Development and Validation of the Low Sit–High Step Test for Assessing Lower Extremity Function in Sarcopenia

Objective: The study aimed to evaluate the validity and reliability of the newly developed Low Sit–High Step (LS-HS) Test designed to assess lower-extremity muscle strength in the diagnosis of sarcopenia. Design: The study included 205 participants divided into four groups (possible sarcopenia, sarcopenia, young control, and middle-to-older control). The LS-HS Test was compared across groups, and its ability to distinguish sarcopenia and possible sarcopenia was evaluated. Internal consistency, inter-rater and test–retest reliability, and diagnostic accuracy were assessed to determine the test’s validity and reliability. Results: LS-HS Test scores were higher in participants with possible sarcopenia and sarcopenia (p