Background: Much of human behavior revolves around use of the hand, yet distal arm motor deficits are not part of the NIH Stroke Scale (NIHSS), and so their measurement is omitted from many guidelines and care pathways. We examined the frequency of distal arm motor deficits and their functional implications. Methods: Patients in the STRONG Study were examined 1-10d and again 90 d post-stroke. Grip force, expressed as the ratio of paretic/nonparetic hands, and the NIHSS were measured serially. The modified Rankin (mRS) and Fugl-Meyer arm motor (FM) scales were measured at d90. Results: There were 763 patients, with age = 62.5±15.0 (mean±SD), acute NIHSS = 4 [2-9] (median [IQR]), and day 90 mRS median = 2 [1-3]. Grip force was available in 748 acutely and in 439 at d90. Weakness in grip strength was present in 60.2% acutely and 52.2% at d90. Acutely, grip force was not related to NIHSS total score (r=.04, p=.3) after accounting for proximal motor deficits (NIHSS Q5); at d90, there was a weak relationship (r= -0.15, p<.0001). Proximal weakness was only partially related to distal motor deficits at both timepoints (r = -0.48 to -0.53, p<.0001). At d90, grip force explained 24.6% of the variance in mRS score (p<.0001). D90 grip force showed convergent validity, correlating strongly with the distal arm motor FM score (r=.64, p<.0001). Conclusions: In this mild-moderate stroke population, distal arm motor deficits were common, were poorly captured by the NIHSS total score, and did not simply echo proximal arm motor deficits. Distal arm motor deficits were strongly related to level of global disability at d90. These findings argue that measurement of distal arm motor deficits should be included in guidelines and care pathways after stroke.