Crushing a bug

I often doubt or second guess the things I say in lessons. Sometimes it’s just a lack of clarity. I don’t always think ‘on my feet’ very well and use a lot of extra words that just don’t get my point across clearly.
 
Sometimes I say the wrong thing. 
 
Yesterday I used an analogy with a student that I’m not sure about.  She was playing a soft, romantic, broken chord pattern in both hands and encountered several problems: her soft was nearly inaudible, and uneven, and the small knuckle of her fingers collapsed. All of these problems were interrelated of course!
 
Part of the issue was the piano in my teaching studio: it has stiff keys that are hard for students to adjust to.  Part of the issue was also a recurring problem with this student of inattention to hand position, and flow. 
 
So, I wanted to give this student a kinesthetic experience to get the desired affect: I suggested curved fingers, and under each finger she was crushing brittle little bugs. I wanted something that would give her a sense of stability in the structure of her finger, that she could then transfer all the way to the key-bed.
 
The result was very effective: she had a consistent sound, and she achieved a projecting soft dynamic immediately. 
 
My fear, though, is that the idea of crushing something with her fingertips could lead to a complete isolation of the fingers. Instead of integrating her arm, the rest of her body would be cut off by a tight wrist and her fingers would try doing all the work. 
 
In the short term this was an effective strategy. I’m curious to see how this student develops and whether it inhibits her technique later.
 
Have you found a better, more technically sound, analogy for this type of problem? Any thoughts about how to adapt this analogy to a good technical approach? I’d love to hear from you! Please send me an email by clicking here.