Change of Direction Analysis with 3D Force Plates
Change of Direction (COD) is central to sport, and it is just as important in rehabilitation, where cutting and pivoting tasks reveal how well someone can control and redirect their body. This lab uses 3D force plates and synchronized video to analyze planned cutting movements, so you can see not only how quickly an athlete changes direction, but how they generate the change in momentum. With a 3D force plate and Noraxon’s MR software users can examine the three-dimensional ground reaction force curve during braking, redirection, and propulsion.
Why Analyze Change of Direction Performance?
A stopwatch can tell you how fast a cut was. It cannot tell you why. 3D force plate data shows how an athlete slows down, plants, and redirects, and which strategy they use to do it.
Key metrics include:
Ground contact time, peak vertical force, peak braking force, peak mediolateral force, braking impulse, and mediolateral impulse.
Together, these measures support performance monitoring, return-to-sport planning, and rehabilitation assessment. Comparing right and left cuts can also show whether apparent asymmetries are real, or simply the result of differences in approach speed, cut direction, or task familiarity.
Learning Objectives
Identify the Phases of a Cut
Label initial contact, peak vertical loading, braking, redirection, and toe-off on the force-time curve, and learn which boundaries can be identified reliably from force alone.
Compare Right and Left Plant Strategies
Calculate interlimb differences and consider what else would need to be measured before interpreting asymmetry as a functional deficit.
Quantify Key COD Metrics
Measure contact time, peak forces, and impulses across repeated trials, and understand why a large peak force does not necessarily mean a large impulse.
Connect Kinetics, Kinematics, and Neuromuscular strategy
Use synchronized video to relate trunk lean, foot placement, and knee alignment to the force patterns you record, and use synchronized EMG to evaluate muscle contraction and co-constrations before the plant leg hits the force plate.
