A real-time biomechanical feedback system for training rowers

A system was developed that quantifies rowing mechanics while an athlete trains on a rowing ergometer. The system consists of a Concept II rowing ergometer instrumented with a load cell and a series of potentiometers, a data acquisition computer and custom software. Kinematic and kinetic rowing data are displayed in the form of a two-dimensional stick figure animation, overlaid with kinematic and kinetic profiles. The software allows data to be saved and later replayed.Static and dynamic error analyses were performed to determine the accuracy and limitations of the system. Static measurements compared joint locations predicted by the RowTrainer system with values measured directly. Average static joint position errors ranged from 2 mm to −25 mm, with a typical joint location error being 10 mm. Using three-dimensional motion analysis, both dynamic and static error analyses were conducted. Average dynamic joint errors ranged from ±1 mm to −44 mm, with typical errors on the order of ±10 mm. Errors in joint positions resulted in average knee and hip joint angle errors of 9.6° and 5.8°, respectively. Additionally, the average handle horizontal velocity error during the drive phase was −1.8%.