center of the axle as depicted by 42 u2032 and effectively locking the device 10 in the extended leg position shown in fig4 c in the embodiment shown due to the deflection of axle 42 and the positioning of lobe 48 within tube 16 some torque must be applied via the axle slot 50 to rotate axle 42 clockwise to unlock and begin retracting foot tube 22 alternative constructions of member 16 such as a circular tube will provide slightly different operation of device 10 for instance lobe 48 would then preferably be adapted to be in constant contact with tube 16 to prevent foot tube 22 from inadvertently lowering when in the retracted position similarly axle assembly 40 could be configured so as not to be concealed within member 16 and therefore member 16 may be but need not be tubular if axle assembly 40 does not extend through member 16 then lobe 48 on axle 42 could be made to contact an exterior surface of member 16 when axle 42 is in selected rotational positions it will be appreciated that platform assemblies are load bearing structures that may carry people and equipment such as with portable staging and seating equipment therefore extendible leg device 10 should be suitably constructed for instance the structural members of the device 10.