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

Area of Science:

• Gerontology
• Kinesiology
• Biomedical Engineering

Background:

• Sarcopenia, characterized by muscle mass and strength loss, poses a significant health risk, particularly in older adults.
• Early detection of sarcopenia is crucial for timely intervention and management.
• Existing assessment tools may lack cost-effectiveness, clinical practicality, or sensitivity for early-stage detection.

Purpose of the Study:

• To evaluate the validity, reliability, and diagnostic accuracy of the novel Low Sit-High Step (LS-HS) Test.
• To assess the LS-HS Test's sensitivity in identifying early-stage sarcopenia and functional decline.
• To establish the LS-HS Test as a cost-effective and clinically practical tool for lower-extremity assessment.

Main Methods:

• A cross-sectional study involving 205 participants across four groups: probable sarcopenia, sarcopenia, young controls, and middle-to-older adult controls.
• Comparison of LS-HS Test scores with standard assessments for lower-extremity function.
• Reliability analysis using Cronbach's alpha and Intraclass Correlation Coefficient (ICC).
• Multinomial logistic regression and Receiver Operating Characteristic (ROC) curve analysis for predictive power and diagnostic accuracy.

Main Results:

• LS-HS Test scores were significantly higher in individuals with probable sarcopenia and sarcopenia (p<0.05).
• LS-HS performance was a significant predictor of both probable sarcopenia and sarcopenia (p<0.001).
• The test demonstrated excellent internal consistency (Cronbach's α = 0.938) and very high reliability (ICC = 0.998).
• ROC analysis showed high diagnostic accuracy for probable sarcopenia (AUC = 0.768) and sarcopenia (AUC = 0.704).

Conclusions:

• The LS-HS Test is a valid, reliable, and sensitive measure of lower-extremity functional capacity.
• It effectively identifies early functional decline associated with the sarcopenia spectrum.
• The LS-HS Test serves as a practical and effective alternative for routine clinical assessment and sarcopenia monitoring.