Ch 6 - Prosthetic and Orthotics: Lower Limb Orthoses Flashcards
Where is the COG while standing?
Midline and just anterior to the S2 vertebra
What is the Line of gravity (weight line)?
Line passing through the COG to the ground
How many points of pressure are needed in orthotic devices?
3 points of pressure are needed for proper control of a joint
Where does the line of gravity pass through the spine?
Behind the cervical vertebrae, in front of the thoracic vertebrae, and behind the lumbar vertebrae
Where does the line of gravity pass through the hip?
Slightly posterior to the hip joint and tends to passively extend the hip joint
Where does the line of gravity pass through the knee?
Anterior to the knee joint and tends to passively extend the knee
–
Where does the line of gravity pass through the ankle?
1 to 2 inches anterior to the ankle joint and tends to dorsiflex the ankle
During the “quiet” standing phase, where does the line of gravity pass?
- Posterior to hip joint
- Anterior to knee joint
- Anterior to ankle joint
How are Thermoplastics molded?
Soften and become moldable when heated
– Cold-temp can be molded at temp just above body temp (< 80°C or < 180°F)
What are AFO’s used for?
Weakness affecting the ankle and subtalar joints
What are Posterior leaf spring AFO’s used for?
Flaccid foot drop
Describe a Posterior leaf spring AFO.
Very thin plastic band behind the ankle allowing the patient to overpower the brace during push-off/plantar flexion phase, yet allowing dorsiflexion assist and positioning of the foot during swing phase
Describe a Semirigid plastic AFO.
Trim line is just behind the malleoli and provides increased
mediolateral stability of the ankle and dorsiflexion positioning of the foot
What is a Semirigid plastic AFO used for?
Foot drop with some extensor tone and/ or mediolateral instability of the ankle
Describe a Rigid (solid) plastic AFO.
Trim line at the malleoli or anterior to the malleoli with no motion allowed at the tibiotalar or subtalar joint
