A motorized prosthetic or orthotic lower-limb device (100,10) comprising: a first segment including a joint member and a second segment coupled with the first segment via the joint member; an actuator (144,12) configured to control motion of the second segment relative to the first segment; sensors, wherein one or more of the sensors are for providing a data stream comprising a first absolute angle of the first segment at a foot-off event and a second absolute angle of the first segment at a foot strike event; and a control system for operating the POD, comprising: a reactive layer configured to command and control motion of the second segment relative to the first segment; and an inference layer configured to: receive the data stream comprising a first absolute angle of the first segment at a foot-off event and a second absolute angle of the first segment at a foot strike event; determine a difference between the first absolute angle and the second absolute angle; determine a relative vertical displacement of the POD between the foot-off event and the foot strike event based at least on the determined difference between the first absolute angle and the second absolute angle, identify a current type of locomotion of a user of the POD based at least on the determined relative vertical displacement; and transmit information regarding the locomotion activity to the reactive layer to control motion of the second segment relative to the first segment. a first segment including a joint member and a second segment coupled with the first segment via the joint member; an actuator (144,12) configured to control motion of the second segment relative to the first segment; sensors, wherein one or more of the sensors are for providing a data stream comprising a first absolute angle of the first segment at a foot-off event and a second absolute angle of the first segment at a foot strike event; and a control system for operating the POD, comprising: a reactive layer configured to command and control motion of the second segment relative to the first segment; and an inference layer configured to: receive the data stream comprising a first absolute angle of the first segment at a foot-off event and a second absolute angle of the first segment at a foot strike event; determine a difference between the first absolute angle and the second absolute angle; determine a relative vertical displacement of the POD between the foot-off event and the foot strike event based at least on the determined difference between the first absolute angle and the second absolute angle, identify a current type of locomotion of a user of the POD based at least on the determined relative vertical displacement; and transmit information regarding the locomotion activity to the reactive layer to control motion of the second segment relative to the first segment. a reactive layer configured to command and control motion of the second segment relative to the first segment; and an inference layer configured to: receive the data stream comprising a first absolute angle of the first segment at a foot-off event and a second absolute angle of the first segment at a foot strike event; determine a difference between the first absolute angle and the second absolute angle; determine a relative vertical displacement of the POD between the foot-off event and the foot strike event based at least on the determined difference between the first absolute angle and the second absolute angle, identify a current type of locomotion of a user of the POD based at least on the determined relative vertical displacement; and transmit information regarding the locomotion activity to the reactive layer to control motion of the second segment relative to the first segment. receive the data stream comprising a first absolute angle of the first segment at a foot-off event and a second absolute angle of the first segment at a foot strike event; determine a difference between the first absolute angle and the second absolute angle; determine a relative vertical displacement of the POD between the foot-off event and the foot strike event based at least on the determined difference between the first absolute angle and the second absolute angle, identify a current type of locomotion of a user of the POD based at least on the determined relative vertical displacement; and transmit information regarding the locomotion activity to the reactive layer to control motion of the second segment relative to the first segment.