Influence of chair seat forward tilt angle on upper limb dexterity improvement in seated tasks: a pilot study

[Purpose] This study aimed to investigate the influence of seat-forward tilt angles on improving upper limb dexterity in seated tasks and to contribute to the development of seating strategies. [Participants and Methods] Seventeen healthy men (age, 20.0 ± 0.5 years; height, 175.1 ± 4.9 cm; and body weight, 63.8 ± 6.7 kg) participated in this study. The forward tilt angles of the seat were set at 0°, 15°, and 30°, with knee pads used in all conditions. The Purdue Pegboard task was used to assess upper limb dexterity, with participants inserting pins into holes in the board for 60 s. Additionally, a visual analog scale was used to evaluate the perceived ease of the task. [Results] The Purdue Pegboard task scores were 30.0 ± 2.5, 30.6 ± 2.7, and 32.5 ± 2.9 for the 0°, 15°, and 30° conditions, respectively. The visual analog scale scores were 75.3 ± 9.8, 76.4 ± 14.6, and 84.1 ± 11.1 for the 0°, 15°, and 30° conditions, respectively. Both measurements showed significantly higher values under the 30° condition than under the other two conditions. [Conclusion] These results suggest that a tilt angle of 30° provides the most significant ease and upper limb dexterity.