Does the Finger-to-Nose Test measure upper limb coordination in chronic stroke?

Background: we aimed to kinematically validate that the time to perform the finger-to-nose test (fnt) assesses coordination by determining its construct,convergent and discriminant validity. methods: experimental,criterion standard study. both clinical and experimental evaluations were done at a research facility in a rehabilitation hospital. forty individuals (20 individuals with chronic stroke and 20 healthy,age- and gender-matched individuals) participated.. both groups performed two blocks of 10 to-and-fro pointing movements (non-dominant/affected arm) between a sagittal target and the nose (reachin,reachout) at a self-paced speed. time to perform the test was the main outcome. kinematics (optotrak,100hz) and clinical impairment/activity levels were evaluated. spatiotemporal coordination was assessed with slope (ijc) and cross-correlation (lag) between elbow and shoulder movements. results: compared to controls,individuals with stroke (fugl-meyer assessment,fma-ue: 51.9 ± 13.2; box & blocks,bbt: 72.1 ± 26.9%) made more curved endpoint trajectories using less shoulder horizontal-abduction. for construct validity,shoulder range (β = 0.127),lag (β = 0.855) and ijc (β = −0.191) explained 82% of fnt-time variance for reachin and lag (β = 0.971) explained 94% for reachout in patients with stroke. in contrast,only lag explained 62% (β = 0.790) and 79% (β = 0.889) of variance for reachin and reachout respectively in controls. for convergent validity,fnt-time correlated with fma-ue (r = −0.67,p < 0.01),fma-arm (r = −0.60,p = 0.005),biceps spasticity (r = 0.39,p < 0.05) and bbt (r = −0.56,p < 0.01). a cut-off time of 10.6 s discriminated between mild and moderate-to-severe impairment (discriminant validity). each additional second represented 42% odds increase of greater impairment. conclusions: for this version of the fnt,the time to perform the test showed construct,convergent and discriminant validity to measure ul coordination in stroke. © 2017 the author(s).