[Detective Knowledge] Basics of Footprint Analysis

Basic knowledge of footprintology.
Flat footprints: barefoot footprints × coefficient = height; (shoe print length - footprint allowance - inner-outer difference mark difference) × coefficient = height.
Three-dimensional footprint: (barefoot footprint - footprint difference) × coefficient = height; (shoe footprint length - footprint allowance - inner-outer difference - mark difference) × coefficient = height.
The coefficient is a variable. For adults: Northeasterners - 6.875; Shanghai residents - 6.75; Zhejiang - 6.65; Shaanxi - 6.734; Chongqing - 6.856; Inner Mongolia - left 6.672 right 6.687. Gait characteristics: 1) Footprint marks: bump marks, step marks, push marks, kick marks, scratch marks; 2) Support features: seating marks, pressure marks, pressure marks, twist marks; 3) Kicking features: kick marks, gouge marks, picking marks, lifting marks, picking marks, scratches, sweep marks
Small feet wearing big shoes: step length shortens, step width narrows, step angle smaller, heavy pressure points shift backward, footprint edges are incomplete, many hollow edges, especially large front tip empty edges, worsening picking marks and prone to abrasion marks.
Shouting 'Wearing Small Shoes': stride length increases, step width widens, step angle decreases, pressure increases on both sides of the forefoot and forefoot, front chapter weight presses forward and shifts forward, heel weight shifts backward and heel side presses heel, and the longitudinal length of the foot arch shortens, resulting in marks of buckling, bumping, pressing, pushing, and worsening sitting marks.
Stride length features refer to the pattern in a set of footprints reflecting the relationship between walking and the coordination of both feet and the characteristics of bipedal movement movements.
In stride length characteristics, the combination of both feet can form several geometric diagrams, but the geometric composition of step length, width, angle, and features is the most optimal for reflecting the pattern.
1. Stride length refers to the longitudinal length between the corresponding points of the two adjacent left and right footprints. It is divided into left step length and right step length.
Adult males: over 80cm is long, 70cm~80cm is a middle step, below 70cm is a short step; For women, reduce this by 10cm on this basis.
2. Step width refers to the distance between the center point of one heel and the walking line of the opposite foot. Abduction steps are divided into divided step steps, parallel step step, overlapping heel cloth, and interlaced cloth. Retreat step is divided into: pointed step, combined pointed step, overlapping pointed step, crossing pointed step, with the inner edge of the front palm as the reference. \3. Step angle refers to the angle formed by the intersection of the foot's centerline and the same side walking line at the center point of the heel, which can be divided into left step angle and right step angle.
According to the size of the step angle, it is divided into: outward step, inward step step, and straight walk.
0°~5° is the straight step,
5.1°~10° is the small abduction step,
10.1°~20° is the middle-lateral step, and above
20.1° is the large abduction step.
Naming method: step angle, step width, step length, such as small abduction separation middle step.