Comparison of muscle quality and functional capacity between Japanese and Brazilian older individuals

Non invasive techniques for direct muscle quality assessment after exercise intervention in older adults: a systematic review

BACKGROUND

The aging process induces neural and morphological changes in the human musculoskeletal system, leading to a decline in muscle mass, strength and quality. These alterations, coupled with shifts in muscle metabolism, underscore the essential role of physical exercise in maintaining and improving muscle quality in older adults. Muscle quality's morphological domain encompasses direct assessments of muscle microscopic and macroscopic aspects of muscle architecture and composition. Various tools exist to estimate muscle quality, each with specific technical requirements. However, due to the heterogeneity in both the studied population and study methodologies, there is a gap in the establishment of reference standards to determine which are the non-invasive and direct tools to assess muscle quality after exercise interventions. Therefore, the purpose of this review is to obtain an overview of the non-invasive tools used to measure muscle quality directly after exercise interventions in healthy older adults, as well as to assess the effects of exercise on muscle quality.

MAIN TEXT

To address the imperative of understanding and optimizing muscle quality in aging individuals, this review provides an overview of non-invasive tools employed to measure muscle quality directly after exercise interventions in healthy older adults, along with an assessment of the effects of exercise on muscle quality.

RESULTS

Thirty four studies were included. Several methods of direct muscle quality assessment were identified. Notably, 2 studies harnessed CT, 20 utilized US, 9 employed MRI, 2 opted for TMG, 2 adopted myotonometry, and 1 incorporated BIA, with several studies employing multiple tests. Exploring interventions, 26 studies focus on resistance exercise, 4 on aerobic training, and 5 on concurrent training.

CONCLUSIONS

There is significant diversity in the methods of direct assessment of muscle quality, mainly using ultrasound and magnetic resonance imaging; and a consistent positive trend in exercise interventions, indicating their efficacy in improving or preserving muscle quality. However, the lack of standardized assessment criteria poses a challenge given the diversity within the studied population and variations in methodologies.. These data emphasize the need to standardize assessment criteria and underscore the potential benefits of exercise interventions aimed at optimizing muscle quality.

Cervical Multifidus and Longus Colli Ultrasound Differences among Patients with Cervical Disc Bulging, Protrusion and Extrusion and Asymptomatic Controls: A Cross-Sectional Study

The aim of this study was to analyze the differences in morphological and histological features of the cervical multifidus (CM) and longus colli (LC) muscles among patients with cervical disc bulging, protrusion, or extrusion. Fifteen patients with cervical disc bulging (20% male, mean age: 48.5, standard deviation (SD) 7.5 years), fifteen with cervical disc protrusion (6% male, mean age: 43, SD 7.8 years), and fifteen with cervical disc extrusion (40% male, mean age: 44, SD 8 years) diagnosed via clinical and imaging findings participated in this study. Additionally, fifteen asymptomatic controls (40% male, mean age: 40.4, SD 9.7 years) were also included. The following ultrasound measurements, cross-sectional area (CSA), anterior-posterior distance (APD), lateral dimension (LD), and mean echo-intensity (EI) of the CM and LC at C5-C6 level were examined by an assessor blinded to the subject's condition. The results revealed no group ×side significant differences among the groups (p > 0. 00625). However, group effects were found for APD and MEI of the CM (p = 0.006 and p < 0.001, respectively) and CSA, APD and MEI of the LC (all, p < 0.001). The LD of the LC muscle and the APD and LD of the CM were negatively associated with related disability (p < 0.01; p < 0.05 and p < 0.01, respectively), and pain intensity was negatively associated with LC APD and LD (both p < 0.05). These results suggest that US can be used to detect bilateral morphological changes in deep cervical flexors and extensors to discriminate patients with cervical disc alterations.

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.

Effect of subcutaneous adipose tissue and muscle thicknesses on rectus femoris and vastus intermedius ultrasound echo intensities: a cadaver study

PURPOSE

The purpose of this study was to examine the effect of subcutaneous adipose tissue (SCAT) thickness and rectus femoris (RF) muscle thickness on RF and vastus intermedius (VI) echo intensity using human cadavers.

METHODS

The echo intensity of the RF and VI was measured in 11 legs of seven cadavers under three conditions: intact condition (Model 1), SCAT removed (Model 2), and SCAT and RF removed (Model 3).

RESULTS

RF echo intensity in Model 1 (69.2 ± 20.3 a.u.) was significantly lower than that in Model 2 (83.4 ± 15.9 a.u.) (P = 0.003). VI echo intensity in Models 1 to 3 showed similar results to RF echo intensity (P = 0.003 to 0.001). Regarding the relationship between VI echo intensity and VI muscle thickness, the regression lines shifted upward in a parallel fashion in the order Model 1, Model 2, and Model 3. Multiple regression analysis revealed that the variation in RF echo intensity was explained by RF muscle thickness (P = 0.036) and SCAT thickness (P = 0.001), while the variation in VI echo intensity was explained by RF muscle thickness (P = 0.035).

CONCLUSION

These results suggest that SCAT thickness and RF muscle thickness induce lower RF echo intensity, while RF muscle thickness induces lower VI echo intensity.

Muscle Quality of Knee Extensors Based on Several Types of Force in Multiple Sclerosis Patients with Varying Degrees of Disability

Background and Objectives: Multiple sclerosis (MS) tends to affect muscle performance, mainly in the lower extremities. The degree of disability is associated with the loss of strength and muscle mass, to varying extents. Muscle quality (MQ) expresses the amount of force produced relative to the activated muscle mass. The purpose of this study was to compare the MQ of the knee extensors in the main manifestations of strength (isometric, dynamic strength, and power) among patients with differing degrees of neurological disability and evolutionary forms of the disease. We also establish reference values for MQ in MS patients (pwMS). Materials and Methods: In total, 250 pwMS were evaluated according to the Expanded Disability Status Scale (EDSS). The maximum dynamic and isometric forces and muscle power manifested a load of 60% of the maximum dynamics of the knee extensors. The lean mass of the thigh and hip was determined by densitometry, and the MQ was calculated for the three types of force evaluated. Results: The pwMS with relapsing remitting MS (RRMS) presented isometric MQ values that were 15.8% better than those of pwMS with primary progressive MS (PPMS) and 13.8% better than those of pwMS with secondary progressive MS (SPMS). For pwMS with SPMS, the dynamic MQ was 16.7% worse than that of patients with RRMS, while the power MQ was 29.5% worse. By degree of disability (<4 >7.5 EDSS score), patients with better MQ had mild EDSS scores, and patients with severe EDSS scores had 24.8%, 25.9%, and 40.3% worse isometric, dynamic, and power MQ scores, respectively, than those with RRMS. Based on these results, reference values for MQ in pwMS were established. Conclusions: The pwMS with different types of MS do not show differences in lean mass or strength but do show differences in MQ. In pwMS with different EDSS grades, there are no differences in lean mass, but there are differences in strength based on MQ, especially power MQ.