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Force distribution across the heel of the hand during simulated manual chest compression
M Baubin1, J Kollmitzer, A Pomaroli
1Department of Anaesthesia and Intensive Care Medicine, Institute for Emergency Medicine, Innsbruck, Austria.
Insights
Chest compressions during cardiopulmonary resuscitation (CPR) should precisely target the lower sternum. This study found the hypothenar part of the hand delivers more force, guiding optimal hand placement to prevent sternal fractures.
Area of Science:
- Emergency Medicine
- Cardiopulmonary Resuscitation
- Biomechanics
Background:
- Current cardiopulmonary resuscitation (CPR) guidelines emphasize precise hand placement on the lower sternum for effective chest compressions.
- Exact localization of the compression point is crucial during CPR training and practice to maximize efficacy and minimize injury risk.
Purpose of the Study:
- To analyze force distribution across the heel of the hand during simulated chest compressions.
- To determine differences in force patterns between the right and left hands in direct sternal contact.
- To identify optimal hand positioning for chest compressions to reduce sternal fracture risk.
Main Methods:
- A laboratory investigation involving 12 anaesthetists performing simulated chest compressions on a force-sensing mat.
- Measurement of total force, force distribution (thenar vs. hypothenar), and hand breadth in contact with the sternum.
- Determination of the distance between maximal force points for both right and left hand placements.
Main Results:
- The mean total force was similar for the right (644 N) and left (621 N) hands.
- The hypothenar part of the hand consistently exerted significantly higher force than the thenar part, regardless of hand used.
- The distance between maximal force points was 2.2 cm, equivalent to approximately one and a half finger breadths.
Conclusions:
- The hypothenar region of the hand is the primary force-exerting area during chest compressions.
- To minimize the risk of sternal fractures from overly cephalad compressions, rescuers should use their right hand if positioned on the patient's right, and vice versa.
Abstract:
According to most published guidelines of cardiopulmonary resuscitation chest compression is performed on the lower half of the sternum by compressing the sternum with the heel of one hand and the other hand on top of the first. In all guidelines and during CPR training great importance is attributed to exact localisation of the so-called compression point. In a laboratory investigation we assessed the force distribution across the heel of the hand and defined the total breadth in contact with the sternum. In order to find out whether there is any difference in the force pattern with the right or the left hand in direct contact with the sternum we determined the resultant maximal force of that part of the heel of the hand exerting the maximal force. A total of 12 anaesthetists performed simulated chest compressions onto a flat surface covered with an integrated force sensor mat. The distance between the most ulnar part and the most radial part of the hand was determined to be 9.2 cm. Similar mean total forces were measured (right hand in contact: 644 N; left hand in contact: 621 N). In all except one anaesthetist the hypothenar part of the heel exerted a significantly higher force compared to the thenar part, independent of whether the right hand or the left hand was in contact. The distance between points of maximal force when the right hand or when the left hand in contact was 2.2 cm corresponding to the breadth of one and a half fingers. To reduce the potential risk of sternal fractures by chest compressions applied too far in a cephalad direction, we recommend use of the right hand in contact if the rescuer kneels at the right side of the patient and vice versa.