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Biomedical subjects

P J Holliday

Publications and source records attributed to P J Holliday.

At least 19 recordsLinked to original sources
PubMed2005

Understanding and measuring powered wheelchair mobility and manoeuvrability. Part I. Reach in confined spaces.

PURPOSE: To determine: (1) what wheelchair manoeuvrability factors are important and (2) the effects of powered wheelchair design on the ability to reach in a confined space. METHOD: The relative importance of five aspects of wheelchair manoeuvrability was determined through a survey of users of wheelchairs (N = 52) and health care professionals and others (N = 89). A single young, non-disabled subject undertook repeated trials of reach distance on to a counter at the end of a corridor whose width could be adjusted by moving Styrofoam walls. RESULTS: Reaching, moving in confined spaces and avoiding collisions were more important than speed and avoiding the need to drive backwards. The rear wheel drive powered wheelchair was found to allow the greatest reach when driving backwards into the space and the wheelchair which moved in a sideways direction allowed greatest reach in the narrowest corridor. CONCLUSIONS: The survey concluded that manoeuvring in small spaces and reaching without collisions were important. The powered wheelchair with sideways capability afforded the greatest reach in confined spaces except when the rear wheel drive chair was driven in backwards. The survey respondents did not place a high priority on avoiding backwards driving but some people find this difficult to do safely.

Comprehension↗
PubMed1996

Psychological indicators of balance confidence: relationship to actual and perceived abilities.

BACKGROUND: This study compares several psychological indicators of balance confidence in relation to physical performance, past and current experience, gender bias, and other perceptions of daily functioning. METHODS: Sixty community-dwelling ambulatory elders (aged 65-95) were administered the Falls Efficacy Scale (FES), the Activities-Specific Balance Confidence Scale (ABC), and three dichotomous questions on fear of falling, activity avoidance, and perceived need for personal assistance to ambulate outdoors. Performance measures on walking (average speed) and balance (static posturography) were obtained on a subsample of 21 subjects. RESULTS: Balance confidence assessed by the ABC and self-perceived need for personal assistance with outdoor ambulation were the only indicators significantly associated with the performance measures. As expected, perceived balance capabilities were more strongly related to current behavior (frequency of doing specific activities) than to past experience (fall history). Gender differences in self-report emerged for the global fear-of-falling indicator but not for the two efficacy ratings. CONCLUSIONS: Psychological indicators of balance confidence are important to measure both in conjunction with balance test performance and as a legitimate focus of rehabilitation. Of the various indicators assessed here, the dichotomous fear-of-falling question appears to have the least utility. Perceived need for personal assistance to ambulate outdoors has merit as an initial clinical screening question for discriminating persons on the basis of both physical ability and confidence. The ABC scale appears to have the greatest utility as an evaluative index for older persons at a moderate to high level of functioning.

Accidental Falls↗
PubMed1994

A prospective study of postural balance and risk of falling in an ambulatory and independent elderly population.

BACKGROUND: An ability to predict risk of future falling is needed in order to target high-risk individuals for preventive intervention. The purpose of this study was to compare the ability of different measures of postural balance to predict risk of falling prospectively in an ambulatory and independent elderly population. METHODS: Balance tests were performed on 100 volunteers (aged 62-96), and falling was then monitored prospectively over a one-year period. The balance testing comprised measurements of: (a) spontaneous postural sway, (b) induced anterior-posterior sway, (c) induced medial-lateral sway, (d) anticipatory adjustments preceding volitional arm movements, (e) timed one-leg stance, and (f) performance on a clinical balance assessment scale. Small pseudorandom platform motions were used to perturb balance in the induced-sway tests. Using force plates, the spontaneous- and induced-sway responses were quantified in terms of the amplitude, speed, and mean frequency of the center-of-pressure displacement; input-output models were also used to parameterize the induced-sway performance. RESULTS: Although a number of measures showed evidence of significant differences between fallers and nonfallers, the differences were most pronounced for measures related to the control of lateral stability. Lateral spontaneous-sway amplitude (blindfolded conditions) was found to be the single best predictor of future falling risk, particularly for the large group of falls that were precipitated by a biomechanical perturbation. This measure was able to predict future falling risk with moderate accuracy, even in those individuals with no recent history of falling. CONCLUSIONS: The results suggest that control of lateral stability may be an important area for fall-preventative intervention. The ability of a simple and safe force-plate measure of spontaneous postural sway to predict future falling risk suggests a possible clinical application as a preliminary screening tool for risk of falling.

Accidental Falls↗
PubMed1994

The impact of new lifting technology in long term care: a pilot study.

1. The researchers conducted a pilot study to test a new lifting system developed with the assistance of nurses. 2. The lift system consists of a portable battery operated power unit that the nurse carries to the bedside and attaches to an overhead track; the ability to share the portable power unit among several track locations is economical. 3. The new lifting system was found to reduce the number of staff necessary to execute patient lifts. This staff saving amounted to 50% of one full time equivalent person per nursing unit. 4. Nurses perceived that less effort was required using the new lifting system compared to a conventional floor model wheeled lifting device.

Adult↗
PubMed1993

Functional performance measures: are they superior to self-assessments?

BACKGROUND: It has been suggested that performance measures of functional status have several advantages over self-report measures for both clinical and research purposes, including: greater patient acceptability, interpretability, reproducibility, sensitivity to change, and the focus on actual ability rather than presumed capability. This article challenges this assumed superiority of "objective," "behavioral" measures by directly comparing self-assessments and blindly rated performance assessments on a specific item by task basis, using an identical rating format. METHODS: A set of 14 performance tasks, consisting of a range of functional abilities (including simulations of cooking and sweeping), was administered to 99 community-dwelling older adults (aged 60-92) who had previously completed a 50-item instrumental activities of daily living (IADL) questionnaire. A subsample was retested 2 weeks later, and reassessed at 1 year. RESULTS: Of 182 subjects willing and able to complete the IADL questionnaire, only 99 attempted at least one of the performance tasks. Tasks that took longer to complete were not necessarily associated with a greater number of errors, nor did accuracy ratings correspond well with difficulty ratings. Good correspondence (greater than 80% agreement) between observed and perceived difficulty was found for only one-third of the item/task matchings. Generally, the rater tended to underestimate difficulty relative to subjective assessments. CONCLUSIONS: Relative to questionnaires, performance measures were not found to be psychometrically superior, more acceptable to respondents, easier to administer, or easier to interpret. Neither type of measure by itself distinguishes between motivation and capability, reflects adaptations made in everyday living, or accounts for personal preferences or reasons for difficulty.

Activities of Daily Living↗
PubMed1993

Are activity-based assessments of balance and gait in the elderly predictive of risk of falling and/or type of fall?

OBJECTIVE: To determine whether an activity-based test of balance and gait is predictive of the risk of: (1) falling in situations that are related to specific tasks evaluated as part of the test, (2) experiencing falls precipitated by different classes of biomechanical events, or (3) falling in general; and to compare the predictive ability of the activity-based test for the falls described in (2) and (3) to that of a posturography test that has been found previously to be predictive of falling risk. DESIGN: Cohort study. SETTING: Baseline tests performed in balance laboratory; subsequent history of falling monitored prospectively for 1 year in two residential-care facilities. PARTICIPANTS: Seventeen male and 83 female consecutive volunteers (mean age = 83, SD = 6) who were independent in activities of daily living and able to stand unaided. MEASUREMENTS: Independent variables were derived from an activity-based balance-and-gait test and a posturography test. Dependent variables were the numbers of subjects with one or more: (1) falls in specific situations related to activity-based test items, (2) falls related to general classes of biomechanical precipitant, and (3) falls in general. MAIN RESULTS: Subjects who were rated as "abnormal" in activity-based test items related to transfers, turning or reaching were more likely to experience one or more falls in related situations in everyday life. Activity-based scores were predictive of risk of experiencing falls with no obvious biomechanical precipitant and falls precipitated by center-of-mass perturbation, but not falls precipitated by base-of-support perturbation. In comparison, a posturographic measure of spontaneous medial-lateral postural sway (blindfolded conditions) failed to predict falls having no biomechanical precipitant, but provided the best predictions of both center-of-mass and base-of-support falls, as well as risk of falling in general. CONCLUSIONS: Activity-based testing of certain tasks (transfer, turning, reaching) may be useful in indicating a specific need for intervention to reduce the risk of falling during related everyday activities. In terms of predicting falling risk, a static posturography test may provide better prediction overall of the different classes of falls and may be useful as a quick and simple screening tool to help identify high-risk individuals.

Accidental Falls↗
PubMed1992

Clinical and laboratory measures of postural balance in an elderly population.

The objective of this cross-sectional study was to compare scores on the Balance Scale with laboratory measures of postural sway and other clinical measures of balance and mobility. Thirty-one elderly subjects were assessed on the clinical measures and the laboratory tests of postural sway while standing still and in response to pseudorandom movements of the platform. The average correlation between the Balance Scale and the spontaneous sway measures was -.55. It was slightly lower (r = -.38) for the same parameters measured during the pseudorandom tests. There were high correlations between the Balance Scale and the Balance Sub-Scale developed by Tinetti (r = .91), Barthel Mobility sub-scale (r = .67), and timed "Up and Go" (r = -.76). The Balance Scale was the most efficient measure (effect size > 1) to statistically discriminate between subjects according to their use of each type of mobility aide (walker, cane, no aids). These data contribute to existing information on the performance of the Balance Scale and supports the validity of the Balance Scale in this geriatric population.

Activities of Daily Living↗
PubMed1991

Fear of falling and postural performance in the elderly.

A cross-sectional study was performed to investigate the association between fear of falling and postural performance in the elderly. One hundred ambulatory and independent volunteers (aged 62-96) were subjected to five types of balance tests: (a) spontaneous postural sway, (b) induced anterior-posterior sway, (c) induced medial-lateral sway, (d) one-leg stance, and (e) a clinical balance assessment scale. Pseudorandom platform motions were used in the induced-sway tests. The subjects were classified into both "faller"/"nonfaller" and "fear"/"no-fear" categories, to allow the influence of fear of falling and falling history to be separated in the analyses. Subjects who expressed a fear of falling were found to exhibit significantly poorer performance in blindfolded spontaneous-sway tests and in eyes-open, one-leg stance tests. The clinical scale was the only balance measure that showed a significant association with retrospective, self-reported falling history. We could not ascertain whether the fear of falling affected balance-test performance in an artifactual manner, or whether the fear and poorer performance were related to a true deterioration in postural control. Until this issue can be resolved, balance-test performance should be interpreted with caution when testing apprehensive individuals. Furthermore, studies of postural control and falling should allow for the potentially confounding influence of fear of falling.

Accidental Falls↗
PubMed1990

Aging and postural control. A comparison of spontaneous- and induced-sway balance tests.

Two different balance testing methods were compared: (1) measurement of spontaneous postural sway during quiet standing, and (2) measurement of induced postural sway in response to an applied postural perturbation. Eyes-open tests were performed in 64 healthy young and elderly adults and in five elderly subjects with a history of falling. In both balance tests, the sway was defined in terms of the displacement of the center of pressure on the feet. Spontaneous sway was quantified using a number of different amplitude- and frequency-based parameters. Induced sway was measured in response to anterior-posterior acceleration of a platform on which the subject stood. The induced-sway test was specially designed to be safe and nonthreatening for elderly subjects; thus, the platform perturbation was confined to small accelerations and a gentle pseudorandom motion was used. To derive a measure of postural stability, the data from this test were fitted with a model that was then used to predict the response to sudden (transient) perturbations, thereby simulating the response in actual falls. Although both induced- and spontaneous-sway measures demonstrated significant aging-related decreases in stability, the differences were more pronounced for the induced-sway data. Conversely, some of the spontaneous-sway measures were much more successful in distinguishing the fallers from the nonfallers. There was a significant correlation between induced-sway and certain spontaneous-sway measures in the normal young adults; however, in the elderly normals and fallers, the data from the two types of balance tests either showed no correlation or, for certain spontaneous-sway measures, tended to show an inverse relationship.

Acceleration↗
PubMed1989

Oxybutynin chloride for geriatric urinary dysfunction: a double-blind placebo-controlled study.

Twenty-four incontinent elderly institutionalized subjects with detrusor instability participated in a double-blind placebo-controlled trial of oxybutynin chloride. Patients were randomly assigned to oral oxybutynin 5 mg or placebo twice daily. Administration continued for 8 days; a 6-day washout period was followed by the alternative treatment. Incontinence was recorded using a bedside electronic monitor. Four subjects withdrew because of side-effects before completing the trial. There were no clinically significant differences between the oxybutynin and placebo treatments. Both groups experienced side-effects, of which dry mouth was the commonest. Thus, oxybutynin does not appear to be more effective than placebo for the treatment of incontinence in the presence of detrusor instability in elderly institutionalized people.

Aged↗
PubMed1982

The relationship of postural sway in standing to the incidence of falls in geriatric subjects.

A double-blind study was undertaken to determine the relationship (if one exits) between the extent of postural sway in standing of individual elderly subjects and their frequency of falling. A total of 205 subjects were studied; their average age was 81.8 years. Thirty per cent of the men, and 46% of the women, had one or more falls; the proportion of all subjects with one or more falls was 42%. The average speed of sway was significantly greater (P less than 0.05) for those who fell one or more times in a year than for those who did not fall. In this group of institutionalized elderly, there was no sex-related difference in the mean speed of sway; moreover, no age-related trend was demonstrated by the regression of mean speed upon age for all subjects. The mean speed of sway even for the non-fallers was found to be greater than that measured in a sample of non-institutional elderly subjects studied in the past. Thus, mean speed of postural sway was found to be only of statistical value for determining the risk of falling among these institutionalized elderly. We found postural sway to be an indicator of a tendency to fall, but the difference was less than might have been expected. No trend of increasing postural sway correlating with the increased frequency of falls was found.

Accidents↗
PubMed1982

Volume fluctuations in the residual limbs of lower limb amputees.

This study evaluated residual limb volume fluctuations of new and mature amputees in order to better plan for definitive limb prostheses. A measurement system based on a water displacement technique was used to measure cross-sectional area profiles of lower extremity amputation residual limbs. Reliable data were obtained for 32 of the 49 subjects participating in this study. Residual limb shrinkage cannot be characterized by any single pattern and therefore the date for fitting of a final prosthesis cannot be predicted precisely from regular volume measurements. Every amputee studied demonstrated an increase in body weight. Changes in residual limb volume early postoperatively were dictated by interaction of shrinkage and opposite effect of weight gain . Mature amputation limbs were observed to fluctuate in volume, and these fluctuations tended to correspond to body weight changes. For 3 general patterns of volume change observed early postoperatively, the best estimate of time to fit a final prosthesis appears to be about 150 days postamputation.

Adolescent↗
PubMed1981

Urinary dysfunction in a geriatric long-term care population: prevalence and patterns.

More complete data on th prevalence and types of urinary dysfunction in geriatric institutional patients are essential for the management of their urologic problems. Over a 13-month period, a prospective study was conducted of all new admissions to a hospital for long-term care. Eighty percent (277/347) of the newly admitted patients were geriatric (65 or older). Urinary dysfunction was identified in 69.3 percent of the geriatric group; 38.3 percent were incontinent, 20.2 percent bore a urinary diversion device, and 10.8 percent were symptomatic without incontinence. Obtaining reliable information about urologic status posed a significant problem, particularly as 27 percent of the subjects had a mental disorder, including organic brain syndrome or confusion. Thirty percent of all patients questioned were unable to give any history of their own health status. Questioning of both staff and patient to determine reliability of the data revealed that the given information was correct in 77 percent of patients who acknowledged genitourinary dysfunction, and in 83 percent of those who denied it. The study failed to elicit useful data concerning the specificity of symptoms, urologic history, diagnosis and management of urinary dysfunction in this series of geriatric patients under long-term institutional care.

Aged↗