The Contributions of Knee Extension Strength and Hand Grip Strength to Factors Relevant to Physical Frailty: The Tanno-Sobetsu Study.

Sarcopenia is the core factor of frailty. This study specifically focused on lower limb muscle strength and examined muscle indices that indicate the risk of frailty or pre-frailty in older adults. The study included 327 community-dwelling individuals aged ≥65 years (43.7% male) who participated in the cohort. Frailty was defined based on five symptoms: weight loss, low activity level, exhaustion, weakness and slowness. Participants were classified into frail (three or more applicable), pre-frail (one to two applicable) and non-frail groups. Muscle strength (knee extension strength, toe grip strength and hand grip strength) were assessed, and appendicular muscle mass was assessed via a bioelectrical impedance analysis. The adjusted odds ratio (OR) of muscle indices for with frailty (frail group vs. pre-frail group) or pre-frailty (pre-frail group vs. non-frail group) were calculated. The prevalence of frail and pre-frail was 7% and 40%, respectively. Adjusted for age, sex, albumin and medical history, knee extension strength was significantly associated with frailty (odds ratio 0.95, 95% CI 0.92-0.98), while hand grip strength was associated with pre-frailty (odds ratio 0.92, 95% CI 0.88-0.97) but not with other muscle indices. This study is significant for identifying knee extension strength as a factor relevant to frailty in older adults considered pre-frailty, emphasizing the importance of this specific muscle measure in predicting and managing frailty.

Preserved Lower Limb Muscle Mass Prevents Insulin Resistance Development in Nondiabetic Older Adults.

OBJECTIVE: To investigate roles of sarcopenia indexes in prediction of development of insulin resistance in nondiabetic older adults. DESIGN: A 2-year follow-up cohort. SETTING AND PARTICIPANTS: The Tanno-Sobetsu study, a prospective observational cohort, included 194 community-dwelling nondiabetic older adults during 2017-2019. METHODS: Lower limb, upper limb, appendicular, and trunk muscle masses by a bioelectrical impedance analysis, grip strength, knee extension torque, and walking speed were measured in study participants aged ≥65 years (79 men and 115 women) at baseline. Muscle mass and strength were divided by the weight, and then multiplied by 100 to calculate the weight ratio (%). Insulin resistance was assessed by homeostasis model (HOMA-IR) at baseline, and the study participants whose HOMA-IR was less than 1.73 at baseline were followed for a maximum of 2 years. The study endpoint was development of insulin resistance defined as HOMA-IR ≥1.73. The adjusted hazard ratio (HR) of each sarcopenia component for development of insulin resistance was calculated. RESULTS: Lower limb muscle mass (HR 0.88, 95% CI 0.79-0.98) and appendicular muscle mass (HR 0.89, 95% CI 0.81-0.99), but not other sarcopenia components, were associated with the development of insulin resistance, independently of sex and age, HOMA-IR, and waist circumference at baseline. CONCLUSIONS AND IMPLICATIONS: The loss of lower limb muscle mass is a significant risk factor for development of insulin resistance independently of obesity in nondiabetic older adults. The lower limb muscle mass may be a novel target of interventions for the prevention of diabetes in older adults.

Walking Speed Is Better Than Hand Grip Strength as an Indicator of Early Decline in Physical Function with Age in Japanese Women Over 65: A Longitudinal Analysis of the Tanno-Sobetsu Study Using Linear Mixed-Effects Models.

The decline in physical function with age is a major contributor to the need for long-term care. Age-related changes in hand grip strength, knee extension, and walking speed have been reported in cross-sectional studies, but longitudinal data are needed. This longitudinal study measured changes in these three measures among community-dwelling adults aged 65-89 years who participated in general health examinations between 2017 and 2019. Analyses were stratified by sex. Linear mixed-effects models adjusted for confounding factors were used to examine the interaction of different patterns of change with age of the three measures. A total of 284 participants were included in the analysis. The interaction term of age × walking speed, with age × handgrip strength as the reference, was statistically significant in women and showed different patterns in walking speed and hand grip strength. In men, none of the age × physical function interaction terms were significant in any model. For early recognition of the onset of physical function decline in older adults, any of the three measures may be used in men, but walking speed may be more suitable than hand grip strength in women. These findings may be useful in devising sex-specific screening strategies.

Toe Grip strength declines earlier than hand grip strength and knee extension strength in community-dwelling older men: a cross sectional study.

BACKGROUND: The aim of this study is to examine the age-related changes in the toe grip strength and its differences from hand grip strength and knee extension strength using cross-sectional data. METHODS: Of participants aged 65 years over who underwent health checkups for lifestyle-related diseases in 2018, 307 men and women met the criteria. Toe grip strength, hand grip strength, and knee extension strength were also measured as optional tests. The participants were divided into five groups categorized by every 5 years of age (Group 65-85). The data were analyzed with multiple comparisons using the linear mixed multilevel model to examine the following categories: association between age and muscle strength, differences in the pattern of change, and gender, using the 65-69 years group as a reference. RESULTS: In men, there were interaction effects between the factors of age and muscle, but in women there were not. Toe grip strength was significantly lower in Group 70, 75, 80, and 85 in men, lower in Group 85 than in 65 in women. Hand grip strength was significantly lower in Group 85 than in 65 in both men and women. There was no significant difference in knee extension strength among the age groups for both men and women. CONCLUSIONS: The decline in toe grip strength may occur earlier and in a different pattern from hand grip strength and knee extension strength in men.

Association of Social Capital and Locus of Control with Perceived Health during the COVID-19 Pandemic in Japan.

Previous studies have indicated that social capital and locus of control influence mental health. Accordingly, we investigated the effect of social capital and locus of control on perceived physical and mental health in the general Japanese population during the COVID-19 pandemic. In order to conduct a cross-sectional study, in 2021, three thousand citizens were randomly selected from the Chitose City Resident Register according to ten strata of sex and age classes between 30 years and 79 years. Because thirteen persons moved away from the city, the survey was conducted for the remaining 2987 citizens. A total of 1430 citizens (712 males, 718 females) responded to the survey with their written informed consent (response rate, 47.9%). As a result, social capital measured three dimensions, namely social support, social participation, and trust and reciprocity, and internal locus of control was significantly inversely associated with it, but external locus of control was significantly positively associated with impaired physical and mental health in male and female subjects after adjustment of lifestyle habits and lifestyle change affected by the pandemic. Strengthening social capital and internal locus of control, and weakening external locus of control, may improve physical and mental health, even if the pandemic would bring about distress. Further longitudinal study is needed to examine the causal relationship among them.

Repeated standing back extension exercise: Influence on muscle shear modulus change after lumbodorsal muscle fatigue.

BACKGROUND: In low back pain, multifidus muscle fibers reportedly exhibit increased stiffness. Low back pain was associated with lumbodorsal muscle fatigue. There is no report of using shear modulus to verify the mechanism of an immediate effect of exercise on low back pain. Here, temporary lumbodorsal muscle fatigue was created, simulating fatigue-related nonspecific low back pain. OBJECTIVE: To assess the effect of standing back extension exercise on fatigued lumbodorsal muscle based on the results of multifidus muscle elasticity measured using shear wave elastography. METHODS: Thirty-three healthy subjects were randomly divided into three groups. The subjects performed the Biering-Sorensen test as the fatigue-task of the lumbodorsal muscle before the standing back extension exercise. The fatigue-exercise group exercised five sets after completing the fatigue-task. The fatigue-non-exercise group remained standing for the same duration as the fatigue-exercise group without doing the exercise after the fatigue-task. The non-fatigue-exercise group exercised five sets of without performing the fatigue-task. As intra-group and inter-group factors, the shear modulus of the multifidus muscle was compared before and after the exercise. RESULTS: The shear modulus of the multifidus muscle after the standing back extension exercise was significantly lower in the fatigue-exercise group, and no significant decrease was observed in the fatigue-non-exercise and non-fatigue-exercise group. CONCLUSIONS: The standing back extension exercise improved the shear modulus of the fatigued multifidus muscle. Therefore, it was suggested that the change in the elasticity of fatigued muscle might lead to the prevention of low back pain caused by muscle fatigue.

Lower limb muscle mass is associated with insulin resistance more than lower limb muscle strength in non-diabetic older adults.

AIM: We examined the association of muscle mass and muscle strength with insulin resistance, focusing on lower limb muscles. METHODS: This was a cross-sectional study, and participants were registered in 2017 from the Tanno-Sobetsu Study, a population-based cohort study. After excluding individuals aged <64 years or with a history of diabetes mellitus, 272 non-diabetic older adults (116 men, 156 women) met the inclusion criteria. According to the homeostasis model assessment of insulin resistance, the participants were divided into two groups; that is, the insulin resistance group (homeostasis model assessment of insulin resistance ≥1.73) and non-insulin resistance group (homeostasis model assessment of insulin resistance <1.73). Muscle mass (lower limb, upper limb, appendicular and trunk) and muscle strength (grip strength and knee extension torque) were measured and divided by the weight, and then multiplied by 100 to calculate the weight ratio (%). The adjusted odds ratio (OR) of each muscle index for risk of insulin resistance was calculated separately for both men and women. RESULTS: Lower limb muscle mass (OR 0.72, 95% CI 0.55-0.92 in men; OR 0.69, 95% CI 0.51-0.96 in women, respectively) and appendicular muscle mass (OR 0.75, 95% CI 0.61-0.94 in men; OR 0.72, 95% CI 0.54-0.95 in women, respectively), but not other muscle indexes, were associated with risk of insulin resistance, after adjusting for age, body mass index, highly sensitive C-reacting protein and smoking habits. CONCLUSIONS: Lower limb muscle mass of non-diabetic older adults is independently related to insulin resistance. Geriatr Gerontol Int 2019; 19: 1254-1259.

Reproducibility of elastic modulus measurement of the multifidus using the shear wave elastography function of an ultrasound diagnostic device.

[Purpose] This study aimed to obtain evidence of the musculo-physiological involvement in the effect of physiotherapy on low back pain by examining the reproducibility of elasticity measurements of the multifidus muscle at different trunk angles via the shear wave elastography function of an ultrasound diagnostic device. [Participants and Methods] This study included 11 healthy adults. Measurements were conducted with participants in the prone position, and the elasticity of the superficial and deeper layers of the multifidus muscle was measured under the following 3 conditions: trunk at neutral position, trunk flexed at 40°, and trunk extended at 20°. Next, intraclass correlation coefficients (1, 1) were calculated to examine the intrarater reliability. [Results] All intraclass correlation coefficients for the superficial and deeper layers of the multifidus muscle were ≥0.85 for all 3 conditions. [Conclusion] Regardless of the trunk position, the elastic modulus measurement of inner muscles via shear wave elastography serves as an assessment of biological changes in individuals with lower back pain in response to interventions.

Change in the circulation and activity of the lower erector spinae muscles after repeated trunk extension movement.

BACKGROUND: The optimum repetition number of standing back-extension exercise (SBEE) effective for the prevention and improvement of low back pain (LBP) is unknown. OBJECTIVE: To determine the effect of physiotherapy on LBP by investigating the optimum repetition number of SBEE via optical analysis and electromyographic (EMG) examination of the multifidus muscles. METHODS: Hemodynamics and multifidus muscle activity were examined in 16 healthy adult men using near-infrared spectroscopy and surface EMG after performing repetitive SBEE. RESULTS: Oxidized hemoglobin (Oxy-Hb) levels significantly increased in the second extension phase but decreased in the third and subsequent extension phases; deoxidized hemoglobin (deOxy-Hb) levels increased in the third and subsequent extension phases. In the standing phase, no significant difference was observed; in the third and subsequent phases, Oxy-Hb levels decreased and deOxy-Hb levels increased. Muscular activity significantly decreased in the second standing phase but increased in the third and subsequent phases. No significant difference was observed in the extension phase with respect to the number of SBEE repetitions performed. In healthy individuals, hemodynamics improved up to second repetition of SBEE; subsequent repetitions may decrease hemodynamics because of increased activity of the multifidus muscles. CONCLUSIONS: In healthy individuals, hemodynamics improved up to second repetition of SBEE.

Differences in physical activity between seasons with and without snowfall among elderly individuals residing in areas that receive snowfall.

[Purpose] This study aimed to examine the influence of climatic conditions on the daily physical activities of elderly individuals by comparing the physical activity during seasons with and without snowfall. [Participants and Methods] In total, 35 participants attending the Health Promotion Program conducted by Chitose City Office participated in this study. The survey for the seasons with snowfall was conducted in February 2016, while the survey for the seasons without snowfall was conducted in September 2015. The physical activity of the participants was measured using a Kenz Lifecorder GS accelerometer. [Results] Physical activity was found to be significantly lower during seasons with snowfall than in seasons without snowfall. Multivariate analysis revealed that physical activity significantly increased with lower temperature during the seasons with snowfall, and it significantly increased with higher temperature and decreased with larger amounts of precipitation during the seasons without snowfall. [Conclusion] It was found that the climatic conditions affect the level of physical activity during seasons with and without snowfall. A lower level of physical activity was observed in areas that received snowfall than in areas that did not receive snowfall.

Reliability and Validity of Seated Hip Extensor Strength Measurement by Handheld Dynamometer in Older Adults.

BACKGROUND AND PURPOSE: Muscle strength measurements with the handheld dynamometer are sometimes performed according to manual muscle testing. However, measuring hip extensor muscle strength in the prone position is difficult, since the some older adults have kyphosis or flexion contracture of the lower limbs. Alternatively, there is the standing position method of manual muscle testing, which accomodates those malalignments; however, it is known that the muscle strength of the lower limb that is not measured affects the measurement result. Hence, we devised the hip extensor strength measurement in a sitting position for healthy males in previous studies. This study examined the reliability and validity of the sitting measurement by a handheld dynamometer in older adults. METHODS: Participants were 40 older adults (age [SD] = 82.4 [4.3] years). Measurements of isometric hip extensor muscle strength using a handheld dynamometer in 3 positions (sitting, standing, and prone) were conducted twice. A surface electromyogram was used to measure the activity of the gluteus maximus and the semitendinosus muscles. The reliability of muscle strength in each posture was examined with Cronbach α coefficient, intraclass correlation coefficients (ICCs1,1), and Bland-Altman analysis. The concurrent validity of muscle strength for the sitting and standing positions with reference to the prone position was examined with Spearman rank correlation and Bland-Altman analysis. Furthermore, muscle strength and muscle activity were compared between each posture. RESULTS: The Cronbach α coefficient was 0.75. For each posture, the ICC1,1 was 0.86 to 0.87, with no systematic error in the sitting and prone positions. The sitting and standing positions were significantly associated with the prone position (rs = 0.72 and 0.42), with no systematic error between the sitting and prone positions. Proportional error was demonstrated between the standing and prone positions (P < .01). There was no significant difference in muscle strength between any posture. Gluteus maximus muscle activity was significantly higher in the sitting versus standing position (P < .05). CONCLUSION: The measurement of hip extensor muscle strength in the sitting position is a reliable and valid method in older adults, which can be effective even when the prone position is not possible.

Effects of movement from a postural maintenance position on lumbar hemodynamic changes.

[Purpose] To investigate the effects of movement from a postural maintenance position on lumbar hemodynamic changes, in order to prevent lower back pain and develop exercise therapy. [Subjects and Methods] Twenty-five healthy adults (mean age: 23.2 years) participated in the study. During flexion-extension exercise, the subjects moved their trunks gradually to a flexed position from an upright posture while sitting and standing, and then returned to and maintained an upright (re-upright) position. In the extension-flexion exercise, the subjects moved their trunks gradually from an upright posture to an extended position, and back while maintaining an upright (re-upright) position. Lumbar spinal muscle activity and hemodynamic changes were evaluated during both exercises. [Results] During the flexion and extension exercises, increased trunk-flexion angle caused increased muscle activity, decreased oxygenated hemoglobin in the multifidus muscle, and increased deoxygenated hemoglobin in the multifidus and lumbar erector spinae muscles. Moreover, the muscle activities were nearly the same in the re-upright and upright positions, and total hemoglobin also increased. [Conclusion] In both standing and sitting positions, holding the trunk in a flexed position causes ischemic hemodynamic changes in the multifidus muscle; however, the hyperemic response when returning the trunk to an extended position may improve circulation.

Upper extremity muscle tone and response of tidal volume during manually assisted breathing for patients requiring prolonged mechanical ventilation.

[Purpose] The aim of the present study was to examine, in patients requiring prolonged mechanical ventilation, if the response of tidal volume during manually assisted breathing is dependent upon both upper extremity muscle tone and the pressure intensity of manually assisted breathing. [Subjects] We recruited 13 patients on prolonged mechanical ventilation, and assessed their upper extremity muscle tone using the modified Ashworth scale (MAS). The subjects were assigned to either the low MAS group (MAS≤2, n=7) or the high MAS group (MAS≥3, n=6). [Methods] The manually assisted breathing technique was applied at a pressure of 2 kgf and 4 kgf. A split-plot ANOVA was performed to compare the tidal volume of each pressure during manually assisted breathing between the low and the high MAS groups. [Results] Statistical analysis showed there were main effects of the upper extremity muscle tone and the pressure intensity of the manually assisted breathing technique. There was no interaction between these factors. [Conclusion] Our findings reveal that the tidal volume during the manually assisted breathing technique for patients with prolonged mechanical ventilation depends upon the patient's upper extremity muscle tone and the pressure intensity.

Test-retest reliability of expiratory abdominal compression with a handheld dynamometer in patients with prolonged mechanical ventilation.

[Purpose] The present study aimed to examine the test-retest reliability of expiratory abdominal compression with a handheld dynamometer in patients with prolonged mechanical ventilation. [Subjects and Methods] We recruited 18 patients with prolonged mechanical ventilation. All patients had impaired consciousness. The mode of the ventilator was synchronized intermittent mandatory ventilation. The abdomen above the navel was vertically compressed using a handheld dynamometer in synchronization with expiration. Expiratory abdominal compression was performed two times. We measured the tidal volume during expiratory abdominal compression. There was an interval of 5 minutes between the first and second measurements. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were performed to examine the test-retest reliability of expiratory abdominal compression with a handheld dynamometer. [Results] The test-retest reliability of expiratory abdominal compression was excellent (ICC(1, 1): 0.987). Bland-Altman analysis showed that there was no fixed bias and no proportional bias. [Conclusion] The findings of this study suggest that expiratory abdominal compression with a handheld dynamometer is reliable and useful for patients with respiratory failure and prolonged mechanical ventilation.

Parameters affecting the tidal volume during expiratory abdominal compression in patients with prolonged tracheostomy mechanical ventilation.

[Purpose] The aim of this study was to clarify physical parameters affecting the tidal volume during expiratory abdominal compression in patients with prolonged tracheostomy mechanical ventilation. [Methods] Eighteen patients with prolonged mechanical ventilation were included in this study. Expiratory abdominal compression was performed on patients lying in a supine position. The abdomen above the navel was vertically compressed in synchronization with expiration and released with inspiration. We measured the tidal volume during expiratory abdominal compression. [Results] The mean tidal volume during expiratory abdominal compression was higher than that at rest (430.6 ± 127.1 mL vs. 344.0 ± 94.3 mL). The tidal volume during expiratory abdominal compression was correlated with weight, days of ventilator support, dynamic compliance and abdominal expansion. Stepwise multiple regression analysis revealed that weight (ß = 0.499), dynamic compliance (ß = 0.387), and abdominal expansion (ß = 0.365) were factors contributing to the tidal volume during expiratory abdominal compression. [Conclusion] Expiratory abdominal compression increased the tidal volume in patients with prolonged tracheostomy mechanical ventilation. The tidal volume during expiratory abdominal compression was influenced by each of the pulmonary conditions and the physical characteristics.

Measuring seated hip extensor strength using a handheld dynamometer: an examination of the reliability and validity of the protocol.

[Purpose] The purpose of this study was to examine the reliability and validity of measurements of hip extensor muscle strength using a handheld dynamometer (HHD) with subjects in a sitting position. In doing so, we also aimed to establish a modified method of measurement for patients with flexion contractures in the trunk and lower extremities. [Subjects and Methods] In 20 healthy males, hip extensor muscle strength was measured using a handheld dynamometer in sitting, prone, and standing positions by contracting the hip extensor muscle isometrically with the knee flexed at 90 degrees. For each position, we investigated the relative and absolute reliability and validity of the measurements, and compared muscle strength between the different positions. [Results] The reliability and validity of measurements were highest in the sitting position and higher in both the sitting and standing positions as compared with those in the prone position. [Conclusion] Our findings suggest that measurements taken in a sitting position are accurate in assessing hip extensor muscle strength and would be applicable to patients with flexion contractures in the trunk and lower extremities.

Comparison of changes in tidal volume associated with expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation.

[Purpose] This study was designed to compare and clarify the relationship between expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation, with a focus on tidal volume. [Subjects and Methods] The subjects were 18 patients on prolonged mechanical ventilation, who had undergone tracheostomy. Each patient received expiratory rib cage compression and expiratory abdominal compression; the order of implementation was randomized. Subjects were positioned in a 30° lateral recumbent position, and a 2-kgf compression was applied. For expiratory rib cage compression, the rib cage was compressed unilaterally; for expiratory abdominal compression, the area directly above the navel was compressed. Tidal volume values were the actual measured values divided by body weight. [Results] Tidal volume values were as follows: at rest, 7.2 ± 1.7 mL/kg; during expiratory rib cage compression, 8.3 ± 2.1 mL/kg; during expiratory abdominal compression, 9.1 ± 2.2 mL/kg. There was a significant difference between the tidal volume during expiratory abdominal compression and that at rest. The tidal volume in expiratory rib cage compression was strongly correlated with that in expiratory abdominal compression. [Conclusion] These results indicate that expiratory abdominal compression may be an effective alternative to the manual breathing assist procedure.