The Clinical application of Podiatric Biomechanics David N Dunning DipPodM. MChS. MSc. PGCert.(sports pod)

Aims of podiatric management Every facet of upright activity is a biomechanical event. As we have seen the foot is designed to take stress. The objective of any treatment intervention is to: Reduce the stress on the structures to an acceptable level. Return the limb to as close to normal as possible

Pronation Pronation is good Excessive pronation is bad Lack of resupination is very bad

Pronation Pronation – Abduction, Eversion and Dorsi-flexion Supination – Adduction, Inversion and Plantar-flexion What are the main shock absorbers?

Management options 1 st Aid (R.I.C.E.) Drugs Physical therapies Orthoses Footwear Exercise Advice Surgery

Rest Ice Compression Elevation Rest – if possible. In some conditions some pain is acceptable to the committed athlete. Ice – in the acute stages. Compression – not always easy to do. Elevation – following activity. (Whilst icing)

Drugs The use of steroid injections is very useful in some cases but for instance in Achillodynia they are to be avoided as they have been associated with spontaneous rupture. NSAIDs can be useful. But there is evidence that there long term use can delay the healing process. (Elongates the Regeneration phase)

Physical therapies Frictions and mobilisations, but not in the acute phase Ultra sound etc. – this can enhance the inflammatory process thus reducing the “lag time” to the next two phases. Stretching and strengthening.

Orthoses There are many different types. Not just medial wedges. Tri-planar (casted) devices. Preformed (non-casted) orthoses Must be used in all shoes? More later

Footwear Shock absorption – good or bad? Rear-foot control. Heel tabs. Must be stable – Muscle conflict.

Exercise Stretching involves:- 1) Keeping the Tri-ceps Surae group functional through it’s full range. 2) Therapeutically re- organising the fibres of both muscles to help in rehabilitation.

Eccentric exercises. Eccentric muscle action – contraction whilst lengthening. Plyometrics – hopping, bounding or depth jumps ??? (Are these types of exercise really appropriate for structures that may be in a weakened state???)

Advice Change activity where possible. Look closely at all footwear. Fit for purpose

Foot orthoses The functional foot orthosis is an orthosis, which is designed to promote structural integrity by resisting all stance phase forces, that would cause abnormal skeletal motion or position, while allowing normal motion during the stance phase of gait. William P. (Bill) Orien (2001)

The orthosis must: Support any forefoot deformity that would exert an abnormal retrograde force on the rear foot: Resist abnormal extrinsic or intrinsic forces that would cause excessive medial or lateral distribution of weight into the rear foot, causing abnormal sub talar joint and mid tarsal joint pronation or supination during the time of gait that the heel is bearing weight;

Promote normal rear foot pronation during the contact period of gait for shock absorption and assist in re-supination of the foot as it moves toward propulsion. Resist forces that promote abnormal pronation of the rear foot during the stance phase of gait.

A non-functional foot orthosis The noun orthosis is derived from the Greek Ortho- meaning to correct or straighten. The standard arch support of old can not be referred to as a foot orthosis unless it straightens or corrects an abnormality. Generally the material is too soft to resist ground reaction forces, or if it is of a hard material, because of its’ position, it would be too uncomfortable to wear. FHL – Either the foot hurts or the back hurts!!

Pre-formed or non-casted devices. These are foot orthoses that have a functional element yet are not made from a positive cast. Bearing in mind Dr. Oriens’ definition then if an “off the shelf” device can achieve these aims it can be referred to as “functional”

A functional device should:- Support for forefoot anomalies. Resist forces acting on the calcaneus. Provide shock absorption. Provide for normal function. Fit well. Be manufactured with the appropriate materials.

Preformed devices. Vectorthotic is just one example Soft EVA cover. Hot glue stick on forefoot posting Marked for 1 st ray cut out. Hard but heat mouldable shell. Clip on rear foot posts.

Foot orthoses Control the mechanics of the foot and lower limb

Slipper casts

Foot orthoses and shoe adaptation go “hand in glove” Excuse the expression

To recap:- Treatment options. Advice Physio, drugs etc. Strapping – short term Serial casting Temporary orthoses Preformed, work shop manufactured Balanced (casted) orthoses Footwear Adaptations, Modular or bespoke Surgery

Case histories FHL Bunnions Achillodynia Heel spur syndrome Metatarsalgia Diabetes RhA