Mechanical limitation of compression depth in a common CPR training manikin

Current CPR guidelines recommend a chest compression depth of 5–6 cm. During an in-hospital training project using a widely adopted manikin (Resusci Anne, Laerdal Medical), integrated distance sensors consistently recorded compression depths below this target range. Further mechanical evaluation showed that a depth of 6 cm is not physically achievable with this model; the maximum displacement did not exceed 5.7 cm, even when measurements included chest components as recommended by the manufacturer. Although limited to a single, widely used manikin, these findings highlight the need to reassess calibration and mechanical design to ensure alignment with guideline-based CPR training and accurate performance feedback.