Hand Tension as a Gesture Segmentation Cue (Harling 1997)

Summary:
The premise of this paper is that hand tension can be used to aid segmentation of a sequence of gestures. The proposed idea is to look for places in time where the hand tension is minimized and treat these minimums as places to to segment the sequence of gestures. The model used to measure hand tension treats each finger as a rod of fixed length attached to two ideal springs whose tensions are calculated using Hooke's law and summed to produce an estimate of finger tension. Overall hand tension is computed by simply summing the tensions of each finger of the hand.
Gestures are split into four classifications, combinations of static and dynamic hand postures and hand locations. An experiment using a Power Glove to collect data from simple sequences of sign language gestures was performed. The Power Glove's limitation of only 4 levels of measurable tension and the study size of only one user contributed to the lack of robustness of the data used in the experiment.

Discussion:
The definition of posture and gesture are distinguished by the exclusion or inclusion of hand location and orientation information. I think these definitions are influenced by the hardware used for gathering data.
A solution to segmentation problem posed by a referenced paper is to hold a posture for one minute before it is recognized. This is quite a while in computer time, and seems unnecessarily long.
The hand tension segmentation algorithm does not attempt to recognize a posture until after a minimum value of hand tension that follows a possible gesture is identified. This enforced delay in recognition may seem a bit slow to the user and pushes the response time just outside the real-time range.
The hand tension model described cannot correctly segment gestures in which individual fingers increase and decrease tension at the same rate since the finger tensions are summed and there would be no drop in overall tension.
The calculation of hand tension doesn't account for tension in the palm of the hand, which is an important part of overall hand tension. The hand tension model could be improved by considering the direction of tension between adjacent fingers. Adjacent fingers whose tension lies in opposite directions should increase overall tension.