I recently watched a few slow-motion videos of world-class long jumpers. Almost universally, they swing both arms forward at the beginning of the jump, and then thrust their arms outward and backwards during the descent before the landing. I then imagined them with arm feathers and it seemed as if the backward movement of forelimbs with aerodynamic surfaces providing some lift and thrust would allow the jump to be higher and longer.
Perhaps the long jumper arm thrust technique might begin to explain how theropod forelimb feathers that developed for other reasons might have been adapted to aid in jumping during prey pursuit. The feathered forelimbs could prolong "air time" during a jump, perhaps contribute to an "in air" modification of the jump trajectory, and eventually lead to short flights if the backward thrusts were repeated during the jump.
Just a thought for the group to consider.
Sent from my iPad2