Andrew Easton (33) intervened as PC Alexander Clarke, who was on cycle patrol in Larbert, went to detain a woman he saw carrying a baseball bat.
Stirling Sheriff Court was told that the incident began about 7.10pm on January 3 as PC Clarke cycled to the flats at St George’s Court to deal with an unrelated matter.
Prosecutor Kyrsten Buist said PC Clarke “became aware” of the woman walking along the pavement carrying the baseball bat and got off his bike and attempted to put her in handcuffs.
Miss Buist said the officer then heard shouting behind him and saw Easton about ten feet away pulling what he thought was a machete from the wasteband of his trousers.
The depute fiscal said the bicycle cop activated his panic alarm and “a number of police units” including firearms officers were sent to the scene.
After a further stand-off, Easton fled and PC Clarke, seeing that he no longer had what had appeared to be a machete, ran at him, caught up with him and detained him until other officers arrived a short time later.
A machete scabbard was found on the pavement.
Miss Buist said that until that point PC Clarke had thought that what was involved was an actual machete, not just a machete sheath.
She said the incident was “genuinely alarming and frightening for the officer”.
Easton, of St George’s Court, pleaded guilty on indictment to threatening behaviour.
Sheriff Wyllie Robertson deferred sentence until next month for a criminal justice social work report on Easton and released him on bail.