How should a responder position their body while giving chest compressions?

Positioning the body correctly while giving chest compressions is crucial for both the effectiveness of the compressions and the safety of the responder. When the responder's shoulders are positioned directly over their hands, it ensures that the force applied during compressions is maximized. This alignment helps distribute the weight correctly, allowing for deeper compressions at the proper rate, which is vital for helping circulate blood to the brain and other vital organs.

Having the arms straight and elbows locked as part of this position allows the responder to utilize their body weight effectively without overexerting themselves, helping to sustain the energy required for continued compressions. This technique also reduces the risk of injury to the rescuer's arms and shoulders, enabling them to maintain a steady rhythm during the process.

In contrast, leaning back with arms bent would hinder effective force application and could lead to improper compression depth and rate. Positioning the hands above the head or sitting on the ground would entirely compromise the effectiveness of the compressions, as neither position allows for appropriate leverage or body weight utilization.