in the model-predicted muscle forces and activations which agree with previously reported compensation patterns and match more closely the timing of electromyography for the plantar flexor and hamstring muscles. This was the first study to create musculoskeletal simulations of individuals after stroke with subject-specific muscle force and activation data. The results of this study suggest that subject-specific muscle force and activation data enhance the ability of musculoskeletal simulations to accurately predict muscle coordination in individuals after stroke. 1. Introduction Musculoskeletal simulations have the potential to provide insight into muscle coordination and function for individuals with gait deficits. Previous musculoskeletal simulations have shown how muscle coordination can be altered based on changes in muscle properties [1–4]. A current limitation of musculoskeletal simulations, however, is that the appropriate muscle properties to use for a specific individual are unknown. For a particular subject or population (e.g., stroke), muscle parameters may differ greatly from default model values, and it has been suggested that selection of muscle parameters can have a relevant impact on simulation results [5–7]. Muscle weakness, characterized by lower forces during a maximal volitional contraction, is a major limiting factor affecting performance of poststroke gait [8]. The two main causes of poststroke muscle weakness are disuse atrophy [9] and impaired muscle activation by the central nervous system [10]. Studies have shown a reduction in skeletal muscle mass and an increase in intramuscular fat in the paretic limb of stroke
The Stem Heat Balance Method to Measure Transpiration: Evaluation of a New Sensor  [PDF]
Robert J. Lascano, Timothy S. Goebel, Jill Booker, Jeffrey T. Baker, Dennis C. Gitz III
Agricultural Sciences (AS) , 2016, DOI: 10.4236/as.2016.79057
Abstract:
The measurement of crop transpiration (Tcrop) under field conditions and throughout the growing season is difficult to obtain. An available method uses stem flow gauge sensors, based on the conservation of energy and mass, where the calculated sap flow (F) is a direct measure of Tcrop. This method has been extensively tested on agronomic, horticultural, ornamental aspects and tree crops and the general consensus is that F is a measure of Tcrop. A new sap flow gauge (EXO-SkinTM Sap Flow) sensor, with different placement and number of thermocouples, compared to the original sensor, was introduced, resulting in a different energy balance equation to calculate F. Our objective was to compare values of Tcrop obtained with the new sensor on cotton (Gossypium hirsutum, L) plants to values measured with lysimeters. For this purpose, cotton plants were grown in 11-liter pots in a greenhouse experiment and hourly and daily values of Tcrop were compared for eight days. We used linear regression analysis to compare the hourly and daily values of T
Diagnostic peritoneal lavage: a review of indications, technique, and interpretation
Jill S Whitehouse, John A Weigelt
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine , 2009, DOI: 10.1186/1757-7241-17-13
Abstract: Diagnostic peritoneal lavage (DPL) is an invasive, rapid, and highly accurate test for evaluating intraperitoneal hemorrhage or a ruptured hollow viscus. DPL plays a role in both blunt and penetrating abdominal trauma. First described in 1965, DPL replaced the four-quadrant abdominal tap, boasting a higher sensitivity and specificity in identifying intraabdominal injury [1]. Today DPL is performed less frequently, as it has been replaced by focused abdominal sonography for trauma (FAST) and helical computed tomography (CT). Yet, each of these diagnostic modalities has unique advantages and disadvantages.DPL is the only invasive test of the three, but while lacking organ specificity it remains the most sensitive test for mesenteric and hollow viscus injuries [2,3]. FAST exams are rapid, noninvasive, and can be repeated multiple times throughout the resuscitation period. They are more user-dependent than DPL or CT scanning. Both FAST and DPL ineffectively evaluate retroperitoneal and diaphragmatic injuries and poorly identify solid organ injuries. Abdominopelvic CT scanning still requires a hemodynamically normal patient, is costly, and carries a small but significant lifetime risk of malignancy [4,5]. However, CT scanning reliably diagnoses solid organ injuries and evaluates the retroperitoneum, but its sensitivity and specificity for blunt bowel and mesenteric injuries is not superior to DPL [6]. As a result of these differences, all three tests continue to play important roles when evaluating a trauma patient for abdominal injuries.Since DPL is performed less commonly today, a review of its indications, technique, and interpretation is pertinent.DPL is indicated in both blunt and a selective group of penetrating abdominal injuries. In blunt injuries, DPL has a number of indications but is dependent upon the patient's condition and availability of CT scanning and FAST. DPL is useful for patients who are in shock and when FAST capability is not available. Hypotensive
Lessons Towards Developing An Integrated Tool-support for Small Team Meetings
Virallikattur S Dhenesh,Elena Sitnikova,Jill Slay
International Journal of Information Engineering and Electronic Business , 2012,
Abstract: Teams within organisations meet regularly to review their progress and engage in collaborative activities within a team setting. However, the uptake of tools to support their activities within team meetings is limited. Research efforts on understanding the reasons for low rates of tool adoption and learning lessons in developing tools that could be readily adopted by team members within team meetings are largely unexplored. This qualitative study focuses on learning lessons towards developing an integrated tool-support for small team meetings within organisations using focus groups. Discussions were based on a tool-kit framework generated by observing their team meetings in an earlier study. The discussions were recorded and the transcripts were analysed using grounded theory approach to generate stories on team processes and potential tools that could assist team members during each process. The lessons derived from the study were based on three aspects of tool-support namely the potential users of the proposed tool-kit, processes within the team meetings that would be influenced by the introduction of the tool-kit and the technological aspects of the tool-kit.
Revisiting the Reliability of Diagnostic Decisions in Sex Offender Civil Commitment
Richard L. Packard,Jill S. Levenson
Sexual Offender Treatment , 2006,
Abstract: Levenson (2004) investigated the inter-rater reliability of DSM-IV diagnoses commonly assessed by forensic evaluators in sex offender civil commitment proceedings and determined that the reliability of civil commitment selection (kappa = .54) and DSM-IV diagnostic categories (kappa = .23 - .70) were poor. The current study first reviews the limitations of using kappa in reliability studies and the reasons why the statistic may lead to paradoxical findings. Next, using Levenson’s data as a demonstration, alternative statistical analyses measuring raw proportions of agreement, odds and risk ratios, and estimated conditional probabilities were utilized to examine reliability. Agreement on the existence of the majority of the diagnosed disorders was rather high despite low values of kappa. The proportions of total agreement in diagnostic decisions ranged from 68% to 97%, indicating that, overall, civil commitment evaluations were a reliable process. The strengths and limitations of alternative methods of measuring inter-rater reliability are illustrated, and implications for policy and practice are discussed.
Diagnostic Reliability and Sex Offender Civil Commitment Evaluations: A Reply to Wollert (2007)
Dennis M. Doren,Jill S. Levenson
Sexual Offender Treatment , 2009,
Abstract: A recent article by Richard Wollert (2007) purports to demonstrate that the diagnostic inter-rater reliability of sex offender civil commitment evaluations is not high enough to be worthy for courtroom testimony. That author relies on a series of analyses to support that argument. Unfortunately, those analyses were flawed in serious ways, raising doubt about the overall conclusions drawn. This article delineates Wollert’s inaccurate assumptions, addresses methodological flaws, and offers an alternative interpretation regarding the accuracy of sexual offender civil commitment assessments.
Patterns and predictors of place of cancer death for the oldest old
Anna Lock, Irene Higginson
BMC Palliative Care , 2005, DOI: 10.1186/1472-684x-4-6
Abstract: A Cross-sectional analysis of national data was performed. The study included all people aged 75 and over dying of cancer in England and Wales between 1995 and 1999. The population was divided into exclusive 5 year age cohorts, up to 100 years and over. Descriptive analysis explored demographic characteristics, cancer type and place of death.Between 1995 and 1999, 315,462 people aged 75 and over were registered as dying from cancer. The number who died increased each year slightly over the 5 year period (1.2%). In the 75–79 age group, 55 % were men, in those aged 100 and over this fell to 16%. On reaching their hundreds, the most common cause of death for men was malignancies of the genital organs; and for women it was breast cancer.The most frequent place of death for women in their hundreds was the care home; for men it was hospitals. Those dying from lymphatic and haematopoietic malignancies were most likely to die in hospitals, those with head and neck malignancies in hospices and breast cancer patients in a care home.The finding of rising proportions of cancer deaths in institutions with increasing age suggests a need to ensure that appropriate high quality care is available to this growing section of the population.Between 1991 and 2001 [1], the UK the population aged over 85 rose by 29.6%. Further since the 1950's the number of people aged over 100 has doubled every decade [2]. A shrinking wage earning group and the growing number of dependent older people is creating a society in which taxable income will fall, whilst demands on health and social services are already rising. This growing section of older people are often socially excluded and at risk of experiencing a combination of linked problems such as unemployment, poor skills, low incomes, poor housing, high crime environments, bad health and family breakdown [3]. Age-based discrimination can be experienced with poorer access to and availability of health care services [4,5].Cancer is more common with
Qualitative studies of obesity: A review of methodology  [PDF]
Ian Brown, Jill Gould
Health (Health) , 2013, DOI: 10.4236/health.2013.58A3010
Abstract:

BACKGROUND: There is a developing interest in qualitative research to understand the perspectives and experiences of people living with obesity. However, obesity is a stigmatised condition associated with negative stereotypes. Social contexts emphasizing large body size as a problem, including research interviews, may amplify obesity stigma. This study reviews the methodology employed by qualitative studies in which study participants were obese and data collection involved face-to-face interviews. METHODS: Database searches identified qualitative studies meeting inclusion criteria from 1995 to 2012. Following screening and appraisal data were systematically extracted and analyzed from 31 studies. RESULTS: The studies included 1206 participants with a mean age of 44 years and mean BMI of37 kg/m2. Women (78.8%) outnumbered men (21.2%) by four to one. Socio-economic background was not consistently reported. The studies employed similar, typically pragmatic, qualitative methodologies, providing rich textual data on the experience of obesity derived from face-to-face interviews. The majority considered quality issues in data collection, analyses and generalizability of findings. However, the studies were weak as regards researcher reflexivity in relation to interviewer characteristics and obesity stigma. CONCLUSIONS: The impact of obesity stigma has not been attended to in the qualitative research. Clear information about study

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