Association between knee extensor and ankle plantarflexor muscle thickness and echo intensity with postural sway, mobility and physical function in older adults

Relationship between quadriceps muscle architecture and lower limb strength and physical function in older adults community-dwelling individuals: a cross-sectional study

Background and objective

Factors related to muscle architecture may lead to functional limitations in activities of daily living in the older adults. This study aimed to investigate the relationship between quadriceps femoris (QF) architecture and physical function in older adults community-dwelling people.

Methods

The study included 25 community-dwelling older adults participants aged over 60 years (14 women and 11 men) who were not engaged in regular physical activity. The rectus femoris (RF) and vastus intermedius (VI) muscle thicknesses as well as the RF cross-sectional area (CSA) were assessed using 2D ultrasonography. The 30 Seconds Chair Stand test (30sCST) and Timed Up and Go Test (TUG) were used to assess lower body muscle power and functional mobility, respectively.

Results

The QF muscle architecture showed moderate and large correlations with the 30sCST (r range = 0.45-0.67, p < 0.05) and TUG (r range = 0.480-0.60, p < 0.05). RF thickness was a significant (p < 0.01) independent predictor of 30sCST (R 2 = 0.45) and TUG (R 2 = 0.36). VI thickness was a significant (p < 0.05) independent predictor of 30sCST (R 2 = 0.20) and TUG (R 2 = 0.231). RF CSA was a significant independent predictor of the 30sCST (R 2 = 0.250, p < 0.05) and TUG (R 2 = 0.27, p < 0.01). Multiple linear regression models explained 38% of the 30sCST variance and 30% of the TUG variance in the older adults group.

Conclusion

Quadriceps muscle group directly affects basic activities of daily living in the older adults. Ultrasound measurements, which are non-invasive tools, are extremely valuable for understanding the limitations of activities of daily living in the older adults.

Association between physical fitness tests and neuromuscular properties

PURPOSE

While various fitness tests have been developed to assess physical performances, it is unclear how these tests are affected by differences, such as, in morphological and neural factors. This study was aimed to investigate associations between individual differences in physical fitness tests and neuromuscular properties.

METHODS

One hundred and thirty-three young adults participated in various general physical fitness tests and neuromuscular measurements. The appendicular skeletal muscle mass (ASM) was estimated by bioelectrical impedance analysis. Echo intensity (EI) was evaluated from the vastus lateralis. During submaximal knee extension force, high-density surface electromyography of the vastus lateralis was recorded and individual motor unit firings were detected. Y-intercept (i-MU) and slope (s-MU) from the regression line between the recruitment threshold and motor unit firing rate were calculated.

RESULTS

Stepwise multiple regression analyses revealed that knee extension strength could be explained (adjusted R2 = 0.712) by ASM (β = 0.723), i-MU (0.317), EI (- 0.177), and s-MU (0.210). Five-sec stepping could be explained by ASM (adjusted R2 = 0.212). Grip strength, side-stepping, and standing broad jump could be explained by ASM and echo intensity (adjusted R2 = 0.686, 0.354, and 0.627, respectively). Squat jump could be explained by EI (adjusted R2 = 0.640). Counter-movement jump could be explained by EI and s-MU (adjusted R2 = 0.631). On the other hand, i-MU and s-MU could be explained by five-sec stepping and counter-movement jump, respectively, but the coefficients of determination were low (adjusted R2 = 0.100 and 0.045).

CONCLUSION

Generally developed physical fitness tests were mainly explained by morphological factors, but were weakly affected by neural factors involved in performance.

Exploring the associations between skeletal muscle echogenicity and physical function in aging adults: A systematic review with meta-analyses

BACKGROUND

Assessment and quantification of skeletal muscle within the aging population is vital for diagnosis, treatment, and injury/disease prevention. The clinical availability of assessing muscle quality through diagnostic ultrasound presents an opportunity to be utilized as a screening tool for function-limiting diseases. However, relationships between muscle echogenicity and clinical functional assessments require authoritative analysis. Thus, we aimed to (a) synthesize the literature to assess the relationships between skeletal muscle echogenicity and physical function in older adults (≥60 years), (b) perform pooled analyses of relationships between skeletal muscle echogenicity and physical function, and (c) perform sub-analyses to determine between-muscle relationships.

METHODS

CINAHL, Embase, MEDLINE, PubMed, and Web of Science databases were systematically searched to identify articles relating skeletal muscle echogenicity to physical function in older adults. Risk-of-bias assessments were conducted along with funnel plot examination. Meta-analyses with and without sub-analyses for individual muscles were performed utilizing Fisher's Z transformation for the most common measures of physical function. Fisher's Z was back-transformed to Pearson's r for interpretation.

RESULTS

Fifty-one articles (n = 5095, female = ∼2759, male = ∼2301, 72.5 ± 5.8 years, mean ± SD (1 study did not provide sex descriptors)) were extracted for review, with previously unpublished data obtained from the authors of 13 studies. The rectus femoris (n = 34) and isometric knee extension strength (n = 22) were the most accessed muscle and physical qualities, respectively. The relationship between quadriceps echogenicity and knee extensor strength was moderate (n = 2924, r = -0.36 (95% confidence interval: -0.38 to -0.32), p < 0.001), with all other meta-analyses (grip strength, walking speed, sit-to-stand, timed up-and-go) resulting in slightly weaker correlations (r:  -0.34 to -0.23, all p < 0.001). Sub-analyses determined minimal differences in predictive ability between muscle groups, although combining muscles (e.g., rectus femoris + vastus lateralis) often resulted in stronger correlations with maximal strength.

CONCLUSION

While correlations were modest, the affordable, portable, and noninvasive ultrasonic assessment of muscle quality was a consistent predictor of physical function in older adults. Minimal between-muscle differences suggest that echogenicity estimates of muscle quality are systemic. Therefore, practitioners may be able to scan a single muscle to estimate full-body skeletal muscle quality/composition, while researchers should consider combining multiple muscles to strengthen the model.

Effects of Real-Time Feedback Methods on Static Balance Training in Stroke Patients: A Randomized Controlled Trial

BACKGROUND

The purpose of this study was to investigate the effects of real-time feedback methods on static balance training in stroke patients. There are two types of real-time feedback methods, as follows: one is Knowledge of Result (KR), and the other is Knowledge of Performance (KP).

METHOD

Thirty stroke patients participated in this study and were randomly assigned to the KR group (n = 15) or the KP group (n = 15). All of the groups underwent real-time feedback training for four weeks (30 min per session, five sessions per week). The primary outcomes were sway length, sway velocity, and area 95%, which were assessed before and after the intervention. The secondary outcomes included the Berg Balance Scale, the Fugl Meyer Assessment for Lower Extremity, the Postural Assessment Scale for Stroke Trunk Impairment Scale, and the Fall Efficacy Scale. A group × time interaction was assessed using two-way ANOVA with repeated measures.

RESULT

There was a significant increase over time in all outcomes (p < 0.05). Significant differences were observed for a group × time interaction in sway length and area 95% (p < 0.05).

CONCLUSIONS

Real-time feedback training for static balance enhanced stroke patients' static balance abilities, clinical outcome assessments, and promoted self-efficacy against falls.

Relationship between phase angle and lower-extremity function in older adults: Itabashi Longitudinal Study on Aging

OBJECTIVE

Evaluating muscle quality instead of its mass has gained attention in diagnosing sarcopenia. The aim of this study was to examine whether phase angle (PhA) as a bioelectrical impedance analysis (BIA)-derived muscle quality indicator is associated with overall lower extremity function better than appendicular skeletal muscle mass index (ASMI) in community-dwelling older adults.

METHODS

This cross-sectional study used data from the Itabashi Longitudinal Study on Aging, a community-based cohort study. A sex-stratified multivariate logistic regression analysis was conducted using PhA and ASMI as exposures, and low physical function defined as short physical performance battery score <10 as the outcome, adjusted for age, being overweight, knee pain, and non-communicable diseases. Discrimination of low physical function was compared using the receiver operating characteristic curve.

RESULTS

This study included 1464 participants (age 76 [73-80] y; 757 women), with 58 men (8%) and 66 women (9%) exhibiting low physical function. The multivariate odds ratio (OR; 95% confidence interval [CI]) for low physical function among the highest quartile, compared with the lowest quartile were significant in PhA in multiple sites (e.g., OR, 0.09; 95% CI, 0.03-0.32] for men and 0.12; 95% CI, 0.04-0.33 for women in the left leg) but not in ASMI (OR, 0.51; 95% CI, 0.19-1.34 for men and 0.56; 95% CI, 0.21-1.47 for women). Legs and whole-body PhA outperformed the ASMI in discriminating low physical function (P < 0.001).

CONCLUSION

PhA reflected physical function better than ASMI; using PhA instead of ASMI in BIA-based morphometric evaluation may add information on low physical function and enhance the diagnostic value of sarcopenia.

Meta-Analysis on the Association between Echo Intensity, Muscle Strength, and Physical Function in Older Individuals

BACKGROUND

The use of ultrasonographic echo intensity (EI) to evaluate skeletal muscle quality and its effects on strength, explosive power, and physical function (PF) in older individuals remains unclear. This meta-analysis evaluated the associations among EI, muscle strength (MS), and PF in older individuals.

METHODS

We conducted a systematic search of the PubMed, Embase, Web of Science, SPORT Discus, and CINAHL databases through October 2022 to identify primary studies examining the association between EI and MS/PF. Effect sizes were computed using a random-effects model and presented using forest plots. Pearson correlation coefficient (r) and I2 statistics were used to measure heterogeneity.

RESULTS

This meta-analysis included 24 patients. EI demonstrated a negative association with maximal strength (r=-0.351; 95% confidence interval [CI], -0.411 to -0.288; p<0.001) and explosive power (r=-0.342; 95% CI, -0.517 to -0.139; p=0.001) in older individuals. Handgrip strength also showed a significant negative correlation with EI (r=-0.361; 95% CI, -0.463 to -0.249; p<0.001). However, we observed only a small and non-significant negative association between EI and gait speed (r=-0.003; 95% CI, -0.083 to -0.077; p=0.943), and a weak non-significant correlation with the chair stand test (r=0.072; 95% CI, -0.045 to 0.187; p=0.227).

CONCLUSION

Increased EI was associated with lower strength and power but not with gait speed or chair test performance in older individuals. Further large-sample studies with long-term follow-up are needed to improve frailty prediction and risk assessment in this population.

Implementation and Core Components of a Multimodal Program including Exercise and Nutrition in Prevention and Treatment of Frailty in Community-Dwelling Older Adults: A Narrative Review

Increasing disability-free life expectancy is a crucial issue to optimize active ageing and to reduce the burden of evitable medical costs. One of the main challenges is to develop pragmatic and personalized prevention strategies in order to prevent frailty, counteract adverse outcomes such as falls and mobility disability, and to improve quality of life. Strong evidence reports the effectiveness of exercise interventions to improve various physical parameters and muscle function that are cornerstones of frailty. Other findings also suggest that the interactions between nutrition and physical exercise with or without health behavior promotion prevent the development of frailty. Multimodal programs, including structured exercise, adequate dietary intervention and health behavior promotion, appear increasingly consensual. However, in order for implementation in real-life settings, some pitfalls need to be addressed. In this perspective, structuring and tailoring feasible, acceptable and sustainable interventions to optimize exercise training responses are essential conditions to warrant short, medium and long-term individual benefits. The different components of exercise programs appear to be fairly consensual and effective. However, specific composition of the programs proposed (frequency, intensity, type, time, volume and progressiveness) have to be tailored to individual characteristics and objectives in order to improve exercise responses. The intervention approaches, behavioral strategies and indications for these programs also need to be refined and framed. The main objective of this work is to guide the actions of healthcare professionals and enable them to widely and effectively implement multimodal programs including exercise, nutrition and behavioral strategies in real-life settings.

Ultrasound measures of muscle morphology in people with multiple sclerosis are associated with muscle performance and functional mobility

BACKGROUND

Neurologically-based muscle weakness is a common symptom in people with multiple sclerosis MS (MS), who may also exhibit muscle morphology changes and intrinsic muscle dysfunction. Diagnostic ultrasound (sonography) is a non-invasive, inexpensive, and clinically feasible method to measure muscle morphology. The purpose of this study was to investigate possible asymmetries in lower limb muscle morphology and performance in people with MS, and to assess the relationships of muscle morphology measures with individual patient characteristics, muscle performance, and functional mobility.

METHODS

This cross-sectional study was conducted at the Washington, DC Veterans Affairs Medical Center. The study participants were 29 Veterans with MS (52% female, 79% African-American, 48.6 ± 11.2 years old, Mean Expanded Disability Status Scale: 3.6 ± 1.4) who completed seated knee extension isokinetic strength and power tests, functional assessments (Timed 25-Foot Walk - T25FW, 5-Times Sit-to-Stand - 5STS), and quantitative B-mode ultrasound image acquisition of the rectus femoris muscle to derive morphology measures (thickness and echogenicity). The limb with weaker knee extension strength was identified as the more-involved limb. Differences between the more and less-involved limb were quantified using a t-test for all muscle morphology and muscle performance measures. Relationships between muscle morphology and patient characteristics, muscle performance, and functional mobility were evaluated using bivariate and multivariate analyses.

RESULTS

The rectus femoris thickness from the more-involved limb was lower (p<0.001) than that of the less-involved limb, whereas echogenicity was not different between the two limbs (p=0.147). Rectus femoris thickness of the more-involved limb was directly related to age (r=-0.63, p<0.001), muscle strength (r=0.53, p=0.003) and power (r=0.53, p=0.003), and gait speed (r=0.42, p=0.024); whereas its echogenicity was positively associated only with muscle strength (r=-0.46, p=0.013) and power (r=-0.50, p=0.006). Together rectus femoris thickness and echogenicity of the more involved limb explained 44% and 48% of the variance in muscle strength and power, respectively (p<0.001).

CONCLUSION

This study supports the ability of sonography to measure muscle morphology in people with MS, identify asymmetries, and quantify associations with important clinical correlates. Compared with more invasive and costly alternatives, sonography is a clinically feasible, relatively low-cost tool that can be used to assess muscle morphology in people with MS. Further research is warranted to determine the potential clinical utility of sonographic measures of muscle morphology in evaluating changes due to disease progression or therapeutic interventions in this population.

The Influence of Knee Extensor and Ankle Plantar Flexor Strength on Single-Leg Standing Balance in Older Women

Impaired balance is a significant risk factor for falls among older adults. The precise impact of lower-extremity muscles, including the proportion of muscle strength, on the performance of single-leg standing balance tests in older individuals is very interesting. The aim of this study is to examine the correlation between the knee extensor (KE), ankle plantar flexor (AP) muscle strength, and performance in single-leg standing balance tests in older females. Additionally, it aims to evaluate the combined proportion of KE and AP muscle strength in maintaining balance during single-leg standing. A total of 90 older females (mean age 67.83 ± 8.00 years) were recruited. All participants underwent maximum voluntary isometric contraction (MVIC) testing of the KE and AP muscles, as well as single-leg standing balance tests with eyes open (SSEO) and eyes closed (SSEC). To examine the influence of KE and AP muscle strength on balance performance, multiple regression analysis was conducted. Low correlations were found between SSEO and MVIC of KE and AP muscles, but moderate correlations were found with percentage of MVIC to body weight ratio (%MVIC/BW). The best model for SSEO included 0.99 times of the %MVIC/BW of AP and 0.66 times that of KE muscles as independent predictor variables (r = 0.682). In conclusion, AP muscle strength was found to have a greater impact on single-leg standing balance compared with KE muscle strength.

Ultrasonographic findings in long COVID: A cross-sectional study of 312 patients

Background

Fatigue and muscle weakness are common complaints in COVID-19 survivors. However, little is still known about the skeletal muscle qualitative and quantitative characteristics after hospitalization due to moderate and severe COVID-19.

Objectives

To assess rectus femoris and vastus intermedius muscle thickness (MT) and rectus femoris echo intensity (EI) and to establish its association with demographic, clinical, functional, and inflammatory parameters in long COVID patients after hospital discharge.

Methods

Cross-sectional study with 312 COVID-19 patients (53.53% male; age: 54.59 ± 13.50 years), with a laboratory-confirmed diagnosis of COVID-19. Patients were assessed 3-11 months after hospital discharge. We evaluated MT of the right rectus femoris and vastus intermedius and EI of the right rectus femoris using a portable ultrasound system, 6-13 MHz, broadband linear transducer. We corrected EI using the subcutaneous fat thickness. Ultrasonographic parameters were tested in association with demographic (sex and age); functional (Handgrip strength measurement, Timed Up and Go, 1 min Sit-to-Stand test, EuroQoL-5 Dimensions-5 Levels, World Health Organization Disability Assessment Schedule (WHODAS 2.0), Post-COVID-19 Functional Status, Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT), Medical Research Council (MRC) sum score, Borg Dyspnea Scale, MRC Dyspnea score, Visual Analogue Scale (VAS), Epworth Sleepiness Scale, Insomnia Severity Index, Functional Independence Measurement (FIM), and Functional Oral Intake Scale); clinical (length of hospital stay, intubation, and presence of comorbidities such as systemic hypertension, diabetes, obesity, chronic obstructive pulmonary disease, asthma), and inflammatory data assessed by the C-reactive protein and D-dimer serum concentrations.

Results

Rectus femoris MT was associated with age, handgrip strength, Epworth Sleepiness Scale, and subcutaneous fat thickness (r² = 27.51%; p < 0.0001). Vastus intermedius MT was associated with age, pain intensity, handgrip strength, Epworth Sleepiness scale, FIM, and time since hospital discharge (r² = 21.12%; p < 0.0001). Rectus femoris EI was significantly associated with the male sex, TUG, Epworth Sleepiness Scale, and C-Reactive Protein levels (r² = 44.39%; p < 0.0001). Mean MT of rectus femoris and vastus intermedius are significantly different (p < 0.001).

Conclusion

After hospital discharge, long COVID patients present qualitative and quantitative skeletal muscle characteristics associated with a combination of demographic, clinical, and functional parameters.

Associations between Muscle-Tendon Morphology and Functional Movements Capacity, Flexibility, and Balance in Older Women

Loss of functional movement capacity in older adults is related to adverse changes in musculotendinous morphology, but this relationship is poorly understood. This study examined the associations between musculotendinous morphology and functional movements, flexibility, and balance ability. Ninety-nine older women (66.6 ± 4.6 years, body mass index 23.5 ± 3.3 kg∙m−2) were recruited from Chonburi Province, Thailand. During one 90-min visit, muscle ultrasound imaging of vastus lateralis, biceps femoris, and medial gastrocnemius muscles, and tendon ultrasonography of the Achilles tendon and patellar tendon were performed. Measures were also obtained for the straight leg raise, passive dorsiflexion, balance, and functional tests (Five Times Sit to Stand (5TSTS), Timed Up and Go (TUG), 10-Meter Fast Walk Test (10-MFWT), and 6-Minute Walk Test (6-MWT)). The results specify that functional movement performance correlates most strongly with medial gastrocnemius muscle thickness (5TSTS (r = −0.26), TUG (r = −0.44), 10-MFWT (r = 0.41), and 6-MWT (r = 0.48) all p < 0.05) and that vastus lateralis muscle thickness and medial gastrocnemius muscle thickness correlate positively with balance ability (r = 0.24, 0.34; p < 0.05) and negatively with fear of falling. It appears that muscle mass, rather than other morphological parameters, such as muscle quality or fascicle length, is the main factor affecting the susceptibility of older women to frailty.

Association of mobility capacity with the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles in community-dwelling older adults

We examined the association of mobility capacity with muscle thicknesses and echo intensities of the trunk and lower extremity muscles measured using an ultrasound imaging device in community-dwelling older adults. The participants were 57 community-dwelling older adults. Mobility capacity was assessed based on the measurement of usual and maximal walking speeds and timed up-and-go (TUG) time. Muscle thickness and echo intensity of the trunk and lower extremity muscles were measured using an ultrasound imaging device. Finally, sagittal spinal alignment was assessed based on the measurement of thoracic kyphosis, lumbar lordosis, and sacral anterior inclination angles in the standing position using a Spinal Mouse. Stepwise regression analysis showed that the tibialis anterior muscle thickness, tibialis posterior muscle echo intensity, and body weight were significant and independent factors of usual walking speed, with a coefficient of determination (R²) of 0.25. The thicknesses of the thoracic erector spinae and obliquus externus abdominis muscles were significant and independent factors of maximal walking speed (R² = 0.26). Moreover, only age was a significant and independent factor for TUG time (R² = 0.10). The results of this study suggested associations 1) between slow usual walking speed and low tibialis anterior muscle thicknesses and high echo intensity of the tibialis posterior muscle and 2) between slow maximal walking speed and low thoracic erector spinae and obliquus externus abdominis thicknesses in community-dwelling older adults.