LAUSR

BACKGROUND Ophthalmic surgeons experience high levels of physical strain in the neck, lower back, and buttocks. While ergonomic interventions may help to solve these problems, only a few studies have reported chair designs for ophthalmic microsurgery. OBJECTIVE To design a chair that reduces the physical strain on surgeons and examine its effectiveness in improving posture and reducing seat pressure. METHODS A prototype chair with a three-dimensional seat surface and a sliding adjustment mechanism for the backrest was designed to fit the surgeon's body. A conventional chair (A) and the prototype chair (B) were compared during microsurgeries performed by five surgeons. Seat pressure was measured using a pressure-sensing device, and the pelvic tilt angle was measured using a gyroscope sensor. RESULTS A paired t-test indicated significant differences between the chairs: average seat pressure was 70.4±12.7 mmHg for A and 40.5±3.8 mmHg for B (p = 0.008); the maximum seat pressure was 242.2±19.7 mmHg for A and 170.5±38.5 mmHg for B (p = 0.024); contact area was 906.1±114.5 cm2 for A and 1,255.9±60.1 cm2 for B (p < 0.001); and relative value of the pelvic tilt angle was -13.7°±3.7° for A and -7.1°±4.9° for B (p = 0.032). CONCLUSIONS The prototype chair was associated with lower seat pressure and maintenance of a more neutral posture than the conventional chair, indicating that it may help to reduce physical strain in ophthalmic surgeons.