Research Square · Oct 28, 2026
Anatomically Matched Lower Limb Muscle-Specific Strength Using CT-Derived Quadriceps and Hamstring Volumes in Older Adults with Sarcopenia
By Jung GS, Park C, Ye AY et al.
Background We aimed to estimate lower limb muscle-specific strength (MSS) by normalizing knee strength to computed tomography (CT)–derived volumes of the corresponding muscle groups and to examine its relationships with muscle quantity, absolute strength, and clinical outcomes in older adults with sarcopenia. Methods In this cross-sectional study, 50 older adults with sarcopenia (10 men, 40 women; mean age 71 ± 6.2 years) were assessed. Skeletal muscle index (SMI) was measured using bioelectrical impedance analysis (BIA), together with handgrip strength (HGS) and knee extensor and flexor strength. Quadriceps and hamstring volumes were quantified using automated three-dimensional CT volumetry. Extensor and flexor MSS were calculated by normalizing each maximal strength to the corresponding ipsilateral muscle volume. Clinical outcomes including physical performance, activities of daily living, falls efficacy, quality of life, fatigability, depressive symptoms, and cognitive function were also assessed. Results CT-derived volumes correlated highly with BIA-derived segmental lean mass (r = 0.852–0.905). SMI correlated with HGS and lower limb strength, and HGS correlated with knee strength but was not associated with extensor or flexor MSS. Extensor and flexor MSS were moderately correlated (r = 0.602). In exploratory analyses, Korean Falls Efficacy Scale scores correlated negatively with knee strength and both MSS measures (− 0.523 to − 0.412) but not with SMI or HGS. Conclusions CT-based muscle group-specific volumetry enabled anatomically matched estimation of lower limb MSS. MSS was distinct from conventional muscle quantity and absolute strength, and may provide complementary information on lower limb muscle function.