Unit 4: Foot Orthotics Flashcards Preview

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Flashcards in Unit 4: Foot Orthotics Deck (37)
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1
Q

What are foot orthotics defined as

A

Inserts that are placed into a patient’s shoes, adaptions to a patient’s shoes and bespoke footwear

2
Q

Applications of foot orthoses

A
Congenital abnormalities: club foot, pes cavus, planovalgus
Diseases: polio
Inflammatory conditions: RA
Metabolic conditions: gout
Degenerative conditions: OA
Diabetes
PVD
3
Q

Describe club foot

A

Equinovarus. Unknown cause but associated with severe neurological conditions e.g. spina bifida

4
Q

What are the 2 forms of club foot

A

Mild and severe
Mild: postural, can be corrected by manipulation, associated with breech birth
Severe: fixed, requires surgery to salvage foot function

5
Q

What are pes cavus and planovalgus

A

Arched foot and flat foot: can arise spontaneously or in association with neuro disorders (cerebral palsy)

6
Q

What is poliomyelitis caused by

A

Viral infection of the anterior horn cells of the spinal cord. Usually water borne

7
Q

Consequences of poliomyelitis

A

Foot deformities and foot length discrepancy

Sensation remains normal

8
Q

Which joints does RA typically affect

A

Small joints of the hands and feet

9
Q

Why does foot trauma tend to take longer to heal than hand trauma

A

Vascular supply is not as good

10
Q

Causes of gout

A

Abnormal purine metabolism leading to high uric acid levels e.g. due to treatment with antimetabolite drugs in cancer patients

11
Q

Why does diabetes mellitus lead to foot trauma

A

Ineffective insulin control leads to peripheral neuropathy. Causes insensitivity and disrupted microvascular function

12
Q

What 2 things is PVD commonly associated with

A

Diet and smoking

13
Q

What are the 3 types of functional disorder

A

Deformity
Instability
Insensitivity

14
Q

What are the objectives of orthotic treatment of irreducible deformity

A

Accommodate the deformity to obtain acceptable distribution of the weight-bearing forces
Compensate for loss of ankle/foot joint motion

15
Q

What problems can irreducible deformity cause

A

Abnormal initial contact with the ground
Abnormal plantar pressure distribution
Abnormal, generally restricted, movements of the ankle and joints during dynamic activities

16
Q

How is abnormal contact with the ground corrected

A

‘Fill-in’ the space between the foot and ground created by the deformity

17
Q

How are abnormal plantar pressure distributions treated

A

Moulding the orthosis accurately to the foot shape, taking into account pressure sensitive and pressure tolerant tissue areas

18
Q

How should abnormal ankle joint movement be compensated for

A

Designing an orthosis which deforms in a controlled manner to simulate normal joint movement

19
Q

What are the objectives of treating instability with an orthosis

A

Prevent abnormal joint movements resulting from the instability
Compensate for any loss of ankle or foot joint function

20
Q

How is normal initial foot contact re-established

A

Position and hold the ankle in normal plantigrade alignment

21
Q

How is abnormal plantar pressure treated

A

Use an orthosis that resists collapsing of the foot

22
Q

What factors contribute to tissue breakdown

A

Direct tissue pressure
Shear stress
Rate and duration of tissue loading

23
Q

How to reduce direct pressure

A

Use a moulded interface

24
Q

How to minimise shear stress

A

Reduce MTP extension between heel-off and toe-off by stiffening the support surface. Should also incorporate a heel cushion and rocker modification

25
Q

Problems caused by fixed equinus foot deformity

A

Initial ground contact with the forefoot
Excessive pressure on the forefoot because of reduced area of support
Loss of normal ankle joint function

26
Q

Elements of a foot orthosis designed to treat foot equinus

A

Built-up heel: simulates plantigrade ankle position
Moulded insole: redistributes pressure
Cushion heel: simulates plantarflexion at heel contact
Rocker sole: compensates for loss of dorsiflexion, assists roll-over prior to toe off

27
Q

Problems associated with fixed varus deformity

A

Initial contact on the lateral aspect of the heel
Excessive pressure on the lateral aspect of the plantar surface
Loss of subtalar joint function

28
Q

Elements of a foot orthosis designed to treat fixed varus

A

Medial sole
Built up heel
Moulded insole: shaped to redistribute pressure across the plantar surface

29
Q

Problems caused by an unstable pronating foot

A

Foot collapses into valgus = excessive pressure on medial aspect of foot
Absent subtalar supination/pronation = less functional gait pattern

30
Q

Elements of a foot orthosis designed to treat pronating foot (DIRECT methods)

A

Moulded arch support to hold the medial arch

AFO for severe cases: applies 3-point force system across the subtalar joint

31
Q

Indirect methods of treating pronating foot

A

Wedge/float the heel of the shoe to promote supination at heel contact
Moulded heel cup

32
Q

Problems caused by toe clawing

A

Excessive pressure under the metatarsal heads as the heel leaves the ground to initiate push off
Loss of final toe extension movement

33
Q

Elements of a foot orthosis designed to treat toe clawing

A

Metatarsal support: applies corrective force for realignment

Stiffener in the sole of the orthosis: resists excessive dorsiflexion, reduces loss of push-off

34
Q

What are the early indicators of high pressure areas

A

Corns and callousing

35
Q

What methods are used to identify patients at risk of tissue breakdown due to high pressure areas

A

Barefoot assessment using pressure platforms

In-shoe pressure monitoring systems

36
Q

How are high pressure areas treated

A

Adapted plaster of Paris cast

Extra-depth insole with associated boot/shoe

37
Q

Describe the structure of the extra-depth insole

A

High density closed cell foam base
Intermediate medium density layer
Thin top cover of soft leather or neoprene