Biomechanics is the study of human motion. It is vital to analysis human motion when determining what causes injuries, and therefore how we can prevent them re-occurring.
Biomechanical analysis can involve:
gait analysis - study of your walking pattern.
running analysis
video analysis or motion capture analysis
sports biomechanics - sport specific analysis
workplace analysis - study of how you do you job
biomechanics of running, sprinting, swimming, throwing etc.