Swimming

The video above, created by AnyBody Technology, uses biomechanical softwares to depict which muscles are activated during different swimming techniques - Front Crawl, Back Stroke, Breast Stroke & the Butterfly.

Here's a link to their youtube webpage, they've done some awesome work...



http://www.youtube.com/user/anybodytech

Gotta get into the pool

Backstroke
Muscles that can be seen contracting include

The abdomens, Hip Flexors, Glutes

Thighs - Quadriceps(pushing towards the surface), the Hamstrings pushing down away from the surface during the flutter kick.
Legs - Tibialis Anterior, Soleus

* The flutter kick doesn't help a swimmer with speed during the backstroke, it helps to balance the swimmer and stabilize their body during movement

Arms - Deltoids(post. & ant.), Triceps, Biceps

Torso - It looks like your chest also is contracting, but a majority of the power will come from the back - specifically the Latismus Dorsi(which gives the V shape, it function is to bring the arm back to normal stance(The Anatomical Position)

The Rhomboid, Teres Maj. & Min, Erector Spinae