This experiment by the inventor, Dr. G. H. Hanson, in 1970 revealed that a relatively primitive and largely hand-made SPEED bracket prototype could propel itself through an arc of 30 degrees relative to a rigid wire.
NOTE: 1. The dent in his left index finger
2. The torsional deflection of the spring
3. The band - archwire alignment after release
4. How far the band has moved away from his thumb