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Results for “Obstacles”

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At least 19 recordsLinked to original sources

PubMed1991

Stepping over obstacles: gait patterns of healthy young and old adults.

Falls associated with tripping over an obstacle can be devastating to elderly individuals, yet little is known about the strategies used for stepping over obstacles by either old or young adults. The gait of gender-matched groups of 24 young and 24 old healthy adults (mean ages 22 and 71 years) was studied during a 4 m approach to and while stepping over obstacles of 0, 25, 51, or 152 mm height and in level obstacle-free walking. Optoelectronic cameras and recorders were used to record approach and obstacle crossing speeds as well as bilateral lower extremity kinematic parameters that described foot placement and movement trajectories relative to the obstacle. The results showed that age had no effect on minimum swing foot clearance (FC) over an obstacle. For the 25 mm obstacle, mean FC was 64 mm, or approximately three times that used in level gait; FC increased nonlinearly with obstacle height for all subjects. Although no age differences were found in obstacle-free gait, old adults exhibited a significantly more conservative strategy when crossing obstacles, with slower crossing speed, shorter step length, and shorter obstacle-heel strike distance. In addition, the old adults crossed the obstacle so that it was 10% further forward in their obstacle-crossing step. Although all subjects successfully avoided the riskiest form of obstacle contact, tripping, 4/24 healthy old adults stepped on an obstacle, demonstrating an increased risk for obstacle contact with age.

Adult↗

PubMed1989

Obstacles to family practitioners' use of screening tests: determinants of practice?

The effect of nine obstacles on family physicians' screening practices is reported. Family physicians, responding to a survey of periodic health screening practices, were asked to check the obstacles that affected their use of the screening tests listed. In the survey, 129 members of the American Academy of Family Physicians and 146 members of the Society of Teachers of Family Medicine responded. The most frequently reported obstacles to screening were cost to the patient, patient refusal, inconvenience to the patient, and lack of facilities or equipment. The tests for which the most obstacles were reported were sigmoidoscopy, tonometry, and mammography. The Society of Teachers of Family Medicine physicians were more likely to list cost, patient reluctance, inconvenience to the patient, "the literature does not recommend to use the test," time to perform the tests, and high rate of false positives and negatives. American Academy of Family physicians were more likely to report two obstacles, lack of facilities or equipment and risk to the patient. An analysis of the relationship between obstacle report and test utilization indicated that for only five of the nine obstacles were physicians who listed the obstacle less likely to use the test than physicians who did not list the obstacle. Obstacles related with decreased test use were those that affected the physician's ability to perform the test or the efficacy of the test itself while "inactive" obstacles were those that more directly affected and emanated from patients.

Attitude of Health Personnel↗

PubMed1987

Lateral diffusion in an archipelago. The effect of mobile obstacles.

Lateral diffusion of mobile proteins and lipids (tracers) in a membrane is hindered by the presence of proteins (obstacles) in the membrane. If the obstacles are immobile, their effect may be described by percolation theory, which states that the long-range diffusion constant of the tracers goes to zero when the area fraction of obstacles is greater than the percolation threshold. If the obstacles are themselves mobile, the diffusion constant of the tracers depends on the area fraction of obstacles and the relative jump rate of tracers and obstacles. This paper presents Monte Carlo calculations of diffusion constants on square and triangular lattices as a function of the concentration of obstacles and the relative jump rate. The diffusion constant for particles of various sizes is also obtained. Calculated values of the concentration-dependent diffusion constant are compared with observed values for gramicidin and bacteriorhodopsin. The effect of the proteins as inert obstacles is significant, but other factors, such as protein-protein interactions and perturbation of lipid viscosity by proteins, are of comparable importance. Potential applications include the diffusion of proteins at high concentrations (such as rhodopsin in rod outer segments), the modulation of diffusion by release of membrane proteins from cytoskeletal attachment, and the diffusion of mobile redox carriers in mitochondria, chloroplasts, and endoplasmic reticulum.

Cell Membrane↗

PubMed1991

Inverse perspective mapping simplifies optical flow computation and obstacle detection.

We present a scheme for obstacle detection from optical flow which is based on strategies of biological information processing. Optical flow is established by a local "voting" (non-maximum suppression) over the outputs of correlation-type motion detectors similar to those found in the fly visual system. The computational theory of obstacle detection is discussed in terms of space-variances of the motion field. An efficient mechanism for the detection of disturbances in the expected motion field is based on "inverse perspective mapping", i.e., a coordinate transform or retinotopic mapping applied to the image. It turns out that besides obstacle detection, inverse perspective mapping has additional advantages for regularizing optical flow algorithms. Psychophysical evidence for body-scaled obstacle detection and related neurophysiological results are discussed.

Algorithms↗

PubMed1991

Visual control of locomotion: strategies for changing direction and for going over obstacles.

Dynamics of gait adjustments required to go over obstacles and to alter direction of locomotion when cued visually were assessed through the measurement of ground reaction forces, muscle activity, and kinematics. The time of appearance of obstacles of varying heights, their position within the step cycle, and cue lights for direction change were varied. Direction change must be planned in the previous step to reduce the acceleration of the body center of mass toward the landing foot to 0. The inability of steering within the step cycle is due to the incapacity of muscles to rotate the body and translate it along the mediolateral axes. For obstacle avoidance, Ss systematically manipulated the gait patterns as a function of obstacle height and position and the time available within the ongoing step. Greater supraspinal involvement in control of locomotion is found.

Adult↗

PubMed1989

Wheelchair obstacle course performance in right cerebral vascular accident victims.

The initial experiment of this paper investigated the role of hemispatial neglect in wheelchair-related accidents of right-hemisphere stroke victims. Twelve subjects with and 12 subjects without neglect of left space drove their wheelchairs through an obstacle course. Two types of obstacle course errors were evaluated: direct hits and sideswipes. The neglecting group made significantly more direct hits but there were no significant differences between groups in sideswipe errors. In Experiment 2, the nonneglecting group's data were compared with a left-hemisphere stroke group without neglect and three motor control groups to investigate if their errors resulted from motor deficits. The right-hemisphere stroke group made significantly more left-sided errors and errors in contralateral space than any other group. In Experiment 3, 13 subjects with neglect were taught to scan to the left which resulted in significant decreases in direct hits but not in sideswipes on the obstacle course. These results suggest that obstacle course performance is sensitive to more than hemispatial neglect.

Accident Proneness↗

PubMed1988

Obstacles to effective professional education programming by a voluntary health association: findings from a national survey.

The American Cancer Society (ACS) conducted a nationally representative survey of ACS professional education committee volunteer chairpersons and ACS staff responsible for professional education programs in Divisions and Units of the Society. The survey questionnaire included a set of 25 items (15 in the chairperson questionnaires) representing potential obstacles to effective professional education programming. Subjects rated these obstacles on a four-point scale indicating the extent to which they were perceived as problems in professional education. The survey identified which potential obstacles to professional education programming by a voluntary health association were considered to be most problematic. These included competition from other providers of oncology professional education, outdated audiovisuals and publications, and the recruitment and retention of physician volunteers. The survey verified that there were differences within the organizational structure of the association. In particular, small Units of the Society faced more problems than did Divisions and large Units. The survey found differences in perceived problems between volunteers and staff, particularly in that staff found outdated audiovisuals and publications to be more of a problem than did chairpersons. In general, however, there was a commonality of opinion among all respondents as to which obstacles posed more of a problem than others in professional education.

American Cancer Society↗

PubMed1990

Problems, obstacles, and complications of limb lengthening by the Ilizarov technique.

Difficulties that occur during limb lengthening were subclassified into problems, obstacles, and complications. Problems represented difficulties that required no operative intervention to resolve, while obstacles represented difficulties that required an operative intervention. All intraoperative injuries were considered true complications, and all problems during limb lengthening that were not resolved before the end of treatment were considered true complications. The difficulties that occurred during limb lengthening include muscle contractures, joint luxation, axial deviation, neurologic injury, vascular injury, premature consolidation, delayed consolidation, nonunion, pin site problems, and hardware failure. Late complications are those of loss of length, late bowing, and refracture. Joint stiffness may also be a permanent residual complication. Pain and difficulty sleeping are other problems that arise during limb lengthening, especially in the more extensive cases. Forty-six patients had 60 limb segments lengthened between 1.0 and 16.0 cm, with a mean of 5.6 cm. The average treatment time was approximately one month per centimeter for single-level lengthenings with no deformity and 1.2 months per centimeter with deformity correction. The lengthening index for double-level lengthening was 0.57 month per centimeter with no deformity and 0.90 month per centimeter with correction of deformity. In adults, the lengthening index was 1.7 months per centimeter for single-level and 1.1 months per centimeter for double-level lengthening. There were 35 problems that had to be resolved in the outpatient clinic. There were 11 obstacles that required additional operative intervention to resolve. There were 27 true complications, of which 17 were considered minor and ten were considered major complications. Of the major complications, three interfered with achieving the original goals of treatment. All three required further operative intervention to achieve the original goal. These were nonunion in one and late bowing in two. Despite these problems, obstacles, and complications, the original goals of surgery were achieved in 57 of the 60 limb segments treated. Patient satisfaction was achieved in 94% of 46 cases.

Adult↗

PubMed1975

Obstacles to utilization of prepaid mental health care.

The coverage of out-of-hospital expenses for mental health care through prepayment and insurance programs has been a major advance in removing the economic barriers to early detection, diagnosis, and treatment of mental disorders. However, obstacles to obtaining treatment block many eligible people from receiving help. The authors conducted a study among members of the United Auto Workers union to identify these roadblocks. Among the obstacles were differences in perceptions of need for treatment and in attitudes toward treatment, and lack of awareness of eligibility for benefits among three key groups - consumers, referral agents, and providers. The authors urge psychiatry to help in removing these obstacles.

Attitude of Health Personnel↗

PubMed1991

Is the Oedipus complex still the cornerstone of psychoanalysis? Three obstacles to answering the question.

Current controversies about the centrality of the Oedipus complex in psychoanalysis are difficult to resolve unless we address three obstacles in the way of rational examination. The first is that the Oedipus complex, Freud's "shibboleth" of psychoanalysis, is politically controversial. Second is the great difficulty in agreeing upon the definition and boundaries of the Oedipus complex, especially the necessary complexities introduced with the negative Oedipus complex, female sexuality, the nature of the preoedipal, and counteroedipal fantasies and actions. The third obstacle involves basic questions of psychoanalytic epistemology: our criteria for evidence to prove or disprove any particular proposition. I conclude that the awareness of these difficulties signifies a certain maturation in our thinking and that the complexity introduced by these obstacles can in time provide the groundwork for a set of formulations that is richer and closer to the complexities and ambiguities of the clinical situation.

Ego↗

PubMed1991

[Prevention of athletic injuries by changing the regulations. Experiences with a military obstacle track].

During a period of 12 months of military conscription, all of the injuries occurring on the obstacle track at the Antvorskov Barracks in Slagelse were registered. During the period of investigation, the regulations for employing the track were altered so that the heights of jumping down from obstacles were considerably reduced. The object of this investigation was to demonstrate any possible effect on the pattern of injuries. During the period, a total of 26 injuries were registered (3.78 injuries/conscript/1,000 hours activity). As compared with previous investigations, the frequency of injuries was reduced and practically all of the serious injuries were prevented. The proposed alterations in the techniques are recommended in future when conscripts employ the military obstacle track.

Adult↗

PubMed1979

[A study of the obstacles to reduction in congenital dislocation of the hip (author's transl)].

Investigation on ten patients with typical congenital dislocation of the hip generalized joint laxity indicated the changes in the antero-inferior part of the acetabulum, which are mainly adhesion and narrowing produced by the capsule pulled superoposteriorly, as the major obstacle for successful reduction. Inverted limbus, pulvinar mass and ligamentum teres may represent secondary obstacles mostly due to iatrogenic procedures. The purpose of the closed reduction is to get rid of the obstacles during the conservative treatment. The cause of the failure of conservative treatment of congenital dislocation of the hip is a misjudgement of true reduction, allowing enough cavity for the femoral head in the antero-inferior part of the joint without the presence of the capsule between the femoral head and the acetabular cartilage. To get better understanding of the true reduction, tangential view in the arthrography of the hip joint gives us more precise data about the antero-inferior part of the joint because the acetabulum faces the joint cavity laterally and anteriorly.

Arthrodesis↗

PubMed1991

Obstacles to implementing cancer clinical trials.

There are numerous obstacles to implementing and conducting clinical trials. Patient accrual and the costs of clinical trials are difficult problems for researchers. Additional obstacles to implementing clinical trials are patient-related, physician-related, and nurse-related barriers.

Clinical Trials as Topic↗

PubMed1992

Research in social work practice: benefits of and obstacles to implementation in the Department of Veterans Affairs.

Although research is an important part of social work practice in health care, there is little systematic information that sheds light on research productivity, the benefits of conducting research, or the obstacles that must be overcome. This article represents the viewpoints of nearly all the directors of social services departments in the largest multihospital system in the United States, the Department of Veterans Affairs. The organizational characteristics of hospitals and the attitudes of the directors about research were important correlates of research productivity. Although lack of time, resources, and interest were cited as common obstacles, more than one-third of the departments were conducting or involved in at least one study. Information about the research efforts of other social services departments was considered an important resource, particularly for departments with no ongoing studies. The implications of these findings for social work research in health care are discussed.

Attitude↗

PubMed1987

Obstacles to the utilization of vocational services: an analysis of the literature.

While employment has been linked to positive clinical outcomes with drug abusers, research suggests that many treatment programs do not emphasize vocational services and under-utilize vocational resources. This article summarizes potential client-, program-, and societal-level obstacles to vocational rehabilitation service delivery identified in past studies with both substance abusers and other related client groups. Obstacles identified for related groups are integrated with issues relevant to drug treatment clients. This analysis is based on literature published over the last 20 years.

Counseling↗

PubMed1992

Primary mental health care: indications and obstacles.

This paper considers indications and obstacles for the development of primary mental health care practice in both developed and under-developed countries. Both are considered as this represents the South African reality. While a significant body of literature has documented the need for primary mental health care, the obstacles (especially in terms of the co-modification of health) to its fruition are seldom addressed.

Attitude to Health↗

PubMed1976

[The epistemological obstacle in the constitution of social sciences].

I. General conception. The author contends that the constitution of science requires the completion of two different tasks: a) a negative-critical one, i.e. the clearing of the theoretical field through expurgating all pre-scientific ideologies jeopardizing the growth of scientific concepts; and b) a positive-constructive one, or the actual building up of a science through the production of the formal-abstract object, using ontically indeterminate raw material. Those tasks have characteristics that differ from the formal and factic-natural sciences to the social sciences. The reasons for the differences are: a) the former two have established objects, whereas the latter ones have their objects in the process of undergoing constitution, and thus possessing and oscillating ambiguity; b) the former two sciences have specific methods related to their specific objects, whereas the latter ones have a host of methods, all of them advocating scientific status; c) the former two sciences integrate their concepts into systems so as to constitute the unity of their meaning, whereas the latter ones lack a systematic integration. The consequence is that sciences already constituted (formal and factic-natural sciences) have, by the same token, established the co-implication of both moments (negative-critical and positive-constructive), to the extent that they are in the midst of universes admitting some law-system. Social sciences, on the contrary, set a double register of problems: a) "in-themselves", as they suppose the opening of a new way to approach the object; and b) "for-themselves", as long as that opening is performed at the expense of pre-scientific ideologies that bar the developments to be done "in-themselves". Furthermore, the double task is not accomplished in the same fashion in logic-formal sciences and factic-natural ones, both groups having an apodictic adequation (absolute in the first group, relative in the second one) between the context of discovery and the context of justification, be it formal or experimental, whereas in social sciences there is no such adequation, as they are still searching and trying to establish the mutually foundating relationship between both contexts. II. The epistemological obstacle in Psychology. Psychology, belonging to the general class of social sciences, is subject to two kinds of epistemological obstacles: a) those stemming from "common sense", born and nourished in the naïve, day-to-day experience, and being used as a general canon for usual as well as entirely new situations; they reach the status of a pre-critical "knowing", based solely on beliefs, and advocating to provide the grounds for our opinion on singular and general subjects; and b) those stemming from the "speculative discourse", understood as a system of notions encircling themselves and pretending to have an analogical reference to real objects, when analogy only actualizes objects that are absent...

Humans↗

PubMedDate not supplied

Women in academic medicine: perceived obstacles to advancement.

To investigate perceived obstacles to the advancement of women in academic medicine, we sent a questionnaire assessing perceptions of the fairness and supportiveness of the academic environment to the 229 female teaching and research faculty of the School of Physicians & Surgeons at Columbia University. The overall response rate was 85%. Forty-six percent believed that they had not had the same professional opportunities as their male colleagues, 52% believed that salaries were not equivalent for men and women in similar positions, and 50% believed that promotions were awarded in a biased manner. Thirty percent reported that sexist behavior was common and that sexual harassment occurred in the workplace. Eighty-one percent experienced conflicts between their professional and personal lives and most believed that the institution failed to adequately address the needs of women with children. This survey indicates that there are significant perceived obstacles to the advancement of women in academic medicine that must be addressed.

Career Mobility↗