During cooperation of the cam elements, {HEAD ~ the engagement elements} engage for affecting {TAIL ~ resilient displacement} of the stirrup from its neutral position during initial forward displacement of the boot member 
During cooperation of the cam elements , { HEAD ~ the engagement elements } engage for affecting { TAIL ~ resilient displacement } of the stirrup from its neutral position during initial forward displacement of the boot member
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH