He didn’t know whether he was on his head or his heels.
This is a saying which I associate with emotional turmoil.

Hard on the heels of means close behind.  If you walk too close to the person in front, you may step on the heel of their shoe!

Kicking one’s heels means at a loose end or with some time to kill.

Never to put a foot wrong is to have an unusually good record of sensible behaviour.

Pull the rug from under someone’s feet is a metaphor which describes refuting someone’s arguments for example.

Wrong-footed perhaps comes from marching where all the troops are in-step.  The metaphor describes putting another person in the wrong or embarrassing them. 

The boot is on the other foot.
This saying is about someone who has one set of standards for themselves and another for others. 

Foot in the door describes a pushy door-to-door salesman, who prevents the occupant from closing the door in his face, by putting his foot in the doorway.  It can also describe someone’s access to an opportunity or admittance to a workplace.

Set foot means step.

Time may be required to find your feet  in a new job, perhaps.

Getting onto your feet may mean standing up or getting established in life.

To fall on your feet is to let lucky.  Cats have a reputation for always landing on their feet.

Two left feet is what a clumsy dancer has.

Shake a leg means look lively.

Bandy legs or bow legs are not straight.

I mentioned put your best foot forward in an earlier post, which leads to today’s verse:

Micah 6:8 And what does the Lord require of you?
To act justly and to love mercy and to walk humbly with your God.