an unusual lawn mower injury the authors report a case of foot trauma produced by a piece of the lawn mower blade which was fired projectilewise from the machine while it was in operation at hit the calcaneous and remained trapped in the bone the wound healed after removal of the foreign body wound debridement and systemic and local antibiotic prophylaxis in the professional literature available no report has been found on a missile injury produced by a piece of rotating lawn mower knife propranolol in yawning prophylaxis a case report objective yawning is a frequent behavior with circadian effects sometimes its frequency is very high and it is disturbing however there is no evidencebased treatment for yawningmethod this is a case report of a man with severe yawning from about 2 years agoresults yawning reduced after taking propranololconclusion current evidence suggests that propranolol may decrease yawning through its thermoregulation effect it is worthwhile conducting controlled clinical trials to study whether propranolol is an effective treatment for yawning