The extraordinarily long “Humanoid Robot” thread shows the passionate disagreement between those who believe that the world is better served by humanoid-shaped robots vs. those who believe that dedicated non-humanoid robots would be better.
But I’m sure that we can all agree that medically-prescribed prosthetic hands would be better served by robotic hands with the flexibility and dexterity of real human hands. This is a real challenge. I recall a little girl in my first grade class who was missing both her hands and used prosthetics with grasping devices that resembled needle-nose pliers. (1958)
The key insight for me is that hand motions can be described by an “alphabet” of motions that can be combined into the majority of actual hand movements. Imagine that! It’s the leap from a robot trying to mimic human hand motions (analagous to Chinese ideograms) and a robot programmed with a couple of dozen movements which can be combined into hundreds of potential movements (analagous to an alphabet).
Cool!
Indian researchers have extracted the specific hand motions practiced in the’ Indian classical dance form known as Bharatanatyam.
Reconstructing hand gestures with synergies extracted from dance movements
Scientific Reports volume 15, Article number: 41670 (2025)
….
The mudras are represented as fundamental syllables of motion. These syllables were then employed to reconstruct 75 diverse hand gestures, including American Sign Language (ASL) postures, a dataset of natural hand grasps and traditional mudras. Comparative analysis between mudra-derived synergies achieved superior reconstruction accuracy (95.78% for natural grasps and 92.99% for mudras) compared to synergies derived from natural grasps (88.92% for natural grasps and 82.51% for mudras). The results suggest that the structured and intentional nature of Bharatanatyam mudras leads to much stronger representation of syllables of movements that have superior generalizability and precision. Additionally, the reconstructed gestures were successfully mapped onto Mitra, a humanoid robot with five degree of freedom hand using a continuous joint-mapping approach. This research highlights the potential of dance inspired structured learning in enhancing dexterity, rehabilitation, and motor control, paving the way for more efficient gesture-based interaction models in robotics, prosthetics and rehabilitation. … [end quote]
Here is a video of some mudras. Try them out to see how agile your own hands are!
Here is a video of Bharatanatyam dance, a hymn to the Hindu god Shiva (who is often portrayed with multiple arms). Note the hand gestures (mudras) which are part of telling the story.
I have danced continuously since my mother enrolled me in a ballet class at age 4. I continue to dance almost daily and I plan to continue. A study on Parkinson’s disease revealed that an eight-week integrated dance therapy led to significant improvements in both cognition and quality of life. (And I’m pretty sure that these patients weren’t dancing Zumba with its fast, complex footwork.)
Back to robots…whether humanoid, parts of humans or even non-humanoid, I think that the designers of robots will benefit from the concept of a movement alphabet.
Wendy
