A 52-year-old man is found dead in his apartment after 8 hours. On external examination, purple-red discoloration is noted over the dependent parts of the body. Which of the following is the commonest site of livor mortis appearance in a body lying in supine position?

Explanation

## Livor Mortis: Commonest Sites **Key Point:** Livor mortis (hypostasis) appears in dependent areas due to gravitational pooling of deoxygenated hemoglobin in capillaries and venules after death. ### Position-Dependent Distribution In a **supine position** (lying on back), the dependent areas are: - Posterior trunk (back) - Buttocks - Posterior aspects of limbs - Occiput and posterior neck The **posterior aspect of trunk and buttocks** is the commonest site because: 1. Maximum surface area in contact with the ground 2. Largest gravitational gradient for blood pooling 3. Least muscular compression resistance ### Clinical Significance | Position | Dependent Areas | Livor Distribution | |----------|-----------------|--------------------| | Supine | Posterior trunk, buttocks | Posterior body surface | | Prone | Anterior chest, abdomen | Anterior body surface | | Lateral | Side in contact | Lateral aspect | | Hanging | Lower limbs, genitals | Distal dependent parts | **High-Yield:** The location of livor mortis can help determine: - Body position at time of death - Whether body was moved post-mortem (livor does not blanch or shift after 8–12 hours) - Approximate time since death (becomes fixed after 8–12 hours) **Clinical Pearl:** If livor mortis is found on the anterior surface but the body is in supine position, it suggests the body was moved after death (livor was already fixed in a different position). **Warning:** Do not confuse livor mortis with bruising — livor mortis does not blanch with pressure in early stages (first 2–3 hours it may blanch; after 8–12 hours it becomes fixed and non-blanching).