LE Orthotics Flashcards
How do you identify the anatomic knee joint center?
Find the level of the adductor tubercle and the level of the medial tibial plateau. The knee joint center is the midpoint
Describe what happens when the orthotic knee joint is located proximal to the anatomic knee joint center.
The thigh band moves distal with respect to the leg
Pressures on the thigh will be anterior proximal and posterior distal
Pressure on the leg/calf will be anterior
Describe what happens when the orthotic knee joint is located distal to the anatomic knee joint center.
The thigh band moves proximal with respect to the leg
Pressures on the thigh will be anterior distal and posterior proximal
Pressure on the leg/calf will be posterior
Describe what happens when the orthotic knee joint is located anterior to the anatomic knee joint center.
The thigh band moves distal with respect to the leg.
Pressures on the thigh will be anterior distal and posterior proximal
Pressure on the leg/calf will be anterior
Describe what happens when the orthotic knee joint is located posterior to the anatomic knee joint center.
The thigh band moves proximal with respect to the leg.
Pressures on the thigh will be anterior proximal and posterior distal
Pressure on the leg/calf will be posterior
Describe what happens when the orthotic ankle joint is located anterior to the anatomic joint.
Calf band will move posterior and proximal with dorsiflexion; pressure will be anterior
Calf band will move posterior and distal with plantarflexion; pressure will be anterior
Describe what happens when the orthotic ankle joint is located posterior to the anatomic joint.
Calf band will move anterior and distal with dorsiflexion; pressure will be posterior
Calf band will move anterior and proximal with plantarflexion; pressure will be posterior
Describe what happens when the orthotic ankle joint is located proximal to the anatomic joint.
Calf band will move posterior and distal with dorsiflexion; pressure will be anterior
Calf band will move anterior and distal with plantarflexion; pressure will be posterior
Describe what happens when the orthotic ankle joint is located distal to the anatomic joint.
Calf band will move anterior and proximal with dorsiflexion; pressure will be posterior
Calf band will move posterior and proximal with plantarflexion; pressure will be anterior
How does a pin in the anterior channel function?
Dorsiflexion stop
How does a pin function in the posterior channel?
Plantarflexion stop
How does a spring in the anterior channel function?
Dorsiflexion resist, plantarflexion assist
How does a spring in the posterior channel function?
Plantarflexion resist, dorsiflexion assist
What columns of the spine are involved in a compression fracture?
Anterior
What columns of the spine are involved in a burst fracture?
Anterior and middle
What compartments might be impacted in a fracture-dislocation? How might they be impacted?
Anterior failure due to compression and rotational shear
Middle failure due to distraction and rotational shear
Posterior failure due to rotational shear
What is a hangman’s fracture?
Traumatic spondylolisthesis of the axis (C2); C2 slips anterior (HALO indicated)
What vertebrae is involved in a Jefferson fracture? What orthosis is indicated?
C1
HALO
What is an odontoid fracture? What is the mechanism of injury? What orthosis is indicated?
C2 involvement
Shear and compression
HALO indicated
Where is the initial position for pins for a HALO? How many pins? What is the appropriate torque?
1 cm proximal to the eyebrows and tip of ears
Anterior placement at the equator (widest point) at the lateral 1/3 of the eyebrow
Posterior placement 1-2 cm posterior to the ear, directly opposition anterior pins
Torque 6-8 lb/in
What is the function of a dorsal/palmar bar?
Maintain the palmar arch
What is the function of the opponens bar?
Maintain the thumb in opposition, terminates just proximal to the MP joint
What is the function of the thumb adduction stop?
Maintains the web space; terminates just proximal to the IP joint
When is a thumb post indicated?
Flail thumb; it needs to extend beyond the nail bed but leave thumb pad free
What is a mallet finger?
Occurs with a extensor tendon rupture; characterized by persistent flexion of the DIP joint
What is a boutineer deformity?
Flexion of the PIP joint with hyperextension at the DIP
What is a swanneck deformity?
Hyperextension of the PIP joint with flexion of the DIP; indicative of volar plate deficiency
What does a positive Froment’s sign indicate?
Ulnar nerve palsy
What happens when someone with median nerve palsy is asked to make a fist?
Ape hand
What occurs with radial nerve palsy?
Loss of wrist extension and MP extension
Describe De Quervain’s tenosynovitis
Tested for using Finklestein’s test; symptoms include Pain near the base of your thumb
Swelling near the base of your thumb
Difficulty moving your thumb and wrist when you’re doing something that involves grasping or pinching
A “sticking” or “stop-and-go” sensation in your thumb when moving it
What nerve is compressed with carpal tunnel syndrome?
Median
What nerve is super painful when you hit your “funny bone”?
Ulnar
What palsy would result in a benediction sign if you asked them to open their hand? Note: this is sometimes called “claw” or “ulnar claw”
Ulnar
Where are the ground reaction forces at initial contact?
Anterior hip
Anterior knee
Posterior ankle
Where are the ground reaction forces at loading response?
Posterior hip
Posterior knee
Posterior ankle
Where are the ground reaction forces at mid stance?
Posterior hip
Anterior knee
Anterior ankle
Where are the ground reaction forces at terminal stance?
Posterior hip
Anterior knee
Anterior ankle
Where are the ground reaction forces at pre-swing?
Posterior hip
Posterior knee
Anterior ankle
In Guillian-Barre syndrome, in what order does weakness occur? In what order does strength recover?
Onset: distal to proximal
Recovery: proximal to distal
Describe cauda equina
Comprises nerve roots below the spinal cord
What is the most common congenital spinal deformity?
Spina bifida
Describe alignment which would best promote stability in bilateral KAFOs
Fixed dorsiflexion, locked knee, hip in hyperextension
When are the hip extensors most active?
Loading response
Flaccid paralysis is most commonly seen in what type of motor nerve injury?
Lower motor nerve
What compartment does the tibial nerve innervate? What gait deviation would you anticipate with a tibial nerve lesion?
Posterior
Plantarflexion contracture
What position of the glenohumeral joint prevents subluxation?
Internal rotation, abduction
