I for one would like to know what you can tell from a particular set of footprints. Thanks
Looking at a set of the missing persons shoes provides the first bits of information. No two people create wear patterns in their shoes "exactly" the same way. Some people drag their heels, some walk on the sides, some walk mostly on the front half. If someone is "pigeon toed" it will create a specific wear pattern.
So...take into account, unique wear pattern, stride (distance from the heel of the leading foot to the toe of the lagging foot), pitch (the angle in or out for each foot from a center line) and straddle (the distance between the left and right foot). Now depending on what training a tracker has, they can read between 80+ and 100+ pressure releases and indicators in each print. Some are obvious and some are what are called "sub surface" and take a lot of experience and "dirt time" to master. For example, a "pock" is an impression in the print that may be a unique design item in the tread pattern, a thumb tack or stone stuck in the shoe. A "reverse pock" is a hole that leaves material sticking up in a print. Keep in mind that a print is a negative of the shoe or bare foot that left it. Some pressure releases tell you that the person is going to make a turn to the left or right, some tell you speed (along with a change in stride). When a person on a hike suddenly figures out they are lost, they go into a moment of panic and you get what we call a "Fred Astaire" where there are a whole bunch of prints in a small circle as they spin around looking for some point of reference...then you usually get an "explode off" which is the front half of a print with the material all thrown out the back as the take off running from a stop in blind panic...until they tire out, sit down and take stock of the situation.
So in brief:
Speed
Mental state
Unique wear patterns that assure you that you are on the "right track"
Carrying something
Time since track was made
Physical injuries
And a whole lot more depending on your skill level.
Back in the early 80's we developed the four man tracking team.
Think of a diamond. At the top point is the lead tracker, on either side are two more trackers or sign cutters and the bottom point is the radio/map (now gps/EMS person.
When the lead tracker loses the print, the two wing trackers start looking until they find the next print. If not, the lead tracker moves ahead of the group until he picks up the next print and then the rest of the team moves up with him/her. The nagivation/ems person is there to keep track of location of evidence, keep in touch with command and to render first aid to the trackers and first responder care to the subject.
I and many other trackers use a "tracking stick". Mine is an old ski pole with the basket removed. I put O rings around the shaft of the pole. From the tip to the first O ring is the stride. First to second is straddle. When I lose the track, I put the first O ring on the toe of the last track, and some where in a 360 degree circle is the next print, unless the changed speed and the stride got longer and you have to do a bit of looking.
Hope this gives so some answers!
Or else you are wondering why you asked.... :scared: