Motion-limiting wrist procedures have demonstrated both efficacy and reproducibility as a treatment for alleviating painful wrist conditions, but the reduction of pain achieved is necessarily accompanied by a marked loss of wrist motion. However, no study demonstrates a functional difference between variable degrees of wrist motion. The hypothesis of this study is that wrist motion is directly correlated with functional ability. Using a prospective, randomized, crossover design, we randomized 42 men and women above 45 years of age with normal wrists to wear both a partially restricted and a highly restricted splint for 24 hours each. Serving as their own controls, objective and subjective outcome measurements were taken at baseline and after each of the 2 splinting periods. The specific measurements included range of motion parameters (flexion/extension, radioulnar deviation, supination/pronation, circumduction), subjective surveys (Disabilities of the Arm, Shoulder, and Hand; Patient Rated Wrist Evaluation; and Modern Activity Subjective Survey), and an objective timed test (Modern Activity Timed Test; MATT). The simulated flexion/extension arc of motion for baseline, partially restricted, and highly restricted conditions were 138 degrees , 58 degrees , and 20 degrees , respectively. Median Disabilities of the Arm, Shoulder, and Hand scores for the 3 conditions significantly increased from 1.8 to 14.4 and 20.8 (p <.01), respectively. In addition, Patient Rated Wrist Evaluation results increased from 2.5 to 16.4 and 27.1, and the Modern Activity Subjective Survey results increased from 0.3 to 9.1 and 14.9 across restricted motion conditions. Modern Activity Timed Test results matched the perceived difficulty reflected by the subjective surveys, demonstrating significant increases in performance time for 6 of the 8 individual MATT items as well as significant differences for the sum of all tasks (MATT score) between the highly and partially restricted conditions. Use of low-profile splinting to restrict wrist motion demonstrates a direct correlation between restriction of wrist motion and functional disability.