Casting Technique Flashcards
what are the types of casting techniques
neutral position cast partial weightbearing cast pronated cast rectus cast vacum cast computer imaging
Neutral Position Cast Factors
STJ in neutral position
MTJ maximally pronated
ankle joint to 90’ or 1st resistance, whichever comes first
proper technique for a neutral position cast requires
that the STJ be in neutral position with the MTJ joint maximally pronated
most partial or full weight bearing techniques do not allow for control of the
MTJ
cast evaluations are based on 10 points, what are they
- overall quality
- cast markings
- straight lateral border
- 5th digit in line with the lateral column
- 1/3-2/3 rule
- plantar bisection passes through the 2nd MT
- hallux parallel to the supporting surface
- FF to RF relationship matches the FF to RF relationship of the foot
- Appropriate thumb position
- Good skin lines
the lateral border should be straight in what planes
transverse and sagittal plantes
what does a straight lateral border indicate
that the oblique MTJ joint axis is fully pronated
a supinated oblique MTJ axis will causes
- the cast to be convex laterally
- the FF to be plantarflexed on the RF
the 5th digit should be
neither dorsiflexed (very common) or plantarflexed (less common)
what happens when the 5th ray is dorsiflexed
the 5th MT i relatively plantarflexed, causing apparent increase in FF varus by supinating the longitudinal MTJ axis
when viewing the plantar surface of the cast, the heel should be
bisected
if the plantar heel bisection is extended distally it should pass through what MT
2nd MT
if the plantar heel bisection passes lateral to the 2nd MT, the MTJ was
supinated
what is the 1/3-2/3 Rule?
- the lateral 1/3 of the longitudinal arch should be flat
- the middle 1/3 should be gradually sloping upward
- medial 1/3 should be rapidly sloping upward
in the STJ is pronated, the flat lateral portion is likely to be
> 1/3
if the STJ is supinated, the flat lateral portion is likely to be
< 1/3
generally a dorsiflexed hallux indicates
a plantarflexed 1st ray (may be a good thing)
a plantarflexed hallux indicates
a dorsiflexed 1st ray (almost never a good thing)
the FF to RF relationship in the cast should match what
the FF to RF relationship in the foot
an increased varus position of the FF in the cast compared to that of the foot indicates that the foot was casted with the MTJ
supinated
decreased varus/increased valgus position in the cast compared to the foot indicates the STJ
was pronated
what does the thumb position indicate?
where/how the foot was loaded
no thumb print means what?
that the foot was not loaded
a thumb position falling more medial than just the 4th and 5th ray may suggest what?
supinate the MTJ
a thumb position too far distal may have caused the 5th digit to be
dorsiflexed
what do good skin lines indicate
good contact of plaster to skin
describe the plaster techniques used for casting
- two 5x30 plaster strips, each folded in half
- 1/2 inch to 1 inch fold on one side of the length of plaster
- back half goes around the heel. Front half goes around the forefoot. Foot is then positioned
what is the most important thing to remember when using STS
- to put the plastic bag on the foot 1st
- put it on like a sock
- position the foot
