The entry position of the hands during butterfly is a topic of conversation on many swimming decks. Disregarding the pitch of the hands, the distance between the hands during the entry must be considered.
There are 3 different options:
- Shoulder Width Apart
- Greater than Shoulder Width Apart
- Less than Shoulder Width Apart
There are positives and negatives to each of these options and I feel a few of these options should be used by the majority of swimmers. However, the principle of individuality must be adhered for stroke biomechanics, so let's break down who may benefit from each of these three options. These are listed in order of least appropriate for success, in my opinion.
Less than Shoulder Width Apart
This position requires either a large outsweep after entry, in order to achieve a high elbow position and propel forward during the propulsion phase of butterfly.
This large outsweep increases the time of the catch and likely increasing the distance per stroke. This stroke may be an advantageous for those with a high tempo requiring for an increase in distance per stroke. Those individuals who are shorter (likely a shorter distance per stroke) and have poor undulation (likely poor thoracic spine motion) would likely succeed most with this stroke.
This stroke may be disadvantageous as it decreases the space between the rotator cuff muscles and the acromion. This decrease in space may increase irritation to the rotator cuff and result in an injury. For this reason, it is rarely used in elite flyers.
Wider than Shoulder Width Apart
This style uses an entry wider than shoulder width and uses less of an outsweep and more of a direct pull. This motion likely decreases the distance per stroke and increases the tempo.
This is advantageous in swimmers with a taller swimmer with a more flexible spine. This style of fly was successful for Michael Phelps, likely due to his size, flexibility, and already long distance per stroke.
For shorter, immobile swimmers, this likely increases the tempo too much, not balancing stroke rate and tempo. Also, weak swimmers will likely not be able to bring their hands under their body for an ideal catch.
Shoulder Width Apart
This entry is in between the aforementioned styles, likely contributing the benefits of both types of butterfly. For this, I feel it is most applicable to the majority of swimmers.
This stroke requires a small outsweep, allowing intermediate distance per stroke and tempo.
There are not many disadvantages to this technique, for the typical body structure, hence the wide applicability.
As you see, the entry is highly individualized, however the initial catch is not as individualized. The goal of the initial catch is to achieve an early vertical forearm as early as possible to enhance the power of the stroke. For this, it is key for the hands to enter sufficiently wide so that an immediate "grab" on the water occurs.
As you can see, different strokes are for different folks. Individualization is key for success and finding what stroke fits each individual is necessary. This is why emulating elite, like Michael Phelps, is not necessarily the key for your success. Work with your body's advantages and disadvantages, and pick the ideal biomechanics! If you consider Phelps' anthropometrics it is clear why Michael Phelps had a wide butterfly entry.
Lastly, keep in mind these are suggestions, as not everyone fits this model and just because you are tall and have a flexible spine, doesn't mean a wider entry is ideal for you. Instead, once mastery of the shoulder width apart entry occurs, then attempt to slowly modify the other aspects to optimize your fly.