Friday, November 09, 2007

buckets of physiological fun

This post is part of my occasional series on playing the double bass using a human body. Okay, very occasional. You can read the other post here if you like.

One of the odd things about the human body is that it didn't evolve primarily in order to play the double bass. Our body structures were produced by adaptations to pressures and demands having little to do with double bass playing. Demands such as - carrying buckets.

That's right, there seems to have been quite a lot of bucket-carrying in our evolutionary past, and we have the elbows to prove it:

Carrying angle -

When the arm is extended, with the palm facing forward or up, the bones of the humerus and forearm are not perfectly aligned. The deviation from a straight line (generally on the order of 5-10°) occurs in the direction of the thumb, and is referred to as the carrying angle (visible in the right half of the picture, right). In females the carrying angle is greater than in males.[1]

The carrying angle can influence how objects are held by individuals - those with a more extreme carrying angle may be more likely to supinate the forearm when holding objects in the hand to keep the elbow closer to the body.

- extracted from a Wikipedia article about the elbow

You can see your own carrying angle if you stand in front of a mirror and externally rotate (supinate) your shoulder until your palm faces forward. It's different for every person, though as the Wikipedia article notes, it tends to be greater for women - since women's hips are wider, they need more clearance for those buckets. It will also tend to be larger on your dominant side, meaning most of us are right-arm bucket-carriers.

Of what importance is this to the inquiring bass player, besides a new and hopeless pickup line ("Hey baby, what's your carrying angle?") At least for German-bow players, there's a continuous need to get the elbow onto or above the plane of the string - our elbows tend to dangle down below, accommodating our carrying angles but compromising the weight and support of our bow arms.

In order to correct for the carrying angle, we tend to lift our elbows and rotate the arm inward - pronating the bow into the instrument. If you use the larger muscles of the back and shoulder to do this, by lifting and compressing the shoulder forward, you'll also compromise the structure of the arm. Which will also disrupt the transfer of weight to the string, and possibly cause long-term injuries. Damn those bucket-schlepping ancestors!

Somehow we have to find a way to keep the chest open, the shoulder lowered and relaxed, and still create the internal rotation to lift the elbow and transfer the weight into the string. It sounds hopelessly complicated, I know - but when you see it in action, it looks effortlessly graceful, almost like we evolved to do this after all. Next time you watch a great string player, pay attention to how he or she rotates the arm - what happens to the shoulder, is the elbow straight or slightly bent, and can you tell where the pronation or supination are happening? How does this change on the lower and upper strings, through different bowings, articulations, and expressive demands?

And when the concert is over, do they still have the strength left to carry a bucket or two?


Bill said...

As an observer, not a bass player, I was compelled to look up French and German bow to get the difference straight in my mind. (Not the first time I have done this, sad to say!) Lo and behold, I see Mr He-who-is-not-to-be-named is blamed for making the French bow popular for soloists.. Just can't get away from that fellow! :-)

Bill in Dallas

Matt Heller said...

French-bow popularizer - I didn't realize! All the more reason to despise him.

I might try and post a video to demonstrate what I'm talking about with carrying angle, since it's difficult to describe in words. Thanks for reading, Bill!

Stan Haskins said...

Nice post, Matt - I wrote a response to it here: