Timing is crucial and there is next to no margin for error at this phase: a jump that begins too early or late off the table can mean the difference between an excellent, average or poor effort. Each athlete has their own method of generating as much inrun speed as possible, depending on such intricacies as crouch depth, hip and knee angle, arm placement, or how far the torso is positioned over the knees. Body weight is also a significant factor (see power-to-weight ratio), which has led to some athletes' health becoming a concern over the past two decades.