According to a first aspect there is provided a walking aid (WA) 100 usable asa medical device, suitable for supporting a mobility impaired disabled userwhilemoving through a set of movements correlating to a walking motion. The WA 100comprises an exoskeleton 500, a power source in the form of a battery pack orothersimilar onboard power pack (not shown) together with its associated powersupplycables (not shown), and a control system (not shown).The exoskeleton 500 comprises a rigid pelvic support member or hip frame 15including a pelvic harness 96, and a pair of leg structures 50 (a first legstructure andsecond leg structure). Each of the leg structures 50 comprise an upper legstructuralmember 10, a lower leg structural member 11, a foot member 18, a main hipactuator16, 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 auser 600, the upper leg structural member 10 being pivotally engaged at afirst end10a 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 ofthe user 600, the lower leg structural member 11 being pivotally engaged at afirst end11a thereof to a second end Nib of the upper leg structural member 10 by akneejoint 12.At a first end 10a of the upper leg member 10 is a 14 joint 14 that pivotallyengages the upper leg member 10 with the 14 frame 15. The hip joint 14 definesahip axis 14A that in use is located relative to the user 600 at or approximateto thenatural axis of hip rotation in an anterior/posterior direction of movement.In apreferred embodiment, each hip joint 14 is configured relative to the hipframe 15with its axis of rotation 14A extending downwardly in a lateral direction atan angle ofbetween zero and ten degrees, and more preferably of about four degrees. Thisinclination of the axis of rotation 14A mimics a human beings upper legalignment.- 62 ¨The inclination allows for more natural transfer of the cent
