The purpose was to evaluate the effect of a metacarpal phalangeal joint blocking splint combined with exercises, aimed at regaining strength, manipulative skills, and a normal pattern of movement of the hands in patients with rheumatoid arthritis (RA). All patients were measured three times: before the start of the therapy, after finishing the therapy, and at three months follow-up. Outcome measures were grip strength, pinch strength (Jamar dynamometer and pinchmeter), active range of motion (goniometer), dexterity (Sequential Occupational Dexterity Assessment [SODA]), and experienced functioning in daily life (Michigan Hand Outcome Questionnaire and Disability of Arm, Shoulder, and Hand questionnaire). The hands treated improved significantly on both total SODA score and on the pain score of the SODA. This means that the dexterity improved over time. No significant changes were found on the other outcome measures. This study indicates that intervention on the function of the hands in patients with RA who present an intrinsic-plus posture and movement pattern, improve significantly on dexterity and pain, measured by the SODA.