What ranges of metacarpophalangeal joint flexion and extension are necessary to perform activities without difficulty?

Abstract

Introduction: Although the goal of restoring motion is to reduce limitations imposed on activities, the necessary metacarpophalangeal joint range of motion to perform activities without difficulty remains unclear. This study of 30 healthy participants was conducted to ascertain the flexion and extension range of motion of all finger metacarpophalangeal joints necessary to perform activities without difficulty with restricted angles of all finger metacarpophalangeal joints. Methods: Flexion and extension of finger metacarpophalangeal joints of 30 participants were restricted by orthoses. Flexion was restricted to 70°, 60°, 50°, and 40°. Extension was restricted to −20°, −30°, −40°, and −50°. Participants performed 19 activities at eight different angles in random order. The perceived difficulty in performing each task was scored. Results: Statistically significant differences in difficulty were found between the results of trials performed with angles restricted to 50° and 40° of flexion, and to −40° and −50° of extension compared with those of a normal hand. No significant difference in difficulty was found between the results of trials performed with restriction angles of 70° or 60° of flexion, or −20° or −30° of extension compared with those of a normal hand. Conclusion: Difficulty in performing many activities might not be perceived for flexion or extension range of motion of more than 60° and −30° achieved by hand therapy, even if the range of motion of finger metacarpophalangeal joints is restricted. This study is expected to be useful for determining range of motion goals in patients with limited finger metacarpophalangeal joint movement.