Presentation on theme: "Put the person into the shoe Podiatry. The Foot "Allowing for certain illnesses, how you walk should generally remain with you for life. If we can record."— Presentation transcript:
Put the person into the shoe Podiatry
"Allowing for certain illnesses, how you walk should generally remain with you for life. If we can record an image of how a suspect's foot falls on a particular surface, and we know that this footprint remains consistent, we could then compare it to a mark left by a suspect at a crime scene.
Forensic Podiatry "There are certain characteristics on a person's foot that will remain the same. For example if you have bunions then they will always be present and will give you a certain wear mark. If you've got a very rigid first toe, then that will also give you a certain wear mark, and it doesn't really matter where you are or what you do, you will still have that particular wear mark. "Used on its own this will not necessarily convict a criminal but used alongside other evidence it will present a more robust case to the court."
Senario Who owns the shoe??
Foot Uniqueness – the insole Toe position Length Width Angle of the big toe against medial (inner side of the foot) Longest toe Methods of walking Foot deformity
Cast of the suspects foot
The shape of the foot
Make an impression of your foot on the graph paper and mark up the relative positions of the toes and add the measurement values. Compare the differences between your impression and your colleagues
Bones of the human foot 1: Bones of the human foot: a tarsus, b metatarsus, c phalanges of toes. 2. Bones of the tarsus: 1 talus, 2 calcaneus, w tuberosity of calcaneus, 3 cuboid, 4 to 6 cuneiform bones, 7 navicular. Bones of the metatarsus: 8 to 12 first to fifth metatarsal bones, 13 sesamoids, I big toe, II to IV second to fourth toes, V little toe. Phalanges: 14 first phalanx of big toe, 15 second phalanx of big toe, 16 first phalanx of little toe, 17 second phalanx of little toe, 18 third phalanx of little toe
Patterns of walking
Valgus and Varus ANKLE Talipes Valgus Sole faces away from midline Also called eversion and pronation of the foot. Talipes Varus Sole faces midline. Also called inversion and supination of the foot. GREAT TOE Hallux Valgus (bunion) Great toe heads away from the midline of the body. Hallux Varus (unusual variant in shoe-wearing populations) Great toe heads toward midline of the body.
Foot pronation Sub-Talar Joint Action Foot Function Foot Structure Occurs In Gait Cycle Pronation Mobile Adapter Lowered arches looser joints Foot Flat and Mid-Stance SupinationRigid Lever Heightened arches tighter joints Heel Strike and Push-O You can feel these movements by doing the following: Stand without shoes with feet approximately hip width apart; Keeping the length of your foot in contact with the ground roll your feet inward, so that the ankles get closer together and the medial arch lowers - This action is the motion of Pronation; Still keeping the base of your foot in contact with the ground, roll your feet back to where you started, and then roll outward, in the opposite direction. You will feel as through you are standing on the outside of your feet. This action is the motion of Supination.
A typical wear pattern on a shoe belonging to a person with forefoot varus. The condition causes the foot to bear weight in a more pronated position. The wear is beneath the medial side of the foot, with little wear on the later side. Patterns of walking
Supinated positionPronated Position The feet pointing outwards produces wear on the outside of the heel. The feet pointing Inwards produces wear on the inside of the heel. Wear Patterns from the shoe
Wear Patterns on the shoe
Activity of wearer when imprint was made: Analysis of a plastic footwear impression can also be used help determine the activity of the wearing when the imprint was made. The footwear imprint left by person is different when they are walking, running or carry heavy loads. A footwear impression left by running person will typically deeper in the heel and toe sections of the shoeprint. A person carrying a heavy load such as a body will cause deeper prints than a person not carrying anything. Wear variations
Air Bubbles Air bubbles created in the manufacturing process become class characteristics, but others can be revealed from the user wearing the shoe. Air bubbles revealed through wear and tear have a higher evidential value, their size and shape is an irregularity. Air bubbles created through manufacturing can re occur in the same place in multiple shoes
Insole examination As in barefoot print analysis Additionally: - consider interaction with footwear - consider effects of function -consider foot/shoe size implication of impression -Requires high quality photographs
Cast the insole Spray the insole with a silicone grease Fill the inside of the shoe with casting material and tie any laces Allow to dry for at least two hours Remove the shoe and view the cast
Insole with Ultra Violet light
Cinderella factor Distance between the toes Shape of the big toe Position of the toes Shape of the foot