If you need to analyze motion dynamics, then there is one logical choice – accelerometer. It is best to stick 3-axis accelerometer and capture data while object is moving. To make this possible Eric Ayars have developed simple Arduino based Accelerometer data logger, which stores acceleration data to µ-SD card.
Arduino is able to store data to up to 100separate data-files in FAT16 µ-SD card. Additional features include DEBUG mode, predefined collect time and limited user control. Of course later data has to be uploaded to PC and analyzed separately. Don’t expect high speed logging as it runs on 3.3V Arduino with 8MHz chip.