Orthotics Lab 1: Supramalleolar Orthoses (SMOs) (2/3/17) (3/6)

Question 1

difference between SMOs and IMOs

Answer 1

trimline of SMOs extend above the malleoli, IMOs below the malleoli

Question 2

what motions might an SMO control

Answer 2

supination, pronation, possibly PF depending on posterior superior trimline

Question 3

SMO supination primary and secondary forces

Answer 3

primary: originating laterally at the talus, projecting medially
secondary: originating medially at the medial malleoli/superior trimline directed laterally
secondary: originating medially at the first methead directed laterally

Question 4

SMO pronation primary and secondary forces

Answer 4

primary: originating medially at the talus/navicular directed laterally
secondary: originating laterally at the lateral malleoli/superior trimline directed medially
secondary: originating laterally at the 5th methead projecting medially

Question 5

SMO plantar flexion primary and secondary forces

Answer 5

primary: originating from the calcaneal strap or top of shoe, projecting posteroinferior
secondary: originating from the base of the brace near the met heads, projecting superiorly
secondary: originating from the superior posterior trimline of the brace, projecting anterior

Question 6

would an IMO or SMO demonstrate greater triplanar control

Answer 6

SMO

Question 7

why would an SMO have greater triplanar control than the IMO

Answer 7

because of greater leverage

Question 8

would an IMO or SMO demonstrate PF control

Answer 8

SMO

Question 9

why would the SMO control plantar flexion better than an IMO

Answer 9

because the high posterior trimline is essential to set up a three point pressure system to control PF

Question 10

how does the height of posterior superior trimline affect PF control

Answer 10

it is one of the counterbalancing forces. the longer the posterior trimline, the greater the leverage to control PF.

Question 11

when would you recommend an SMO over an IMO

Answer 11

when medial and lateral control is not adequately obtained using an IMO.

also when PF needs to be controlled

Question 12

is the SMO designed to correct a flexible deformity or support a rigid deformity

Answer 12

if the brace is aligned to neutral, then the orthosis was used to correct a flexible deformity.

if it is not aligned in neutral, it was used to correct a rigid deformity.

Question 13

reason for calcaneal relief footplate?

Answer 13

to provide greater stability of the subtalar joint by saddling the calcaneous in the heel cup

Question 14

when does a partial footplate terminate

Answer 14

just posterior (proximal) to or right at the met heads

Question 15

when does a full footplate terminate

Answer 15

just past the toes

Question 16

when would a partial footplate be appropriate

Answer 16

if the patient has active toe extension and is able to activate this motion through swing for adequate toe clearance

Question 17

when would a full footplate be ncessary

Answer 17

lack active toe extension for clearance through swing phase

Question 18

when is a semi-rigid or flexible footplate warranted

Answer 18

when the individual will be ambulating

Question 19

are corrections made closer anatomically to the foot and may have greater impact in an IMO or shoe

Answer 19

IMO