VIDEO: Check Out What a Swimmer Looks Like at a MusculoSkeletal Level

Ever wondered exactly what your arms and legs were doing during each of the four primary competitive swimming strokes: backstroke, breaststroke, butterfly, and freestyle?

We came across this video today on Facebook, and found the original source (as best as we can tell) on a YouTube channel called “anybodytech” from 2008.

The video looks at a muscular and skeletal level at what is happening during each of the four major strokes. When a muscle turns purple, that means it is activated.

The research for these videos was done by a doctor Nakamisha at the Tokyo Institute of Technology. In the video’s info, there is a link to see more information on each video.

If you were ever wondering why, exactly, butterfly is so exhausting, this video gives a good indication – the arm muscles are constantly activated. Unlike the other strokes, there’s never any significant period of relaxation.

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where’s the video?


if you are really a geek you can listen to a tough lecture on how their analysis system was developed:

What is unknown is the swimmer used. Obvious differences in technique will play a role in which muscles are activated. Would love to see:

Ledecky for free
Phelps fly
Pearsol back
and a variety for breast depending on technique


I’d like to see the musculoskeletal breakdown of this stroke:

Do yourself a favor and take a few minutes to watch that. It is a true gem of the internet and something any swimming fan will enjoy.


Hey i’ve seen this before in the Olympics. He didn’t start with the cross-stroke but switched to it toward his final sprint. Now i know where he went to train.


So that’s how Thorpe did it.


You see, when the arm goes under water, the shoulder loses the ability to pull backwards…..

Becky D

It’s too bad Thorpe didn’t use this technique, because it he had, he’d be injury free.

I know that because the the internet said so.

About Braden Keith

Braden Keith

Braden Keith is the Editor-in-Chief and a co-founder of He first got his feet wet by building The Swimmers' Circle beginning in January 2010, and now comes to SwimSwam to use that experience and help build a new leader in the sport of swimming. Aside from his life on the InterWet, …

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