Table 3.

Finite-state machine transition conditions

Transition	Description	Condition
	Knee joint is hyperextended, and
	Prosthesis shank is rotating forward, and
	Prosthesis shank is inclined forward, and
	Prosthesis is rapidly unloaded
	Prosthesis is unloaded, and
	Knee joint is extending
	Knee joint has zero velocity, or
	Prosthesis is loaded
	Prosthesis is unloaded, and
	Knee joint is flexed past threshold
	Prosthesis is loaded, and
	Prosthesis was previously unloaded, or
	Prosthesis shank rotating backward, or
	Prosthesis shank is not inclined forward
	Knee joint begins flexing, and
	Slow walking speed detected, and
	Walking speed above threshold
	Prosthesis is unloaded, and
	Knee joint is extending
	Knee joint is flexed past threshold, and
	Knee joint is extending
	Knee joint is fully extended, or
	Knee joint is flexing
	Knee joint is hyperextended, and
	Prosthesis is unloaded, and
	Shank axial acceleration above threshold
	Prosthesis is loaded, or
	Time in state beyond threshold

Finite-state machine transition conditions depend upon measured sensor inputs (see caption for Tables 2 and 3) and several threshold parameters: knee angle ( ), shank angle ( ) and angular velocity ( ), shank axial force ( ) and yank ( ), walking speed estimation ( ), shank axial acceleration ( ), and time ( ).