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Biomedical subjects

S R Lord

Publications and source records attributed to S R Lord.

66 records · Page 4Linked to original sources
PubMed1991

Visual acuity and contrast sensitivity in relation to falls in an elderly population.

Visual acuity and contrast sensitivity were measured in 95 residents of a hostel for the aged (mean age = 83 years) using a dual-contrast letter chart and the Melbourne Edge Test (MET). Vision (as measured by visual acuity, the MET, low-contrast visual acuity, and difference between high- and low-contrast acuity) decreased significantly with age and all four measures were significantly correlated. Subjects with a clinical eye disorder had poorer vision than those without a disorder although the differences were not significant. Visual acuity and contrast sensitivity were not associated with body sway when subjects were standing on a firm base. However, when the subjects were placed in a situation which provided reduced support (standing on a compliant surface), body sway was associated with poor visual acuity and contrast sensitivity. There was also a difference in contrast sensitivity between those who fell one or more times in a year of follow-up and those who did not fall. It appears that reduced vision may be a predisposing factor to postural imbalance and falls in elderly persons.

Accidental Falls↗
PubMed1991

Postural stability and associated physiological factors in a population of aged persons.

A battery of 13 visual, vestibular, sensorimotor, and balance tests was administered to 95 elderly persons (mean age 82.7 years) to examine the relationships between specific sensorimotor functions and measures of postural stability. When subjects stood on a firm surface, increased body sway was associated with poor tactile sensitivity and poor joint position sense. When subjects stood on a compliant surface (which reduced peripheral sensation) with their eyes open, increased body sway was associated with poor visual acuity and contrast sensitivity, reduced vibration sense, and decreased ankle dorsiflexion strength as well as reduced joint position sense. Increased body sway with eyes closed on the compliant surface was associated with poor tactile sensation, reduced quadriceps and ankle dorsiflexion strength, and increased reaction time. Poor performance in two clinical measures of postural stability was associated with reduced sensation in the lower limbs as measured by joint position sense, tactile sensitivity and vibration sense, reduced quadriceps and ankle dorsiflexion strength, and slow reaction times. The prevalence of vestibular impairments was high in this group, but vestibular function was not significantly associated with sway under any of the test conditions. The results suggest that reduced sensation, muscle weakness in the legs, and increased reaction time are all important factors associated with postural instability. An analysis of the percentage increases in sway under conditions where visual and peripheral sensation systems are removed or diminished, compared with sway under optimal conditions, indicated that peripheral sensation is the most important sensory system in the maintenance of static postural stability.

Aged↗
PubMed1991

Physiological factors associated with falls in an elderly population.

OBJECTIVE: To determine whether a battery of 13 sensorimotor, vestibular, and visual tests discriminates between elderly fallers and elderly non-fallers. DESIGN: One-year prospective study. SETTING: Conducted at a 124-bed Hostel for Aged Persons, in Sydney, Australia. PARTICIPANTS: Ninety-five persons aged between 59 and 97 years (mean age 82.7 years) took part in the study. Of the 29 non-participants, four were ill, five were absent (on holidays, etc), and 20 declined. Residents were generally independent in activities of daily living although personal care assistance was available. RESULTS: Eighty-four participants were available for follow-up. In the follow-up year, 40 subjects experienced no falls, 11 subjects fell one time only, 33 residents fell on two or more occasions. There was a total of 145 falls. Discriminant function analysis identified proprioception in the lower limbs visual contrast sensitivity, ankle dorsiflexion strength, reaction time, and sway with the eyes closed as the variables that significantly discriminated between subjects who experienced multiple falls and subjects who experienced no falls or one fall only. This procedure correctly classified 79% of subjects into multiple faller or non-multiple faller groups. Quadriceps strength was poorer in the multiple fallers compared with the non-fallers and once-only fallers, although the difference was not statistically significant. There was little difference in the mean scores for the tests of vestibular function in the non-fallers, once-only fallers, and multiple fallers. CONCLUSION: It appears that this approach highlights some key physiological factors that predispose elderly individuals to falls.

Accidental Falls↗
PubMed1990

Visual field dependence in elderly fallers and non-fallers.

Two tests of visual field dependence (a measure of reliance upon the spatial framework provided by vision in the perception of the upright)--roll vection and the rod and frame test--were administered to 136 participants aged fifty-nine to ninety-seven years. It was found that the fifty-nine participants who had experienced one or more falls in the past year were significantly more visually field dependent in both tests compared with the seventy-seven participants who had not fallen. Mean error in perception of the true vertical in the rod and frame test was 20.7 degrees for the fallers and 17.2 degrees for the non-fallers. Mean error in perception of the true vertical in the roll vection test was 6.6 degrees for the fallers and 3.6 degrees for the non-fallers. The test of roll vection was the better discriminator between fallers and non-fallers, which may be due in part to less misunderstanding of the required task by the participant. The results suggest that tilted or rolling visual stimuli may be factors leading to postural instability and falls in the elderly. The findings support the claim that greater dependence on visual information shown by fallers may be the result of reduced proprioceptive and vestibular function resulting from increased age and chronic health problems.

Accidental Falls↗
PubMed1987

General practice preceptors and the undergraduate curriculum.

The responses of general practitioner preceptors to a questionnaire on issues that were related to undergraduate medical education in general practice were examined. Principal component analyses were carried out on the data to identify core components of active general practice that are important to undergraduate teaching. Three clear components were identified: a management component, a patient component, and a community component. These three components confirm that there are content areas that are common to the experience of education in general practice.

Australia↗
PubMed1986

Femoral neck fractures: admissions, bed use, outcome and projections.

A number of epidemiological studies have shown that the incidence of femoral neck fractures in industrialized countries increases at an exponential rate with age and that age-adjusted incidence rates are approximately twice as high in women than in men. Femoral neck fractures often have serious consequences for the aged, including permanently limiting their mobility, which results in increased dependence on others and hence an increased probability of being admitted to an institution. In this study, hospital inpatient statistics for New South Wales were examined to elucidate age-related trends in admissions to hospital for acute care, length of stay, bed use and outcome of this condition. Projections of the number of persons expected to suffer from femoral neck fractures, the associated number of bed-days that are required and the expected cost of hospital care to the year 2011 have been made. It seems probable that hospital services will not be provided at the necessary rate to cater for the expected increase in bed use from femoral neck fractures and other age-related conditions. Therefore, rational planning of scarce hospital resources will be required. Reductions in acute care hospital bed use for patients with femoral neck fractures could be made by reducing the number of technical failures in surgical treatment, providing more intensive nursing care to reduce postoperative and bed-rest complications, and by providing integrated slow-stream beds for the physical and social rehabilitation of patients.

Adult↗
PubMedDate not supplied

Measuring human functional age: a review of empirical findings.

A review of empirical functional age studies published in English was conducted. Types of biomarkers used in functional age studies included sensorimotor, cognitive, psychosocial, behavioral, anthropometric, biomedical, physiological, and dental variables. Previous criticisms of the validity and utility of functional age research were evaluated with reference to empirical studies. While some of these criticisms remain valid, areas of research currently using established biomarkers to predict functional outcomes were identified, including driving, falls, and cognitive functioning. It was concluded that the success of functional age research is dependent on the relevance of biomarkers to specific functional outcomes.

Adult↗
PubMedDate not supplied

Sensori-motor function in older persons with diabetes.

Twenty-five persons with diabetes (aged 55-83 years) who were living independently in the community, and 40 age- and sex-matched non-diabetic controls were assessed for tactile sensitivity, vibration sense, proprioception, quadriceps strength and body sway. In both men and women, those with diabetes performed significantly worse in tests of body sway on firm and compliant surfaces compared with the control subjects after controlling for weight and body mass index. The female diabetic subjects also performed significantly worse in tests of peripheral sensation and strength compared with controls. Age-related declines in sensori-motor function were greater in the diabetic group (r = 0.55-0.75) than in the controls (r < 0.44), while within the diabetic group, duration of diabetes and vibration sense were significantly correlated with sway on a compliant (foam rubber) surface with the eyes open (partial r = 0.52, p < 0.01 and r = 0.55, p < 0.01, respectively). The study findings provide evidence that older people with diabetes have problems with stability and related sensori-motor factors which may place them at increased risk of falls.

Adult↗
PubMedDate not supplied

Visual contributions to postural stability in older adults.

BACKGROUND: With advancing age, there is a generalized reduction in visual functioning which has been associated with impaired postural stability and increased risk of falls. However, little is known about which visual abilities are the most important in the control of postural sway when standing. OBJECTIVE: To determine whether specific visual abilities predict stability when standing on firm and compliant surfaces. METHODS: Tests of visual function, peripheral sensation, strength, reaction time and sway were administered to 156 community-dwelling men and women aged 63-90 years. The visual tests included high- and low-contrast visual acuity, contrast sensitivity, depth perception, stereopsis and lower visual field size. Postural sway was measured with eyes open on a firm and a compliant foam rubber surface. RESULTS: On the firm surface, sway was significantly associated with only one sensorimotor measure: proprioception in the lower limbs. In contrast, on the compliant surface, sway was associated with all of the visual measures, quadriceps strength and reaction time. Multiple regression analysis revealed that contrast sensitivity, stereopsis and quadriceps strength were significant independent predictors of total sway when subjects stood on the compliant surface. CONCLUSION: The study findings confirm the importance of vision, in particular contrast sensitivity and stereopsis, in the control of posture under challenging conditions, and suggest some mechanisms for the association between impaired vision and falls in older people.

Accidental Falls↗
PubMedDate not supplied

Balance confidence improves with resistance or agility training. Increase is not correlated with objective changes in fall risk and physical abilities.

BACKGROUND: While the fear of falling is a common psychological consequence of falling, older adults who have not fallen also frequently report this fear. Fear of falling can lead to activity restriction that is self-imposed rather than due to actual physical impairments. Evidence suggests that exercise can significantly improve balance confidence, as measured by falls-related self-efficacy scales. However, there are no prospective reports that correlate change in balance confidence with changes in fall risk and physical abilities as induced by participating in a group-based exercise program. OBJECTIVE: The primary purpose of this prospective study was to examine the relationship between the change in balance confidence and the changes in fall risk and physical abilities in older women with confirmed low bone mass after 13 weeks of exercise participation. The secondary purpose of this study was to examine the relationship between the change in balance confidence and the change in physical activity level. METHODS: The sample comprised 98 women aged 75-85 years with low bone mass. Participants were randomly assigned to one of three groups: resistance training (n = 32), agility training (n = 34), and stretching (sham) exercises (n = 32). The 50-min exercise classes for each study arm were held twice weekly at a local YMCA community centre. RESULTS: Both resistance training and agility training significantly improved balance confidence by 6% from baseline after 13 weeks. However, the change in balance confidence was only weakly correlated with improved general physical function and not significantly correlated with the changes in fall risk score, postural stability, gait speed, or physical activity level. As well, we observed balance confidence enhancement in the presence of increased fall risk or deterioration in physical abilities. CONCLUSIONS: Two different types of exercise training improved balance confidence in older women with low bone mass. This change in balance confidence was significantly correlated with change in general physical function. Because of the observation of discordance between balance confidence change and changes in fall risk and physical abilities, those who design group-based exercise programs for community-dwelling older adults may wish to consider including an education component on factors that influence fear of falling. Objective changes in fall risk factors cannot be assumed to mirror change in fear of falling and physical abilities in older adults in the short-term.

Accidental Falls↗
PubMedDate not supplied

Weight and overweight in a group of parliamentarians and senior public servants in New South Wales.

The health of 75 NSW State Government members of parliament and 192 senior public servants who have undergone routine health check-ups over the last seven years was assessed. It was found that 67% of members of parliament and 57% of senior public servants were overweight. Many overweight participants thought that their diets were average, their exercise and fitness adequate and that they were only a little overweight. Most thought their excess weight was not harmful. However, excess weight was found to be associated with other physiological variables including increased blood pressure, plasma cholesterol, triglyceride and urate levels.

Adult↗