The Differences between functionality status and muscle quality in older women

Purpose: Sarcopenia is a progressive skeletal muscle disorder leading to increased risks of falls, fractures, and physical disability. This study aimed to investigate the relationship between bioelectrical impedance analysis (BIA) and functional testing in older women, emphasizing the importance of combining functional and strength assessments for a comprehensive evaluation of muscle quality. Methods: The study involved 55 older women divided into two groups based on their performance in the 30-Second Chair Stand Test (30CST): Group 1 (≥15 repetitions) and Group 2 (<15 repetitions). Muscle strength (knee extensors and flexors), handgrip strength and body composition parameters were assessed. Results: Statistically significant differences were observed between groups for knee extensors and flexors strength, back flexors strength, and handgrip strength (P< .05). Group 2 demonstrated weaker knee flexors, extensors and handgrip strength. BIA parameters revealed higher body fat mass and soft lean mass in Group 2 (P< .05). However, no significant differences were found in limb-specific lean mass normalized to height (L S.L.M./height²). The findings highlighted the inadequacy of BIA alone in assessing muscle quality and the importance of functional testing. Conclusions: Assessing muscle quality in older women requires a combination of functional tests like 30CST, and lower limb strength measurements. Functional training should be incorporated to enhance muscle quality and reduce the risk of sarcopenia-related impairments. Keywords: sarcopenia, muscle strength, body composition, elderly, functional testing Introduction The novel index of functional capacity is muscle quality (MQ), there is no universal consensus on the definition or assessment method for MQ.1 MQ is commonly defined as a ratio of muscle strength and muscle mass. The question is which factors can be contributed to this term and how these factors relate to muscle strength.2 It is worth to mention that this explanation considers the functional importance of the structure, the general tissue features of the skeletal muscle, and, in the end, the ability to produce force.3 It would seem that it is influenced by muscle composition, metabolism, and neuromuscular function. MQ should be defined as all muscle-associated physiological factors that influence the force-generating capability of skeletal muscle tissue. While the focus of improving muscular force generation traditionally centers on increasing muscle quantity (muscle hypertrophy), recent efforts have focused on improving MQ for enhance muscle function.4 The distinction between MQ and muscle quantity is an important aspect of functional assessment as two individuals with similar mass may not be capable of producing equivalent amounts of force.5 MQ is also defined as the amount of strength or power per unit of muscle mass. Highter MQ relates to increase muscle strength, function, physical performance, and vice versa.6 The distinction between MQ and muscle quantity is an important aspect of functional assessment, as two individuals with similar muscle mass may not be capable of producing equivalent amounts of force. Similarly and counterintuitively, individuals with smaller amounts of muscle mass may be more effective at producing force than those with greater amounts. Differences in MQ between individuals may help explain why certain muscles are stronger than others, despite similar sizes. However, MQ may also vary between limbs, generating potential for injury if not properly corrected.5 MQ is increasingly relief upon as a biomarker of muscle health in low functioning aging adult population. In the case of seniors, the level of the so-called functionality related to the level of everyday activity and self-service activities. Aging can lead to declines in muscle fibers quantity, quality, and strength.7Experiencing difficulty in activities of daily living (ADL) and relying on others is not only related to decreased quality of life but also increased likelihood of long-term nursing home placement.8 There is a growing body of literature about functionality improvement in which older adults are trained on specific tasks, such as chair rise or movements needed to perform daily task to reduce disability in late life and as a result of various disease.9–11Functionality depends on many factors, including proper functioning of the nervous system or the appropriate state of musculoskeletal system. While the condition of the nervous system can be improved by repetitive activities, the condition of the active musculoskeletal system can similarly be improved by exercises. There are many tools used in everyday physiotherapy practice to assess the level of functional fitness of seniors. One of them is the chair test recommended by EWGSOP2 (the European Working Group on Sarcopenia in Older People). The