Episodic memory and executive function impairments in non-demented older adults: which are the respective and combined effects on gait performances?

Gait control depends in part on cognition. This study aims to examine the separate and combined effects of episodic memory and executive function impairments on the mean value and the coefficient of variation (CoV) of stride time among non-demented older community dwellers. Based on a cross-sectional design, 1458 older community dwellers without dementia (70.6 ± 4.9 years; 49.2 % female) were recruited and separated into cognitively healthy individuals (CHI) and individuals with cognitive impairment. A score ≤5/6 on the Short Mini-Mental State Examination defined episodic memory impairment. Impaired executive function was defined by errors on the clock-drawing test. Mean value and CoV of stride time were measured by the GAITRite® system. A total of 517 participants (35.5 %) had cognitive impairment in at least one cognitive domain. Participants with memory impairment (P = 0.006) and those with combined cognitive impairments (P < 0.001) had greater (i.e., worse gait performance) mean value of stride time (P = 0.006) compared to CHI. Participants with combined cognitive impairment had a greater CoV of stride time (i.e., worse gait performance) compared to CHI (P = 0.004) and to those with separate memory impairment (P = 0.037). Among participants with combined cognitive impairments, mean value and CoV of stride time had the highest effect size (respectively, effect size = 0.49 [95 % confidence interval (CI) 0.27;0.71] and effect size = 0.40 [95 %CI 0.18;0.62]). Participants with episodic memory or executive impairments had a greater mean value and CoV of stride time compared to those with no cognitive impairment. Combined episodic memory and executive impairments exceeded the sum of separate impairments on gait performances, suggesting a complex interplay going beyond a simple additive effect.     

Effect of a walking program on gait characteristics in patients with osteoarthritis

This paper reports the results of a study of the gait of 102 patients with osteoarthritis of theknee. Functional status was measured by a 6-min test of walking distance; the stride characteristics associated with the walk test were assessed. Stride characteristics were measured by a StrideAnalyzer. Patients were randomized to an 8-week educational and walking program (the intervention group) or to a weekly telephone survey (the control group). The intervention group patients had a 15% increase in walking distance (P < 0.0001) and increases of 9.1% in stride length at freewalking speeds (P < 0.007) and 17% in stride length at fast walking speeds (P < 0.01) comparedtothe control group. The results of this study have shown that the walking and educational program was effective in improving gait function in patients with osteoarthritis of the knee.     

Gait energetic efficiency in older adults with and without knee pain: results from the Baltimore Longitudinal Study of Aging

With aging, customary gait patterns change and energetic efficiency declines, but the relationship between these alterations is not well understood. If gait characteristics that develop with aging explain part of the decline in energetic efficiency that occur in most aging individuals, then efforts to modify these characteristics could delay or prevent mobility limitation. This study characterizes gait patterns in older persons with and without knee pain and tests the hypothesis that changes in gait characteristics due to knee pain are associated with increased energetic cost of walking in older adults. Study participants were 364 men and 170 women aged 60 to 96 years enrolled in the Baltimore Longitudinal Study of Aging (BLSA), of whom 86 had prevalent knee pain. Gait patterns were assessed at participant self-selected usual pace in the gait laboratory, and the energetic cost of walking was assessed by indirect calorimetry during self-selected usual pace walking over 2.5 min in a tiled corridor using a portable equipment. Participants with knee pain were less energetically efficient than those without pain (oxygen consumption 0.97 vs. 0.88 ml/(10 m · 100 kg); p = 0.002) and had slower gait speed and smaller range of motion (ROM) at the hip and knee joints (p < 0.05, for all). Slower gait speed and lower knee ROM in participants with knee pain and longer double support time and higher ankle ROM in participants without knee pain were associated with lower energetic efficiency (p < 0.05, for all). Slower gait speed and lower knee ROM were correlates of knee pain and were found to mediate the association between age and oxygen consumption. Although knee pain is associated with a higher energetic cost of walking, gait characteristics associated with energetic efficiency differ by pain status which suggests that compensatory strategies both in the presence and absence of pain may impact gait efficiency.     

Medium-intensity,high-volume “hypertrophic” resistance training did not induce improvements in rapid force production in healthy older men

The aim of the study was to determine whether it is possible to improve both maximum and rapid force production using resistance training that is typically used to induce muscle hypertrophy in previously untrained older men. Subjects (60–72 years) performed 20 weeks of “hypertrophic” resistance training twice weekly (n = 27) or control (n = 11). Maximum dynamic and isometric leg press, as well as isometric force over 0–100 ms, and maximum concentric power tests were performed pre- and post-intervention. Muscle activity was assessed during these tests by surface electromyogram of the vastus lateralis and medialis muscles. Muscle hypertrophy was assessed by panoramic ultrasound of the vastus lateralis. The intervention group increased their maximum isometric (from 2268 ± 544 to 2538 ± 701 N) and dynamic force production (from 137 ± 24 to 165 ± 29 kg), and these changes were significantly different to control (isometric 12 ± 16 vs. 1 ± 9 %; dynamic 21 ± 12 vs. 2 ± 4 %). No within- or between-group differences were observed in rapid isometric force or concentric power. Relative increases in vastus lateralis cross-sectional area trended to be statistically greater in the intervention group (10 ± 8 vs. 3 ± 6 %, P = 0.061). It is recommendable that resistance training programs for older individuals integrate protocols emphasizing maximum force/muscle hypertrophy and rapid force production in order to induce comprehensive health-related and functionally important improvements in this population.     

Infant motor development and cognitive performance in early old age: the Helsinki Birth Cohort Study

Motor development and cognitive development in childhood have been found to be fundamentally interrelated, but less is known about the association extending over the life course. The aim of this study was to examine the association between early motor development and cognitive performance in early old age. From men and women belonging to the Helsinki Birth Cohort Study, who were born between 1934 and 1944 and resided in Finland in 1971, 1279 participated in cognitive performance tests (CogState®, version 3.0.5) between 2001 and 2006 at an average age of 64.2 years (SD 3.0). Of these, age at first walking extracted from child welfare clinic records was available for 398 participants. Longer reaction times in cognitive tasks measuring simple reaction time (SRT), choice reaction time (CRT), working memory (WM), divided attention (DA), and associated learning (AL) indicated poorer cognitive performance. Adjustment was made for sex, age at testing, father’s occupational status and own highest attained education, and occupation in adulthood. Average age of learning to walk was 12.2 months (SD 2.1). After adjusting for covariates, earlier attainment of learning to walk was associated with shorter reaction times in cognitive performance tasks (SRT 10.32 % per month, 95 % CI 0.48–21.12, p = 0.039; CRT 14.17 % per month, 95 % CI 3.75–25.63, p = 0.007; WM 15.14 % per month, 95 % CI 4.95–26.32, p = 0.003). People who learned to walk earlier had better cognitive performance in early old age. The earlier attainment of motor skills may track over to early old age and possibly reflect greater cognitive reserve in older age.     

Effect of resistance training with different frequencies and detraining on muscular strength and oxidative stress biomarkers in older women

The aim of this study was to compare the effect of resistance training (RT) performed with different frequencies followed by a detraining period on muscular strength and oxidative stress (OS) biomarkers in older women. Twenty-seven physically independent women (68.8 ± 4.8 years, 69.1 ± 14.3 kg, 156.0 ± 6.5 cm, and 28.3 ± 4.9 to kg.m⁻²) were randomly assigned to perform a RT program for 2 or 3 days per week (G2X = 13 vs. G3X = 14) for 12 weeks followed by 12 weeks of detraining period. One repetition maximum (1RM) tests were used as measures of muscular strength (three exercises, three attempts for each exercise, 3–5 min of rest between attempts, and 5 min of rest between exercises). Advanced oxidized protein products (AOPP) and total radical-trapping antioxidant parameter (TRAP) were used as oxidative stress indicators. Both groups increased muscular strength after 12 weeks of training (P < 0.05) in chest press (G2X = +11.9 % vs. G3X = +27.5 %, P < 0.05), knee extension (G2X = +18.4 % vs. G3X = +16.7 %, P > 0.05), and preacher curl (G2X = +37.6 % vs. G3X = +36.7 %, P > 0.05). On the other hand, 12 weeks of detraining were not sufficient to eliminate the major effects produced by RT on muscular strength, although a significant decrease (P < 0.05) has been observed for chest press (G3X = −9.1 % vs. G2X = −10.2 %, P > 0.05), knee extension (G2X = −14.9 % vs. G3X = −12.1 %, P > 0.05), and preacher curl (G2X = −20.5 % vs. G3X = −17.4 %, P > 0.05). Pre- to post-training, both groups showed significant (P < 0.05) increases in TRAP (G2X = +6.9 % vs. G3X = +15.1 %) with no statistical significant difference between the groups (P > 0.05), and the scores remained elevated compared to pre-training after 12 weeks of detraining. AOPP was not changed by RT or detraining (P > 0.05). The results suggest that a 12-week RT program with a frequency of 2 days per week may be sufficient to improve muscular strength and OS in older women and detraining for 12 weeks does not completely reverse the changes induced by RT.     

Do frailty and cognitive impairment affect dual-task cost during walking in the oldest old institutionalized patients?

The objective of this study was to investigate dual-task costs in several elderly populations, including robust oldest old, frail oldest old with MCI, frail oldest old without MCI, and frail elderly with dementia. Sixty-four elderly men and women categorized into frail without MCI (age 93.4 ± 3.2 years, n = 20), frail with MCI (age 92.4 ± 4.2 years, n = 13), robust (age 88.2 ± 4.1 years, n = 10), and patients with dementia (age 88.1 ± 5.1 years, n = 21). Five-meter gait ability and timed-up-and-go (TUG) tests with single and dual-task performance were assessed in the groups. Dual-task cost in both 5-m habitual gait velocity test and TUG test was calculated by the time differences between single and dual-task performance. The robust group exhibited better 5-m gait and TUG test performances in the single and dual-task conditions compared with the other three groups (P < 0.001), and the frail and frail + MCI groups exhibited better performances than the dementia group (P < 0.001). No significant differences were observed between the frail and frail + MCI groups. However, all groups exhibited lower gait velocities in the verbal and arithmetic task conditions, but the dual-task cost of the groups were similar. Robust individuals exhibited superior single and dual-task walking performances than the other three groups, and the frail and frail + MCI individuals exhibited performances that were superior to those of the patients with dementia. However, the dual-task costs, i.e., the changes in gait performance when elderly participants switch from a single to a dual task, were similar among all four of the investigated groups. Therefore, these results demonstrated that the magnitude of the impairment in gait pattern is independent of frailty and cognitive impairment status.     

Intra-individual lap time variation of the 400-m walk,an early mobility indicator of executive function decline in high-functioning older adults?

Higher intra-individual lap time variation (LTV) of the 400-m walk is cross-sectionally associated with poorer attention in older adults. Whether higher LTV predicts decline in executive function and whether the relationship is accounted for by slower walking remain unanswered. The main objective of this study was to examine the relationship between baseline LTV and longitudinal change in executive function. We used data from 347 participants aged 60 years and older (50.7 % female) from the Baltimore Longitudinal Study of Aging. Longitudinal assessments of executive function were conducted between 2007 and 2013, including attention (Trails A, Digit Span Forward Test), cognitive flexibility and set shifting (Trails B, Delta TMT: Trials B minus Trials A), visuoperceptual speed (Digit Symbol Substitution Test), and working memory (Digit Span Backward Test). LTV and mean lap time (MLT) were obtained from the 400-m walk test concurrent with the baseline executive function assessment. LTV was computed as variability of lap time across ten 40-m laps based on individual trajectories. A linear mixed-effects model was used to examine LTV in relation to changes in executive function, adjusted for age, sex, education, and MLT. Higher LTV was associated with greater decline in performance on Trails B (β = 4.322, p < 0.001) and delta TMT (β = 4.230, p < 0.001), independent of covariates. Findings remained largely unchanged after further adjustment for MLT. LTV was not associated with changes in other executive function measures (all p > 0.05). In high-functioning older adults, higher LTV in the 400-m walk predicts executive function decline involving cognitive flexibility and set shifting over a long period of time. High LTV may be an early indicator of executive function decline independent of MLT.     

Effects of eccentric-focused and conventional resistance training on strength and functional capacity of older adults

The aim of the study was to assess the effect of eccentric training using a constant load with longer exposure time at the eccentric phase on knee extensor muscle strength and functional capacity of elderly subjects in comparison with a conventional resistance training program. Twenty-six healthy elderly women (age = 67 ± 6 years) were randomly assigned to an eccentric-focused training group (ETG; n = 13) or a conventional training group (CTG; n = 13). Subjects underwent 12 weeks of resistance training twice a week. For the ETG, concentric and eccentric phases were performed using 1.5 and 4.5 s, respectively, while for CTG, each phase lasted 1.5 s. Maximum dynamic strength was assessed by the one-repetition maximum (1RM) test in the leg press and knee extension exercises, and for functional capacity, subjects performed specific tests (6-m walk test, timed up-and-go test, stair-climbing test, and chair-rising test). Both groups improved knee extension 1RM (24–26 %; p = 0.021), timed up-and-go test (11–16 %; p < 0.001), 6-m walk test (9–12 %; p = 0.004), stair-climbing test (8–13 %; p = 0.007), and chair-rising test (15–16 %; p < 0.001), but there was no significant difference between groups. In conclusion, the strategy of increasing the exposure time at the eccentric phase of movement using the same training volume and intensity does not promote different adaptations in strength or functional capacity compared to conventional resistance training in elderly woman.     

Performance variance on walking while talking tasks: theory, findings, and clinical implications

Dual tasks that involve walking and cognitive interference tests are commonly used in mobility assessments and interventions. However, factors that explain variance in dual-task performance costs are poorly understood. We, therefore, examined the moderating effects of two putative constructs, postural reserve and hazard estimate, on performance on a walking while talking paradigm. Participants were 285 non-demented older adults (mean age = 76.9 years; %female = 54.4). Postural reserve was operationalized as the presence or absence of clinical gait abnormalities. An empirical factor, based on measures of executive functions, served as a marker for hazard estimate. The moderation effects of postural reserve and hazard estimate on dual-task costs were examined via two-way interactions in a joint linear mixed effect model. Significant dual-task costs were observed for gait speed (95% CI = 30.814 to 39.121) and cognitive accuracy (95% CI = 6.568 to 13.607). High hazard estimate had a protective effect against decline in gait speed (95% CI = −8.372 to −0.151) and cognitive accuracy (95% CI = −8.372 to −0.680). Poor postural reserve was associated with reduced decline in gait speed (95% CI = −9.611 to −0.702) but did not moderate the decline in cognitive accuracy (95% CI = −3.016 to 4.559). Assessing postural reserve and hazard estimate can help improve mobility risk assessment procedures and interventions for individuals with cognitive and movement disorders.     

Self-monitored versus supervised walking programs for older adults

Walking is an effective, well accepted, inexpensive, and functional intervention. This study compared the outcomes and changes in walking behavior of self-monitored (SM) and supervised (SU) walking interventions for older adults.Participants were assigned to SM (n = 21) and SU (n = 21) walking groups according to their place of residence. Both groups exercised and wore a pedometer for 3 months.The outcome measures were step count, body mass index (BMI), and physical function. Two-way repeated-measure ANOVA and independent t tests were used to compare the intervention effects. We also plotted the trends and analyzed the walking steps weekly.Only BMI exhibited a group × time interaction. The pre-posttest differences showed knee extension muscle strength (KEMS) and Timed Up and Go test were significantly improved in the SM group, whereas BMI, KEMS, 30-s sit-to-stand, functional reach were significantly improved, but 5-m gait speed significantly slower in the SU group. For participants attending ≥50% of the sessions, those in the SM and SU groups had similar results for all variables, except for 2-min step (2MS) and daily walking step counts.Both self-monitored and supervised walking benefit older adults in most physical functions, especially lower-extremity performance, such as muscle strength, balance, and mobility. The effects of both programs do not differ significantly, except for BMI and 2MS (ie cardiopulmonary endurance). We recommend pedometer-assisted self-monitored walking for older adults because of its ability to cultivate exercise habits over the long term, whereas supervised walking to establish effective exercise intensity.     

Neuromuscular adaptations to water-based concurrent training in postmenopausal women: effects of intrasession exercise sequence

This study investigated the effects of different exercise sequences on the neuromuscular adaptations induced by water-based concurrent training in postmenopausal women. Twenty-one healthy postmenopausal women (57.14 ± 2.43 years) were randomly placed into two water-based concurrent training groups: resistance training prior to (RA, n = 10) or after (AR, n = 11) aerobic training. Subjects performed resistance and aerobic training twice a week over 12 weeks, performing both exercise types in the same training session. Upper (elbow flexors) and lower-body (knee extensors) one-repetition maximal test (1RM) and peak torque (PT) (knee extensors) were evaluated. The muscle thickness (MT) of upper (biceps brachii) and lower-body (vastus lateralis) was determined by ultrasonography. Moreover, the maximal and submaximal (neuromuscular economy) electromyographic activity (EMG) of lower-body (vastus lateralis and rectus femoris) was measured. Both RA and AR groups increased the upper- and lower-body 1RM and PT, while the lower-body 1RM increases observed in the RA was greater than AR (34.62 ± 13.51 vs. 14.16 ± 13.68 %). RA and AR showed similar MT increases in upper- and lower-body muscles evaluated. In addition, significant improvements in the maximal and submaximal EMG of lower-body muscles in both RA and AR were found, with no differences between groups. Both exercise sequences in water-based concurrent training presented relevant improvements to promote health and physical fitness in postmenopausal women. However, the exercise sequence resistance–aerobic optimizes the strength gains in lower limbs.     

Exercise-training-induced changes in metabolic capacity with age: the role of central cardiovascular plasticity

Although aging is typically associated with a decline in maximal oxygen consumption (VO_2max), young and old subjects, of similar initial muscle metabolic capacity, increased quadriceps VO_2max equally when this small muscle mass was trained in isolation. As it is unclear if this preserved exercise-induced plasticity with age is still evident with centrally challenging whole body exercise, we assessed maximal exercise responses in 13 young (24 ± 2 years) and 13 old (60 ± 3 years) males, matched for cycling VO_2max (3.82 ± 0.66 and 3.69 ± 0.30 L min⁻¹, respectively), both before and after 8 weeks of high aerobic intensity cycle exercise training. As a consequence of the training both young and old significantly improved VO_2max (13 ± 6 vs. 6 ± 7 %) and maximal power output (20 ± 6 vs. 10 ± 6 %, respectively) from baseline, however, the young exhibited a significantly larger increase than the old. Similarly, independently assessed maximal cardiac output (Q_max) tended to increase more in the young (16 ± 14 %) than in the old (11 ± 12 %), with no change in a-vO₂ difference in either group. Further examination of the components of Q_max provided additional evidence of reduced exercise-induced plasticity in both maximal heart rate (young −3 %, old 0 %) and stroke volume (young 19 ± 15, old 11 ± 11 %) in the old. In combination, these findings imply that limited central cardiovascular plasticity may be responsible, at least in part, for the attenuated response to whole body exercise training with increasing age.     

Motor imagery of gait in non-demented older community-dwellers: performance depends on serum 25-hydroxyvitamin D concentrations

Hypovitaminosis D has been associated with poorer physical and cognitive performances in older adults. The objectives of this study were (1) to measure and compare the time to perform (pTUG) and to imagine (iTUG) the Timed "Up & Go" test (TUG) test, and the time difference between these two performances (i.e., TUG delta time) in non-demented community-dwelling older adults with and without lower serum 25-hydroxyvitamin D (25OHD) concentrations and (2) to examine the association between the TUG delta time and serum 25OHD concentrations. Durations of pTUG, iTUG and TUG delta time, and serum 25OHD concentrations (severe insufficiency <10 ng/mL; moderate insufficiency: 10–30 ng/mL; normal status >30 ng/mL) were measured in 359 non-demented participants (mean age 70.4 ± 4.8 years; 40.7 % women). Participants with severe 25OHD insufficiency (15.6 %) had higher TUG delta time compared to those with moderate insufficiency (P = 0.010) and normal status (P = 0.048). TUG delta time was negatively associated with serum 25OHD concentrations (P < 0.010). Accurate motor imagery of gait was explained in part by serum 25OHD concentrations, increased discrepancy between pTUG and iTUG being associated with lower serum 25OHD concentrations.     

Satellite cells in human skeletal muscle; from birth to old age

Changes in satellite cell content play a key role in regulating skeletal muscle growth and atrophy. Yet, there is little information on changes in satellite cell content from birth to old age in humans. The present study defines muscle fiber type-specific satellite cell content in human skeletal muscle tissue over the entire lifespan. Muscle biopsies were collected in 165 subjects, from different muscles of children undergoing surgery (<18 years; n = 13) and from the vastus lateralis muscle of young adult (18–49 years; n = 50), older (50–69 years; n = 53), and senescent subjects (70–86 years; n = 49). In a subgroup of 51 aged subjects (71 ± 6 years), additional biopsies were collected after 12 weeks of supervised resistance-type exercise training. Immunohistochemistry was applied to assess skeletal muscle fiber type-specific composition, size, and satellite cell content. From birth to adulthood, muscle fiber size increased tremendously with no major changes in muscle fiber satellite cell content, and no differences between type I and II muscle fibers. In contrast to type I muscle fibers, type II muscle fiber size was substantially smaller with increasing age in adults (r = −0.56; P < 0.001). This was accompanied by an age-related reduction in type II muscle fiber satellite cell content (r = −0.57; P < 0.001). Twelve weeks of resistance-type exercise training significantly increased type II muscle fiber size and satellite cell content. We conclude that type II muscle fiber atrophy with aging is accompanied by a specific decline in type II muscle fiber satellite cell content. Resistance-type exercise training represents an effective strategy to increase satellite cell content and reverse type II muscle fiber atrophy.

Electronic supplementary material

The online version of this article (doi:10.1007/s11357-013-9583-2) contains supplementary material, which is available to authorized users.     

Aging and physical mobility in group-housed Old World monkeys

While indices of physical mobility such as gait speed are significant predictors of future morbidity/mortality in the elderly, mechanisms of these relationships are not understood. Relevant animal models of aging and physical mobility are needed to study these relationships. The goal of this study was to develop measures of physical mobility including activity levels and gait speed in Old World monkeys which vary with age in adults. Locomotor behaviors of 21 old ( = 20 yoa) and 24 young ( = 9 yoa) socially housed adult females of three species were recorded using focal sample and ad libitum behavior observation methods. Self-motivated walking speed was 17% slower in older than younger adults. Likewise, young adults climbed more frequently than older adults. Leaping and jumping were more common, on average, in young adults, but this difference did not reach significance. Overall activity levels did not vary significantly by age, and there were no significant age by species interactions in any of these behaviors. Of all the behaviors evaluated, walking speed measured in a simple and inexpensive manner appeared most sensitive to age and has the added feature of being least affected by differences in housing characteristics. Thus, walking speed may be a useful indicator of decline in physical mobility in nonhuman primate models of aging.     

Battery of behavioral tests in mice that models age-associated changes in human motor function

Motor function in humans can be characterized with tests of locomotion, strength, balance, and endurance. The aim of our project was to establish an analogous test battery to assess motor function in mice. Male C57BL/6 mice were studied at 3 (n = 87), 20 (n = 48) and 26 (n = 43) months of age. Tests assessed locomotion, strength, balance/coordination, and endurance capacity in mice. Motor function was reduced in the older groups of mice for the locomotion, strength, and endurance subdomains (p < 0.001). As indicated with a summary score, motor function declined by 7.4 % from 3 to 20 months and by 13.5 % from 20 to 26 months. Based on comparison with previously published data in humans, the magnitude and relative time course of changes were similar in mice and humans in each subdomain except balance/coordination. Power calculations confirmed that the age-associated differences depicted by several of the individual tests and domain summary scores would be sufficient to assess the efficacy of interventions aimed at prevention or treatment of motor dysfunction with aging. The current study describes a mouse model that characterizes age-associated changes in clinically relevant domains of motor function and indicates that the preclinical model can be used to test strategies to attenuate age-associated declines in motor function.

Electronic supplementary material

The online version of this article (doi:10.1007/s11357-013-9589-9) contains supplementary material, which is available to authorized users.     

Effects of robot (SUBAR)-assisted gait training in patients with chronic stroke: Randomized controlled trial

Background:SUBAR is a new ground walking exoskeletal robot. The objective of this study is to investigate SUBAR-assisted gait training''s effects in patients with chronic stroke.Methods:This preliminary study is a prospective randomized controlled trial. Thirty adults were enrolled 6 months after the onset of stroke with functional ambulation category scores ≥ 3. Patients were randomly assigned to receive robot-assisted gait training (SUBAR group, n = 15) or conventional physiotherapy (control group, n = 15). All patients received a total of 10 treatment sessions of 30 minutes each for 3 weeks. Before and after the 10-treatment sessions, patients were evaluated. The primary outcome is the 10 meter walk test and the secondary outcomes were the functional ambulation category scale, the Motricity Index-Lower, Modified Ashworth Scale (MAS), timed up and go, Rivermead Mobility Index, Berg Balance Scale (BBS), and gait analysis.Results:In the SUBAR group, MAS and step length were significantly improved between pre- and posttreatment measurements (Δmean ± SD: −1.1 ± 1.6 and 5.5 ± 7.6, P = .019 and .016, respectively). The SUBAR group improved the stride length and step length of the affected limb but not significantly. The control group had significant improvements in the BBS, MAS, and stride length between pre- and posttreatment measurements (Δmean ± SD: 3.5 ± 4.6, −0.8 ± 1.5, and 6.5 ± 9.5; P = .004, .031, and .035, respectively). The BBS improved more in the control group than in the SUBAR group. There were no other differences between the SUBAR group and the control group.Conclusion:Our results suggest that SUBAR-assisted gait training improved gait parameters in patients with chronic stroke. However, there was no significant difference in most outcome measures compared to conventional physiotherapy. Further research is warranted to measure the effects of SUBAR-assisted gait training.     

Effects of exercise frequency on functional fitness in older adult women

This study evaluated the effects of exercise frequency on functional fitness in older women participating in a 12-week exercise program. Participants (67.8+/-4.6 years) were divided into three different exercise groups (I, II, and III; n=34) and a control group (Group C; n=11). Group I participated in a 90-min exercise program once a week, for 12 weeks, while Group II attended it twice a week, and Group III attended three times a week. The exercise program consisted of a 10-min warm-up, 20 min of walking, 30 min of recreational activities, 20 min of resistance training, and a 10-min cool-down. The following items were measured before and after the program: muscular strength, muscular endurance, dynamic balance, coordination, and cardiorespiratory fitness (6-min walking distance). Comparisons of baseline and post-intervention measures showed significantly greater improvements in body weight, coordination, and cardiorespiratory fitness for Group III compared to the other groups (p<0.05). In addition, the greatest improvements in body fat, muscular endurance, and dynamic balance were also observed in Group III (p<0.05). However, no significant differences were found in muscular strength. Older women who participate in an exercise program three times a week gain greater functional fitness benefits than those who exercise less frequently. In order to improve functional fitness in older women, an exercise frequency of at least three times each week should be recommended.     

Distinguishing exercise intolerance in early‐stage pulmonary hypertension with invasive exercise hemodynamics: Rest V E/VCO2 and ETCO2 identify pulmonary vascular disease

BackgroundAmong subjects with exercise intolerance and suspected early‐stage pulmonary hypertension (PH), early identification of pulmonary vascular disease (PVD) with noninvasive methods is essential for prompt PH management.HypothesisRest gas exchange parameters (minute ventilation to carbon dioxide production ratio: V _E/VCO₂ and end‐tidal carbon dioxide: ETCO₂) can identify PVD in early‐stage PH.MethodsWe conducted a retrospective review of 55 subjects with early‐stage PH (per echocardiogram), undergoing invasive exercise hemodynamics with cardiopulmonary exercise test to distinguish exercise intolerance mechanisms. Based on the rest and exercise hemodynamics, three distinct phenotypes were defined: (1) PVD, (2) pulmonary venous hypertension, and (3) noncardiac dyspnea (no rest or exercise PH). For all tests, *p < .05 was considered statistically significant.ResultsThe mean age was 63.3 ± 13.4 years (53% female). In the overall cohort, higher rest V _E/VCO₂ and lower rest ETCO₂ (mm Hg) correlated with high rest and exercise pulmonary vascular resistance (PVR) (r ~ 0.5–0.6*). On receiver‐operating characteristic analysis to predict PVD (vs. non‐PVD) subjects with noninvasive metrics, area under the curve for pulmonary artery systolic pressure (echocardiogram) = 0.53, rest V _E/VCO₂ = 0.70* and ETCO₂ = 0.73*. Based on this, optimal thresholds of rest V _E/VCO₂ > 40 mm Hg and rest ETCO₂ < 30 mm Hg were applied to the overall cohort. Subjects with both abnormal gas exchange parameters (n = 12, vs. both normal parameters, n = 19) had an exercise PVR 5.2 ± 2.6* (vs. 1.9 ± 1.2), mPAP/CO slope with exercise 10.2 ± 6.0* (vs. 2.9 ± 2.0), and none included subjects from the noncardiac dyspnea group.ConclusionsIn a broad cohort of subjects with suspected early‐stage PH, referred for invasive exercise testing to distinguish mechanisms of exercise intolerance, rest gas exchange parameters (V _E/VCO₂ > 40 mm Hg and ETCO₂ < 30 mm Hg) identify PVD.