Effects of a chair for ophthalmic microsurgery on pressure distribution and pelvic tilt in surgeons.

Abstract

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. To design a chair that reduces the physical strain on surgeons and examine its effectiveness in improving posture and reducing seat pressure. 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. 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). 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.