Multifactorial exercise and dance-based interventions are effective in reducing falls risk in community-dwelling older adults: A comparison study

BackgroundFalls and injuries related to falls in older adults are a significant health care issue that affects the elderly population. Research suggests that exercise interventions can be effective in improving falls risk factors.Research questionAre there differences in falls risk reduction between two exercise interventions (The Lebed Method - TLM and Stay Active and Independent for Life – SAIL) for community-dwelling older adults?MethodsA quasi-experimental pre- and post-test design was used for this study. One hundred and sixty-three older individuals aged between 60–79 years of age participated in the study. Assessments of falls risk (using the physiological profile assessment), simple reaction time, bilateral knee extension strength, proprioception, balance, visual acuity, and mobility (using timed-up-and-go, TUG) were performed. Analysis of covariance was conducted to compare the differences between the two interventions. Pre-intervention assessments were used as the covariate.ResultsSAIL participants’ falls risk were reduced more than TLM. Reaction and TUG times were faster for SAIL participants. However, those individuals who participated in TLM had greater knee extension strength for both legs compared to SAIL participants.SignificanceOverall, both interventions were effective in reducing falls risk for older adults. The greater number of improved falls risk factors attained with the SAIL program suggests that multifactorial interventions may be more effective at reducing falls risk. However, since TLM also showed better improved strength, both dance-based and multifactorial interventions can be effective at reducing falls risk factors for older adults.     

Efficacy of lateral stair walking training in patients with chronic stroke: A pilot randomized controlled study

BackgroundPatients with chronic stroke have reduced capacity for performing activities of daily living (ADLs) and are at increased risk for falls during walking due to long-term changes to muscle tone and force, as well as movement control.Research questionTo investigate the efficacy of lateral stair walking training on muscle strength of affected lower extremities, balance, ADLs, and gait ability in patients with chronic stroke.MethodsThe experimental group received 15 min of lateral stair walking exercise along with 15 min of traditional physiotherapy, whereas the control group received only traditional physiotherapy for 30 min. Both groups received the intervention once a week for 12 weeks. Outcome measurements included muscle strength, postural assessment scale for stroke patients (PASS), Fugal–Meyer assessment for lower extremity (FMA-LE), Barthel index (BI), timed up and go test (TUG), and the gait parameters which were determined by the Reha-Watch system.ResultsA total of 24 participants completed the study. The experimental group showed significant improvements in hip extensor, flexor, and abductor strength of the affected limb, FMA-LE, BI, TUG, and gait parameters of stride length, velocity, and cadence. Significant differences in affected limb ankle plantar strength (p = 0.024), PASS (p = 0.017), BI (p = 0.039), TUG (p = 0.049), and gait velocity (p < 0.001) were observed between the 2 groups.SignificanceLateral stair walking training alongside physical therapy resulted in significant improvements in hip muscle strength and gait parameters in patients with chronic stroke. Our results support the incorporation of lateral stair walking training into clinical rehabilitation programs. Lateral stair walking training in patients with chronic stroke can be used as an effective treatment to improve gait, balance performance, and ADLs.     

The association between bladder dysfunction,balance and falls in women with multiple sclerosis: The specific contribution of fear of falling

BackgroundBladder dysfunction is the most common autonomic disturbance in people with MS (PwMS). Only a few studies have examined the relationship between bladder dysfunction and falls in PwMS. Bladder dysfunction has been deemed only a secondary outcome measure, and classified by a gross measure providing a limited perspective of this disturbing symptom. Furthermore, no study to date has focused on the relationship between bladder dysfunction and balance performance in PwMS.Research questionDetermine the relationship between bladder dysfunction with balance, falls and fear of falling in women with MS.MethodsThe study was observational, including 44 women with MS, mean age 46.3 (SD = 5.7), all with at least a mild bladder dysfunction. Outcome measures included the Urinary Incontinence Quality of Life Scale (I-QoL), Bladder Control Scale (BLCS), Timed Up and Go Test (TUG), Four Square Step Test (FSST), Falls Efficacy Scale International (FES-I), Falls status, and posturography.ResultsParticipants performed the TUG in 14.1 s (S.D. = 11.1), and the FSST in 20.5 s (S.D. = 22.4). A relatively large proportion (68.2 %) of women was classified as fallers. However, no differences were found between those classified as fallers (n = 30) or non-fallers (n = 14) in terms of the I-QoL and the BLCS, controlling for age, EDSS and number of vaginal deliveries. Significant correlations scores were found between the I-QoL, BLCS and FES-I (rho ∼0.47), while controlling for age, EDSS and number of vaginal deliveries. No associations were demonstrated between the bladder dysfunction outcome scores and either the TUG and/or FSST.SignificanceWomen afflicted with MS and suffering from bladder dysfunction tend to fall and present with more balance difficulties compared with disability-matched PwMS. Nevertheless, once bladder dysfunction is detected, the perceived severity of the condition is not associated with balance and prevalence of falling, but rather on fear of falling.     

Evaluating the contribution of reactive balance to prediction of fall rates cross-sectionally and longitudinally in persons with multiple sclerosis

BackgroundFalls are common in persons with multiple sclerosis (PwMS). Reactive postural control—one’s response to a balance perturbation—is likely an aspect of fall risk; however, the relationship between reactive posture and falls is poorly understood in PwMS.ObjectiveWe evaluated tibialis anterior muscle onset latency (TA latency) after balance perturbations as a predictor of fall rates in PwMS, controlling for clinical, functional, sensory, psychological, and cognitive factors.MethodAt baseline of the 18-month cohort study, 122 participants with MS (EDSS = 2.23) were included. Assessments were conducted every 6 months.ResultsOf the original 122 participants at the baseline collection, data were available from 41, 39, and 34 people at the 6, 12, and 18 month follow-ups, respectively. Percent fallers at the four time points were 35.3%, 12.2%, 15.4%, and 20.5%. Cross-sectionally (i.e., at baseline), the Timed Up-and-Go, Falls Efficacy Scale – International (FES-I), and TA latency after perturbations were significant predictors of retrospective falls rates using negative binomial regression. Longitudinally, random-effects negative binomial regression found that trait-level FES-I, Stroop Color-Word, and TA latency were significant predictors for falls rates.ConclusionDelays in automatic postural responses seem to account uniquely for fall rates in PwMS—beyond clinical, balance, or mobility measures. These delays may contribute to the increased fall rate in PwMS. In addition to brief self-report instruments (FES-I) and cognitive assessments, muscle onset after balance perturbations may be a valuable tool for predicting falls in those with MS.     

Structural and functional foot and ankle characteristics associated with falls in older people

BackgroundFalls affect approximately one in three older people, and foot problems are amongst the modifiable potential risk factors.Research questionwhat are the associations between foot and ankle functional and structural characteristics with falls in community-dwelling older adults?MethodOne hundred eighty-seven community-dwelling older adults (106 females) aged 62–90 years (mean 70.5 ± 5.2) from Isfahan, Iran were recruited. Foot and ankle structure and function (including foot posture, range of motion, muscle strength, deformity, pain and plantar loading patterns during walking) were measured. Fall history was documented in the preceding year. Univariate analyses compared fallers and non-fallers on all variables to determine significant differences and logistic regression analysis identified variables independently associated with falls.ResultsSeventy-four participants (39.9 %) had experienced a fall in the previous year. Logistic regression analysis revealed that less first metatarsophalangeal joint extension (odds ratio 0.82, 95 % CI 0.73−0.91), less plantarflexor muscle strength (odds ratio 0.29, 95 % CI 0.15−0.55), greater pressure-time integral in the medial forefoot (odds ratio 2.65, 95 %CI 1.10–6.38), greater center of pressure velocity in the forefoot (odds ratio 1.27, 95 % CI 1.07–1.49) and greater foot pain (odds ratio 1.09, 95 % CI 1.02–1.16) were significantly and independently associated with falls after accounting for physiological falls risk factors.SignificanceWe have identified several structural and functional foot and ankle characteristics associated with falling in older people. Future development of interventions to help prevent or treat these potentially modifiable risk factors may help decrease the risk of falling in this population.     

Obesity and falls in older women: Mediating effects of muscle quality,foot loads and postural control

BackgroundObesity is associated with an increased risk of falls in older women. However, it is not certain whether factors commonly associated with obesity and falls mediate this risk.Research questionDo lower-limb muscle quality, foot loads and postural control mediate the relationship between obesity and falls in women aged 60 years and older?MethodsAt baseline, 246 female participants underwent obesity screening (BMI≥30 kg/m²), and measurements of muscle quality (isokinetic dynamometer and dual-energy X-ray absorptiometry), foot loads (pressure platform) and postural balance (force platform). Incident falls were recorded at the end of the 18-month follow-up period via participant recall. To test whether, and to what extent, biomechanical factors mediated the relationship between obesity and falls, the Natural Indirect Effects (NIE), Natural Direct Effect (NDE) and proportion mediated were calculated using the counterfactual approach. Significance level was set at p < .05.Results204 participants (83 %) completed the follow-up. As expected, obesity was associated with a higher risk of being a faller (RR: 2.13, 95 % CI: 1.39–3.27). Using the counterfactual approach, only specific torque (NIE: 1.11, 95 % CI: 1.01–1.38) and flatfoot (NIE: 1.10, 95 % CI: 1.01–1.32) were significant mediators of the relationship between obesity and falls. Specific torque and flatfoot mediated 19 % and 21 % of the relationship, respectively.SignificanceLower-limb muscle quality (specific torque) and foot loads (flatfoot) mediate the relationship between obesity and falls in older women. The inclusion of muscle strengthening and podiatry interventions as part of a fall prevention program may benefit this population.     

The physiology of falling: assessment and prevention strategies for older people

Balance calls upon contributions from vision, peripheral sensation, vestibular sense, muscle strength, neuromuscular control and reaction time. With increased age, there is a progressive loss of functioning of these systems and an increased likelihood of falls. Falls can mark the beginning of a decline in function and independence and are the leading cause of injury-related hospitalisation in older people. By using simple tests of vision, leg sensation, muscle strength, reaction time and standing balance, it is possible to identify accurately older people at risk of falls and assess intervention outcomes. This approach overcomes the limitations associated with traditional methods of assessing falls risk via medical diagnoses, including varied severity between individuals. Using a physiological approach provides information at the impairment and functional capacity levels to assist in understanding falls and developing and evaluating optimal falls prevention strategies for older people.     

Postural balance,muscle strength,and history of falls in end-stage renal disease patients living with a kidney transplant: A cross-sectional study

BackgroundEnd-stage renal disease patients living with a kidney transplant (KT) often present with frailty, functional disability, and mobility impairments that may result in a high risk of falls. Postural balance and muscle strength are implicated in the etiology of falls in the geriatric population, and both may be impaired in KT patients.Research questionWe conducted a cross-sectional investigation to estimate the prevalence of falls, as well as to explore the association between postural balance, muscle strength and history of falls in end-stage renal disease patients living with a KT.MethodsFifty-nine prevalent KT patients (age = 53.2 ± 11 years) were enrolled in this cross-sectional study. Participants were classified as fallers/non-fallers and underwent an objectively-measured assessment of postural balance on a stabilometric platform in eyes open (EO), eyes closed (EC), and dual-task (DT) conditions. Center of pressure (CoP) variables were taken for the analysis. In addition, participants underwent isometric (IM) and isokinetic (IK) assessments of lower limb muscle strength on a multi-joint evaluation system.ResultsThirty-four percent of the study participants reported at least one fall in the previous 12 months. In logistic regression analysis, CoP velocity in EO (OR: 1.23, 95 % CI: 1.06–1.43, p = .007), and IK ankle dorsiflexion strength (OR: 0.87, 95 % CI: 0.77-0.99, p = .034) were independently associated with increased odds of falling.SignificanceThis cross-sectional study indicates that patients living with a KT presented with a prevalence of falls indicative of a high risk of falling. Postural balance and muscle strength are exercise-modifiable factors and further research is warranted to establish to what extent these measures may be implicated in the etiology of falling in this patient group.     

The relationship between hallux grip force and balance in people with diabetes

BackgroundDiabetes accelerates the decline in muscle strength in older people and substantially increases the risk for fall and injury. Weakening of lower extremity muscles, in particular, is a strong predictor for falls, but currently there is no established method for its assessment in clinics. The paper grip test (PGT) offers a qualitative assessment of hallux plantar flexor strength and its usefulness for predicting falls has been demonstrated in non-diabetic populations.Research questionThe aim of this study is to test whether the PGT can be used for a quantitative assessment of lower-extremity strength and to investigate its relationship with isometric muscle strength and balance in people with diabetes and peripheral neuropathy.MethodsIsometric muscle strength of all muscle groups of the foot-ankle was assessed using a dynamometer in sixty-nine people with diabetes and neuropathy. Postural sway and the gripping force exerted by the participants during the PGT was measured for the same participants using a plantar pressure assessment system. These measurements were repeated in regular intervals for 18 months in a longitudinal observational cohort study.ResultsCross-sectional analysis of baseline data showed that people who failed the PGT swayed more. Analysis of longitudinal data showed that increasing hallux grip force is significantly associated with reduced postural sway. No significant association was found between dynamometry-based measurements of strength and postural sway. Hallux grip force was significantly correlated to the strength of all muscle groups of the foot-ankle complex.SignificanceThese results indicate that hallux grip force can assess the strength of the foot-ankle muscles and could potentially be used to identify people at risk of falling. This sets the basis for the development of new screening protocols to assess weakening of the muscles of the foot-ankle and to enhance risk assessment for falls in people with diabetes and peripheral neuropathy.     

Relationship between hip abductor strength,rate of torque development scaling factor and medio-lateral stability in older adults

BackgroundRecently, the rate of torque development scaling factor (RTD-SF) has been proposed as a useful tool that could contribute to a more comprehensive insight into muscular capacity. While lower RTD-SF is associated with ageing and certain neuromuscular diseases, it remains unknown whether this novel measure is associated with the postural control in the older adults.Research questionAre hip abductor muscle strength, RTD and RTD-SF associated with responses to external postural perturbations in medio-lateral direction in older adults?MethodsTwenty healthy older adults (14 females, 6 males) were assessed for hip abductor muscle strength, RTD and RTD-SF, using a custom-built dynamometer. Perturbations were applied at waist level (4 perturbation intensities, 15 repetitions each) using a wire-pull paradigm, with centre-of-pressure (CoP) being recorded with force plates. For each condition (i.e. perturbation intensity), medio-lateral displacement and velocity of the CoP were computed. For both parameters, within-individual variation (representing consistency of the responses), expressed by the standard deviation (SD) of CoP parameters was also considered. Pearson correlation coefficients were computed between parameters of hip muscle capacity and CoP responses and SD values of CoP responses.ResultsRTD-SF was moderately positively related to the consistency of the responses of both CoP displacement and velocity (r = 0.53−0.56; p = 0.011−0.016) at the lowest level of the perturbation magnitude (15 N). No other statistically significant relationships were found (all r < 0.35).SignificanceRTD-SF could play a role in preserving postural balance in older adults when low-intensity perturbations are applied. RTD-SF is a novel outcome measure that could represent an important alternative clinical tool to traditional strength assessments. It could represent a supplementary tool to assess the risk of falls, however, several limitations and ambiguities need to be resolved by future research before it can be utilized in practice.     

Effects of gender on dual-tasking and prioritization in older adults

BackgroundThe ability to produce effective posture and balance while distracted (dual-tasking; DT), is critical for mobility. In particular, individuals implicit prioritization across posture and secondary, distracting stimuli may impact fall risk. However, the impact of gender on DT and prioritization during gait is poorly understood.Research questionDoes gender impact DT effects or prioritization while DT walking?MethodsOne hundred older adults participated. The timed up and go (TUG) was completed with and without a secondary cognitive task (counting backwards by 3′s). Gait (time to complete the TUG), and cognitive (rate of correct numbers listed) performance was recorded during both single tasks and while dual-tasking. DT effects were calculated for cognitive and gait performance. Prioritization was calculated as the difference between cognitive and gait DT effects. The effect of gender on DT and prioritization was assessed, controlling for age and cognitive ability.ResultsGender by condition (single vs. dual-task) interaction effects were observed (Gait: F_1,96 =8.7; p = 0.004; Cognition: F_1,96 =5.2; p = 0.024) such that, compared to male participants, females exhibited smaller cognitive DT effects, and larger gait DT effects. Further, females exhibited significantly larger prioritization scores (F_1,95 =10.0, p = 0.002), indicating a cognitive prioritization compared to males.SignificanceGiven the link between posture-second strategies and falls, the current findings may provide some insight into previous results suggesting an increased fall-risk in older-adult women. However, this study did not investigate falls. Therefore, additional work is necessary to confirm current findings and further investigate the relationship between gender, prioritization, and falls; and its possible clinical relevance.     

Deficits in medio-lateral balance control and the implications for falls in individuals with multiple sclerosis

A major health concern faced by individuals with Multiple Sclerosis (MS) is the heightened risk of falling. Reasons for this increased risk can often be traced back to declines in neurophysiological mechanisms underlying balance control and/or muscular strength. The aim of this study was to assess differences between persons with MS and age-matched healthy adults in regards to their falls risk, strength, reactions and directional control of balance. Twenty-two persons with multiple sclerosis (mean age 56.3 ± 8.9 years) and 22 age-matched healthy adults (mean age 59.1 ± 7.1 years) participated in the study. Assessments of falls risk, balance, fear of falling, lower limb strength, and reaction time were performed. Balance control was assessed under four conditions where the combined effects of vision (eyes open/closed) and standing surface (firm/pliable surface) were evaluated. Results demonstrated that, in comparison to healthy older adults, persons with MS had a significantly higher falls risk, slower reaction times, and weaker lower- limb strength. For balance, persons with MS exhibited greater overall COP motion in both the medio-lateral (ML) and anterior-posterior (AP) directions compared to older adults. Additionally, during more challenging balance conditions, persons from the MS group exhibited greater ML motion compared to sway in the AP direction. Overall, the results confirm that persons with MS are often at a heightened risk of falling, due to the multitude of neuromuscular changes brought about by this disease process. However, the increased ML sway for the MS group could reflect a decreased ability to control side-to-side motion in comparison to controlling AP sway.     

Postural sway,falls, and self-reported neuropathy in aging female cancer survivors

BackgroundFalls are a major public health concern in older adults, and the proportion of older adults that has been diagnosed with cancer is growing. Yet, while falls, peripheral neuropathy, and postural instability are more common in aging cancer survivors, it is unclear how these factors interact.Research questionOur objective was to examine how components of sway related to self-reported neuropathy and falls.MethodsPostural sway during static stance was recorded with an inertial sensor (APDM Opal), placed on the lumbar spine region in 434 older female cancer survivors (mean age 63) and 49 healthy older female control subjects (mean age 63). Measures of sway were resolved into principal components that were compared between women with and women without self-reported falls in the previous 6 months and between those with and without self-reported symptoms of peripheral neuropathy.ResultsCancer survivors had worse sway than healthy control subjects in components related to sway magnitude and mediolateral frequency of sway, but no difference in the component related to resultant / AP sway jerk and frequency. Cancer survivors who reported neuropathy were more likely to have higher resultant / AP sway frequencies and jerk than asymptomatic survivors, while survivors who reported a fall were more likely to have lower frequencies of mediolateral sway than non-fallers. Falls were more strongly associated with mediolateral sway in survivors with more severe neuropathy; whereas falls were more strongly associated with resultant / AP sway frequency in survivors with less severe neuropathySignificancePostural stability, falls, and neuropathy have complex interactions that can vary across components of postural sway. While the frequency of mediolateral sway was associated with falls across our entire cohort, neuropathy influenced the associations between specific characteristics of sway and falls, which may have implications for fall prevention interventions.     

Chronic exercise preserves lean muscle mass in masters athletes

Aging is commonly associated with a loss of muscle mass and strength, resulting in falls, functional decline, and the subjective feeling of weakness. Exercise modulates the morbidities of muscle aging. Most studies, however, have examined muscle-loss changes in sedentary aging adults. This leaves the question of whether the changes that are commonly associated with muscle aging reflect the true physiology of muscle aging or whether they reflect disuse atrophy. This study evaluated whether high levels of chronic exercise prevents the loss of lean muscle mass and strength experienced in sedentary aging adults. A cross-section of 40 high-level recreational athletes ("masters athletes") who were aged 40 to 81 years and trained 4 to 5 times per week underwent tests of health/activity, body composition, quadriceps peak torque (PT), and magnetic resonance imaging of bilateral quadriceps. Mid-thigh muscle area, quadriceps area (QA), subcutaneous adipose tissue, and intramuscular adipose tissue were quantified in magnetic resonance imaging using medical image processing, analysis, and visualization software. One-way analysis of variance was used to examine age group differences. Relationships were evaluated using Spearman correlations. Mid-thigh muscle area (P = 0.31) and lean mass (P = 0.15) did not increase with age and were significantly related to retention of mid-thigh muscle area (P < 0.0001). This occurred despite an increase in total body fat percentage (P = 0.003) with age. Mid-thigh muscle area (P = 0.12), QA (P = 0.17), and quadriceps PT did not decline with age. Specific strength (strength per QA) did not decline significantly with age (P = 0.06). As muscle area increased, PT increased significantly (P = 0.008). There was not a significant relationship between intramuscular adipose tissue (P = 0.71) or lean mass (P = 0.4) and PT. This study contradicts the common observation that muscle mass and strength decline as a function of aging alone. Instead, these declines may signal the effect of chronic disuse rather than muscle aging. Evaluation of masters athletes removes disuse as a confounding variable in the study of lower-extremity function and loss of lean muscle mass. This maintenance of muscle mass and strength may decrease or eliminate the falls, functional decline, and loss of independence that are commonly seen in aging adults.     

Low thigh muscle mass is associated with coronary artery stenosis among HIV-infected and HIV-uninfected men: The Multicenter AIDS Cohort Study (MACS)

BackgroundHIV-infected individuals are at increased risk for both sarcopenia and cardiovascular disease. Whether an association between low muscle mass and subclinical coronary artery disease (CAD) exists, and if it is modified by HIV serostatus, are unknown.MethodsWe performed cross-sectional analysis of 513 male MACS participants (72% HIV-infected) who underwent mid-thigh computed tomography (CT) and non-contrast cardiac CT for coronary artery calcium (CAC) during 2010–2013. Of these, 379 also underwent coronary CT angiography for non-calcified coronary plaque (NCP) and obstructive coronary stenosis ≥50%. Multivariable-adjusted Poisson regression was used to estimate prevalence risk ratios of associations between low muscle mass (<20th percentile of the HIV-uninfected individuals in the sample) and CAC, NCP and obstructive stenosis.ResultsThe prevalence of low thigh muscle mass was similar by HIV serostatus (20%). There was no association of low muscle mass with CAC or NCP. However, low thigh muscle mass was significantly associated with a 2.5-fold higher prevalence of obstructive coronary stenosis, after adjustment for demographics and traditional CAD risk factors [PR 2.46 (95% CI 1.51, 4.01)]. This association remained significant after adjustment for adiposity, inflammation, and physical activity. There was no significant interaction by HIV serostatus (p-interaction = 0.90).ConclusionsIn this exploratory analysis, low thigh muscle mass was significantly associated with subclinical obstructive coronary stenosis. Additional studies involving larger sample sizes and prospective analyses are needed to confirm the potential utility of measuring mid-thigh muscle mass for identifying individuals at increased risk for obstructive CAD who might benefit from more aggressive risk factor management.     

Impact of strength and balance on Functional Gait Assessment performance in older adults

BackgroundThe Functional Gait Assessment (FGA) evaluates postural stability in gait and predicts fall risk in older adults. Individual tasks within the FGA consider aspects of mobility assumed to require strength and/or balance to complete. Identifying how quantitative measures of strength and balance relate to FGA performance would allow for more targeted interventions based on one’s pattern of performance on different tasks.Research QuestionIs performance on the FGA (total score and individual task scores) related to measures of strength and balance in healthy older adults?MethodsIn a cross-sectional study, healthy older adults (N = 46) were evaluated with the FGA, measures of knee extensor strength, and balance (static stance and weight shifting) (N = 46). Correlational analyses were performed between FGA scores (total and individual) and measures of strength and balance.ResultsTotal FGA performance was positively correlated with knee extensor strength (maximum torque and rate of torque development). Individual FGA tasks of walking backwards (task 9) and stair climbing (task 10) had the highest correlations with strength measures. Total FGA performance was correlated with reduced postural sway in static balance tasks, but not with balance performance on the weight shifting tasks. The individual FGA task that challenged proprioceptive (task 7) inputs for balance was associated with static balance.SignificanceThe total FGA score is related to domains of strength and static balance. The results indicate that the FGA can be influenced by reduced strength and balance. The pattern of performance on individual FGA tasks may indicate whether reduced postural stability in gait is related to deficits in strength or balance domains in this older population.     

Dynamic walking stability of elderly people with various BMIs

BackgroundFalls are one of the major causes of injury in the elderly. Obesity may be related to the risk of falling. Understanding the dynamic stability mechanisms of obese elderly people during gait is important as it may be associated with fall protection.Research questionDoes obesity affect the dynamic walking stability of elderly people?MethodsThis is a prospective study. Fifty-three elderly participants, aged 60–82 years, were categorized into body mass index (BMI) groups. In single-limb support experiments, the center of mass velocity (COMv), center of mass acceleration (COMa), region of velocity stability (ROSv) and region of acceleration stability (ROSa) were calculated using kinematic data sampled from a motion analysis system. In addition, all participants were assessed for the dynamic balance ability test scale (DBATS). Statistical analyses were performed by one-way ANOVA, Kruskal–Wallis/Wilcoxon nonparametric tests, or bivariate Pearson/Spearman correlation analysis.ResultsDuring walking, peak COMv and COMa decreased with increasing BMI (Normal BMI: 1.20 ± 0.14 m/s, 1.66 ± 0.36 m/s²; High BMI: 1.14 ± 0.11 m/s, 1.56 ± 0.30 m/s²; Higher BMI: 1.04 ± 0.15 m/s, 1.47 ± 0.25 m/s²). At toe-off (TO), the normalized participants’ center of mass (COM) is significantly more anterior in the Higher BMI group (Normal BMI: -0.30 ± 0.09, High BMI: -0.23 ± 0.07, Higher BMI: -0.16 ± 0.10), their normalized COMv and COMa (Normal BMI: 1.40 ± 0.16, 0.53 ± 0.11; High BMI: 1.33 ± 0.13, 0.49 ± 0.11; Higher BMI: 1.21 ± 0.16, 0.46 ± 0.11) are slower. The mean DBATS score of the Higher BMI group was the highest, indicating the weakest dynamic balance ability.SignificanceThe COM dynamic stability parameters indicate that obesity may worsen balance, with the peak COMv and ROSv most affected. With increasing BMI, the dynamic stability and balance of elderly people both decreased.     

Exercise attenuates the weight-loss-induced reduction in muscle mass in frail obese older adults

PURPOSE: To evaluate the effect of adding exercise to a hypocaloric diet on changes in appendicular lean mass and strength in frail obese older adults undergoing voluntary weight loss. METHODS: Thirty frail older (age, 70 +/- 5 yr) obese (body mass index, 37 +/- 5 kg.m) adults were randomly assigned to 6 months of diet/behavioral therapy (diet group, n = 15) or diet or behavioral therapy plus exercise that incorporated progressive resistance training (PRT; diet + exercise group; n = 15). Body composition was assessed using dual-energy x-ray absorptiometry, and muscle strength was assessed using one-repetition maximum. The volume of upper extremity (UE) and lower extremity (LE) exercise training was determined by multiplying the average number of repetitions performed by the average weight lifted during the first three exercise sessions and during the last three exercise sessions of the study. RESULTS: The diet and the diet + exercise groups had similar (P > 0.05) decreases in weight (10.7 +/- 4.5 vs 9.7 +/- 4.0 kg) and fat mass (6.8 +/- 3.7 vs 7.7 +/- 2.9 kg). However, the diet + exercise group lost less fat-free mass (FFM; 1.8 +/- 1.5 vs 3.5 +/- 2.1 kg), LE lean mass (0.9 +/- 0.8 vs 2.0 +/- 0.9 kg), and UE lean mass (0.1 +/- 0.2 vs 0.2 +/- 0.2 kg) than the diet group (P < 0.05). The diet + exercise group had greater increases in percent of weight as FFM (FFM / weight x 100) than the diet group (7.9 +/- 3.3 vs 5.4 +/- 3.7%; P < 0.05). Despite lean mass losses, the diet + exercise group increased UE and LE strength in response to exercise (17-43%), whereas the diet group maintained strength. The volume of UE and LE exercises correlated with the amount of UE and LE lean mass (r = 0.64-0.84; P < 0.05). CONCLUSION: Exercise added to diet reduces muscle mass loss during voluntary weight loss and increases muscle strength in frail obese older adults. Regular exercise that incorporates PRT should be used to attenuate muscle mass loss in frail obese older adults on weight-loss therapy.