Could doing CPR with a foot cause harm to the recipient?
In a situation where the rescuer were unable to continue due to fatigue of the arms, is there a way to safely do CPR with the foot?
Mechanically, if you have good enough foot control to be able to meet compressions guidelines, then a compression is a compression. But there are a few things to consider. Most importantly, what a good compression is and how to achieve it, and whether you can achieve it with your foot.
To begin, CPR guidelines are updated regularly based upon research into effectiveness and outcomes.
Rate and depth are the 2 primary factors in maximizing circulation while allowing the heart enough filling time. (page 39)
Placement is also important for minimizing trauma to the ribcage (i.e. dislocating and breaking ribs, which can puncture lungs etc)
Guidelines FOR ADULTS only:
Depth: 2 - 2.4 inches (5 to 6 cm).
Placement: middle of sternum, interlocking fingers, and pulling fingers back so the heel of the palm is what presses on the sternum.
BUT going back to the reason why we do compressions, if someone drops without a pulse and is in need of CPR, they would likely die without it.
So if you were to do CPR with the narrowest part of your foot, focusing on controlling depth and rate, would the risks of fracture from too wide of a pressure base be better than NO COMPRESSIONS at all (or too weak ones) because your arms fatigue out?
I speculate that most people would prefer to have foot CPR and risk fractures/pneumothorax in order to not (almost certainly) die. However this part of the discussion would perhaps belong better in philosophy.se; I would be very interested to see a if there is a good argument for not doing it, or a discussion of litigation vs Good Samaritan laws.
But the point of this response was a discussion of the biomechanics of CPR for a foot.