arm 26 of the actuating means 20 generally towards the trigger means 30 the trigger means comprises a grip portion 33 which is exteriorly accessible and generally configured to be gripped by one or more fingers of the hand of the user as that hand surrounds or otherwise grips the handle 14 of the crutch assembly 10 the grip portion 33 is pivotally secured as at 35 and includes a contact member 37 also a guide and retaining structure associated with the grip 33 includes an outwardly extending pin 39 mounted within a somewhat elongated groove 38 the retaining pin and groove 39 and 38 respectively serve to limit the amount of travel of the grip as it is pressed inwardly or normally biased outwardly due to the action of the hand of the user and or the biasing spring structure 32 further the contact member 37 may be in the form of a peripherally grooved roller slidably mounted at least minimally along the length of the arm 26 a trigger safety means is generally indicated as 40 and includes a movably mounted ratchet type structure 42 having at least one but preferably a plurality of outwardly extending retaining fingers 43 and 44 the ratchet structure 42 is engaged and biased inwardly by a spring member 45 towards and into engagable relation with an outermost free end 47 of the grip 33 when in the position shown in fig1 and 7 the grip 33 is prevented from being pivoted inwardly into actuating relation to the arm 26 however upon a downward thrust of a finger operated lever 46 by the hand of the user the.