Functional performance differences between the Genium and C-Leg prosthetic knees and intact knees

Microprocessor prosthetic knees (MPKs) have advanced technologically, offering new features to decrease impairment and activity limitations for persons with transfemoral amputation (TFA). The Genium knee is functionally untested, and functional differences between it and intact knees are unknown. This study sought to determine whether Genium use improves functional performance compared with the C-Leg. A randomized experimental crossover design was used, with a cross-section of five nonamputee controls for comparison to normal. Twenty community-ambulating persons with TFA were trained and tested for accommodation with study components. All subjects (n = 25) were assessed using the Continuous-Scale Physical Functional Performance-10 (CS-PFP10) assessment. Subjects with TFA used both MPK systems. Genium use improved upper-body flexibility, balance, and endurance domain scores (7.0%-8.4%, p </= 0.05) compared with the C-Leg. Only in the endurance domain did Genium users score significantly lower than nonamputees (22.4%, p = 0.05). Comparing the C-Leg with nonamputees, CS-PFP10 total (2.0%-24.4%, p = 0.03) and all domains except upper-body strength were lower than nonamputees (-13.4% to -28.9%, p </= 0.05). Nonetheless, regardless of knee condition, subjects with TFAs did not equal or surpass nonamputees in any functional domain, suggesting room for improvements in TFA functional performance.

CONCURRENT VALIDITY OF THE CONTINUOUS SCALE-PHYSICAL FUNCTIONAL PEFORMANCE-10 (CS-PFP-10) TEST IN TRANSFEMORAL AMPUTEES

The Continuous Scale-Physical Functional Performance-10 (CS-PFP-10) test consists of 10 standardized daily living tasks that evaluate overall physical functional performance and performance in five individual functional domains: upper body strength (UBS), upper body flexibility (UBF), lower body strength (LBS), balance and coordination (BAL), and endurance (END). This study sought to determine the concurrent validity of the CS-PFP-10 test and its functional domains that involve the lower extremities (LBS, BAL, or END) in comparison to measures that have established validity for use in persons with transfemoral amputation (TFA). Ten TFA patients functioning at K3 or higher (Medicare Functional Classification Level) completed the study. Participants were assessed performing the CS-PFP-10, Amputee Mobility Predictor (AMP), 75 m self-selected walking speed (75 m SSWS) test, timed down stair walking (DN stair time), and the limits of stability (LOS) balance test. Concurrent validity was assessed using correlation analysis. The AMP, 75 m SSWS, LOS, and the DN stair time tests were strongly correlated (r = ± 0.76 to 0.86) with their paired CS-PFP-10 domain score (LBS, BAL, or END) and CS-PFP-10 total score. These findings indicate that the lower limb and balance domains of the CS-PFP-10 are valid measures to assess the physical functional performance of TFA patients.

Vitamin D status is associated with grip strength in centenarians

Low serum concentrations of 25-hydroxyvitamin D (25(OH)D) have been associated with poor physical function in older adults, but few, if any, studies have examined this relationship in the very old. Therefore, the purpose of this study is to examine this relationship in the very old. Serum 25(OH)D concentrations were obtained from 194 centenarians and near centenarians (98 years and older). The associations between 25(OH)D concentrations and measures of physical function were evaluated with unadjusted and adjusted regression models. We found that 35% of centenarians had 25(OH)D concentrations less than 50 nmol/L. Adjusted mean grip strength was lower for centenarians with 25(OH)D concentrations less than 75 nmol/L than for centenarians with higher concentrations (P<0.05). However, there were no differences in the Georgia Centenarian Study (GCS) Composite Scale, a global measure of physical function, between those with higher and lower 25(OH)D concentrations. We conclude that low 25(OH)D concentrations are associated with poor grip strength, but not GCS Composite Scale, in the very old. Considering the high burden of poor physical function in older adults, understanding the relationship between vitamin D and different measures of physical function, including strength, becomes increasingly important.

Effects of testosterone and progressive resistance exercise in healthy, highly functioning older men with low-normal testosterone levels

CONTEXT

Aging in men is associated with reduced testosterone (T) levels and physiological changes leading to frailty, but the benefits of T supplementation are inconclusive.

OBJECTIVE

We studied the effects of T supplementation with and without progressive resistance training (PRT) on functional performance, strength, and body composition.

DESIGN, SETTING, AND PARTICIPANTS

We recruited 167 generally healthy community-dwelling older men (66 ± 5 years) with low-normal baseline total T levels (200-350 ng/dL).

INTERVENTION

Subjects were randomized to placebo or transdermal T gel [2 doses targeting either a lower (400-550 ng/dL) or higher (600-1000 ng/dL) T range] and to either PRT or no exercise for 12 months.

MAIN OUTCOME MEASURE

The primary outcome was functional performance, whereas secondary outcomes were strength and body composition.

RESULTS

A total of 143 men completed the study. At 12 months, total T was 528 ± 287 ng/dL in subjects receiving any T and 287 ± 65 ng/dL in the placebo group. In the PRT group, function and strength were not different between T- and placebo-treated subjects, despite greater improvements in fat mass (P = .04) and fat-free mass (P = .01) with T. In the non-PRT group, T did not improve function but improved fat mass (P = .005), fat-free mass (P = .03), and upper body strength (P = .03) compared with placebo. There were fewer cardiovascular events in the T-treated groups compared with placebo.

CONCLUSIONS

T supplementation was well tolerated and improved body composition but had no effect on functional performance. T supplementation improved upper body strength only in nonexercisers compared with placebo.

Elevated energy coupling and aerobic capacity improves exercise performance in endurance-trained elderly subjects

Increased maximal oxygen uptake (V(O(2)max)), mitochondrial capacity and energy coupling efficiency are reported after endurance training (ET) in adult subjects. Here we test whether leg exercise performance (power output of the legs, P(max), at V(O(2)max)) reflects these improvements with ET in the elderly. Fifteen male and female subjects were endurance trained for a 6 month programme, with 13 subjects (69.5 ± 1.2 years old, range 65-80 years old; n = 7 males; n = 6 females) completing the study. This training significantly improved P(max) (Δ17%; P = 0.003), V(O(2)max) (Δ5.4%; P = 0.021) and the increment in oxygen uptake (V(O(2))) above resting (ΔV(O(2)m-r) = V(O(2)max) - V(O(2)rest; Δ9%; P < 0.02). In addition, evidence of improved energy coupling came from elevated leg power output per unit V(O(2))at the aerobic capacity [Δ(P(max)/ΔV(O(2)m-r)); P = 0.02] and during submaximal exercise in the ramp test as measured by delta efficiency (ΔP(ex)/ΔV(O(2)); P = 0.04). No change was found in blood lactate, muscle glycolysis or fibre type. The rise in P(max) paralleled the improvement in muscle oxidative phosphorylation capacity (ATP(max)) in these subjects. In addition, the greater exercise energy coupling [Δ(P(max)/ΔV(O(2)m-r)) and delta efficiency] was accompanied by increased mitochondrial energy coupling as measured by elevated ATP production per unit mitochondrial content in these subjects. These results suggest that leg exercise performance benefits from elevations in energy coupling and oxidative phosphorylation capacity at both the whole-body and muscle levels that accompany endurance training in the elderly.

Exercise efficiency is reduced by mitochondrial uncoupling in the elderly

A reduction in exercise efficiency accompanies ageing in humans. Here we evaluated the impact of changes in the contractile-coupling and mitochondrial-coupling efficiencies on the reduction in exercise efficiency in the elderly. Nine adult (mean, 38.8 years old) and 40 elderly subjects (mean, 68.8 years old) performed a cycle ergometer test to measure O2 uptake and leg power output up to the aerobic limit ( ). Reduced leg power output per unit O2 uptake was reflected in a drop in delta efficiency (εD) from 0.27 ± 0.01 (mean ± SEM) in adults to 0.22 ± 0.01 in the elderly group. Similar declines with age were apparent for both the leg power output at and the ATP generation capacity (ATPmax) determined in vivo using (31)P magnetic resonance spectroscopy. These similar declines resulted in unchanged contractile-coupling efficiency values (εC) in the adult (0.50 ± 0.05) versus the elderly group (0.58 ± 0.04) and agreed with independent measures of muscle contractile-coupling efficiency in human quadriceps (0.5). The mitochondrial-coupling efficiency calculated from the ratio of delta to contractile-coupling efficiencies in the adults (εD/εC = 0.58 ± 0.08) corresponded to values for well-coupled mitochondria (0.6); however, εD/εC was significantly lower in the elderly subjects (0.44 ± 0.03). Conversion of ATPmax per mitochondrial volume (ATPmax/Vv[mt,f]) reported in these groups into thermodynamic units confirmed this drop in mitochondrial-coupling efficiency from 0.57 ± 0.08 in adults to 0.41 ± 0.03 in elderly subjects. Thus, two independent methods revealed that reduced mitochondrial-coupling efficiency was a key part of the drop in exercise efficiency in these elderly subjects and may be an important part of the loss of exercise performance with age.

A combined aerobic and resistance exercise program improves physical functional performance in patients with heart failure: a pilot study

BACKGROUND

Recent guidelines for exercise in patients with heart failure (HF) recommended aerobic and resistance exercise as being safe and effective; however, the clinical and functional significance of these combined training modalities has not been established. In this pilot study, combined aerobic and resistance training was hypothesized to improve physical function, muscle strength, and health-related quality of life (HRQOL) compared with an attention control wait list (ACWL).

METHODS

The 10-item Continuous Scale Physical Functional Performance Test (CS-PFP10), which simulates common household chores; muscle strength (handgrip and knee extension); and HRQOL (Kansas City Cardiomyopathy Questionnaire) were evaluated at baseline (T1) and at 12 weeks (T2). The home-based moderate-intensity walking and resistance training program was performed 5 days a week.

RESULTS

Twenty-four New York Heart Association class II to III HF patients (mean [SD] age, 60 [10] years; mean [SD] left ventricular ejection fraction, 25% [9%]) were randomized to a combined aerobic and resistance exercise program or to an ACWL group. Of the total group, 58% were New York Heart Association class III HF patients, 50% were white, and 50% were female. The CS-PFP10 total scores were significantly increased in the exercise group, from 45 (18) to 56 (16). The Kansas City Cardiomyopathy Questionnaire overall summary score was significantly improved (P < .001) at T2 in the exercise intervention group compared with the ACWL group.

CONCLUSIONS

Participants provided the home-based, combined aerobic and resistance exercise program had significantly improved physical function, muscle strength, symptom severity, and HRQOL compared with the ACWL group. The findings of this study must be interpreted cautiously owing to the limitations of a small sample, data collection from a single center, and differences between control and interventions groups at baseline. A combined aerobic and resistance exercise approach may improve physical function in stable HF patients, but further study in a larger, more diverse population is recommended. However, in this study, the CS-PFP10 instrument demonstrated its ability to identify functional health status in HF patients and thus warrants further testing in a larger sample for possible use in clinical practice.

Combined aerobic and resistance exercise program improves task performance in patients with heart failure

OBJECTIVES

To assess the effects of a home-based aerobic and resistance training program on the physical function of adults with New York Heart Association (NYHA) class II and III patients and systolic heart failure (HF).

DESIGN

Randomized controlled trial.

SETTING

Home based.

PARTICIPANTS

Stable patients (N=24; mean age, 60 ± 10 y; left ventricular ejection fraction, 25% ± 9%; 50% white; 50% women) with New York Heart Association (NYHA) classes II and III (NYHA class III, 58%) systolic heart failure (HF).

INTERVENTION

A 12-week progressive home-based program of moderate-intensity aerobic and resistance exercise. Attention control wait list participants performed light stretching and flexibility exercises.

MAIN OUTCOME MEASURES

A 10-item performance-based physical function measure, the Continuous Scale Physical Functional Performance test (CS-PFP10), was the major outcome variable and included specific physical activities measured in time to complete a task, weight carried during a task, and distance walked. Other measures included muscle strength, HRQOL (Minnesota Living With Heart Failure Questionnaire, Epworth Sleepiness Scale), functional capacity (Duke Activity Status Index), and disease severity (brain natriuretic peptide) levels.

RESULTS

After the exercise intervention, 9 of 10 specific task activities were performed more rapidly, with increased weight carried by exercise participants compared with the attention control wait list group. Exercise participants also showed significant improvements in CS-PFP10 total score (P<.025), upper and lower muscle strength, and HRQOL (P<.001) compared with the attention control wait list group. Adherence rates were 83% and 99% for the aerobic and resistance training, respectively.

CONCLUSIONS

Patients with stable HF who participate in a moderate-intensity combined aerobic and resistance exercise program may improve performance of routine physical activities of daily living by using a home-based exercise approach. Performance-based measures such as the CS-PFP10 may provide additional insights into physical function in patients with HF that more commonly used exercise tests may not identify. Early detection of subtle changes that may signal declining physical function that are amenable to intervention potentially may slow further loss of function in this patient population.

Living environment and mobility of older adults

BACKGROUND

Older adults often elect to move into smaller living environments. Smaller living space and the addition of services provided by a retirement community (RC) may make living easier for the individual, but it may also reduce the amount of daily physical activity and ultimately reduce functional ability.

OBJECTIVE

With home size as an independent variable, the primary purpose of this study was to evaluate daily physical activity and physical function of community dwellers (CD; n = 31) as compared to residents of an RC (n = 30).

METHODS

In this cross-sectional study design, assessments included: the Continuous Scale Physical Functional Performance - 10 test, with a possible range of 0-100, higher scores reflecting better function; Step Activity Monitor (StepWatch 3.1); a physical activity questionnaire, the area of the home (in square meters). Groups were compared by one-way ANOVA. A general linear regression model was used to predict the number of steps per day at home. The level of significance was p < 0.05.

RESULTS

Of the 61 volunteers (mean age: 79 ± 6.3 years; range: 65-94 years), the RC living space (68 ± 37.7 m(2)) was 62% smaller than the CD living space (182.8 ± 77.9 m(2); p = 0.001). After correcting for age, the RC took fewer total steps per day excluding exercise (p = 0.03) and had lower function (p = 0.005) than the CD.

CONCLUSION

On average, RC residents take 3,000 steps less per day and have approximately 60% of the living space of a CD. Home size and physical function were primary predictors of the number of steps taken at home, as found using a general linear regression analysis.

Continuous scale physical functional performance test: appropriateness for middle-aged adults with and without Parkinson's disease

PURPOSE

Functional measures are needed that are applicable to middle-aged adults with neurological disorders who are on the threshold of disability. One potential measure is the Continuous Scale Physical Functional Performance Test (CS-PFP), which has been normalized and validated to older adults but performance is unknown for adults younger than the age of 65 years with and without neurological disorders. The purposes of this investigation were (1) to compare scores on the CS-PFP of nondisabled adults in three age groups from 35 to 64 years with two groups of individuals older than the age of 65; (2) to determine whether there is a ceiling effect for nondisabled middle-aged adults; and (3) to determine whether performance of individuals in early stages of Parkinson's disease (PD) age 45 to 64 years differ significantly from performance of similarly aged nondisabled adults.

METHODS

Data were obtained from three samples: (1) 37 adults with PD (45-54 and 55-64 years; 57% female), (2) 70 nondisabled adults (35-44, 45-54, and 55-64 years; 69% female); (3) 72 nondisabled older adults (65-74 and 75-85 years; 79% female). The CS-PFP was administered in a single test session for each subject. Analysis of variance was performed for group differences with adjustment of sex as a covariate followed by a Student-Newman-Keuls post hoc analysis.

RESULTS

For nondisabled individuals, the CS-PFP total and domain scores were significantly lower in the oldest group (75-85 years) compared to all other age groups and significantly higher in the younger two groups (35-44 and 45-54 years) compared to the older groups. There was no ceiling effect for any domain score or total score for the adults younger than 65 years. For individuals with PD, both age groups had significantly lower scores on the CS-PFP than did the nondisabled counterparts.

CONCLUSIONS

Results from the nondisabled middle-aged individuals provide comparison data to be used clinically or in investigations of middle-aged adults with neurological dysfunction. Comparison of middle-aged individuals with PD to middle-aged nondisabled adults illustrates the true extent of functional difficulty experienced by individuals with PD and demonstrates the importance of using age appropriate comparison data. The CS-PFP is particularly applicable to middle-aged adults with compromised functional performance for their age but is too high to be effectively quantified with other assessment measures.

Aerobic reserve and physical functional performance in older adults

BACKGROUND

older adults can be limited in their performance of daily tasks due to an inadequate aerobic capacity. Aerobic capacity below minimum physiological thresholds required to maintain independence leaves older adults with little, or no, aerobic reserve.

OBJECTIVE

the aim of this study was to measure functional performance and aerobic reserve in older adults during the serial performance of daily tasks.

SUBJECTS

twenty-nine (n = 29) men and women (n = 23 females) 70-92 years of age participated in this study.

METHODS

performance based physical function was assessed using the Continuous-Scale Physical Functional Performance test (CS-PFP). A Cosmed K4b(2) portable metabolic system was used to measure VO(2PEAK) and oxygen uptake during the serial performance of a battery of daily tasks (VO(2PFP)). Aerobic reserve was calculated as the difference between VO(2PEAK) and VO(2PFP).

RESULTS

the correlation coefficient between aerobic reserve and functional performance was r = 0.50(P = 0.006). Participants utilized 32.2 +/- 8.1%, 42.7 +/- 10.8%, and 50.3 +/- 12.3% of VO(2PEAK) for the low, moderate, and high workloads of the CS-PFP, respectively.

CONCLUSIONS

light housework and carrying groceries require 40 to 50% of peak oxygen consumption. This information can be used by clinicians and health professionals working with older adults as a guide to how much aerobic fitness is needed to perform ADLs and maintain independence. These can then be used as guides for assessment and for setting training goals in older adults.

A comparison of physical functional performance and strength in women with fibromyalgia, age- and weight-matched controls, and older women who are healthy

BACKGROUND AND PURPOSE

The purpose of this study was to compare functionality and strength among women with fibromyalgia (FM), women without FM, and older women.

SUBJECTS

Twenty-nine women with FM (age [X+/-SD]=46+/-7 years), 12 age- and weight-matched women without FM (age=44+/-8 years), and 38 older women who were healthy (age=71+/-7 years) participated.

METHODS

The Continuous Scale-Physical Functional Performance Test (CS-PFP) was used to assess functionality. Isokinetic leg strength was measured at 60 degrees/s, and handgrip strength was measured using a handgrip dynamometer.

RESULTS

The women without FM had significantly higher functionality scores compared with women with FM and older women. There were no differences in functionality between women with FM and older women. Strength measures for the leg were higher in women without FM compared with women with FM and older women, and both women with and without FM had higher grip strengths compared with older women.

DISCUSSION AND CONCLUSION

This study demonstrated that women with FM and older women who are healthy have similar lower-body strength and functionality, potentially enhancing the risk for premature age-associated disability.

Best practices for physical activity programs and behavior counseling in older adult populations

Physical activity offers one of the greatest opportunities for people to extend years of active independent life and reduce functional limitations. The article identifies key practices for promoting physical activity in older adults, with a focus on those with chronic disease or low fitness and those with low levels of physical activity. Key practices identified: (a) A multidimensional activity program that includes endurance, strength, balance, and flexibility training is optimal for health and functional benefits; (b) principles of behavior change including social support, self-efficacy, active choices, health contracts, assurances of safety, and positive reinforcement enhance adherence; (c) manage risk by beginning at low intensity but gradually increasing to moderate physical activity, which has a better risk:benefit ratio and should be the goal for older adults; (d) an emergency procedure plan is prudent for community-based programs; and (e) monitoring aerobic intensity is important for progression and motivation. Selected content review of physical activity programming from major organizations and institutions is provided.

Continuous-scale physical functional performance test: validity, reliability, and sensitivity of data for the short version

BACKGROUND AND PURPOSE

The Continuous-Scale Physical Functional Performance Test (CS-PFP) can be used to obtain valid, reliable, and sensitive measurements of physical functional capacity. This test requires a fixed laboratory space and approximately 1 hour to administer. This study was carried out in 4 steps, or substudies, to develop and validate a short, community-based version (PFP-10) that requires less space and equipment than the CS-PFP.

SUBJECTS AND METHODS

Retrospective data (n=228) and prospective data (n=91) on men and women performing the CS-PFP or the PFP-10 are reported. A 12-week exercise program was used to examine sensitivity to change. Data analyses were done using paired t-test, Pearson correlation, intraclass correlation coefficient (ICC), and delta index (DI) procedures.

RESULTS

The PFP-10 total score and 4 of the 5 domain scores were statistically similar (within 3%) to those of the CS-PFP. The PFP-10 upper-body strength domain score was 17% lower, but was highly correlated (ICC=.97). Community and established laboratory PFP-10 scores were similar (ICC=.85-.97). The PFP-10 also is sensitive to change (DI=.21-.54).

DISCUSSION AND CONCLUSION

The PFP-10 yields valid, reliable, and sensitive measurements and can be confidently substituted for the CS-PFP.

Leg extensor power, cognition, and functional performance in independent and marginally dependent older adults

BACKGROUND

physical and cognitive function must be integrated and optimised in performance of daily activities. Age-related loss of physical function can result in poor performance of necessary daily activities and possibly lead to increased dependency and a change of living status.

OBJECTIVES

(1) to evaluate average differences in physiological, cognitive, and functional performance of older adults from two different levels of independence, (2) to examine contributions of leg power, cognition, and functional performance to level of independence.

DESIGN

cross-sectional study of self-reported 'independent' versus 'marginally dependent' older adults.

SUBJECTS

35 older adults (77.2 +/- 6 years) were placed into independent (n = 18) or marginally dependent (n = 17) groups based upon the Medical Outcomes Study SF36 physical function scores (independent: SF36PF > or = 85, marginally dependent: SF36PF < 85) and living status.

METHODS

assessment of physical function includes the dependent variable, SF36PF. Assessment of physical, cognitive, and functional performance include the independent variables of leg extensor power, reaction time, processing speed, memory, attention, and functional performance. Functional performance is assessed by the Continuous Scale Physical Functional Performance Test.

RESULTS

independent older adults have greater performance on leg power, reaction time, processing speed, memory, and functional performance than marginally dependent older adults. Functional performance is an independent predictor of level of independence. Leg power and cognition were separate small but significant predictors of independence.

CONCLUSIONS

independent older adults have greater physiological, cognitive and functional performance than marginally dependent older adults. Individuals with greater functional performance tend to remain independent.

Daily Ambulation Activity and Task Performance in Community-Dwelling Older Adults Aged 63-71 Years With Preclinical Disability

BACKGROUND

The purpose of this study was to examine differences in daily ambulation activity and task modification between community-dwelling older adults above and below an empirically derived physical threshold that has been linked to independence.

METHODS

20 community-dwelling older adults (72.8 +/- 6 years) were categorized into groups based on functional performance using the Continuous scale Physical Functional Performance Test total score (Cs-PFP). Individuals with Cs-PFP > or =57 were assigned to the high functioning group (HIGH; n=10) with all others assigned to the lower functioning group (LOW; Cs-PFP<57; n=10). Dependent variables included steps/day, number of tasks reported with difficulty, and number of tasks reported with modification.

RESULTS

HIGH took significantly more steps/day (HIGH: 9503 +/- 4623; LOW: 5048 +/- 2917, p=.019) compared to LOW. Groups reported having difficulty with a similar number of tasks (HIGH: 0.4 +/- 1; LOW: 1.0 +/- 1, p=.092) but LOW reported modifying a significantly larger number of tasks (HIGH: 0.3 +/- 1; LOW 1.4 +/- 1, p=.049).

CONCLUSIONS

Older adults with preclinical disability have reduced daily ambulatory activity compared to older adults with high function despite a similar independent living status. Individuals compensate for reduced physical reserves by modifying the method of performing a task. Identifying early declines in physical ability through task modification and daily ambulation will provide the opportunity for timely intervention to older adults desiring to remain independent within a community-dwelling environment.

Resistance training on physical performance in disabled older female cardiac patients

PURPOSE

We evaluated the value of resistance training on measures of physical performance in disabled older women with coronary heart disease (CHD).

METHODS

The study intervention consisted of a 6-month program of resistance training in a randomized controlled trial format. Training intensity was at 80% of the single-repetition maximal lift. Control patients performed light yoga and breathing exercises. Study participants included 42 women with CHD, all >or= 65 yr of age and community dwelling. Subjects were screened by questionnaire to have low self-reported physical function. The primary study measurements related to the performance of 16 household activities of the Continuous Scale Physical Functional Performance test (CSPFP). These ranged from dressing, to kitchen and cleaning activities, to carrying groceries and walking onto a bus with luggage, and a 6-min walk. Activities were measured in time to complete a task, weight carried during a task, or distance walked. Other measures included body composition, measures of aerobic fitness and strength, and questionnaire-based measures of physical function and depression score.

RESULTS

Study groups were similar at baseline by age, aerobic capacity, strength, body composition, and in performing the CSPFP. After conditioning, 13 of 16 measured activities were performed more rapidly, or with increased weight carried, compared with the control group (all P < 0.05). Maximal power for activities that involved weight-bearing over a distance, increased by 40% (P < 0.05).

CONCLUSIONS

Disabled older women with CHD who participate in an intense resistance-training program improve physical capacity over a wide range of household physical activities. Benefits extend beyond strength-related activities, as endurance, balance, coordination, and flexibility all improved. Strength training should be considered an important component in the rehabilitation of older women with CHD.

Effect of strength and power training on physical function in community-dwelling older adults

BACKGROUND

The performance of daily tasks, such as stair climbing or lifting an object, requires both muscle strength and power. Age-associated reductions in strength and power can affect an older adult's ability to complete daily tasks such as stair climbing and lifting a child.

METHODS

The purposes of this study were to determine whether power training was more efficacious than strength training for improving whole-body physical function in older adults and to examine the relationship between changes in anaerobic power and muscle strength and changes in physical function. Thirty-nine men and women (mean age +/- SD = 72.5 +/- 6.3 years) with below-average leg extensor power were randomly assigned to control (C, n = 15), strength-training (ST, n = 13) or power-training (PT, n = 11) groups. The ST and PT groups met 3 days per week for 16 weeks; the C group maintained usual activity and attended three lectures during the course of the study. Primary outcome measures included the Continuous Scale Physical Functional Performance test, maximal strength, and anaerobic power.

RESULTS

After baseline was controlled for, the Continuous Scale Physical Functional Performance test total score was significantly greater for the PT group than for the ST (p =.033) and C (p =.016) groups. Maximal strength was significantly greater for the ST group than for the C group (p =.015) after the intervention. There was no significant difference between groups for peak anaerobic power.

CONCLUSIONS

Power training was more effective than strength training for improving physical function in community-dwelling older adults.

Maximal voluntary and functional performance levels needed for independence in adults aged 65 to 97 years

BACKGROUND AND PURPOSE

Age-related loss of muscle mass and cardiovascular endurance can lead to impairments in muscle force production and cardiac function that, in turn, limit performance in activities essential to everyday living. The purposes of this study were: (1) to identify the "breakpoint" or threshold of maximal voluntary performance and performance in ordinary daily function and (2) to evaluate the predictive validity of the threshold to identify the ability to live independently without self-reported functional limitation.

SUBJECTS AND METHODS

Men and women (N=192; mean age=76 years, SD=7, range=65-97) were recruited from single-family community dwellings or retirement communities with multiple levels of care. Physical function was measured with the Continuous-Scale Physical Functional Performance Test (CS-PFP). Maximal voluntary performance measures included peak oxygen consumption (VO(2peak)) and isokinetic knee extensor torque (KET). Segmented linear regression models of the CS-PFP on the physical performance measures were used to determine the threshold values and their confidence intervals. A logistic regression model was used to evaluate the ability of the CS-PFP scores to identify those living independently and to further illustrate the concepts of threshold and physical reserve.

RESULTS

Threshold values identified for VO(2peak) (20 mL x kg(-1) x min(-1)) and KET (2.5 N x m/[kg x m(-1)]) were associated with an average of CS-PFP score of 57 units. The threshold accurately predicted individuals reporting functional limitations.

DISCUSSION AND CONCLUSION

The thresholds provide a mechanism for easily estimating an individual's physical reserve, predicting dependency in living status, and providing unbiased guidance for intervention in late-life independence.

Physical functional performance in persons using a manual wheelchair

STUDY DESIGN

Descriptive study.

OBJECTIVES

To develop a performance-based physical functional measure for people using a manual wheelchair, and to evaluate the feasibility and reliability of the administration of the new procedure.

BACKGROUND

Most performance-based measures of physical function focus on balance and ambulation impairments. Recent developments of performance measures fail to produce a valid and reliable performance-based measure to quantify physical function in people who must rely on upper-body function to mobilize.

METHODS

Eighteen adults (ages 18 to 67 years) who used a nonmotorized wheelchair participated in this study. Volunteers performed selected tasks from the Continuous Scale Physical Functional Performance (CS-PFP) test, modified for persons using a wheelchair. Outcome measures included scores on the Wheelchair Physical Functional Performance (WC-PFP) test and the Sickness Impact Profile (SIP) questionnaire.

RESULTS

Participants had substantial disability (mean total SIP > 20). Total and domain scores of the WC-PFP had no ceiling or floor effects and were reproducible with intraclass correlation coefficients ranging from 0.87 to 0.96. Poorer self-rated health was correlated with poorer performance in the upper-body domain of the WC-PFP (r = -0.45). Those reporting disability in bathing and dressing using the SIP had significantly lower WC-PFP scores, indicating that the WC-PFP had construct validity. A significant correlation was not found between WC-PFP and the ambulation and mobility domains of the SIP.

CONCLUSION

The WC-PFP provides a reliable and quantifiable measure of mobility in persons who use a manual wheelchair.

Anaerobic power and physical function in strength-trained and non-strength-trained older adults

BACKGROUND

Challenging daily tasks, such as transferring heavy items or rising from the floor, may be dependent on the ability to generate short bursts of energy anaerobically. The purposes of this study were to determine if strength-trained (ST) older adults have higher anaerobic power output compared with non-strength-trained (NST) older adults and to determine the relationship between anaerobic power and performance-based physical function.

METHODS

Thirty-five men and women (age 71.5 +/- 6.4 years, mean +/- SD; NST: n = 18, ST: n = 17) were grouped by training status. Outcome variables included relative anaerobic power (Wingate test), physical function measured with the Continuous Scale Physical Functional Performance Test (CS-PFP, scaled 0 to 100), and anthropometric lean thigh volume (LTV). Analysis of covariance (with age and sex as covariates) was used to determine group differences in the dependent variables listed above. Pearson's r was used to determine the relationship between anaerobic power, CS-PFP total score (TOT), and CS-PFP lower body strength domain score (LBS).

RESULTS

The ST group had significantly higher mean anaerobic power (NST 58.9 +/- 16 W/l, ST 96.3 +/- 23 W/l), CS-PFP total (NST 61.2 +/- 13, ST 73.7 +/- 8), and LBS (NST 54.1 +/- 17, ST 70.9 +/- 8) compared with the NST group (p <.05). However, LTV was similar for both groups (NST 3.323 +/- 0.75; ST 3.179 +/- 0.79), which suggests that the ST group had higher muscle quality compared with the NST group. Anaerobic power was significantly related to TOT (r =.611, p =.001) and LBS (r =.650, p =.001).

CONCLUSIONS

High levels of physical function in ST older adults may in part be explained by higher levels of anaerobic power associated with strength training.

Effects of resistance training on physical function in older disabled women with coronary heart disease

We studied whether disabled older women with coronary heart disease can perform resistance training at an intensity sufficient to improve measured and self-reported physical function [n = 30, 70.6 +/- 4.5 (SD) yr]. Compared with the controls, the resistance-training group showed significant improvements in overall measured physical function score using the Continuous-Scale Physical Functional Performance Test (+24 vs. +3%). The Continuous-Scale Physical Functional Performance Test measures physical function for 15 practical activities, such as carrying groceries or climbing stairs. Resistance training led to improved measures for domains of upper body strength (+18 vs. +6%), lower body strength (+23 vs. +6%), endurance (+26 vs. +1%), balance and coordination (+29 vs. -2%), and 6-min walk (+15 vs. +7%). Women involved in the flexibility-control group showed essentially no improvement for physical function measures. No changes were observed for body composition, aerobic capacity, or self-reported physical function in either group. In conclusion, disabled older women with coronary heart disease who participate in strength training are able to train at an intensity sufficient to result in improvements in multiple domains of measured physical functional performance, despite no change in lean body mass.

Large energetic adaptations of elderly muscle to resistance and endurance training

This study determined the cellular energetic and structural adaptations of elderly muscle to exercise training. Forty male and female subjects (69.2 +/- 0.6 yr) were assigned to a control group or 6 mo of endurance (ET) or resistance training (RT). We used magnetic resonance spectroscopy and imaging to characterize energetic properties and size of the quadriceps femoris muscle. The phosphocreatine and pH changes during exercise yielded the muscle oxidative properties, glycolytic ATP synthesis, and contractile ATP demand. Muscle biopsies taken from the same site as the magnetic resonance measurements were used to determine myosin heavy chain isoforms, metabolite concentrations, and mitochondrial volume densities. The ET group showed changes in all energetic pathways: oxidative capacity (+31%), contractile ATP demand (-21%), and glycolytic ATP supply (-56%). The RT group had a large increase in oxidative capacity (57%). Only the RT group exhibited change in structural properties: a rise in mitochondrial volume density (31%) and muscle size (10%). These results demonstrate large energetic, but smaller structural, adaptations by elderly muscle with exercise training. The rise in oxidative properties with both ET and RT suggests that the aerobic pathway is particularly sensitive to exercise training in elderly muscle. Thus elderly muscle remains adaptable to chronic exercise, with large energetic changes accompanying both ET and RT.

Ageing, muscle properties and maximal O(2) uptake rate in humans

This paper asks how the decline in maximal O(2) uptake rate (VO(2),max) with age is related to the properties of a key muscle group involved in physical activity - the quadriceps muscles. Maximal oxygen consumption on a cycle ergometer was examined in nine adult (mean age 38.8 years) and 39 elderly subjects (mean age 68.8 years) and compared with the oxidative capacity and volume of the quadriceps. VO(2),max declined with age between 25 and 80 years and the increment in oxygen consumption from unloaded cycling to VO(2),max (delta VO(2)) in the elderly was 45 % of the adult value. The cross-sectional areas of the primary muscles involved in cycling - the hamstrings, gluteus maximus and quadriceps - were all lower in the elderly group. The quadriceps volume was reduced in the elderly to 67 % of the adult value. Oxidative capacity per quadriceps volume was reduced to 53 % of the adult value. The product of oxidative capacity and muscle volume - the quadriceps oxidative capacity - was 36 % of the adult value in the elderly. Quadriceps oxidative capacity was linearly correlated with delta VO(2) among the subjects with the slope indicating that the quadriceps represented 36 % of the VO(2) increase during cycling. The decline in quadriceps oxidative capacity with age resulted from reductions in both muscle volume and oxidative capacity per volume in the elderly and appears to be an important determinant of the age-related reduction in delta VO(2) and VO(2),max found in this study.

A lifetime of fitness. Exercise in the perimenopausal and postmenopausal woman

The peri- and postmenopausal woman experiences physiologic changes of aging that include alterations in hormone levels. Research has shown that the perimenopausal and postmenopausal woman can benefit significantly from exercise, whether endurance or strength training. Exercise can improve the quality of life and attenuate some of the physiologic changes associated with aging. Additionally, exercise can ameliorate the decline in fitness and bone, prevent chronic disease, and promote functional independence. Women who exercise regularly throughout life are physiologically 20 to 30 years younger than their sedentary counterparts. Fitness is a lifetime endeavor that has many positive benefits. Weightbearing activities are especially important as bone loss increases in the perimenopausal phase of life. Women should perform aerobic exercise 3 to 7 days per week for 15 to 60 minutes at 65% to 70% HRreserve. Strengthening exercises should be done 2 to 3 days per week at 40% to 80% 1RM with appropriately selected exercises. An exercise program should be functional and enjoyable. There is no better motivation to exercise than having a partner to work out with and keep the motivation alive. Most important, age itself is not a deterrent to exercise.

Exercise: effects on physical functional performance in independent older adults

BACKGROUND

Age-related loss in physiologic capacities contributes to the decline in physical function in the elderly population. Despite the beneficial effects of exercise interventions on maximal physiologic capacity measures, the functional benefits have not been shown in independently living older adults. The objective of this study was to evaluate exercise in independent older adults for significant and meaningful improvements in physical function, not detected by commonly used measures of physical function.

METHODS

In a randomized controlled study, 49 independently living men and women were assigned to either a nonexercise control group (Control; n = 26) or an exercise training group (Exercise; n = 23). Participants (age = 76+/-4) in good general health were recruited from retirement communities or apartments. The combined endurance and strength training was performed at 75% to 80% intensity; the groups met 3 times/week for 6 months of supervised sessions. Outcome measures included physical capacity, health status, and physical function using a newly developed performance test--the Continuous Scale-Physical Functional Performance test (CS-PFP).

RESULTS

Compared to the Control group, the Exercise group showed significant increases in maximal oxygen consumption (11%) and muscle strength (33%). No significant differences were found between groups for changes in the Sickness Impact Profile, SF-36 scales, or the 6-minute walk. However, the CS-PFP score improved significantly in the Exercise group (14%, effect size 0.80).

CONCLUSIONS

Independent older adults gain meaningful functional benefits from several months of exercise training. The public health importance of physical activity may relate not just to its role in preventing decline, but also to its role in enhancing physical function.

The effect of strength and endurance training on gait, balance, fall risk, and health services use in community-living older adults

BACKGROUND

The study tested the effect of strength and endurance training on gait, balance, physical health status, fall risk, and health services use in older adults.

METHODS

The study was a single-blinded, randomized controlled trial with intention-to-treat analysis. Adults (n = 105) age 68-85 with at least mild deficits in strength and balance were selected from a random sample of enrollees in a health maintenance organization. The intervention was supervised exercise (1-h sessions, three per week, for 24-26 weeks), followed by self-supervised exercise. Exercise groups included strength training using weight machines (n = 25), endurance training using bicycles (n = 25), and strength and endurance training (n = 25). Study outcomes included gait tests, balance tests, physical health status measures, self-reported falls (up to 25 months of follow-up), and inpatient and outpatient use and costs.

RESULTS

There were no effects of exercise on gait, balance, or physical health status. Exercise had a protective effect on risk of falling (relative hazard = .53, 95% CI = .30-.91). Between 7 and 18 months after randomization, control subjects had more outpatient clinic visits (p < .06) and were more likely to sustain hospital costs over $5000 (p < .05).

CONCLUSIONS

Exercise may have beneficial effects on fall rates and health care use in some subgroups of older adults. In community-living adults with mainly mild impairments in gait, balance, and physical health status, short-term exercise may not have a restorative effect on these impairments.

A comparison of the effects of three types of endurance training on balance and other fall risk factors in older adults

We hypothesized that short-term endurance training improves balance in older adults, if training involves movements that "stress" balance. We tested the hypothesis by looking for a dose-response relationship between movement during exercise and balance improvement. The study was a single-blinded, randomized controlled trial. Subjects were sedentary adults (N = 106) aged 68-85 with at least mild deficits in balance. Exercise groups were: stationary cycle (low movement), walking (medium movement), and aerobic movement (high movement). Subjects attended supervised exercise classes three times a week for three months, followed by self-directed exercise of any type for three months. The primary test of the hypothesis compared changes in balance after three months of supervised exercise. One balance measure (distance walked on a six-meter narrow balance beam) improved in the hypothesized dose-response manner (cycle, 3% improvement; walking, 7% improvement; aerobic movement, 18% improvement: p < 0.02, test of trend). Other balance measures did not improve with exercise. Only walking exercise improved gait speed (by 5%, p < 0.02) and SF-36 role-physical score (by 24%, p < 0.05). VO2max improved with walking (18%, p < 0.004) and aerobic movement (10%, p < 0.01), but improved less with cycling (8%, p > 0.1). Leg strength improved significantly in all exercise groups. The study hypothesis was supported only for one balance measure. Only walking improved at least one measure of all major outcomes (endurance, strength, gait, balance, and health status), suggesting that walking is most useful for all prevention. Cycle exercise appeared least useful.

Continuous-scale physical functional performance in healthy older adults: a validation study

OBJECTIVE

The continuous-scale physical functional performance test (CS-PFP) is an original instrument designed to provide a comprehensive, in-depth measure of physical function that reflects abilities in several separate physical domains. It is based on a concept of physical function as the integration of physiological capacity, physical performance, and psychosocial factors.

SETTING

The test was administered under standard conditions in a hospital facility with a neighborhood setting. The CS-PFP consists of a battery of 15 everyday tasks, ranging from easy to demanding, that sample the physical domains of upper and lower body strength, upper body flexibility, balance and coordination, and endurance. Participants are told to work safely but at maximal effort, and physical functional performance was measured as weight, time, or distance. Scores were standardized and scaled 0 to 12. The test yields a total score and separate physical domain scores.

DESIGN

The CS-PFP was evaluated using 148 older adults-78 community dwellers, 31 long-term care facility residents living independently, and 39 residents with some dependence.

MAIN OUTCOME MEASURES

Maximal physical performance assessment included measures of maximal oxygen consumption (VO2max), isokinetic strength, range of motion, gait, and balance. Psychosocial factors were measured as self-defined health status using the Sickness Impact Profile (SIP), self-perceived function using the Health Survey (SF36), and Instrumental Activities of Daily Living (IADL).

RESULTS

IADL scores were not significantly different among the groups. Test-retest correlations ranged from .84 to .97 and inter-rater reliability from .92 to .99 for the CS-PFP total and 5 domains. Internal consistency was high (Cronbach's alpha, .74 to .97). Both total and individual domain CS-PFP scores were significantly different for the three groups of study participants, increasing with higher levels of independence, supporting construct validity. CS-PFP domain scores were significantly correlated with measures of maximal physical performance (VO2max, strength, etc) and with physical but not emotional aspects of self-perceived function.

CONCLUSION

The CS-PFP is a valid, reliable measure of physical function, applicable to a wide range of functional levels, and having minimal floor and ceiling effect. The total and physical domains may be used to evaluate, discriminate, and predict physical functional performance for both research and clinical purposes.