LECTURE 4: ORTHOTICS Flashcards
-A good Orthotic Evaluation should include assessment of:
- Diagnosis
- Motor Control
- Range of Motion Coordination
- Posture
Sensation - Skeletal Alignment
- Balance
- Strength
- Observational Gait
Analysis
Orthosis Design must do what?
- Control the boney segments of the lower extremity
- Meet musculotendinous objectives: assess ligamentous laxity, mm strength
- Meet motor control objectives
- Meet functional objectives
if you get a patient’s COM over BOS in stance, you will get much better WHAT
PUSH OFF
A device that is attached or applied to the external surface of the body to improve function, restrict or enforce motion, or support a body segment.
ORTHOSES
what is passive force in normal gait?
gravity…GROUND REACTION FORCE!
critical to conservation of energy!
what are the 4 basic functions needed for normal gait?
- WB stability
- stance limb progression
- shock absorption
- energy conservation
*in order of importance!!!
- Weight Bearing Stability
The pattern of muscle control is dictated by
the changing alignment of the body weight
line (vector) to the individual joint. As the
vector moves away from the joint center, a
rotational force or moment develops that
must be controlled by opposing muscles to
preserve postural stability
What is happening with countering muscle force of our patients needing orthoses?
Muscle force needs to counter GRF
- absent
- spastic
- out of phase (not contracting at right time)
in Stance, foot is not moving. Why does GRF move?
COM center of mass
moves over foot
◦ Co-contraction of antagonists
is rare. T/F
true. usually
IC: what if tib ant is not working?
want orthosis to do what tib ant is not doing
(there is a plantar flexor moment, need eccentric control)
LR: what mm are firing?
glutes
quads: stabilize knee
tib ant
GRF: hip flexion, post knee, post ankle
midstance: MM and GRF
torso is rotating in midstance, GRF: moving forward!
-quads UNTIL it zeros out
-plantar flexors
*plantar flexor-knee extensor couple –> UNIQUE POINT IN STANCE!
what is the MOST IMPORTANT THING in midstance?
controlled tibial advancement with ECCENTRIC PF control!
** mm are quiet
in midstance to terminal stance: zero concentric contractions happening! no energy to do this. How?
COM keeps moving! and torque from plantar flexors
*ballistic moment of plantar flexors
*without calf, knee will buckle and they will fall. So short step
when does gastroc come to help soleus?
terminal stance! knee extender
*1.4-2.4x BW is on the forefoot, so NEED STABILITY AT FOOT
In swing phase, what is important for the orthoses?
enough DF in foot
pick up weight in foot
fixing swing phase is easy. What is hardest?
re-establishing 3rd rocker (forefoot rocker, push off)
What are the buckets of pathological patterns?
- structural impairments
- motor unit insufficiency
- peripheral sensory and motor impairment
- central control dysfunction
structural impairments include:
- Contributing
pathologies are:
o Contractures
o Skeletal Deformity
o Musculoskeletal Pain
motor unit insufficiency pathologies include:
Muscle weakness:
* Lower Motor Neuron
Disorders
– Poliomyelitis
– Guillain-Barre’
* Muscular Pathology
– Muscular Dystrophy
*knowing where limb is in space is an advantage
peripheral sensory and motor impairment pathologies
Peripheral Sensory
and Motor
Impairment:
* Cauda Equina Spinal
Cord Injury
* Spina Bifida
* Acute Trauma
central control dysfunction
o Upper motor neuron
lesions
o Brain lesions
- stroke,
- acute head injury
- cerebral palsy
- Cervical and high
thoracic level
lesions
*challenge is spasticity
Patients with motor unit insufficency can…
substitute for local weakness since
sensation and control have been maintained
pathological gait: sensory and motor impairment
causes WHAT broad impairments
- Impaired Sensation delays awareness of floor
contact - Walking ability decreases with each higher level
of spinal cord impairment
what are big things to consider with central control dysfunction?
spasticity
* Patients differ considerably due to variability in loss of
selective control and emergence of primitive control
mechanisms
what is going on with GRF in midstance?
its BEHIND the BOS!
*need eccentric PF
if quads are weak, then at midstanc
hyperextension
if weak plantar flexors (SOLEUS), then patient will…
quads and glutes must fire! bent knees
at terminal stance, orthotists NEED to look at this. What is weak with delayed heel rise?
WEAK PLANTAR FLEXORS
basic goals of orthotic treatment
- prevent deformity: provide optimal skeletal alignment
- provide stability: assist/resist motion
- facilitate function: harness GRF
anytime force is applied with orthoses, what must balance it?
2 other point forces
Is the SVA different from the angle of the ankle?
YES shank to vertical vs DF/PF
UCBL is used when?
usually children with low tone (down,
*controls rearfoot, blocks forefoot ab/add
what is SAFO good for?
*not really DF/PF control, more EVERSION/INVERSION
*effective for low tone
*not a walking orthosis
AFO: solid ankle
increased lever arm, can control SAGITTAL PLANE MOTION!
*directly impacts knee
Control of stance phase (closed chain) foot, ankle and knee position.
AFO-PLS
what is a solid ankle AFO?
VERY flexible–> mainly swing phase OKC. CAN DF AND PF in this brace
*controls inv/ev ankle rolling, but does NOT impact PFs that much
AFO -articulated ankle is what?
articulated ankle AFO with PF stop, DF control strap
*marginally effective in stabilizing weak PF…not great tho
AFO-ground reaction
allows patient to fully transfer weight
*assists WEAK PLANTAR FLEXORS
(contraindicated for knee hyperextension, but this could be bc of weak PFs…)
AFO G/R R/E Articulated
- An articulation is built
into the R/E design.
This permits free
plantarflexion w/ a
dorsiflexion stop and a
smooth transition
through first rocker.
Note: no swing phase
drop foot control, poor
rearfoot control.
when does a patient still require metal and leather orthosis?
AFO: Metal Double Upright, Double Action Ankle (Short Leg Brace)
at risk foot (diabetic neuropathy, metabolic syndrome)
*metal AFO attached to shoe
AFO - Metal Double Upright, Klenzak Ankle
OPEN KC SWING PHASE BRACE
*maybe inv/ev control but no PF/DF stop (stance)
T-strap is what?
AFO: metal double upright with “t-strap”
lateral control or varus control
If medially, valgus control
*does not work if patient does not wrap it around bar
What is a KAFO?
knee ankle foot orthosis
plastic: lots of contact
metal: less contact, heavy
What are the 4 AFO design options?
- conventional thermoformed plastic
- custom fit designs: (typically need PF)
- custom carbon prepreg (grade 3 or less PF)
- advanced ankle
(grade 3 or less PF… these are called multi-function ankles. Offer adjustability)
