Biomedical subjects

S R Lord

Publications and source records attributed to S R Lord.

At least 37 records · Page 2Linked to original sources

PubMed2001

Choice stepping reaction time: a composite measure of falls risk in older people.

BACKGROUND: This study investigated the neuropsychological, sensorimotor, speed, and balance contributions to a new test of choice stepping reaction time (CSRT) and determined whether this new test is an important predictor of falls in older people. METHODS: A total of 477 retirement-village residents aged 62 to 95 years (mean +/- SD, 79.2 +/- 6.2 years) took the CSRT test, which required them to step onto one of four panels that were illuminated in a random order. The subjects also took tests that measured neuropsychological, sensorimotor, speed, and balance function. RESULTS: Multiple regression analysis revealed that poor performance in Part B of the Trail Making Test (a neuropsychological test) and impaired quadriceps strength, simple reaction time, sway with eyes open on a compliant surface, and maximal balance range were the best predictors of increased CSRTs (multiple r(2) =.45). Subjects with a history of falls had significantly increased CSRTs compared with nonfallers (1322 +/- 331 milliseconds and 1168 +/- 203 milliseconds, respectively). Impaired CSRT was a significant and independent predictor of falls, as were two complementary sensory measures (visual contrast sensitivity and lower limb proprioception). Of these measures, CSRT was the most important in predicting falls. Furthermore, the inclusion of CSRT in the model excluded measures of strength, central processing speed, and balance, because these could not provide nonredundant information for the prediction of falls. CONCLUSIONS: This study identifies a new test that provides a composite measure of falls risk in older people and elucidates the relative importance of specific physiological and neuropsychological systems in the initiation of fast and appropriate step responses.

Accidental Falls↗

PubMed2001

Foot pain impairs balance and functional ability in community-dwelling older people.

Foot problem assessments were performed on 135 community-dwelling older people in conjunction with clinical tests of balance and functional ability. Eighty-seven percent of the sample had at least one foot problem, and women had a higher prevalence than men of foot pain, hallux valgus, plantar hyperkeratosis, lesser digital deformity, and digital lesions. Postural sway did not differ between older people with and without each of these foot conditions. However, the presence of specific foot conditions impaired performance in a more challenging balance test and in some functional tests. In particular, older people with foot pain performed worse in a leaning balance test, stair ascent and descent, an alternate step-up test, and a timed six-meter walk. Furthermore, multiple regression analyses revealed that foot pain was a significant independent predictor of performance in each of these tests. These results show that the presence of foot problems, particularly foot pain, impairs balance and functional ability. As foot pain is amenable to treatment, podiatric intervention has the potential to improve mobility and independence in older people.

Aged↗

PubMed2001

The contribution of foot problems to mobility impairment and falls in community-dwelling older people.

OBJECTIVES: To investigate the relationship between foot problems, balance, and functional ability in community-dwelling older people and to determine whether older people with a history of multiple falls exhibit greater foot impairment than those who have not fallen or who have fallen once only. DESIGN: A cross-sectional, retrospective study. SETTING: Falls and Balance Laboratory, Royal North Shore Hospital, Sydney, Australia. PARTICIPANTS: One hundred thirty-five community-dwelling men and women age 75 to 93 (mean age +/- standard deviation, 79.8 +/- 4.1). MEASURES: Foot problem score; postural sway; coordinated stability; stair ascent and descent; an alternate stepping test; timed 6-meter walk; and tests of vision, sensation, strength, and reaction time. RESULTS: Eighty-seven percent of the sample had at least one foot problem. Women had a significantly higher foot problem score than did men. The foot problem score was significantly associated with performance on the coordinated stability test, stair ascent and descent, alternate stepping test, and timed 6-meter walk. Multiple regression analyses revealed that the foot problem score was a significant independent predictor of performance in the coordinated stability test, stair ascent and descent, and the alternate stepping test. Subjects with a history of multiple falls had a significantly higher foot problem score than did those who had not fallen or who had fallen once only, but the prevalence of individual foot conditions or the presence of foot pain did not differ between these groups. CONCLUSIONS: Foot problems are common in older people and are associated with impaired balance and performance in functional tests. Furthermore, older people with a history of multiple falls have greater foot impairment than non- or once-only fallers. These findings provide further evidence that foot problems are a falls risk factor and suggest that the cumulative effect of multiple foot problems is more important in increasing falls risk than the presence or absence of individual foot conditions.

Accidental Falls↗

PubMed2000

Normative data on neuropsychological tests for very old adults living in retirement villages and hostels.

Normative data on neuropsychological tests for very old adults living in retirement villages and hostels are under-represented in the literature. This study reports normative data on the Mini-Mental State Examination, Digit Span Forwards, Digit Span Backwards, the Digit Symbol Substitution Test, the Controlled Oral Word Association Test, the Stroop Neuropsychological Screening Test and the National Adult Reading Test. Age and education showed moderate correlations with neuropsychological test performance. For all tests except the Stroop, differences between residents of retirement villages and hostels were explained by age and education. Men performed better on the NART than women, but this difference was eliminated when education was controlled for statistically.

Age Factors↗

PubMed1999

Effects of shoe collar height and sole hardness on balance in older women.

OBJECTIVE: To determine whether shoe collar height and sole hardness affect balance in older women. DESIGN: A randomized order, cross-over, controlled comparison. SETTING: Intermediate care institution and regional hospital. PARTICIPANTS: Forty-two women aged 60 to 92 years (mean 76, SD = 9.03). The sample comprised 15 hostel (intermediate care) residents, 11 women who lived in a retirement village, and 16 women who lived independently in the community. OUTCOME MEASURES: Postural sway, maximal balance range and coordinated stability. MAIN RESULTS: The subjects underwent assessments of static balance (body sway) and dynamic balance (maximal balance range and coordinated stability) under five conditions: (1) in soft-soled bowls shoes, (2) in hard-soled bowls shoes, (3) in college-style shoes, (4) in college-style shoes with a high (boot) collar, and (5) barefoot. MANOVA analysis indicated that subjects were more stable when wearing the high collar shoes than when wearing the college shoes (P < .001) or when barefoot (P < .05). In contrast, subjects performed similarly in the balance tests in the soft and hard-soled shoes (P = .30) and no better than when barefoot (P = .12 and P = .93, respectively). CONCLUSIONS: The findings indicate that subjects had better balance when wearing shoes with high collars than when wearing shoes with low collars and that sole hardness was not related to balance.

Accidental Falls↗

PubMed1999

Lateral stability, sensorimotor function and falls in older people.

AIMS: To design simple tests of lateral stability for assessing balance in older people and to determine whether poor performances in these tests are associated with impaired vision, lower limb sensation, quadriceps strength, simple reaction time, and falling in this group. DESIGN: A cross-sectional and retrospective study. SETTING: Falls and Balance Laboratory, Prince of Wales Medical Research Institute. PARTICIPANTS: One hundred fifty-six community-dwelling men and women aged 63-90 years (mean age 76.5, SD = 5.1). OUTCOME MEASURES: The maximal lateral sway in a near-tandem stability test with eyes open and closed and the necessity of taking a protective step in the near-tandem stability test with eyes closed. RESULTS: All 156 subjects could complete the near-tandem stability test with eyes open, but only 99 subjects (63.5%) could undertake the test with eyes closed without taking a protective step. Subjects with a history of falls had increased lateral sway both with eyes open and eyes closed as well as poorer visual acuity, proprioception, and quadriceps strength. Fallers were also significantly more likely to take a protective step when undertaking the near-tandem stability test with eyes closed. Multiple regression analysis revealed that impaired lower limb proprioception, quadriceps strength, and reaction time were the best predictors of increased maximal sway in the near-tandem stability test with eyes open. Reduced proprioception and quadriceps strength, in addition to age, were also found to be the best determinants of the necessity of taking a protective step in the near-tandem stability test with eyes closed. CONCLUSIONS: The study findings identify simple new tests that are associated with falling in older people and elucidate the relative importance of specific physiological systems in the maintenance of lateral stability.

Accidental Falls↗

PubMed1999

Footwear and postural stability in older people.

Accidental falls in the older population are common and often result in serious injury. Although a number of factors have been recognized as risk factors for falling, the effect of footwear on postural stability is often overlooked. This article reviews the literature on the effect of various footwear features on postural stability and suggests areas that warrant further investigation.

Accidental Falls↗

PubMed1999

Foot problems, functional impairment, and falls in older people.

Falls in older people are common and may lead to considerable disability. Although a number of risk factors for falling have been identified, the role of foot problems has received relatively little attention in the literature. This article reviews the literature pertaining to the prevalence of foot problems in older people and discusses the relationship of foot problems to functional impairment and falls. In addition, a number of theoretical considerations regarding specific foot conditions and postural instability are outlined.

Accidental Falls↗

PubMed1998

Increased prevalence of fall risk factors in older people following hip fracture.

BACKGROUND: Many people who suffer a hip fracture do not achieve full functional recovery. Simple tests of physical function such as quadriceps strength and postural sway may provide insight into why this population is at increased risk of experiencing further falls and fractures and assist in developing rehabilitation strategies for preventing falls. OBJECTIVE: To determine whether impairments in a range of physiological measures and specific medical conditions are more prevalent in people who have suffered a fall-related hip fracture than in a matched sample of community-dwelling people without a history of falls. METHODS: This case-control study involved 88 older people. The hip fracture group comprised 44 persons aged 64-94 years, assessed on average 7 months following a fall-related hip fracture. An age- and sex-matched control group (older persons who had not fallen in a 12-month period before recruitment) was drawn randomly from community samples. RESULTS: Compared with the control group, the hip fracture group had markedly reduced quadriceps strength and increased body sway when tested on firm and compliant (foam rubber) surfaces. Patients in the hip fracture group also had higher prevalence rates of poor vision, arthritis and stroke, were taking more medications, were less physically active and perceived themselves to be at greater risk of falling than the control group. No significant differences were apparent for cardiovascular conditions, subjective health status and psychoactive medication use between the groups. Multivariate analyses identified quadriceps strength and body sway on the compliant surface as the most important variables for distinguishing between the hip fracture and no hip fracture groups. These two variables correctly classified 92% of the cases, with equal sensitivity and specificity. CONCLUSION: The findings identify an increased prevalence of certain physical fall risk factors among older persons who have suffered a hip fracture. Decreased quadriceps strength and increased postural sway are potentially modifiable. Intervention programs designed to improve performance on these variables among this population require investigation.

Accidental Falls↗

PubMed1997

Home exercise to improve strength and walking velocity after hip fracture: a randomized controlled trial.

OBJECTIVE: To determine the effect of a home exercise program on strength, postural control, and mobility following hip fracture. DESIGN: Randomized controlled trial of 1 month's duration. SETTING: Daily exercise carried out within the subjects' home environments. PARTICIPANTS: Forty-two people 64 to 94 years of age, 35 of whom were living independently in the community and 7 of whom were residing in institutional care. Subjects were recruited on average 7 months after a fall-related hip fracture and randomly allocated to either the intervention or the control group (n = 21 each). The groups were well matched in terms of medical conditions, medication use, disability, and activity levels. INTERVENTION: A "home-based" program of weight-bearing exercise established at a visit by a physiotherapist. MAIN OUTCOME MEASURES: Quadriceps strength, postural sway, functional reach, weight-bearing ability, walking velocity, and self-rated fall risk. The subjects undertook these assessments at the beginning and end of the trial. RESULTS: At pretest, exercisers and controls performed similarly in all tests. At the end of the trial, the intervention group showed significantly greater quadriceps strength in the affected (hip-fractured) leg and increased walking velocity. The intervention subjects also improved their weight-bearing ability and reported reduced subjective falls risk. In contrast, there were no significant improvements in any of the test measures in the controls. Within the intervention group, improvements in quadriceps strength were significantly associated with improved performances in the weight-bearing test measures and with increased walking velocity. CONCLUSIONS: This exercise program improved strength and mobility following hip fracture. Further research is needed to ascertain whether the extent of this improvement in these fall risk factors is sufficient to prevent falls.

Aged↗

PubMed1997

Strength in the lower limbs, visual contrast sensitivity, and simple reaction time predict cognition in older women.

The authors investigated the association between sensorimotor variables indicative of biological aging and cognition. A community sample of 202 women ages 60-86 was assessed on 5 measures of lower limb strength, visual contrast sensitivity (VisCS), and reaction time (RT). Hierarchical multiple regression revealed that the sensorimotor variables explained age-related variance in measures of reasoning and total variance in measures of reasoning after education, health, mood, and physical activity were controlled for. It is concluded that in addition to better known predictors of cognitive aging, such as RT and VisCS, lower limb strength is an important predictor of performance on cognitive tests.

Aged↗

PubMed1997

Effects of group exercise on cognitive functioning and mood in older women.

A randomised controlled trial was conducted to determine whether a 12-month program of group exercise had beneficial effects on physiological and cognitive functioning and mood in 187 older community-dwelling women. The exercisers (n = 94) and controls (n = 93) were well matched in terms of the test measures and a number of health and life-style assessments. The mean number of classes attended by the 71 exercise subjects who completed the program was 59.0 (range 26 to 82). At the end of the trial, the exercisers showed significant improvements in reaction time, strength, memory span and measures of wellbeing when compared with the controls. There was also an indication that anxiety had been reduced in the exercisers. Within the exercise group, improvements in memory span were associated with concomitant improvements in both reaction time and muscle strength. Also, within this group, initial mood measures were significantly inversely associated with improvements at retest, which suggests that the program may have normalised mood states in subjects who had high initial depression, anxiety and stress levels, rather than inducing improvements in all subjects. These findings suggest that group exercise has beneficial effects on physiological and cognitive functioning and wellbeing in older people.

Affect↗

PubMed1996

The effects of a community exercise program on fracture risk factors in older women.

One hundred and seventy-nine women aged 60-85 years (mean age 71.6 years, SD 5.3 years) were randomly recruited from the community to participate in a 12-month randomized controlled trial to determine whether a program of twice-weekly structured exercise has beneficial effects on three factors associated with osteoporotic fractures: quadriceps strength, postural sway and bone density. At initial testing, there were no significant differences in the strength, sway and bone density measures (assessed at the hip and lumbar spine) between the exerciser and control groups. The exercise classes included strengthening, coordination and balance exercises, and approximately 35 min of each class comprised weight-bearing exercise. The mean number of classes attended for the 68 exercisers who completed the program was 59.8 of the 82 classes (72.9%). At the completion of the trial, the intervention group showed significant improvements in quadriceps strength and sway but not bone mineral density when compared with the control group. Indices of fracture risk, indicated by (i) the sum of standard score results and (ii) the sum of quartile grades of the femoral neck bone density, sway and strength measures, decreased significantly in the exercisers at the end of the trial compared with the controls. In conclusion, the program of general aerobic exercise may have reduced overall fracture risk, even though it did not significantly increase bone density. Further long-term studies are required that include acceptable weight-loaded exercises to determine optimal programs for reducing fracture risk factors by improving bone density as well as strength and balance.

Activities of Daily Living↗

PubMed1996

Exercise effect on dynamic stability in older women: a randomized controlled trial.

OBJECTIVE: To determine whether a 12-month program of regular exercise can improve dynamic postural stability in older women. DESIGN: Randomized controlled trial of 12 months' duration. SETTING: Conducted as part of the Randwick Falls and Fractures Study, in Sydney, Australia. PARTICIPANTS: One hundred and twelve community-dwelling women aged 60 to 85 years (mean age 71.2, SD = 5.4). OUTCOME MEASURES: Quantitative measures of dynamic postural stability: maximal balance range and coordinated stability. MAIN RESULTS: Exercise and control subjects were tested before, midway through, and at the end of the trial. The stability measures had good test-retest reliability, and test performances were significantly associated with measures of lower limb muscle strength, reaction time, neuromuscular control, and body sway. At initial testing, exercisers and controls performed similarly in the two stability measures. The mean number of classes attended for the 48 exercise subjects who completed the program was 58.4 (range 26-77). At the end of the trial, the exercise subjects showed significantly improved performance in both the maximal balance range and coordinated stability tests, with no improvement evident in the controls. Improvements in coordinated stability were associated with corresponding improvements in ankle dorsiflexion, hip extension, and hip flexion strength. CONCLUSION: These findings show that exercise can significantly improve dynamic postural stability in older persons and elucidate some possible mechanisms by which such improvements may be mediated.

Accidental Falls↗

PubMed1996

Sensori-motor function, gait patterns and falls in community-dwelling women.

Tests of vision, vestibular function, peripheral sensation, strength, reaction time, balance and gait were administered to 183 community-dwelling women aged 22-99 years. Walking speed, stride length and cadence declined with age with corresponding increases in stance duration and percentage of the stride in the stance phase. Visual acuity and contrast sensitivity, tactile and vibration sense in the lower limb, vestibular function (as assessed by the vestibular X Writing Test), quadriceps and ankle dorsiflexion strength and reaction time were significantly associated with all five gait parameters. Postural sway measures were associated with walking speed, stride length and percentage of the stride in the stance phase. Multiple regression analyses revealed seven sensori-motor measures as significant predictors for one or more of the gait parameters: low contrast visual acuity, tactile sensitivity, vibration sense, vestibular X-test writing performance, quadriceps strength, reaction time and sway. Quadriceps strength was included as a predictor variable for every gait parameter and in each case had the strongest beta weight. Women who fell on two or more occasions in a one-year prospective period had significantly reduced and more variable cadence and significantly increased stance duration (measured in absolute terms and as a percentage of stride) than those who did not fall or fell on one occasion only. The study findings elucidate the relative importance of specific physiological systems in the maintenance of normal gait and identify temporal gait measures that are associated with falling in older people.

Accidental Falls↗

PubMed1996

The effect of exercise on gait patterns in older women: a randomized controlled trial.

BACKGROUND: This study was undertaken to determine (a) whether a program of regular exercise can improve gait patterns in older women, and (b) whether any such improvement in gait is mediated by increased lower limb muscle strength. METHOD: A 22-week randomized controlled trial of exercise was conducted as part of the Randwick Falls and Fractures Study in Sydney, Australia. Subjects were 160 women aged 60-83 years (Mean age 71.1, SD = 5.2) who were randomly recruited from the community. Exercise and control subjects were tested prior to and at the end of the trial. At initial testing, exercisers and controls performed similarly in the strength and gait parameters. They were well matched in terms of age and a number of health and life-style characteristics. RESULTS: At the end of the trial, the exercise subjects showed improved strength in five lower limb muscle groups, increased walking speed, cadence, stride length, and shorter stride times as indicated by both reduced swing and stance duration. There were no significant improvements in any of the strength or gait parameters in the controls. Within the exercise group, increased cadence was associated with improved ankle dorsiflexion strength, and increased stride length was associated with improved hip extension strength. Exercise subjects with initial slow walking speed showed greater changes in velocity, stride length, cadence, and stance duration than those with initial fast walking speed. CONCLUSION: These findings show that exercise can increase gait velocity and related parameters in older persons, and that part of this increase may be mediated by improved lower limb muscle strength.

Aged↗

PubMed1996

Shoe characteristics and balance in older women.

OBJECTIVE: To determine whether shoe characteristics affect balance in older women. DESIGN: Randomized order, cross-over, controlled comparison. SETTING: A retirement village. PARTICIPANTS: Thirty women aged 60 to 89 years (mean 78.7 SD = 8.5). Twenty-five subjects were hostel residents, and five were living independently in the community. OUTCOME MEASURES: Postural sway, maximal balance range, and co-ordinated stability. MAIN RESULTS: The subjects underwent assessments of static balance (body sway) and dynamic balance (maximal balance range and co-ordinated stability) under four conditions: (1) barefoot, (2) in standard low-heeled shoes (walking shoes), (3) in standard high-heeled shoes, and (4) in their own shoes. Manova analysis revealed a significant overall shoe condition effect -- subjects performed best in bare feet or low-heeled shoes and worst in high-heeled shoes. There were no significant differences between subjects with and without foot abnormalities in any of the balance measures or test conditions. CONCLUSION: These findings suggest that bare feet and walking shoes maximize balance, whereas high-heeled shoes constitute a needless balance hazard for older women.

Aged↗

PubMed1996

Simple physiological and clinical tests for the accurate prediction of falling in older people.

A 1-year prospective study was conducted in an intermediate care institution to determine whether a combined assessment of physiological and clinical measures discriminates between elderly fallers and elderly nonfallers. Seventy persons aged between 72 and 96 years (mean 85.6), who were generally independent in activities of daily living, took part in the study, and 66 were available to follow-up. In the follow-up year, 24 subjects experienced no falls, 20 subjects fell one time only and 22 residents fell on two or more occasions. Discriminant analysis identified reaction time, body sway, quadriceps strength, tactile sensitivity, gait impairment, cognitive impairment, psychoactive drug use and age as the variables that significantly discriminated between subjects who experienced falls and those who did not. This procedure correctly classified 86% of subjects into faller and nonfaller groups. These findings suggest that an assessment that combines physiological and clinical factors provides excellent discrimination between elderly fallers and nonfallers.

Accidental Falls↗