A randomized trial of weighted vest use in ambulatory older adults: strength, performance, and quality of life outcomes

Acute effects of axial loading on postural control during walking and turning in people with multiple sclerosis: A pilot study

BACKGROUND

Impaired sensory integration is heavily involved in gait control and accentuates fall risk in individuals with multiple sclerosis (MS). While axial loading has been found beneficial, little is known about the effect of non-specific axial loads on gait parameters and mobility tasks in those with MS.

RESEARCH QUESTION

What are the effects of non-specific axial loading via weighted vests on walking and turning in those with MS.

METHODS

Twelve participants with MS and eleven age- and gender-matched healthy controls participated in a cross-sectional study. All participants completed five trials of continuous walking with turns wearing weighted vests at 0%, 2%, 4%, 5%, and then 0% of their body weight. Gait parameters were measured using wireless inertial sensors. A 2 (group) x 5 (vest weight) multivariate analysis of variance (MANOVA) was performed to determine any significant differences between groups and across weighted vests for each gait variable. Post-hoc analysis and paired t-tests with corresponding effect sizes were also conducted.

RESULTS

A significant between groups main effect was found for group (F (6100) = 14.74, p = .000) in multiple gait parameters (p < 0.05), although no significant main effect was found for weighted vest. Within group analyses indicated significantly increased cadence and gait speed across varying weighted vests for both MS and control groups (p < 0 >05). Increased vest weight from 0%PRE to 2% also had large effect on shortening double support time and increasing stride length in the MS group.

SIGNIFICANCE

This study provided preliminary evidence that non-specific axial loads of varying weights appear to improve certain gait parameters. As such, this modality may offer mobility benefit and serve as an accessible home-based intervention alternative aimed at improving walking in individuals with MS.

Progressive resistance training in a post-acute, older, inpatient setting: A randomised controlled feasibility study

Objectives:

Progressive resistance training can successfully target functional decline in healthy older community-dwelling adults. There are concerns about the safety and acceptance of its use in frail older populations. The aim of this study was to evaluate the feasibility of using progressive resistance training in an older, post-acute, inpatient setting.

Methods:

A randomised controlled feasibility study was conducted. Appropriate older inpatients undergoing post-acute rehabilitation were recruited. Feasibility measures examined were safety, recruitment, outcome measurement, adherence and retention rates and satisfaction. A range of clinical measures were used to capture changes in body structure and function, activity and participation. Assessments were performed on admission to the study and six weeks later.

Results:

A sample of 33 patients were included and randomised to the treatment group (n=16) or the control group (n=17). There were no serious adverse events, adherence rates were 63% and retention rates were 82%. While both groups improved between time 1 and 2, there were no significant differences in clinical measures between the groups.

Conclusion:

Progressive resistance training is a safe and acceptable intervention for use with this population. Further work on the effectiveness of progressive resistance training in this setting is now required.

Combined effects of leg length discrepancy and the addition of distal mass on gait asymmetry

Asymmetries in gait often arise due to some form of physical impairment. For example, a leg length discrepancy (LLD) or the change of limb mass can result in asymmetric gait patterns. Although adding mass and LLD have been studied separately, this research studies how gait patterns change as a result of asymmetrically altering both leg length and mass at a leg's distal end. Spatio-temporal and kinetic gait measures are used to study the combined asymmetric effects of placing LLD and mass on the opposite and same side. There were statistically significant differences for the amount of mass and leg length added for all five parameters. Contrary to our hypothesis, there was no significant interaction between the amount of mass and leg length added. There were cases in all perturbations where a combination of mass and LLD make a gait parameter more symmetric than a single effect. These cases exhibit the potential for configurations with lower overall asymmetries even though each parameter has a slight asymmetry as opposed to driving one parameter to symmetry and other parameters to a larger asymmetry.

Exercise attenuates the major hallmarks of aging

Regular exercise has multi-system anti-aging effects. Here we summarize how exercise impacts the major hallmarks of aging. We propose that, besides searching for novel pharmaceutical targets of the aging process, more research efforts should be devoted to gaining insights into the molecular mediators of the benefits of exercise and to implement effective exercise interventions for elderly people.

Effect of physical activity, social support, and skills training on late-life emotional health: a systematic literature review and implications for public health research

PURPOSE

Given that emotional health is a critical component of healthy aging, we undertook a systematic literature review to assess whether current interventions can positively affect older adults' emotional health.

METHODS

A national panel of health services and mental health researchers guided the review. Eligibility criteria included community-dwelling older adult (aged ≥ 50 years) samples, reproducible interventions, and emotional health outcomes, which included multiple domains and both positive (well-being) and illness-related (anxiety) dimensions. This review focused on three types of interventions - physical activity, social support, and skills training - given their public health significance and large number of studies identified. Panel members evaluated the strength of evidence (quality and effectiveness).

RESULTS

In all, 292 articles met inclusion criteria. These included 83 exercise/physical activity, 25 social support, and 40 skills training interventions. For evidence rating, these 148 interventions were categorized into 64 pairings by intervention type and emotional health outcome, e.g., strength training targeting loneliness or social support to address mood. 83% of these pairings were rated at least fair quality. Expert panelists found sufficient evidence of effectiveness only for skills training interventions with health outcomes of decreasing anxiety and improving quality of life and self-efficacy. Due to limitations in reviewed studies, many intervention-outcome pairings yielded insufficient evidence.

CONCLUSION

Skills training interventions improved several aspects of emotional health in community-dwelling older adults, while the effects for other outcomes and interventions lacked clear evidence. We discuss the implications and challenges in moving forward in this important area.

Exercises including weight vests and a patient education program for women with osteopenia: a feasibility study of the OsteoACTIVE rehabilitation program

STUDY DESIGN

Prospective case series with 1-year follow-up.

OBJECTIVES

The primary aim was to describe the OsteoACTIVE rehabilitation program and evaluate its feasibility in terms of progression, adherence, and adverse events in patients with low bone mineral density (BMD) and a healed forearm fracture. The secondary aim was to assess changes in measures of function and quality of life.

BACKGROUND

Previous studies have shown benefits of weight-bearing activities, resistance exercises, and balance and coordination training for women with low BMD and older adults. However, no studies, to our knowledge, have described or examined a rehabilitation program combining the use of weight vests and patient education in patients with low BMD.

METHODS

Forty-two postmenopausal women with osteopenia and a healed forearm fracture attended the OsteoACTIVE program for 6 months (3 sessions of 60 minutes per week). Feasibility was assessed by documenting training progression (load and exercises), program adherence (aiming for greater than 80%), and adverse events (joint pain, muscle soreness, and falls). Secondary measures included quadriceps strength, BMD, dynamic balance, walking ability, and self-report functional outcome measures. All outcome measures were recorded preintervention (baseline), postintervention, and at 1-year follow-up.

RESULTS

Thirty-five women (83%) completed the 6-month program and 31 women (74%) attended all the follow-up measurement sessions. All participants progressed during the rehabilitation program for both load and type of exercises. Furthermore, 87% of the participants met the a priori goal of 80% adherence, and no participants reported adverse events. Improvements in quadriceps strength and BMD of the femoral trochanter were noted at the end of the 6-month training period (P<.05). At 1-year follow-up, there were significant improvements in quadriceps strength and dynamic balance compared to baseline (P<.05).

CONCLUSION

The OsteoACTIVE rehabilitation program was feasible and achieved progression of training level, had high adherence, and had no adverse events. Positive improvements were established in lower extremity function and femoral trochanter BMD. Clinical trial registered at ClinicalTrials.gov (NCT01357278).

LEVEL OF EVIDENCE

Therapy, level 4.

Effect of air-filled vest on exercise-heat strain when wearing ballistic protection

OBJECTIVES

The purpose was to determine if an air-filled vest worn under ballistic protection reduces physiological strain during exercise in the heat either while wearing a tactical military (TM) protective vest or a law enforcement (LE) concealable vest.

METHODS

Sixteen men (24.5±3.9 years; 179.5±5.6 cm; 84.6±12.3kg) performed either two or four trials of treadmill walking (1.34 m s(-1); 2% grade) over 120 min in a hot, dry environment (37°C, 30% relative humidity, wind speed 3.5 m s(-1)). Participants completed trials wearing a TM or LE, with either the air-filled vest (TMa; LEa) or no vest (TMc; LEc) in random order. During trials, participants wore Army Combat Uniform pants. Physiological variables measured every 5min included gastrointestinal temperature (T GI), mean skin temperature (T sk), and heart rate (HR). Sweat rate (SR) was calculated based on fluid intake and body mass measures.

RESULTS

In the tactical trial (TMa versus TMc), no differences in final T GI (38.2±0.4 versus 38.3±0.4°C), T sk (35.0±0.9 versus 35.0±1.0°C), HR (142±19 versus 143±23 bpm) existed (P>0.05). In the LE trials (LEa versus LEc), no differences in final T GI (38.0±0.4 versus 38.1±0.3°C), T sk (35.3±1.1 versus 35.6±0.9°C), HR (132±20 versus 135±20 bpm) existed (P>0.05). Despite slightly higher SR, there was no statistical difference in TM (1.15±1.13 versus 1.54±0.46 l h(-1); P=0.10) or in LE (1.39±0.52 versus 1.37±0.18 l h(-1); P=0.35) during trials.

CONCLUSION

When participants exercised with a TM or LE while wearing the air-filled vest, there were no thermoregulatory and physiological differences compared to control trials. In our testing conditions, the air-filled device had little effect on physiological responses during prolonged mild exercise in the heat.

Interventions to maintain mobility: What works?

Mobility, in broad terms, includes everything from the ability to move within your immediate environment (e.g., get out of bed) to the ability to drive across the country. Mobility is essential to maintaining independence and wellbeing, particularly for older adults. This is highlighted by the large number of interventions developed for older adults with the goal of maintaining such mobility. The current paper reviews the state of the science with respect to mobility interventions. Inclusion criteria for the review were: (1) articles must have been peer-reviewed; (2) interventions were evaluated in a randomized controlled trial (RCT); (3) studies included a mobility outcome such as lifespace, driving, or walking ability; (4) studies included a sample of healthy community-dwelling older adults (e.g., not investigations of disease conditions); and (5) studies must have reported enough empirical data and detail such that results could potentially be replicated. Three main types of interventions were identified: cognitive training, educational interventions, and exercise interventions. A detailed summary and evaluation of each type of intervention, and the current evidence regarding its effectiveness in maintaining mobility, are discussed. Several interventions show clear evidence of effectiveness, and thus are prime areas for translation of results to the older population. Needs and issues for future intervention research are also detailed.

Tai chi and postural stability in patients with Parkinson's disease

BACKGROUND

Patients with Parkinson's disease have substantially impaired balance, leading to diminished functional ability and an increased risk of falling. Although exercise is routinely encouraged by health care providers, few programs have been proven effective.

METHODS

We conducted a randomized, controlled trial to determine whether a tailored tai chi program could improve postural control in patients with idiopathic Parkinson's disease. We randomly assigned 195 patients with stage 1 to 4 disease on the Hoehn and Yahr staging scale (which ranges from 1 to 5, with higher stages indicating more severe disease) to one of three groups: tai chi, resistance training, or stretching. The patients participated in 60-minute exercise sessions twice weekly for 24 weeks. The primary outcomes were changes from baseline in the limits-of-stability test (maximum excursion and directional control; range, 0 to 100%). Secondary outcomes included measures of gait and strength, scores on functional-reach and timed up-and-go tests, motor scores on the Unified Parkinson's Disease Rating Scale, and number of falls.

RESULTS

The tai chi group performed consistently better than the resistance-training and stretching groups in maximum excursion (between-group difference in the change from baseline, 5.55 percentage points; 95% confidence interval [CI], 1.12 to 9.97; and 11.98 percentage points; 95% CI, 7.21 to 16.74, respectively) and in directional control (10.45 percentage points; 95% CI, 3.89 to 17.00; and 11.38 percentage points; 95% CI, 5.50 to 17.27, respectively). The tai chi group also performed better than the stretching group in all secondary outcomes and outperformed the resistance-training group in stride length and functional reach. Tai chi lowered the incidence of falls as compared with stretching but not as compared with resistance training. The effects of tai chi training were maintained at 3 months after the intervention. No serious adverse events were observed.

CONCLUSIONS

Tai chi training appears to reduce balance impairments in patients with mild-to-moderate Parkinson's disease, with additional benefits of improved functional capacity and reduced falls. (Funded by the National Institute of Neurological Disorders and Stroke; ClinicalTrials.gov number, NCT00611481.).

Exercise for improving balance in older people

BACKGROUND

In older adults, diminished balance is associated with reduced physical functioning and an increased risk of falling. This is an update of a Cochrane review first published in 2007.

OBJECTIVES

To examine the effects of exercise interventions on balance in older people, aged 60 and over, living in the community or in institutional care.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, CENTRAL (The Cochrane Library 2011, Issue 1), MEDLINE and EMBASE (to February 2011).

SELECTION CRITERIA

Randomised controlled studies testing the effects of exercise interventions on balance in older people. The primary outcomes of the review were clinical measures of balance.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently assessed risk of bias and extracted data from studies. Data were pooled where appropriate.

MAIN RESULTS

This update included 94 studies (62 new) with 9,917 participants. Most participants were women living in their own home.Most trials were judged at unclear risk of selection bias, generally reflecting inadequate reporting of the randomisation methods, but at high risk of performance bias relating to lack of participant blinding, which is largely unavoidable for these trials. Most studies only reported outcome up to the end of the exercise programme.There were eight categories of exercise programmes. These are listed below together with primary measures of balance for which there was some evidence of a statistically significant effect at the end of the exercise programme. Some trials tested more than one type of exercise. Crucially, the evidence for each outcome was generally from only a few of the trials for each exercise category. 1. Gait, balance, co-ordination and functional tasks (19 studies of which 10 provided primary outcome data): Timed Up & Go test (mean difference (MD) -0.82 s; 95% CI -1.56 to -0.08 s, 114 participants, 4 studies); walking speed (standardised mean difference (SMD) 0.43; 95% CI 0.11 to 0.75, 156 participants, 4 studies), and the Berg Balance Scale (MD 3.48 points; 95% CI 2.01 to 4.95 points, 145 participants, 4 studies).2. Strengthening exercise (including resistance or power training) (21 studies of which 11 provided primary outcome data): Timed Up & Go Test (MD -4.30 s; 95% CI -7.60 to -1.00 s, 71 participants, 3 studies); standing on one leg for as long as possible with eyes closed (MD 1.64 s; 95% CI 0.97 to 2.31 s, 120 participants, 3 studies); and walking speed (SMD 0.25; 95% CI 0.05 to 0.46, 375 participants, 8 studies).3. 3D (3 dimensional) exercise (including Tai Chi, qi gong, dance, yoga) (15 studies of which seven provided primary outcome data): Timed Up & Go Test (MD -1.30 s; 95% CI -2.40 to -0.20 s, 44 participants, 1 study); standing on one leg for as long as possible with eyes open (MD 9.60 s; 95% CI 6.64 to 12.56 s, 47 participants, 1 study), and with eyes closed (MD 2.21 s; 95% CI 0.69 to 3.73 s, 48 participants, 1 study); and the Berg Balance Scale (MD 1.06 points; 95% CI 0.37 to 1.76 points, 150 participants, 2 studies).4. General physical activity (walking) (seven studies of which five provided primary outcome data). 5. General physical activity (cycling) (one study which provided data for walking speed). 6. Computerised balance training using visual feedback (two studies, neither of which provided primary outcome data). 7. Vibration platform used as intervention (three studies of which one provided primary outcome data).8. Multiple exercise types (combinations of the above) (43 studies of which 29 provided data for one or more primary outcomes): Timed Up & Go Test (MD -1.63 s; 95% CI -2.28 to -0.98 s, 635 participants, 12 studies); standing on one leg for as long as possible with eyes open (MD 5.03 s; 95% CI 1.19 to 8.87 s, 545 participants, 9 studies), and with eyes closed ((MD 1.60 s; 95% CI -0.01 to 3.20 s, 176 participants, 2 studies); walking speed (SMD 0.04; 95% CI -0.10 to 0.17, 818 participants, 15 studies); and the Berg Balance Scale ((MD 1.84 points; 95% CI 0.71 to 2.97 points, 80 participants, 2 studies).Few adverse events were reported but most studies did not monitor or report adverse events.In general, the more effective programmes ran three times a week for three months and involved dynamic exercise in standing.

AUTHORS' CONCLUSIONS

There is weak evidence that some types of exercise (gait, balance, co-ordination and functional tasks; strengthening exercise; 3D exercise and multiple exercise types) are moderately effective, immediately post intervention, in improving clinical balance outcomes in older people. Such interventions are probably safe. There is either no or insufficient evidence to draw any conclusions for general physical activity (walking or cycling) and exercise involving computerised balance programmes or vibration plates. Further high methodological quality research using core outcome measures and adequate surveillance is required.

[Falls and osteoporotic fractures prevention units: proposed Osteoporosis, Falls and Fractures Group of the Spanish Society of Geriatrics and Gerontology]

Since forming the Osteoporosis, Falls and Fractures Group of the Spanish Society (GOCF) of Geriatrics and Gerontology (SEGG) a review was performed of the epidemiology of falls, along with a description of measures that have shown a degree of effectiveness in prevention. We also present the proposal of a common basic model of action in fall prevention units, mainly addressed to the community. Finally, a consensus model falls register is presented, common to community level and institutional areas, with the objective of being useful and easy to fill in at any care level.

One-leg standing test for elderly populations

BACKGROUND

The one-leg standing (OLS) test is one of the balance tests used to diagnose musculoskeletal ambulation disability symptom complex (MARS), a condition newly defined by three professional Japanese medical societies in 2006 to help identify the symptoms of motor organ deterioration and establish preventive strategies. Although many studies have used the OLS test, none has shown conclusively that the test can be used as a practical marker of frailty among elderly people, especially in community settings. Based on the type of epidemiological study -- i.e., descriptive epidemiology and analytical epidemiology (observational and intervention studies) -- we reviewed evidence on three fundamental issues related to the OLS test: (1) testing procedures and reference values; (2) the associations between the OLS time and negative events; (3) improvement of the OLS time by intervention. These issues are key to any discussion of whether the OLS test can be used as a practical marker for predicting frailty in community-dwelling elderly populations.

METHODS

Articles were collected from MEDLINE databases using the search terms "one- leg standing" and the other names included in the same category.

RESULTS

Because various procedures are used to carry out the OLS test, the measured values for the OLS time varied widely from study to study. Some observational studies showed that the OLS time is related to negative events such as falls, declines in activity of daily living, and other morbidity. OLS times could be improved by several interventions.

CONCLUSIONS

This review suggests that the OLS test can be a tool for predicting frailty in community-dwelling elderly populations. However, our review should be interpreted with caution because we did not confirm the evidence level of each of the studies we selected. Further research on this topic is needed.

WITHDRAWN: Interventions for preventing falls in elderly people

BACKGROUND

Approximately 30 per cent of people over 65 years of age and living in the community fall each year; the number is higher in institutions. Although less than one fall in 10 results in a fracture, a fifth of fall incidents require medical attention.

OBJECTIVES

To assess the effects of interventions designed to reduce the incidence of falls in elderly people (living in the community, or in institutional or hospital care).

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (January 2003), Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2003), MEDLINE (1966 to February 2003), EMBASE (1988 to 2003 Week 19), CINAHL (1982 to April 2003), The National Research Register, Issue 2, 2003, Current Controlled Trials (www.controlled-trials.com accessed 11 July 2003) and reference lists of articles. No language restrictions were applied. Further trials were identified by contact with researchers in the field.

SELECTION CRITERIA

Randomised trials of interventions designed to minimise the effect of, or exposure to, risk factors for falling in elderly people. Main outcomes of interest were the number of fallers, or falls. Trials reporting only intermediate outcomes were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Data were pooled using the fixed effect model where appropriate.

MAIN RESULTS

Sixty two trials involving 21,668 people were included.Interventions likely to be beneficial:Multidisciplinary, multifactorial, health/environmental risk factor screening/intervention programmes in the community both for an unselected population of older people (4 trials, 1651 participants, pooled RR 0.73, 95%CI 0.63 to 0.85), and for older people with a history of falling or selected because of known risk factors (5 trials, 1176 participants, pooled RR 0.86, 95%CI 0.76 to 0.98), and in residential care facilities (1 trial, 439 participants, cluster-adjusted incidence rate ratio 0.60, 95%CI 0.50 to 0.73) A programme of muscle strengthening and balance retraining, individually prescribed at home by a trained health professional (3 trials, 566 participants, pooled relative risk (RR) 0.80, 95% confidence interval (95%CI) 0.66 to 0.98) Home hazard assessment and modification that is professionally prescribed for older people with a history of falling (3 trials, 374 participants, RR 0.66, 95% CI 0.54 to 0.81) Withdrawal of psychotropic medication (1 trial, 93 participants, relative hazard 0.34, 95%CI 0.16 to 0.74) Cardiac pacing for fallers with cardioinhibitory carotid sinus hypersensitivity (1 trial, 175 participants, WMD -5.20, 95%CI -9.40 to -1.00) A 15 week Tai Chi group exercise intervention (1 trial, 200 participants, risk ratio 0.51, 95%CI 0.36 to 0.73). Interventions of unknown effectiveness:Group-delivered exercise interventions (9 trials, 1387 participants) Individual lower limb strength training (1 trial, 222 participants) Nutritional supplementation (1 trial, 46 participants) Vitamin D supplementation, with or without calcium (3 trials, 461 participants) Home hazard modification in association with advice on optimising medication (1 trial, 658 participants), or in association with an education package on exercise and reducing fall risk (1 trial, 3182 participants) Pharmacological therapy (raubasine-dihydroergocristine, 1 trial, 95 participants) Interventions using a cognitive/behavioural approach alone (2 trials, 145 participants) Home hazard modification for older people without a history of falling (1 trial, 530 participants) Hormone replacement therapy (1 trial, 116 participants) Correction of visual deficiency (1 trial, 276 participants).Interventions unlikely to be beneficial:Brisk walking in women with an upper limb fracture in the previous two years (1 trial, 165 participants).

AUTHORS' CONCLUSIONS

Interventions to prevent falls that are likely to be effective are now available; less is known about their effectiveness in preventing fall-related injuries. Costs per fall prevented have been established for four of the interventions and careful economic modelling in the context of the local healthcare system is important. Some potential interventions are of unknown effectiveness and further research is indicated.

Life satisfaction in a sample of empty-nest elderly: a survey in the rural area of a mountainous county in China

OBJECTIVE

To estimate the life satisfaction and its predictors between the empty-nest and not-empty-nest elderly.

METHODS

A semi-structured questionnaire including socio-demographic characteristics, physical health, and the Life Satisfaction Index (LSI), UCLA Loneliness Scale (UCLA-LS), and Geriatric Depression Scale (GDS) was administered to 275 empty-nest and 315 not-empty-nest rural elderly in a Chinese county. Linear regression analysis was used to examine the predictors of LSI score.

RESULTS

The empty-nest elderly had lower life satisfaction, lower income, poorer relationships with children, less social support, higher prevalence of chronic diseases, and more feelings of depression and loneliness compared to the not-empty-nest elderly. "Empty-nest status" was negatively related with life satisfaction. Depression was the strongest predictor of life satisfaction in both groups. The second strongest predictor was loneliness among the empty-nest group, while it was chronic diseases among the not-empty-nest group. Marital status and income were correlated with life satisfaction only among the empty-nest elderly.

CONCLUSIONS

The empty-nest elderly were likely to have mental health problems and to feel unsatisfied with their life. These findings also emphasize the importance of mental health as the determinant of life satisfaction among the empty-nest elderly.

Exercise for improving balance in older people

BACKGROUND

Diminished ability to maintain balance may be associated with an increased risk of falling. In older adults, falls commonly lead to injury, loss of independence, associated illness and early death. Although some exercise interventions with balance and muscle strengthening components have been shown to reduce falls it is not known which elements, or combination of elements, of exercise interventions are most effective for improving balance in older people.

OBJECTIVES

To present the best evidence for effectiveness of exercise interventions designed to improve balance in older people living in the community or in institutional care.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (Feb 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 1), MEDLINE (1966 to February 2006), EMBASE (1980 to February 2006), other databases and reference lists of articles. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised trials testing exercise interventions designed to improve balance in older people were included. We excluded trials of interventions targeting individuals with specific conditions in order not to broaden the scope of this review too widely. Trials were included where participants were randomised to receive the following: a single exercise intervention or a multiple exercise intervention and a control group (usual activities or attention or recreational activity). Trials comparing two or more exercise interventions and a control group were also included.

DATA COLLECTION AND ANALYSIS

Three pairs of members of the review team independently assessed trial quality and extracted data. For each trial, relative risk and 95% confidence intervals were calculated for dichotomous outcomes, and mean differences and 95% confidence intervals calculated for continuous outcomes. Where appropriate, results of comparable groups of trials were pooled and 95% confidence intervals calculated.

MAIN RESULTS

For the 34 included studies there were 2883 participants at entry. Statistically significant improvements in balance ability were observed for exercise interventions compared to usual activity. Interventions involving gait; balance; co-ordination and functional exercises; muscle strengthening; and multiple exercise types appear to have the greatest impact on indirect measures of balance. There was trend towards an improvement in balance with cycling on a static cycle. However, there was limited evidence that effects were long-lasting.

AUTHORS' CONCLUSIONS

Exercise appears to have statistically significant beneficial effects on balance ability in the short term but the strength of evidence contained within these trials is limited. Many of these mainly small studies demonstrated a range of methodological weaknesses. The failure across the included studies to apply a core set of standardised outcome measures to determine balance ability restricts the capacity to compare or pool different trials from which firm conclusions regarding efficacy can be made. Further standardisation in timing of outcome assessment is also required as is longer term follow-up of outcomes to determine any lasting effects.

Effects of exercise training with weighted vests on bone turnover and isokinetic strength in postmenopausal women

The effects of 12 wk of exercise training using weighted vests on bone turnover and isokinetic strength were evaluated in postmenopausal women randomly assigned as exercisers (EX; n = 9) or controls (CON; n = 7). Training included 3 multimodal exercise sessions per wk wearing weighted vests. The vest load was progressively increased each wk to a maximum of 15% of body weight. Bone turnover was determined from resting levels of serum osteocalcin and NTx. Knee and ankle strength were measured at 60 degrees/s and 180 degrees/s using an isokinetic dynamometer. After 12 wk, NTx decreased by 14.5% (P <or= .05) in EX, with no significant changes in osteocalcin. EX also showed a 40% (P <or= .05) improvement in ankle plantar-flexion strength at 60 degrees/s. Relative body fat significantly decreased and fat-free mass increased in EX. Exercise compliance was 80%. These findings support the use of progressive exercise training using weighted vests in postmenopausal women.

The links between health-related behaviors and life satisfaction in elderly individuals who prefer institutional living

Background

Life satisfaction among residents of institutions is becoming an important issue in a rapidly aging population. The aim of this cross-sectional study was to investigate the links between life satisfaction and health-related behaviors amongst functionally independent elderly people who prefer institutional living in İstanbul, Turkey.

Methods

The socio-demographic characteristics, health-related behaviors, leisure-time activities and fall histories of 133 residents of an institution in Istanbul were assessed by a structured questionnaire during face-to-face interviews. A validated life-satisfaction index questionnaire (LSI-A) was completed.

Results

The mean age of the study group was 73.9 ± 8.0 (range 60–90 years). Within the group, 22.6% had never married and 14.3% had university degrees. The majority (71.4%) were in the low income bracket. The overall mean LSI-A score was 20.3 ± 5.9. Participants who declared moderate/high income levels had a significantly higher mean LSI-A score than those in the low-income bracket (p = 0.009). Multivariate analysis of the data suggested that leisure-time activities and participation in regular physical activities are significant predictors of LSI-A scores (R²: 0.112; p = 0.005 and p = 0.02, respectively).

Conclusion

The findings imply that regular physical activity and leisure-time activities are significantly related to life satisfaction among residents in institutions. Participation in physical activity and leisure-time activity programs may help to improve the life satisfaction of elderly people living in institutions.

Reference values for the five-repetition sit-to-stand test: a descriptive meta-analysis of data from elders

This meta-analysis was conducted to generate normative values for the 5-repetition sit-to-stand (STS) test suitable for application to individuals at least 60 years of age. A thorough review of the literature yielded 13 papers (14 studies) relevant to this purpose. After the exclusion of potentially unrepresentative data, meta-analysis of these 13 papers indicated that judgments about normal performance should be based on age. Analysis demonstrated that individuals with times for 5 repetitions of this test exceeding the following can be considered to have worse than average performance: 11.4 sec (60 to 69 years), 12.6 sec. (70 to 79 years), and 14.8 sec. (80 to 89 years).

The effect of weighted vest walking on metabolic responses and ground reaction forces

PURPOSE

This study examined how oxygen consumption, relative exercise intensity, vertical ground reaction forces (VGRF), and loading rate (LR) were affected while using a weighted vest (WV) during treadmill walking.

METHODS

A sample of 10 (aged 23.4 +/- 1.7 yr) subjects performed a standardized walking test (4-min stages at 0.89, 1.12, 1.34, 1.56, and 1.79 m x s(-1)) on a treadmill under four weighted vest conditions (0, 10, 15, and 20% of body mass (BM)). Dependent variables included oxygen consumption (VO2), relative exercise intensity, first (F1) and second (F2) peaks of the VGRF curve, and LR.

RESULTS

Repeated-measures ANOVA revealed significant vest versus speed interaction for V O2 and relative exercise intensity. Follow-up contrasts showed significant vest effect differences between 0% BM and all other WV conditions, and between 10 and 20% BM at all speeds for V O2. Follow-up analysis of relative exercise intensity demonstrated no significant vest effect difference at slower speeds, but significant differences at higher speeds. A significant main effect for WV condition was found for F1, F2, and LR. Follow-up testing revealed F1 and F2 at 0% BM were significantly different than at 10, 15, and 20% BM. F1 and F2 at 10% BM were significantly different than 20% BM, whereas F1 at 15% BM was significantly different than at 20% BM. LR at 0% BM was significantly different than at 15 and 20% BM.

CONCLUSION

Using a weighted vest can increase the metabolic costs, relative exercise intensity, and loading of the skeletal system during walking.

Home-based resistance training improves femoral bone mineral density in women on hormone therapy

This study tested whether moderate resistance training would improve femoral bone mineral density (BMD) in long-term users of hormone therapy with low BMD. The study was a 2-year randomized, controlled, trial (RCT) of moderate resistance training of either the lower extremity or the upper extremity. Eighty-five women participated in a 6-month observation period. The setting was center-based and home-based training. The participants were 189 women aged 59-78 years, with total femur T-scores from -0.8 to -2.8 and on hormone therapy (HT) for a minimum of 2 years (mean 11.8 years); 153 completed the trial. Lower extremity training used weight belts (mean 7.8 kg) in step-ups and chair rises; upper extremity training used elastic bands and dumbbells. Measurements were BMD and body composition [dual-energy X-ray absorptiometry (DXA)], bone turnover markers. Total femoral BMD showed a downward trend during the observation period: 0.35%+/-0.18% (P=0.14). The response to training was similar in the upper and lower groups in the primary outcomes. At 2 years, total femoral BMD increased 1.5% (95% CI 0.8%-2.2%) in the lower group and 1.8% (95% CI 1.1%-2.5%) in the upper group. Trochanter BMD increased 2.4% (95% CI 1.3%-3.5%) in the lower group and 2.5% (95% CI 1.4%-3.6%) in the upper group (for both analyses time effect P<0.001). At 1 year, a bone resorption marker (C-telopeptide) decreased 9% (P=0.04). Bone formation markers, bone-specific alkaline phosphatase, decreased 5% (P<0.001), and N-terminal type I procollagen peptide decreased 7% (P=0.01). Body composition (percent lean and percent body fat) was maintained in both groups. We concluded that long-term moderate resistance training reversed bone loss, decreased bone turnover, increased femur BMD, and maintained body composition. The similarity of response in upper and lower groups supports a systemic response rather than a site-specific response to moderate resistance training.

Biomechanics of the heel-raise exercise

The purpose of this investigation was to determine whether increases in internal (muscular) demand would be proportional to increases in the external demand during heel-raise exercise. Seven male (mean age 74.9 +/- 4.8 years) and 9 female (mean age 74.4 +/- 5.1 years) older adults performed both double-leg heel raises and single-leg heel raises under 3 loading conditions (no external resistance and +5% and +10% of each participant's body weight). Kinematic and kinetic dependent variables were calculated using standard inverse-dynamics techniques. The results suggest that although the single-heel raise led to increases in peak net joint moments, power, and mechanical-energy expenditure (MEE), it did so at the expense of range of motion and angular velocity. In addition, increasing the external resistance by 5% of participants' body weight did not elicit significant changes in either the power or the MEE of the ankle joint. These effects should be considered when prescribing these exercises to older adults.

Evaluation of life satisfaction index of the elderly people living in nursing homes

The aim of our study was to evaluate the quality of life of the elderly living in nursing homes. A pool of 183 elderly people living in nursing homes were involved in the study. Data regarding the socio-demographic characteristics and life satisfaction index-A (LSI-A) of the participants were collected by means of a questionnaire during face-to-face interviews. The average LSI-A score of the whole group of participants was 25.26+/-5.51. When the mean LSI-A score of participants in relation to their independent variables was analyzed, no statistically significant differences were found for gender, socio-economic status or body mass indexes (BMI). However, the mean LSI-A score of those elderly people who spent some time in leisure activities was significantly higher than those who did not (p=0.03). In the stepwise linear regression analysis, the education level and place of residence were found to be the statistically significant independent predictors of LSI-A scores in the study group (p=0.05, p=0.001).

Lower-Extremity Kinetic Response to Weighted-Vest Resistance during Stepping Exercise in Older Adults

Stepping activities when wearing a weighted vest may enhance physical function in older persons. Using 3 weighted-vest resistance dosages, this study characterized the lower-extremity joint biomechanics associated with stepping activities in elders. Twenty healthy community-dwelling older adults, ages 74.5 ± 4.5 yrs, performed 3 trials of forward step-up and lateral step-up exercises while wearing a weighted vest which added 0% body weight (BW), 5% BW, or 10% BW. They performed these activities on a force platform while instrumented for biomechanical analysis. Repeated-measures ANOVA was used to evaluate the differences in ankle, knee, and hip maximum joint angles, peak net joint moments, joint powers, and impulses among both steping activities and the 3 loading conditions. Findings indicated that the 5% BW vest increased the kinetic output associated with the exercise activities at all three lower-extremity joints. These increases ranged from 5.9% for peak hip power to 12.5% for knee extensor impulse. The application of an additional 5% BW resistance did not affect peak joint moments or powers, but it did increase the joint impulses by 4–11%. Comparisons between exercise activities, across the 3 loading conditions, indicated that forward stepping preferentially targeted the hip extensors while lateral stepping targeted the plantar flexors; both activities equally targeted the knee extensors. Weighted-vest loads of 5% and 10% BW substantially increased the mechanical demand on the knee extensors, hip extensors (forward stepping), and ankle plantar flexors (lateral stepping).

Effects of long-term resistive training on mobility and strength in older adults with diabetes

BACKGROUND

Strength training has been shown to be beneficial in older adults. However, very little data exist on the effects of strength training in older diabetics.

METHODS

31 community-dwelling older adults with diabetes (mean age = 66.1 years) were randomly assigned to either an exercise (EX) or control (CO) group. The EX group trained the plantar flexors, knee extensors, knee flexors, hip extensors, and hip flexors muscle groups at 50%, 60%, and 70% of 1-repetition maximum, 2.6 days a week, for 24 months. Mobility tests included the timed up and go, 50-foot walk, and walking up and down 8 stairs. Strength and mobility for both groups were evaluated at 6-month intervals.

RESULTS

There was a group and time effect as the EX group increased 31.4% (p <.001) in strength for all muscle groups after the first 6 months of training, and the strength gains were retained for the duration of the training intervention. There was also a group and time effect for mobility as performance increased 8.6% and 9.8% (p =.032 and p = 0.031) for the first 6 and 12 months, respectively, but decreased to 4.6% above baseline at the end of the intervention. There were essentially no changes from baseline strength or mobility values for the CO group.

CONCLUSION

In conclusion, these data suggest that a moderate-intensity resistive-training program can improve mobility and strength for the duration of a 24-month intervention in older adults with diabetes, thus potentially reducing the rate of mobility loss during aging.

Benefits of exercise and dietary measures to optimize shifts in body composition with age

Ageing is associated with changes in body composition, including an increase and redistribution of adipose tissue and a decrease in muscle and bone mass, beginning as early as the fourth decade of life. These changes have significant implications for the health and functioning of the individual because of their associations with chronic disease expression and severity, as well as geriatric syndromes such as mobility impairment, falls, frailty and functional decline. Therefore, understanding the preventive and therapeutic options for optimizing body composition in old age is central to the care of patients in mid-life and beyond. Pharmacological interventions are currently available for maintaining or improving bone mass, and much current interest is focused on anabolic agents that will preserve or restore muscle mass, as well as those that can potentially limit adipose tissue deposition. However, in this brief review, non-pharmacological modulation of body composition through appropriate dietary intake and physical activity patterns, will be discussed. There is sufficient evidence currently to suggest that a substantial portion of what have been considered 'age-related' changes in muscle, fat and bone are in fact related either to excess energy consumption, decreased energy expenditure in physical activity, or both factors in combination. In addition, selective underconsumption of certain macro- or micronutrients contributes to losses of muscle and bone mass. Each of the three compartments will be considered in turn, with recommendations for optimizing the size of these body tissue stores in early adulthood, and minimizing undesirable changes typically seen in middle and old age.

Squatting exercises in older adults: kinematic and kinetic comparisons

PURPOSES

Squatting activities may be used, within exercise programs, to preserve physical function in older adults. This study characterized the lower-extremity peak joint angles, peak moments, powers, work, impulse, and muscle recruitment patterns (electromyographic; EMG) associated with two types of squatting activities in elders.

METHODS

Twenty-two healthy, older adults (ages 70-85) performed three trials each of: 1) a squat to a self-selected depth (normal squat; SQ) and 2) a squat onto a chair with a standardized height of 43.8 cm (chair squat; CSQ). Descending and ascending phase joint kinematics and kinetics were obtained using a motion analysis system and inverse dynamics techniques. Results were averaged across the three trials. A 2 x 2 (activity x phase) ANOVA with repeated measures was used to examine the biomechanical differences among the two activities and phases. EMG temporal characteristics were qualitatively examined.

RESULTS

CSQ generated greater hip flexion angles, peak moments, power, and work, whereas SQ generated greater knee and ankle flexion angles, peak moments, power, and work. SQ generated a greater knee extensor impulse, a greater plantar flexor impulse and a greater total support impulse. The EMG temporal patterns were consistent with the kinetic data.

CONCLUSIONS

The results suggest that, with older adults, CSQ places greater demand on the hip extensors, whereas SQ places greater demand on the knee extensors and ankle plantar flexors. Clinicians may use these discriminate findings to more effectively target specific lower-extremity muscle groups when prescribing exercise for older adults.

Lower-extremity biomechanics during forward and lateral stepping activities in older adults

OBJECTIVE

To characterize the lower-extremity biomechanics associated with stepping activities in older adults.

DESIGN

Repeated-measures comparison of kinematics and kinetics associated with forward step-up and lateral step-up activities.

BACKGROUND

Biomechanical analysis may be used to assess the effectiveness of various 'in-home activities' in targeting appropriate muscle groups and preserving functional strength and power in elders.

METHODS

Data were analyzed from 21 participants (mean 74.7 yr (standard deviation, 4.4 yr)) who performed the forward and lateral step-up activities while instrumented for biomechanical analysis. Motion analysis equipment, inverse dynamics equations, and repeated measures ANOVAs were used to contrast the maximum joint angles, peak net joint moments, angular impulse, work, and power associated with the activities.

RESULTS

The lateral step-up resulted in greater maximum knee flexion (P<0.001) and ankle dorsiflexion angles (P<0.01). Peak joint moments were similar between exercises. The forward step-up generated greater peak hip power (P<0.05) and total work (P<0.001); whereas, the lateral step-up generated greater impulse (P<0.05), work (P<0.01), and power (P<0.05) at the knee and ankle.

CONCLUSIONS

In older adults, the forward step-up places greater demand on the hip extensors, while lateral step-up places greater demand on the knee extensors and ankle plantar flexors.

RELEVANCE

Clinicians may use data from biomechanical analyses of in-home exercises to more effectively target specific lower-extremity muscle groups when prescribing exercise activities for older adults. The forward step-up is recommended for maintaining or improving hip extensor performance; whereas, the lateral step-up is recommended when targeting the knee extensors and ankle plantar flexors.

Effects of exercise on bone density, balance, and self-efficacy in older women

The effects of weighted vest walking and strength-training exercises on bone mineral density (BMD), balance, strength, and self-efficacy were tested in older women. Eighteen women, age 69.2 +/- 3.5 years, were randomly assigned to an exercise group (EG) (n = 9), or a sedentary control group (CG) (n = 9). The EG participated in 32 weeks (three 1-h sessions/week) of supervised strength training and walking, stair climbing, and balance exercises while wearing weighted vests. The CG did not exercise. All women took Ca2+ and vitamin D during the study period. Measures included 1) BMD of the hip and lumbar spine measured by dual-energy X-ray absorptiometry, 2) strength, 3) balance, and 4) scores on a self-efficacy instrument. The EG had significant improvements in bone density of the femoral neck and balance and a significant weight loss (P < 0.05). There were no changes in self-efficacy in either group.

Interventions for preventing falls in elderly people

BACKGROUND

Approximately 30 per cent of people over 65 years of age and living in the community fall each year; the number is higher in institutions. Although less than one fall in 10 results in a fracture, a fifth of fall incidents require medical attention.

OBJECTIVES

To assess the effects of interventions designed to reduce the incidence of falls in elderly people (living in the community, or in institutional or hospital care).

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Group specialised register (January 2003), Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2003), MEDLINE (1966 to February 2003), EMBASE (1988 to 2003 Week 19), CINAHL (1982 to April 2003), The National Research Register, Issue 2, 2003, Current Controlled Trials (www.controlled-trials.com accessed 11 July 2003) and reference lists of articles. No language restrictions were applied. Further trials were identified by contact with researchers in the field.

SELECTION CRITERIA

Randomised trials of interventions designed to minimise the effect of, or exposure to, risk factors for falling in elderly people. Main outcomes of interest were the number of fallers, or falls. Trials reporting only intermediate outcomes were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Data were pooled using the fixed effect model where appropriate.

MAIN RESULTS

Sixty two trials involving 21,668 people were included. Interventions likely to be beneficial: Multidisciplinary, multifactorial, health/environmental risk factor screening/intervention programmes in the community both for an unselected population of older people (4 trials, 1651 participants, pooled RR 0.73, 95%CI 0.63 to 0.85), and for older people with a history of falling or selected because of known risk factors (5 trials, 1176 participants, pooled RR 0.86, 95%CI 0.76 to 0.98), and in residential care facilities (1 trial, 439 participants, cluster-adjusted incidence rate ratio 0.60, 95%CI 0.50 to 0.73) A programme of muscle strengthening and balance retraining, individually prescribed at home by a trained health professional (3 trials, 566 participants, pooled relative risk (RR) 0.80, 95% confidence interval (95%CI) 0.66 to 0.98) Home hazard assessment and modification that is professionally prescribed for older people with a history of falling (3 trials, 374 participants, RR 0.66, 95% CI 0.54 to 0.81) Withdrawal of psychotropic medication (1 trial, 93 participants, relative hazard 0.34, 95%CI 0.16 to 0.74) Cardiac pacing for fallers with cardioinhibitory carotid sinus hypersensitivity (1 trial, 175 participants, WMD -5.20, 95%CI -9.40 to -1.00) A 15 week Tai Chi group exercise intervention (1 trial, 200 participants, risk ratio 0.51, 95%CI 0.36 to 0.73). Interventions of unknown effectiveness: Group-delivered exercise interventions (9 trials, 1387 participants) Individual lower limb strength training (1 trial, 222 participants) Nutritional supplementation (1 trial, 46 participants) Vitamin D supplementation, with or without calcium (3 trials, 461 participants) Home hazard modification in association with advice on optimising medication (1 trial, 658 participants), or in association with an education package on exercise and reducing fall risk (1 trial, 3182 participants) Pharmacological therapy (raubasine-dihydroergocristine, 1 trial, 95 participants) Interventions using a cognitive/behavioural approach alone (2 trials, 145 participants) Home hazard modification for older people without a history of falling (1 trial, 530 participants) Hormone replacement therapy (1 trial, 116 participants) Correction of visual deficiency (1 trial, 276 participants). Interventions unlikely to be beneficial: Brisk walking in women with an upper limb fracture in the previous two years (1 trial, 165 participants).

REVIEWER'S CONCLUSIONS

Interventions to prevent falls that are likely to be effective are now available; less is known about their effectiveness in preventing fall-related injuries. Costs per fall prevented have been established for four of the interventions and careful economic modelling in the context of the local healthcare system is important. Some potential interventions are of unknown effectiveness and further research is indicated.

Measuring Lower Extremity Strength in Older Adults: The Stability of Isokinetic versus 1RM Measures

In order to obtain joint-specific baseline strength characteristics in older adults, clinicians and researchers must have knowledge regarding the relative stability of the various strength tests (the strength difference between repeated measures) and the number of prebaseline practice sessions required to obtain consistent data. To address these needs, the relative multiple-test stability and reliability associated with lower extremity isokinetic and 1-repetition-maximum (1RM) strength measures were assessed in a sample of older adults (N= 30, 65.2 ± 6.3 years), over 4 weeks (T1-T4). Isokinetic ankle plantar-flexion (30°/s) strength and 1RM ankle plantar-flexion, leg-press, and knee-flexion strength exhibited poor stability between Weeks T1 and T2 but stabilized between Weeks T2 and T3 and Weeks T3 and T4. The measures exhibited low incidence of injury and induced low levels of residual muscle soreness. Findings suggest that the 1RM measures require at least 1 prebaseline training session in order to establish consistent baseline performance and are more reliable than isokinetic ankle plantar-flexion tests.

Exercise dose-response effects on quality of life and independent living in older adults

PURPOSE

The purpose of this study was to determine if exercise operates in a dose-response fashion to influence well-being and to postpone dependency.

METHODS

A computer-assisted search was made by using the following key words: resistance training, strength training, function, exercise, elderly, quality of life, frailty, physical activity, independence, performance, aerobic training, mobility, well-being, and disability. Review articles and personal files were also used, and a critical review of research studies meeting the criteria described in the methods section of the article was conducted.

RESULTS

In large sample correlational studies and prospective longitudinal studies, researchers consistently report that measures of physical function in old adults are related to feelings of well-being, and that old adults who are physically active also report higher levels of well-being and physical function, but the results of randomized intervention studies of aerobic and/or resistive strength training do not always support this relationship. Even if changes in well-being and physical function were reported, no evidence was found that levels of intensity operated in a dose-response fashion to influence these changes. Research design problems included ineffective aerobic or strength training treatments, widely varying participation and effort of the research participants, and both treatment and physical function tests that were not appropriate for the physical status of the participants.

CONCLUSION

The most consistent results were that long-term physical activity is related to postponed disability and independent living in the oldest-old subjects. Even in individuals with chronic disease, systematic participation in physical activities enhances physical function.

Lower-Extremity Kinetic Response to Activity Program Dosing in Older Adults

The purpose of this investigation was to determine the effects of two doses of a weighted vest on acute lower-extremity gait kinetics in older adults. Peak ankle, knee, and hip net joint moments were quantified in 56 men and women volunteers (73.8 ± 6.9 years old) enrolled in a 6-month physical activity study. At the initial study visit, participants underwent 6 walking trials (3 with vest, 3 without vest) at their normal pace. During the vest-wearing trials, participants wore a vest loaded with either 0% of body weight (BW) (n= 19), 3% of BW (n= 16), or 5% of BW (n= 21). With acute application of the vests, maximum peak plantarflexion moments increased by 5.7% in the 5% BW group compared to the 0% BW group,p< 0.01. Compared to the 0% vest-weight group, knee extension moments increased by 13.8% when 5% BW was applied,p< 0.01; a marginally significant treatment effect was evident in the 3% BW group,p= 0.04. Despite these acute alterations, knee strength and physical performance did not improve when subjects wore the vests 2 hours a day, 4 days a week for 27 weeks, without additional exercise prescription. These findings suggest that: (a) the acute changes in vest-mediated lower-extremity kinetics are not systemic but joint specific and load dependent, and (b) weighted vest prescription should be greater than 5% BW without prescribed exercise, or should include prescribed exercises, to invoke long-term strength and physical performance gains in older adults.

Knee strength and lower- and higher-intensity functional performance in older adults

PURPOSE

This study characterizes the linear relations among knee strength, work capacity, and lower- and higher-intensity measures of functional performance in ambulatory, high-functioning older adults.

METHODS

Sixty-two seniors (average age = 73.4 +/- 7.3 yr) participated in the study. Isokinetic measures included the peak flexion/extension torque produced during five continuous repetitions and the total flexion/extension work performed during 20 repetitions (60 degrees x s(-1)). Functional measures included lower-intensity tests (timed 8-foot and 50-foot walking tests at the participants' "normal" pace, and a standing reach task) and higher-intensity tests (a timed 50-foot "brisk" walk, timed chair stands, and a timed stair climb).

RESULTS

Isokinetic strength and work capacity measures explained between 41% and 54% of the variance in the higher-intensity functional models and only between 31% and 33% of the variance in the lower-intensity models. The strength of the associations, approximated by the beta coefficients of the strength and work terms, was also greater for the higher-intensity functional tasks.

CONCLUSIONS

Further research is warranted to determine whether exercises that increase knee strength and work capacity, improve brisk walking, stair climbing, and chair standing capabilities in older adults.