Innovative equipment for lower limb muscle strength measurement: Design and application in sarcopenia screening

Background: Grip Strength has been established as a practical and efficient method for screening and diagnosing sarcopenia. It is recognized that with advancing age, there is a more significant decline in lower limb muscle mass compared to the upper limb. However, due to the inherent complexity of assessing lower limb muscle strength compared to measuring Grip Strength, these assessments have not been universally adopted for sarcopenia screening.

Methods: We measured the Forefoot Strength, Heel Strength, Knee Extension Strength, and Hip Extension Strength in 98 participants using portable equipment designed for lower limb muscle strength assessment. We compared the efficacy of using lower limb muscle strength cutoff values with grip strength for the screening of sarcopenia.

Findings: The optimal cutoff values for screening sarcopenia in males using Knee Extension Strength and Hip Extension Strength were 140.1 N and 121.7 N, respectively, while for females they were 91.6 N and 90.4 N, respectively. In binary logistic regression models adjusted for age and body weight, Knee Extension Strength and Hip Extension Strength were found to be associated with sarcopenia in both males and females. Moreover, the efficacy of sarcopenia screening using Knee Extension Strength or Hip Extension Strength cutoff values was superior to that of grip strength alone, and the combination of Knee Extension Strength and Hip Extension Strength cutoff values yielded the best results for sarcopenia screening.

Interpretation: Measurements of Knee Extension Strength and Hip Extension Strength may potentially serve as a promising method for sarcopenia screening.