Because the fascia layer that defines the compartment does not stretch, a small amount of bleeding into the compartment, or swelling of the muscles within the compartment, can cause the pressure to rise greatly. Common causes of compartment syndrome include tibial or forearm fractures, ischemic reperfusion following injury, hemorrhage, vascular puncture, intravenous drug injection, casts, prolonged limb compression, crush injuries and eschars from burns.[7][8] Less common causes include labor and delivery following uncomplicated births and C-sections.[9] Compartment syndrome can also occur following surgery in the Lloyd-Davies lithotomy position, where the patient's legs are elevated for prolonged periods. As of February 2001, any surgery that is expected to take longer than six hours to complete must include compartment syndrome on its list of post-operative complications.