Butterfly Arms

Common mistakes and how to improve yours

Butterfly arms are a continuous simultaneous movement that require significant upper body strength. Correct arm technique keeps the leg kick and body movement balanced. 

The action of the arms is similar to that of front crawl as the arms pull long through the water towards the hips and recover over the water surface. The underwater catch, down sweep and upsweep parts draw a typical keyhole shape through its movement path.

For an in-depth look at all aspects of butterfly stroke including practical exercises to practice and help perfect your technique, download How To Swim Butterfly. 

Clean Hand Entry

The entry of the hands into the water should be finger tips first, leading with the thumb.  Fingers should be together with palms flat and facing outwards.  Arms should be stretched forward with a slightly bent elbow.  Entry should be with arms extended inline with the shoulders.

Effective Catch and Down Sweep

The pitch of the hands changes to a deeper angle with hands almost vertical.

The catch and down sweep should begin just outside the shoulder line.

Palms remain facing in the direction of travel.  The elbow should bend to about 90 degrees to provide the extra power required.  The hands sweep in a circular movement similar to breaststroke, but in a downwards path.

Quick Hand Upsweep

The pitch of the hands changes to face out and upwards towards the water surface.  Elbows extend fully to straighten the arms and hands towards the thighs.

Hands and arms must clear the water on recovery in accordance with ASA Law.  Arms and hands should exit the water little finger facing upwards.

Arms must clear the surface as they are thrown over and forwards.  Palms remain facing outwards, naturally giving a thumb-first entry.

Butterfly Arms: Common Mistakes

The two most common mistakes made when it comes to butterfly arms are an incomplete or short pull and a wide hand entry.

The arm technique is sometimes compared to front crawl when it is taught to beginners in its most basic form.  This it due to the long sweep and the recovery over the water surface.  This is where the similarities end and this comparison can sometimes be taken literally, resulting in an almost double front crawl arm action with an excessive elbow bend. 

The most common mistake made amongst slightly more advanced butterfly swimmers is a wide hand entry.  The hands should enter the water inline with the shoulders.  If the entry is wide of the shoulder line then this will result in a weak and inefficient arm pull.

Simply walking though shallow water of about shoulder depth practicing the arm action in slow motion will help to establish a full sweep and an inline hand entry.

Learn and Improve Your Arm Action With These Simple Exercises

Download these documents to your computer, tablet or mobile device and fine-tune your butterfly arm technique.  Isolate your arms and focus on the key technique points to be sure you get this part of the stroke absolutely right. 

Click here for more butterfly exercises.

All of these documents are PDF format and are compatible with all tablet and mobile devices.  Some computers may need PDF reading software such as Adobe Acrobat.

Related Pages

butterfly stroke › butterfly arms

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