Background: Joint hypermobility refers to joints that move beyond their normal limits. Individuals with hypermobility of the fingers experience difficulties in activities of daily living. Finger orthoses are available for managing hypermobility of the fingers, but their effectiveness has received little attention in scholarly literature. Objectives: To determine if use of custom fit finger orthoses leads to improvements in time needed to perform standardised hand function tests, and attentional demand required to perform these tests, in individuals with joint hypermobility syndrome, Hypermobile Ehlers-Danlos syndrome or Classical Ehlers-Danlos syndrome. Study design: Repeated-measures study. Methods: Fourteen participants performed three different hand function tests (target box and block test, writing and picking up coins), with and without their finger orthoses. Time to complete each test was recorded as a measure of functional performance. Brain activity was recorded in the pre-frontal cortices as a measure of attentional demand. Results: Functional performance significantly improved for all but one test (picking up coins with non-dominant hand) when participants wore finger orthoses (p < 0.05). Activity in the pre-frontal cortex was lower when using the orthosis to perform the coin test (dominant hand; p < 0.05). No differences were observed in other tests (p > 0.05). Conclusions: Results suggested that finger orthoses improved hand function and provided limited evidence to suggest that they may also affect attentional demand. While the limited sample does not provide conclusive evidence supporting the use of finger orthosis in this clinical population, results warrant further investigation in large scale longitudinal studies or randomised controlled trials.