Human hammering (i.e., its "hammer time")

As part of an on-going NIH grant in collaboration with Dr. Jeff Lockman at Tulane University, we are investigating the mechanistic basis of a simple yet difficult motor task, namely hammering. Hammering represents an unusual functional problem in that the individual must both transmit high force (to drive a nail into wood, for example), but also be highly accurate. While every individual will resolve this force-accuracy trade-off differently, we are using both kinematic and kinetic technology to understand the nature of this trade-off. One on-going study is investigating the role of target size (i.e., a large nail versus a small nail), and subsequent effects on both force and accuracy. One of the prime pieces of technology for these studies is a high-impact force platfrom (Kistler 9637B, see below) that can effectively measure the powerful strikes incurred from hammering. We integrate this kinetic technology with video analysis using redlake digital cameras (500 frames/s) that can capture the rapid movements of hammer strikes. One especially intriguing line of inquiry involves hammering in reduced light conditions, such as room that has been darkened, thereby reducing the ability of individuals to perceive depth, an important mode for any individual making a sensitive force-velocity calculation.

Progress on NIH grant to date:

Here are pdf files from recent talks given at the annual 2009 SICB meetings in Boston that summarizes our progress on this grant

Irschick DJ, Henningsen J.  2009.  Trade-offs between force and accuracy in human performance.  Integrative and Comparative Biology. 98.6 pdf

Almedia S, Irschick DJ.  2009.  The kinetics and kinematics of human performance: Trade-offs between force and accuracy Integrative and Comparative Biology. 98.7 pdf