YSK What to do if someone’s choking: Evidence says begin with back blows

Why YSK: > Despite choking being an emergency, until recently there has been limited high-quality evidence to guide bystanders on the most eff…

Interesting because all of my first aid instructions say not to slap people on the back. Why should I believe this over instructors and doctors?
I recently took a first air course. I was told abdominal thrusts were the first course of action. If the person is obese and you can’t get your arms around them, you should try back blows first. You have the person bend over and give them hard palm strikes in the back, not slaps. If you still can’t get the obstruction out, the last option is chest compressions, but that’s likely to break ribs in the process.
Chest compressions is for when the heart stops, and actually won’t do anything for choking. Abdominal compressions, where you put pressure on the diaphragm (not the ribs) is for choking. Also, if you do chest compressions for a stopped heart, you’re going to break a few ribs. Unless you’re doing in wrong.
Chest compressions force air out of the lungs pretty violently. If there’s a blockage in the oesophagus, and you can’t perform abdominal thrusts (due to obesity for example), chest compressions are an acceptable alternative.