Differential determinants of physical daily activities in frail and nonfrail community-dwelling older adults

AbstractBackground/PurposeThe purpose of this study was to determine whether or not daily activities determined by average daily steps are associated with age, gender, body mass index, fear of falling, and physical functions (locomotive function, balance function, and muscle power) in community-dwelling nonfrail and frail older adults.MethodsThis is a cross-sectional study conducted in community-dwelling older adults in Japan. Based on the Timed Up and Go (TUG) test, 629 elderly adults were divided into two groups: 515 were grouped to nonfrail elderly (TUG time less than 13.5 seconds, mean age 77.0±7.2 years) and 114 to frail elderly (TUG time of 13.5 seconds or more, mean age 76.1±7.5 years). Daily physical activities were determined by average daily steps measured by pedometer and four other physical function tests (10-m walk test, single-leg standing, functional reach, and five-chair stand test) were performed along with the assessment of fear of falling.ResultsStepwise regression analysis revealed that age, gender, 10-m walk test, and single-leg standing were significant and independent determinants of the average step counts in the nonfrail elderly (R2=0.282, p<0.001), whereas fear of falling was the only significant and independent determinant of the average step counts in the frail elderly (R2=0.119, p<0.001).ConclusionThese results indicate that differential factors may be related to daily activities depending on the level of frailty in community-dwelling older adults

Differences in muscle coactivation during postural control between healthy older and young adults.

The purpose of this study was to clarify the difference in muscle coactivation during postural control between older and young adults and to identify the characteristics of postural control strategies in older adults by investigating the relationship between muscle coactivation and postural control ability. Forty-six healthy older adults (82.0±7.5 years) and 34 healthy young adults (22.1±2.3 years) participated. The postural tasks selected consisted of static standing, functional reach, functional stability boundary and gait. Coactivation of the ankle joint was recorded during each task via electromyography (EMG). The older adults showed significantly higher coactivation than the young adults during the tasks of standing, functional reach, functional stability boundary (forward), and gait (p<0.01). Postural sway area (ρ=0.42, p<0.05) and functional reach distance (ρ=-0.52, p<0.05) significantly correlated with coactivation during the corresponding task in older adults, i.e., muscle coactivation was significantly higher in the elderly with low postural control ability than in the elderly with high balance ability. Increased muscle coactivation could be a necessary change to compensate for a deterioration in postural control accompanying healthy aging. Further research is needed to clarify in greater detail positive and negative effects of muscle coactivation on postural control

Concept Software Based on Kinect for Assessing Dual-Task Ability of Elderly People

[Objective]: Assessment of fall risk of elderly people is a critical issue. Dual-task (DT) ability is a criterion for risk assessment. We developed new concept software based on Microsoft (Redmond, WA) Kinect™ for assessing DT ability. The software is named "Dual-Task Tai Chi" (DTTC) and includes Tai Chi and number place (Sudoku) components. The purpose of this study is to validate the DTTC test for assessment of DT ability. [Subjects and Methods]: Forty-five community-dwelling elderly (mean age, 74.1±6.6 years) individuals participated in this study. They performed DTTC, locomotive, cognitive, and DT tests. DT ability was evaluated with a 10-m walk under a cognitive-task condition and a 10-m walk under a manual-task condition. The correlation between the time taken to complete the DTTC test and each function test was determined using Pearson correlation coefficients. Stepwise multiple regression analysis was conducted to assess the relationship between the DTTC test results and results of the other tests. [Results]: The time taken to complete the DTTC test was correlated with DT ability, locomotive functioning, and cognitive functioning. Results of stepwise multiple regression analysis confirmed that DT, balance, and cognitive ability are statistically significant. No statistically significant association was found for the other variables. [Conclusions]: The DTTC test quantitatively evaluates a compound function including DT, balance, and cognitive abilities

Effects of toe and ankle training in older people: a cross-over study.

Maintenance of physical function in the elderly is important. Previous studies have focused mainly on training-center-based interventions, accompanied by training staff or equipped with training machinery. The purpose of this study was to investigate the effects of toe and ankle training for the elderly

Effects of balance training on muscle coactivation during postural control in older adults: a randomized controlled trial.

[Background] Recently, several studies have reported age-associated increases in muscle coactivation during postural control. A rigid posture induced by strong muscle coactivation reduces the degree of freedom to be organized by the postural control system. The purpose of this study was to clarify the effect of balance training on muscle coactivation during postural control in older adults. [Methods] Forty-eight subjects were randomized into an intervention (mean age: 81.0 ± 6.9 years) and a control group (mean age: 81.6 ± 6.4 years). The control group did not receive any intervention. Postural control ability (postural sway during quiet standing, functional reach, and functional stability boundary) was assessed before and after the intervention. A cocontraction index was measured during the postural control tasks to assess muscle coactivation. [Results] Cocontraction index values in the intervention group significantly decreased following the intervention phase for functional reach (p < .0125). Cocontraction index values had a tendency to decrease during functional stability boundary for forward and quiet standing tasks. Functional improvements were observed in some of the tasks after the intervention, that is, functional reach, functional stability boundary for forward, one-leg stance, and timed up and go (p < .05). [Conclusions] Our study raised the possibility that balance training for older adults was associated with decreases in muscle coactivation during postural control. Postural control exercise could potentially lead older adults to develop more efficient postural control strategies without increasing muscle coactivation. Further research is needed to clarify in greater detail the effects of changes in muscle coactivation

Development of a New Fall Risk Assessment Index for Older Adults

SummaryBackgroundFalls are the third-leading cause of a bedridden state and are a major cause of morbidity in elderly people. Therefore, it is important to determine an older person’s risk of falling using a simple and reliable method. The aim of the present study was to examine whether our newly developed index for the assessment of complex-task locomotion can predict falls in robust elderly people.MethodsThe new index consisted of four items (stand-up, turn, walk and trip tests). It was used to assess 780 community-dwelling elderly Japanese people (mean age 76.0±7.4 years, 300 men and 480 women) who could complete a Timed Up and Go test in less than 13.5 seconds. We used receiver operating characteristic curves (ROC) to validate the index and to determine its cut-off point to predict falls.ResultsThe area under the curve was 0.15 (p<0.001, 95% CI: 0.675-0.755). The ROC curve analysis enabled the best cut-off (1 point) to discriminate fallers from non-fallers (sensitivity 80.8%, specificity 60.6%).ConclusionWe have demonstrated that the new index is a reliable indicator for falls in elderly people who have higher levels of functional capacity. Our data suggest that a score of more than 1 point by the new index can predict falls in robust elderly people

Reliability and validity of gait analysis by android-based smartphone.

Abstract Smartphones are very common devices in daily life that have a built-in tri-axial accelerometer. Similar to previously developed accelerometers, smartphones can be used to assess gait patterns. However, few gait analyses have been performed using smartphones, and their reliability and validity have not been evaluated yet. The purpose of this study was to evaluate the reliability and validity of a smartphone accelerometer. Thirty healthy young adults participated in this study. They walked 20 m at their preferred speeds, and their trunk accelerations were measured using a smartphone and a tri-axial accelerometer that was secured over the L3 spinous process. We developed a gait analysis application and installed it in the smartphone to measure the acceleration. After signal processing, we calculated the gait parameters of each measurement terminal: peak frequency (PF), root mean square (RMS), autocorrelation peak (AC), and coefficient of variance (CV) of the acceleration peak intervals. Remarkable consistency was observed in the test-retest reliability of all the gait parameter results obtained by the smartphone (p<0.001). All the gait parameter results obtained by the smartphone showed statistically significant and considerable correlations with the same parameter results obtained by the tri-axial accelerometer (PF r=0.99, RMS r=0.89, AC r=0.85, CV r=0.82; p<0.01). Our study indicates that the smartphone with gait analysis application used in this study has the capacity to quantify gait parameters with a degree of accuracy that is comparable to that of the tri-axial accelerometer

Relationship between Rate of Force Development of Tongue Pressure and Physical Performance

In the assessment of skeletal muscle strength, rate of force development (RFD) is clinically identified as a functional index that reflects the effects of aging, but there are few reports on RFD of the tongue. The purpose of this study was to examine the relationship between RFD of tongue pressure (RFD-TP) and oral and whole-body physical performance in older adults, and to clarify its characteristics. We enrolled adults aged &ge;65 years with pathological occlusal contact in premolar and molar regions of teeth in the Tamba-Sasayama area, Japan, from 2017 to 2018. Maximum tongue pressure (MTP) and the speed to reach the maximum tongue pressure (RFD-TP) were evaluated as measures of tongue function. Oral functions related to objective measures of tongue function, such as repetitive saliva swallowing test, oral diadochokinesis, and physical status or performance, such as mini mental state examination, body mass index, skeletal mass index, knee extension force, one-leg standing time, grip strength, walking speed, timed up-and-go test, and five-time chair stand speed was evaluated. No significant correlation was found between MTP and age, but RFD-TP had a significant negative correlation with age. Neither RFD-TP nor MTP showed a significant correlation with oral function. RFD-TP was associated with physical performance, such as knee extension force and one-leg standing time. RFD-TP is more sensitive to aging than MTP. In addition, RFD-TP is related to physical performance and may be useful for the early detection of frailty

Development of a New Fall Risk Assessment Index for Older Adults

Background: Falls are the third-leading cause of a bedridden state and are a major cause of morbidity in elderly people. Therefore, it is important to determine an older person’s risk of falling using a simple and reliable method. The aim of the present study was to examine whether our newly developed index for the assessment of complex-task locomotion can predict falls in robust elderly people. Methods: The new index consisted of four items (stand-up, turn, walk and trip tests). It was used to assess 780 community-dwelling elderly Japanese people (mean age 76.0±7.4 years, 300 men and 480 women) who could complete a Timed Up and Go test in less than 13.5 seconds. We used receiver operating characteristic curves (ROC) to validate the index and to determine its cut-off point to predict falls. Results: The area under the curve was 0.15 (p<0.001, 95% CI: 0.675-0.755). The ROC curve analysis enabled the best cut-off (1 point) to discriminate fallers from non-fallers (sensitivity 80.8%, specificity 60.6%). Conclusion: We have demonstrated that the new index is a reliable indicator for falls in elderly people who have higher levels of functional capacity. Our data suggest that a score of more than 1 point by the new index can predict falls in robust elderly people