Right Hand Prima Donna Syndrome

About two years ago, during one of our Saturday morning long runs, my friend Prateek remarked “I seem to favor my right hand when carrying a running bottle”. I thought it was an interesting (though not very surprising) observation. After all, if you are right-handed, your right hand would definitely be stronger and more inclined to do “more work”.

A few long runs later, I recalled our chat and started paying attention.. how often I was switching hands and whether my right (or left) hand was holding the bottle for longer durations. My observations on the first day were surprising. Since I have a healthy respect for Heisenberg’s Uncertainty Principle and, more recently, this pesky thing called “confirmation bias”, I paid attention for a few more runs.

The observations remained the same. Like Prateek, I too am right-handed. Unlike Prateek however, I was favoring my left hand. Let me dispense with the somewhat ambiguous “favoring” word and describe my experience. My right hand was noticeably getting tired quicker than my left.. By “tired”, I mean my brain was getting a message like “Oh! the bottle is so heavy. Please do something.”

If a right hander’s right hand could arm wrestle against his left, the right would handily be the victor. Every single time, right? So why was my right hand wussing out when it came to sharing the load of a water bottle?

There were three possibilities.

1. My left hand was actually stronger than my right
2. My right hand was a prima donna (“Bah! a menial task like holding a bottle?”)
3. A higher-order proprioception at play

Bear with me as I work out (what might strike you) as a strange analysis path. #1 was easily ruled out. At the outset, I thought #2 might be the culprit but things didn’t add up.

What could be the motive? Surely there was no beauty pageant of body parts or a show of oneupmanship between the right and left hands?

I had seen some runners with unbalanced swinging arms and wondered whether I was doing something similar – was my right arm working ‘harder’? To the best of my continued observations, it was not the case.

A fresh theory struck me. In partner dancing, the two dancers are never equal – one is the lead, the other the follow. The lead uses hand pressure and signals to initiate each move and ensure coordination between the two dancers.

Okay.. so running has none of dancing’s diverse and demanding moves. It is monotonous and has very few degrees of freedom. But the arms gotta swing, right? They gotta swing the ‘right’ way too – not too high to prevent straining the shoulders, and not too low either. Against this backdrop, perhaps the right hand (as lead) had more coordination work to do and hence, the addition of a bottle was too much of a distraction. In short, a higher order proprioception warranted it!

That’s my theory and I’m sticking to it.

I was reminded of this (two years ago) episode after reading this very interesting article on proprioception – sensing your own body is more complicated than you realize. The article requires some careful reading and, as is my usual wont, and I’m sharing the most useful bits.

Proprioception is not the vestibular system — the master controller of our balance and spatial orientation.

And though the two terms are often used interchangeably, proprioception is not kinesthesia. Like proprioception, kinesthesia involves the senses of limb position and movement, but scientists typically view the focus of these two as being quite different. Comparatively, proprioception has more to do with body position, and focuses on the cognitive awareness of the body in space.

Within the tendons that attach muscles to bones are proprioceptors called Golgi tendon organs, which provide the brain with information about muscle tension. This is your sense of how much force you’re exerting. Relatedly, the sense of effort refers to how much effort is required to produce a given motion, and this sense can be thrown off by fatigue from, say, exercise. Tendon organs and muscle spindles also convey to the brain the sense of heaviness, which relates specifically to those occasions when you pick up and move objects.