**5.2 Muscle strength**

*Background and Management of Muscular Atrophy*

mineral, and fat-free body mass. The disadvantages of this technique are that the tools used are not portable [28]. While anthropometric measurements are very easy to do, it is not recommended to diagnose sarcopenia because it has a very high error rate. Anthropometric measurements are performed by measuring the circumference of the upper arm (LLA) or the circumference of the calf [27, 29]. Measurement of muscle mass is made using bio-impedance analysis (BIA), which is chosen for both research and clinical practice. Measurement using BIA has a good correlation value with MRI measurement in measuring body fat mass and body fat-free mass.

Physical performance Walking speed <0.8 m/s

*Measurement of sarcopenia according to the Asian working Group for Sarcopenia [8].*

**Criteria Measuring instrument Threshold**

BIA

*Sarcopenia diagnosis algorithm based on the Asian working Group for Sarcopenia [8].*

• Man <7.0 kg/m2 • Woman <5.4 kg/m2

• Man <7.0 kg/m2 • Woman <5.7 kg/m2

• Man <26 kg • Woman <18 kg

Muscle mass DXA

Muscle strength Grip strength tests

**72**

**Table 2.**

**Figure 2.**

Muscle strength can be measured in several ways, namely the grip strength test, knee extension test, and peak expiratory flow (PEF). The grip strength test is a simple examination so it is both used for clinical practice and research. Studies show this examination has a good correlation with inferior limb strength, mobility, and daily living activities (ADL). Examination of the knee extension is as good as a grip strength test, but this examination requires equipment and training in advance so it is not good for clinical practice. In peak expiratory flow (PEF) tests, it is very good for measuring respiratory muscle strength but cannot be used to measure the overall muscle strength [7]. The criterion for decreasing muscle strength according to the AWGS is less than 20 percentile of the mean population of grip strength tests [8].
