- See: Metatarsalgia: and Running Injuries
- Discussion:
- functional anatomy:
- normal foot during gait will become supple by eversion to allow for wt bearing during heel strike, and will become a rigid lever during push off by heel inversion;
- in neutral position the talonavicular joint should be congruous, indicating that this is the mid position of function of the sub-talar joint complex;
- orthotic device may be used to relieve a specific area of pressure, such as under first, second, or fifth metatarsal, by depression of material in this area
or by providing support adjacent to the area of pressure;
- always examine the soles of the patient's shoes for signs of asymmetrical wear;
- if exact etiology of patient's foot condition remains in doubt, sole of patient's shoe will help show which areas of the foot are being excessively loaded
- Materials:
- silicone (Bauerfiend Viscoped): patients may perceive this material as too hot or too slippery;
- polyprophylene:
- high temperature moldable material;
- highly durable and rigid;
- plastizote (closed cell polyethylene foam):
- (Langer Blueline): shows nonelastic deformation after 3 months of cyclic loading;
- low heat moldable material;
- Symptomatic Flexible Flatfoot Deformity:
- probably most patients w/ symptomatic flexible flat feet should be managed w/ heel cord stretching prior to being prescribed orthotics;
- often patients w/ flexible flat feel and tight heel cords will be made worse w/ shoe orthotics if the equinus deformity is not adressed;
- controversies:
- can orthotics change the osseous relationships in pes planus?
- it has been the observation of many clinicians that the classic medial heel wedges and "arch supports" prescribed for flat feet, do not change the relationship of the talus to the calcaneus nor do they change the relationship of the forefoot to the hindfoot, as evidenced by radiographs taken while the orthotics are being worn;
- in these cases, the orthotic is probably just pressing on the patient's skin, giving the appearance of a correction;
- currently a popular method is to apply a cuneiform pad under the medial border of the heel (not the arch), and a second pad is placed under the lateral edge of the sole along the base of the 5th metatarsal;
- in some cases, the arch will appear to be re-created
- Cavus Foot:
- a cavus foot absorbs energy poorly and may divert forces to structures unaccustomed or poorlly suited to absorb stress;
- cavus feet are especially vulnerable to ligamentous strain, fasciitis, and stress fracture (calcaneus, navicular, or forefoot);
- w/ a rigid foot or a cavus foot, the goal should be to re-distribute the weight onto the sole of the foot by using a soft molded orthotic;
- person with a high arch, that is a cavus foot, should have a shoe w/ good shock absorption, crepe sole and soft uppers;
- Fixed Forefoot Varus:
- appropriate shoe wear includes longitudinal foot orthosis w/ medial metatarsal posting;
- forefoot varus is compensated for by rearfoot subtalar pronation;
- subtalar joint compensatory pronation unlocks transverse tarsal joints, creating a hindfoot hypermobility and loss of a rigid lever from midstance thru push off;
- medial posting acts as a crutch to hold the abnormal forefoot in a normal or nearly normal relationship to the rearfoot and floor
- Orthotics:
- SACH Heels
- allow better shock absorption and reduce forward tibial thrust;
- they are useful in patients with restricted ankle motion (DJD) & fusion) and are often combined with a rocker bottom sole;
- Thomas Heel:
- medial heel wedge tilts the heel into varus and may be helpful in treatment of symptomatic pes planus and plantar fascitis;
- this heel should not be used if calcaneus is in a varus position;
- this heel should extend from mid portion of navicular one the medial side to a line that intersects the longitudinal axis of the fibula on lateral side;
- Metatarsal Pads:
- these transfer weight proximally and can be helpful for patients with sesamoiditis and metatarsalgia;
- Rocker Bottom Shoes and Denver Bars:
- are used in the treatment of metatarsalgia, hallux rigidus, malperferans ulcers, and partial foot amputations;
- references:
- The Influence of Shoe Design on Plantar Pressures in Neuropathic Feet
- UCB insert:
- UCB insert helps correct hindfoot abduction, which in turn will correct supple forefoot by preventing forefoot abduction
The use of running shoes to reduce plantar pressures in patients who have diabetes.
Current Concepts and Correction in the Valgus Foot.
Objective evaluation of insert material for diabetic and athletic footwear.
Interaction of Arch Type and Footwear on Running Mechanics.
Impact of Ankle-Foot Orthoses on Static Foot Alignment in Children with Cerebral Palsy.
Phys Ed: Do Certain Types of Sneakers Prevent Injuries?
Is your prescription of distance running shoes evidence-based?