According to a first aspect there is provided a walking aid (WA) (100) usable as a medical device, suitable for supporting a mobility impaired disabled user while moving through a set of movements correlating to a walking motion. The WA (100) comprises an exoskeleton (500), a power source in the form of a battery pack or other similar onboard power pack (not shown) together with its associated power supply cables (not shown), and a control system (not shown). an The exoskeleton (500) comprises a rigid pelvic support member or hip frame (15) including a pelvic harness (96), and a pair of leg structures (50) (a first leg structure and second leg structure). Each of the leg structures (50) comprise an upper leg structural member (10), a lower leg structural member (11), a foot member (18), a main hip actuator (16), a knee actuator (13) and a main foot actuator (19). The upper leg structural member (10) is for securing with an upper leg (610) of a user (600), the upper leg structural member (10) being pivotally engaged at a first end (10a) thereof to the hip frame (15) by the hip joint (14). The lower leg structural member (11) is for securing with the lower leg (620) of the user (600), the lower leg structural member (11) being pivotally engaged at a first end (11a) thereof to a second end (10b) of the upper leg structural member (10) by a knee joint (12). At a first end (10) of the upper leg member (10) is a hip joint (14) that pivotally engages the upper leg member (10) with the hip frame (15). The hip joint (14) defines a hip axis (14A) that in use is located relative to the user (600) at or approximate to the natural axis of hip rotation in an anterior/posterior direction of movement. In a preferred embodiment, each hip joint (14) is configured relative to the hip frame (15) with its axis of rotation (14A) extending downwardly in a lateral direction at an angle of between zero and ten degrees, and more preferably of about four degrees. This inclination of the axis
