Atrophy of the lower limbs in elderly women: is it related to walking ability?

This study investigated the relationship between walking ability and age-related muscle atrophy of the lower limbs in elderly women. The subjects comprised 20 young women and 37 elderly women who resided in nursing homes or chronic care institutions. The elderly subjects were divided into three groups according to their walking ability. The muscle thickness of the following ten lower limb muscles were measured by B-mode ultrasound: the gluteus maximus, gluteus medius, gluteus minimus, psoas major, rectus femoris, vastus lateralis, vastus intermedius, biceps femoris, gastrocnemius and soleus. Compared to the young group, muscle thicknesses of all muscles except the soleus muscle were significantly smaller in all the elderly groups. There were no significant differences between the fast- and slow-walking groups in the thickness of any muscle. In the dependent elderly group, noticeable muscle atrophy was observed in the quadriceps femoris muscle. The results of this study suggest that the elderly who are capable of locomotion, regardless of their walking speed, show a moderate degree of age-related atrophy, while those who do not walk exhibit more severe atrophy, especially in the quadriceps femoris muscle

Physical Activity Mediates the Relationship between Gait Function and Fall Incidence after Total Knee Arthroplasty

The present study aims to examine (1) the preoperative factors that can predict postoperative falls, (2) whether postoperative physical activity (PA) mediates the relationship between fall incidence and gait function, and (3) whether postoperative PA levels are associated with fall risk in total knee arthroplasty (TKA) patients. Ninety-six patients (mean age: 72.0 ± 6.1 years) who were observed postoperatively for 6 months were selected. Timed up and go (TUG) was assessed as an indicator of gait function. Fall incidence and PA were investigated for 6 months post-TKA. The body mass index, history of preoperative falls, knee pain, knee extensor strength, range of motion in knee flexion, and modified gait efficacy scale were evaluated. Additionally, postoperative PA levels were categorized into three groups-low: <3, 000, moderate: 3, 000 to 4, 000, and high: ≥4, 000 steps/day. The relative fall incidence rate was calculated according to the total number of falls normalized for every 1, 000 steps/day for 6 months postoperatively. Twenty-five (26.0%) of the 96 patients had at least one fall. The TUG, knee pain, and knee extensor strength were identified preoperatively as significant variables affecting postoperative falls. The mediated effects model revealed that postoperative fall incidence was predicted by preoperative TUG and postoperative PA. Postoperative PA was significantly associated with preoperative TUG. Moreover, both the preoperative TUG and postoperative PA were selected as significant variables for predicting fall incidence. Thus, postoperative PA mediates the relationship between gait function and fall incidence after TKA. Furthermore, the relative fall incidence rate associated with a low PA level was significantly higher than that associated with moderate and high PA levels. In conclusion, preoperative assessments of TUG performance, muscle strength, and knee pain were effective in predicting fall risk. Additionally, an increase in PA could contribute to reducing fall risk in TKA patients. Therefore, our results suggest that preoperative screening for fall predictors and managing postoperative PA could reduce the fall incidence in TKA patients

Acute effects of low-load resistance exercise with different rest periods on muscle swelling in healthy young men

The effects of high-load resistance training on muscle strength and muscle mass depend on rest periods between sets. However, whether differences in rest period length during low-load resistance exercise (RE) has an influence on improving muscle characteristics remains unclear. Better understanding such effects would enable us to prescribe low-load resistance exercise more safely and effectivity. The purpose of this study was to investigate the acute effects of low-load RE on muscle swelling with different length rest periods between sets. A total of 42 young men (age, 22.9 ± 2.4 years; height, 172.1 ± 5.4 cm; body mass, 65.6 ± 6.5 kg) were recruited to participate in this study. They were assigned to one of three groups with different rest periods between sets (20 s [seconds], 60 s, or 180 s). A total of 12 sets of 10 repetitions of RE with 30% of one repetition maximum on knee extensor muscles were performed. Muscle thickness of the vastus lateralis was measured using ultrasonography as an indicator of muscle swelling every 3 sets. Muscle thickness significantly increased after 3 sets of RE in the 20-s (3.9 ± 3.3%) and 60-s groups (5.9 ± 3.8%), but only after 12 sets in the 180-s group (4.3 ± 3.1%). RE with rest periods shorter than 60 s could result in exercise-induced muscle swelling after fewer sets of RE

Relationship between ankle plantar flexor force steadiness and postural stability on stable and unstable platforms

[Purpose]This study was aimed at determining the relationship between ankle plantar flexor force steadiness and postural control during single leg standing on stable and unstable platforms.[Methods]For the thirty-three healthy participants, force steadiness, at target torques of 5%, 20%, and 50% of the maximum voluntary torque (MVT) of the ankle plantar flexors, was measured. Force steadiness was calculated as the coefficient of variation of force. Single leg standing on stable and unstable platforms was performed using the BIODEX Balance System SD. The standard deviation of the anteroposterior center of pressure (COP) displacements was measured as the index for postural control. During both measurements, muscle activities of the soleus were collected using surface electromyography.[Results]On the stable platform, the COP fluctuation significantly correlated with force steadiness at 5% of MVT (r = 0.512, p = 0.002). On the unstable platform, the COP fluctuation significantly correlated with force steadiness at 20% of MVT (r = 0.458, p = 0.007). However, the extent of muscle activity observed for a single leg standing on both stable and unstable platforms was significantly greater than the muscle activity observed while performing force steadiness tasks at 5% and 20% of MVT, respectively.[Conclusion]Postural stability during single leg standing on stable and unstable platforms may be related to one’s ability to maintain constant torque at 5% and 20% of MVT regardless of the muscle activity. These results suggest that the required abilities to control muscle force differ depending on the postural control tasks

Extracellular-to-intracellular water ratios are associated with functional disability levels in patients with knee osteoarthritis: results from the Nagahama Study.

INTRODUCTION/OBJECTIVES: To test the hypothesis that greater extracellular-to-intracellular water (ECW/ICW) ratios in lower-limb muscles are associated with worsened functional abilities in patients with knee osteoarthritis (OA). METHODS: We analyzed data from 787 participants (82.2% female; mean age, 69.6 ± 5.3 years) from the Nagahama Prospective Cohort who were ≥60 years old and had radiographically confirmed bilateral knee OA. The Knee Scoring System (KSS) was used to assess functional abilities. Lower-limb ECW/ICW ratios and skeletal mass index values were determined with multi-frequency bioelectrical impedance analysis (BIA). Multiple linear regression analysis was used to test for associations between ECW/ICW ratios and functional abilities. Subgroup analyses based on OA severities and symptomaticity were also conducted. RESULTS: Increased ECW/ICW ratios were associated with a 4.38-point decrease in the KSS function scores (95% confidence interval [CI], 3.15-5.62 points) after adjusting for covariates. This association varied according to the degree of knee symptoms, especially in individuals with radiologically mild OA. ECW/ICW ratios in individuals with asymptomatic mild OA were associated with a 2.14-point decrease in the KSS function score (95% CI, 0.32-3.96 points), whereas those in individuals with severe symptomatic mild OA were associated with a 6.16-point decrease (95% CI, 2.13-10.19 points). CONCLUSIONS: Our findings indicate that higher ECW/ICW ratios are associated with greater functional disability in patients with knee OA. Therefore, ECW/ICW ratio measurements with multi-frequency BIA can serve as valuable indicators for functional disability in patients with knee OA. Key Points • Higher extracellular-to-intracellular water (ECW/ICW) ratios are associated with greater functional disability levels in patients with knee osteoarthritis (OA). • ECW/ICW ratios are useful clinical signs as a biomarker for poor functional abilities in patients with knee OA

Prevalence and physical characteristics of locomotive syndrome stages as classified by the new criteria 2020 in older Japanese people: results from the Nagahama study

BACKGROUND: The Japanese Orthopaedic Association (JOA) proposed the concept of locomotive syndrome (LS) in 2007 for detecting high-risk individuals with mobility limitation. In 2020, the JOA revised the clinical decision limits and introduced LS stage 3, which carried the highest-risk for LS compared to the conventional stages, 1 and 2. The purpose of this study was to characterize the prevalence, comorbidities, and physical characteristics in each LS stage, as per the LS criteria 2020. METHODS: We analyzed 2077 participants (64.9% women; mean age, 68.3 ± 5.4 years) from the Nagahama Study aged ≥60 years. Participants were classified into 4 groups, non-LS and LS stages 1, 2, and 3, based on a 25-question Geriatric Locomotive Function Scale. The prevalence of comorbidities (sarcopenia, osteoporosis, diabetes mellitus, low back pain [LBP], and knee pain) were investigated. Physical characteristics were measured based on the physical performance tests including gait speed, five-times chair-stand, single-leg stand, and short physical performance battery; muscle strength tests including grip, knee extension, hip flexion, and abduction; and body-composition analysis including muscle quantity and quality. Differences in the prevalence of comorbidities between LS stages were tested using the chi-square test. The general linear model was performed for univariate and multivariate analyses with post-hoc test to compare the differences in physical characteristics among the LS stages. RESULTS: The prevalence of LS increased with age, and the mean prevalence of LS stages 1, 2, and 3 were 24.4, 5.5, and 6.5%, respectively. The prevalence of comorbidities, including sarcopenia, osteoporosis, LBP, and knee pain, increased with worsening LS stage. Physical performance tests were significantly different between LS stages 2 and 3; and muscle strength differed significantly between LS stages 1 and 2. Additionally, in terms of body composition analysis, muscle quality but not muscle quantity showed significant differences among all the LS stages. CONCLUSIONS: Our findings suggest that muscle strengthening and dynamic training, including balance training in LS stage 1 and 2, respectively, were needed for preventing the LS progression. Individuals with LS stage 3 should perform dynamic training and muscle strengthening exercises while receiving treatment for comorbidities

Association of Pain History and Current Pain With Sagittal Spinal Alignment and Muscle Stiffness and Muscle Mass of the Back Muscles in Middle-aged and Elderly Women

[Study Design] A cross-sectional study. [Objective] To investigate the association of low back pain history (LBPH) and LBP with sagittal spinal alignment, stiffness assessed using ultrasonic shear wave elastography, and mass of the back muscle in community-dwelling middle-aged and elderly women. [Summary of Background Data] The association of LBPH and LBP with sagittal spinal alignment, stiffness, and mass of the back muscles remains unclear in middle-aged and elderly women. [Participants and Methods] The study comprised 19 asymptomatic middle-aged and elderly women [control (CTR) group], 16 middle-aged and elderly women with LBPH (LBPH group), and 23 middle-aged and elderly women with LBP (LBP group). Sagittal spinal alignment in the standing and prone positions (kyphosis angle in the thoracic spine, lordosis angle in the lumbar spine, and anterior inclination angle in the sacrum) was measured using a Spinal Mouse. The stiffness of the back muscles (lumbar erector spinae and multifidus) in the prone position was measured using ultrasonic shear wave elastography. The mass of the back muscles (thoracic and lumbar erector spinae, lumbar multifidus, and quadratus lumborum) was also measured. [Results] Multiple logistic regression analysis with a forward selection method showed that the stiffness of the lumbar multifidus muscle was a significant and independent factor of LBPH. The stiffness of the lumbar multifidus muscle was significantly higher in the LBPH group than in the CTR group. Multiple logistic regression analysis also indicated that lumbar lordosis angle in the standing position was a significant and independent factor of LBP. The lumbar lordosis angle was significantly smaller in the LBP group than in the CTR group. [Conclusions] Our results suggest that LBPH is associated with increased stiffness of the lumbar multifidus muscle in the prone position, and that LBP is associated with the decreased lumbar lordosis in the standing position in community-dwelling middle-aged and elderly women

Ultrasonographic Changes of the Knee Joint Reflect Symptoms of Early Knee Osteoarthritis in General Population; The Nagahama Study

Objective: Radiographic changes in knee osteoarthritis (OA) are not always associated with symptoms, especially in its early stages. Ultrasonography (US) can detect early changes in the knee joint, but the changes that reflect symptoms have not been fully elucidated. This study aimed to identify US-detectable changes in the knee that are often associated with knee symptoms and demonstrate the feasibility of early diagnosis in symptomatic knee OA using US. Design: In this cross-sectional community-based study, 1, 667 participants aged ≥60 years (1, 103 women [66%]) were included. All participants concurrently underwent US and radiography of the knee and completed the Knee Society Knee Scoring System (KSS) questionnaire. Simple and multiple regression analyses were used to examine the associations between US findings and KSS symptom subscales. Results: Among all participants, medial meniscus protrusion and medial osteophytes, age, and body mass index showed significant associations with KSS symptom scores. Among 894 participants with Kellgren-Lawrence (KL) grade ≤1, medial osteophytes and age were significantly associated with KSS symptom score. US measures were more related to KSS symptoms than KL grades. Conclusions: Among the knee US-detectable changes, medial osteophytes were strongly associated with knee symptoms. Osteophytes are reliable predictors of symptomatic early knee OA, even in participants with few radiographic OA changes

Hyperglycemia in non-obese patients with type 2 diabetes is associated with low muscle mass: The Multicenter Study for Clarifying Evidence for Sarcopenia in Patients with Diabetes Mellitus

AIMS/INTRODUCTION: Hyperglycemia is a risk factor for sarcopenia when comparing individuals with and without diabetes. However, no studies have investigated whether the findings could be extrapolated to patients with diabetes with relatively higher glycemic levels. Here, we aimed to clarify whether glycemic control was associated with sarcopenia in patients with type 2 diabetes. MATERIALS AND METHODS: Study participants consisted of patients with type 2 diabetes (n = 746, the average age was 69.9 years) and an older general population (n = 2, 067, the average age was 68.2 years). Sarcopenia was defined as weak grip strength or slow usual gait speed and low skeletal mass index. RESULTS: Among patients with type 2 diabetes, 52 were diagnosed as having sarcopenia. The frequency of sarcopenia increased linearly with glycated hemoglobin (HbA1c) level, particularly in lean individuals (HbA1c <6.5%, 7.0%, ≥6.5% and <7.0%: 18.5%; HbA1c ≥7.0% and <8.0%: 20.3%; HbA1c ≥8.0%: 26.7%). The linear association was independent of major covariates, including anthropometric factors and duration of diabetes (HbA1c <6.5%: reference; ≥6.5% and <7.0%: odds ratio [OR] 4.38, P = 0.030; HbA1c ≥7.0% and <8.0%: 4.29, P = 0.024; HbA1c ≥8.0%: 7.82, P = 0.003). HbA1c level was specifically associated with low skeletal mass index (HbA1c ≥8.0%: OR 5.42, P < 0.001) rather than weak grip strength (OR 1.89, P = 0.058) or slow gait speed (OR 1.13, P = 0.672). No significant association was observed in the general population with a better glycemic profile. CONCLUSIONS: Poor glycemic control in patients with diabetes was associated with low muscle mass