A modified seated side tapping test in which the arms are crossed also reflects gait function in community-dwelling elderly

[Purpose] Seated side tapping test (SST) performance is associated with mobility impairment in the elderly. Although this test was developed to assess trunk function, interpretation of its results may be confounded by the upper-limb movements in its protocol. Here, this study aimed to validate the association between trunk function and gait function by means of the Arms Crossed SST (AC-SST), a modified version of the SST in which the arms are crossed over the chest, to exclude the effects of the upper limbs. [Subjects and Methods] A total of 116 community-dwelling elderly people were enrolled in the study (mean age: 75.1 ± 5.5 yrs). Measurement categories were gait function (gait speed and TUG), lower extremity strength (knee extension and flexion strength), trunk muscle endurance (trunk extension and flexion endurance), and trunk function (SST and AC-SST). [Results] AC-SST performance significantly correlated with gait function items, as did SST performance. Moreover, AC-SST was one of the significant predictor variables of gait function selected in stepwise multiple regressions. [Conclusion] Gait function associated with performance on the AC-SST, a test of trunk function in which the effects of upper limb function were excluded, reinforcing the importance of trunk function to elderly mobility.