Construction workers frequently perform overhead drilling into concrete, which is associated with a high frequency of pain and disability, presumably due to high shoulder loads and awkward neck postures. My thesis involved the design and evaluation of an Inverted Drill Press, an ergonomic intervention device for overhead drilling. In Study 1, I designed a new Inverted Drill Press based on feedback from focus groups. I then conducted field tests to evaluate the intervention on construction sites and compare it to conventional overhead drilling. Results showed reduced fatigue, improved usability, and improved neck posture with the intervention. Elevated shoulder postures and drilling speed were not improved and reflected areas where the Inverted Drill Press could be refined. In Study 2, I conducted biomechanical modelling to compare shoulder torques during drilling and to identify the optimal placement for the crank on an Inverted Drill Press in order to minimize shoulder torque.