Hand Work

Complete Kinematic and Kinetic Hand Function:
A Method, Mapping and Model

My dissertation was focused on hand function, both where the hand can move and how the hand can apply force, and how function changes due to arthritis and surgery.

Forces and Motions

Using motion capture, ranges of motion were measured for each joint in the hand. Adding a six axis load cell with custom attachments, forces were measured at many positions and directions across the range of motion.

Mapping and Modeling

Each participant had their forces (colored arrows) overlaid on their kinematic range of motion (grey wave shape) to create Individual Maps. These maps were combined for the tested healthy and arthritic populations to develop population maps. Different statistical methods were used to create regional maps and models of how force is applied across the range of motion. These maps allow an individual to be compared to a population, or to compare two populations to understand specific differences in how hands function. Over time, these methods also allow functional tracking, to monitor how function changes as a result of treatment.

Surgical changes

The final part of my dissertation work was to track changes after surgery. Five participants were tested before trapeziectomy, six weeks after surgery, and 12 weeks after surgery. Using the kinematic and kinetic mapping, their function was tracked to see how surgery changed the function.

The big takeaway was that in the twelve weeks following surgery, pain decreased for patients, but the function did not significantly. Most patients had similar size of range of motion, and were able to apply similar forces as before surgery.