Introduction and purpose: Fatigue leads to various disruptions in the musculoskeletal system. Specifically, it has been observed that fatigue disturbs perception of the position of the limbs and the spine as well as posture balancing control and gait kinematics. The purpose of this study is to determine whether orientation of the pelvis undergoes changes after a period of extreme work-related fatigue.

Materials and methods: Orthopaedic Surgery residents in our hospital often work 24-hour shifts in the emergency department, which is considered a tiring activity which constitutes an appropriate model for professional burnout. In order to assess the position of the pelvis, we used pelvis tilt on the sagittal plane which is defined as the inclination of the plane which runs through all four anterosuperior and posterosuperior iliac spines with respect to the horizontal. The pelvic tilt of 19 resident doctors was measured at the beginning of their shifts, 16 hours into their shifts and on completing their 24-hour shift. An analysis was made of the differences between the values obtained and the influence of gender, weight and body mass index.

Results: Fatigue caused by 16 and 24 hour shifts in the emergency department led to a mean decrease in pelvic tilt of 1.1° (significant p=0,014) and 1.6° (significant p=0,003) respectively.

Conclusions: The fatigue caused to resident doctors by their shifts in the emergency department leads to significant pelvic retroversion.

Introduction and purpose: Pelvic tilt (PT) on the sagittal plane when standing can be defined as the rotation of the pelvis on a transverse axis. The use of PT is indicated for patients with chronic lumbar pain and/or spondylolisthesis. Current IP measurement methods require the use of radiographs or very complicated equipment. The purpose of this study is to describe a new fast and easy-to-use IP measurement technique and analyze its validity and reproducibility.

Materials and methods: The measurement system consists in calculating the height of the anterosuperior and posterosuperior iliac spines (to the ground) and the distance between them. Then, by means of a mathematical formula, a determination is made of the inclination of the plane that runs through the four spines with respect to the horizontal. Reproducibility was analyzed through repeat measurements of a group of 12 healthy volunteers. The validity of the method was analyzed by comparing the measurements obtained with those made on the basis of the lateral pelvis radiographs of 30 volunteers.

Results: The system described can be used to calculate the value of IP fast and with no need of radiographs or complicated equipment. The intraclass interobserver correlation coefficient measured for the method was .90 and the interobserver correlation coefficient was .80, which were considered excellent results. The mean errors observed when comparing the values obtained with the radiograph measurements were of less than 2° (R2: .48) (significant p< 0.001).

Conclusions: The measurement method described is easy to use, reproducible and valid vis-á-vis the use of radiographs.