Validity and feasibility of a seated push-up test to indicate skeletal muscle mass in well-functioning older adults

Skeletal muscle mass (SMM) is a major component of the human body (> 30% of the body-weight) and plays crucial role in many bodily functions. However, SMM assessments require a complex and costly machine, which delays the ability to detect abnormalities related to SMM decline and, subsequently, reduces the effectiveness of the clinical management of older adults.

This study aimed to: 1) assess the correlation between upper limb loading during a seated push-up test (ULL-SPUT) and SMM (concurrent validity); 2) compare the SMM of participants who passed and failed a seated push-up test (SPUT; discriminant validity); and 3) explore the ability of a failed SPUT to identify older individuals with low SMM.

Participants (n = 40, age approximately 73 years) were cross-sectionally assessed for their SMM using a portable bioelectrical impedance analysis, and SPUTs were evaluated using digital push-up loading devices that were the size of clinical push-up boards, in three starting positions: 1) high; 2) ring, and 3) long sitting positions.

The ULL-SPUT, especially in a ring sitting position, was significantly correlated to SMM (r_s = 0.457-0.608, p < .005). The SMM and ULL-SPUT were significantly different between participants who passed and failed the SPUT (p < .05). Failure to complete the SPUT - that is, being unable to lift the body up from the floor during the test - showed an excellent ability to indicate participants with an SMM of < 28% of their body-weight (sensitivity > 83%, specificity > 82%, area under the curve = 0.93).

The inability to lift the body up from the floor during sitting using the upper limbs can be used as a screening tool to indicate those with low SMM. Such a simple screening measure may enhance the distribution of healthcare services across various community- and home-based settings, particularly during the coronavirus (COVID-19) pandemic, when hospital services are limited for many individuals, including older adults.