Functional Range of Motion of the Wrist Joint under Varied Grasping Tasks

Currently, the reference values of normal range of motion at the wrist joint are for an open palm position with fingers extended: extension/flexion at 70/75, and radial/ulnar at 20/35. However, functional range of motion when grasping an object is likely to be significantly different from traditional range of motion practiced today. This may have profound effect on occupational therapy practice when treating patients for improving their range of motion. The purpose of this study was to examine functional range of motion of the wrist under varied grasping tasks by position and applied force. Thus far, a convenience sample of 7 healthy participants (mean age 25 + 6), all right-hand dominant, 4 male and 3 female) has been obtained. However, a total of 25 participants will be included in the analysis. The maximum wrist flexion, extension, radial and ulnar deviation was measured using photo and digitalization method under the following conditions: By position (1) neutral, (2) supination, and (3) pronation, and; by applied grip force (1) none, fingers are open, (2) 5% maximum voluntary contraction (MVC), (3) 25% MVC, and (4) 50% MVC. When participants were required to apply more grip force, the observed range of motion, specifically the maximum wrist flexion, extension, and ulnar deviation, decreased. The maximum radial deviation seemed to not be influenced by the applied force. Under the neutral position, the maximum wrist extension values were: 60.0 degrees (fingers are open), 59.1 (5% MVC), 54.6 (25% MVC), 53.7 (50% MVC). The maximum wrist flexion values were: 64.5 degrees (fingers are open), 32.9 (5% MVC), 30.5 (25% MVC), 20.0 (50% MVC). The maximum ulnar deviation were: 30.0 degrees (fingers are open), 28.6 (5% MVC), 24.7 (25% MVC), 21.0 (50% MVC).The maximum radial deviation were: 24.6 degrees (fingers are open), 39.2 (5% MVC), 30.5 (25% MVC), 33.3 (50% MVC). The pilot study suggested that functional range of motion of the wrist was influenced by the measurement position and applied force. Future studies should examine the values using a larger and more representative sample