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Flashcards in Prosthetics & Orthotics Deck (46):
1

For a person with an upper extremity amputation, what is the advantage of choosing a body powered device over a myoelectric device?

(a) Stronger grip force
(b) Better cosmesis
(c) Lighter weight
(d) Less dependence on motor strength

Answer: (c)
Commentary: Main advantages of body powered systems are lower initial costs, lighter weight, easier repairs, and better tension feedback to body. Advantages of myoelectric devices are
cosmesis, less need for motor strength/coordination to operate limb, and stronger grip force.


2013

2

What prosthesis is most appropriate for a 6-month-old child who has a congenital transhumeral
amputation?

(a) Curve shaped “banana” arm
(b) Myoelectric hand Page 15 of 23

(c) Body powered hook
(d) Friction elbow arm

Answer: (a)
Comment: The banana arm is a passive prosthesis designed to help in reaching and bimanual midline activities in the very young child. A myoelectric hand is most appropriate to initiate about age 1 year; a body-powered hook is appropriate for children age 4-5 years; a friction-elbow arm is appropriate about when a child with a transhumeral amputation starts to walk.

Reference: Gaebler-Spira D, Lipschutz R. Pediatric Limb Deficiencies. In: Alexander MA, Matthews DJ, editors. Pediatric rehabilitation: principles and practice. 4th ed. New York: Demos Medical; 2010. p 342-344, see fig13.9, p343,“banana arm.”

2013

3

What aspect of gait is improved when a manual locking knee design is chosen for an individual
with a unilateral transfemoral dysvascular amputation?

(a) Overall gait mechanics with decreased energy consumption
(b) Foot clearance in swing phase
(c) Stability in stance phase
(d) Ability to vary the gait cadence

Answer: (c) Page 19 of 23

Commentary: The only advantage of a manual locking knee is its inherent stability. It is typically used for patients with significant weakness or instability, such as very low level household ambulators or patients using prosthetic limb for transfers. Since the knee does not bend during swing phase it compromises gait mechanics. Toe clearance is more difficult and the prosthetic limb is typically designed to be shorter than the intact limb.

Reference: Huang ME, Miller LA, Lipschutz R, Kuiken TA. Rehabilitation and prosthetic
restoration in lower limb amputation. In: Braddom RL, editor. Physical medicine and
rehabilitation. 4th ed. Philadelphia: Elsevier Saunders; 2011. p 305.

2013

4

What is the benefit of using ankle-foot orthoses (AFOs) for a patient with Duchenne muscular
dystrophy?

(a) Improves the patient’s ambulation Page 20 of 23

(b) Assists the patient with rising from the floor
(c) Prevents contractures when used at rest
(d) Improves wheelchair positioning

Answer: (c)
Commentary: Resting AFOs can help prevent ankle plantar flexion contractures, but are not
required for proper wheelchair positioning. Duchenne muscular dystrophy is an x-linked disease
with progressive muscle weakness/degeneration that is usually diagnosed in early childhood. Loss
of independent ambulation generally occurs in early adolescence, necessitating the transition to a
wheelchair. The progressive weakness leads to compensatory strategies for ambulation such that
AFOs may further impede ambulation or transferring.

Reference: (a) Busby K et al. Diagnosis and management of Duchenne muscular dystrophy, part
2: implementation of multidisciplinary care. Lancet Neurol 2010;9:177-89. (b) McDonald C, Han
J, Carter G. Myopathic disorders. In: Braddom RL, editor. Physical medicine and rehabilitation.
4th ed. Philadelphia: Elsevier-Saunders; 2011. p1126.

2013

5

What aspect of gait is improved when a manual locking knee design is chosen for an individual with a unilateral transfemoral dysvascular amputation?
(a) Overall gait mechanics with decreased energy consumption
(b) Foot clearance in swing phase
(c) Stability in stance phase
(d) Ability to vary the gait cadence

Answer: (c)
Page 19 of 23
Commentary: The only advantage of a manual locking knee is its inherent stability. It is typically used for patients with significant weakness or instability, such as very low level household ambulators or patients using prosthetic limb for transfers. Since the knee does not bend during swing phase it compromises gait mechanics. Toe clearance is more difficult and the prosthetic limb is typically designed to be shorter than the intact limb.

2013

6

A 60-year-old woman had a left total hip arthroplasty 4 weeks ago. During her gait evaluation, she is noted to have a left lateral trunk lean during left stance phase. This gait deviation is most likely a result of weakness in which left lower limb muscle?
(a) Gluteus medius
(b) Gluteus maximus
(c) Tensor fascia lata
(d) Vastus lateralis

Answer: (a)
Commentary: Gluteus medius weakness leads to a Trendelenburg gait. This woman's lateral trunk lean is a compensated Trendelenburg gait. Gluteus medius or hip abductor weakness is common following total hip arthroplasty. In one study, 36 of 76 (47%) patients with total hip arthroplasty had hip abductor weakness. Of those 36 patients, all 36 had weakness in the gluteus medius, 28 had weakness in the gluteus minimus, and 4 had weakness in the tensor fascia latae

2013

7

What prosthesis is most appropriate for a 6-month-old child who has a congenital transhumeral amputation?
(a) Curve shaped “banana” arm
(b) Myoelectric hand
Page 15 of 23
(c) Body powered hook
(d) Friction elbow arm

Answer: (a)
Comment: The banana arm is a passive prosthesis designed to help in reaching and bimanual midline activities in the very young child. A myoelectric hand is most appropriate to initiate about age 1 year; a body-powered hook is appropriate for children age 4-5 years; a friction-elbow arm is appropriate about when a child with a transhumeral amputation starts to walk

2013

8

A 65-year-old woman with diabetes mellitus has been sent to your clinic for evaluation of
appropriate footwear. She had a diabetic foot ulcer 2 months ago over her first metatarsal head,
which is now healed. Examination reveals distal sensory loss and a mild claw foot deformity.
Which footwear/orthotic recommendation is the most appropriate?
(a) Since the wound is healed, no specialized footwear is needed.
(b) Well-fitting regular tennis shoes or sneakers are the best option.
(c) Off-the-shelf diabetic shoe with a custom molded orthotic based on severity of claw foot
deformity is indicated.
(d) Patellar tendon-bearing ankle-foot orthoses to help unload the metatarsal head should be
used.

Answer (c)
Commentary: The patient is at high risk for future diabetic foot ulcers based on her history of
previous ulcers, claw foot deformity and peripheral neuropathy. Based on this risk profile,
specialized footwear is recommended. Patients with diabetes mellitus (DM) without risk factors
for ulcer could be counseled and educated regarding the use of well fitting tennis shoes and
sneakers. While a custom molded shoe could benefit this patient, they are very expensive and
usually needed for patients with severe foot deformity. At this point a prefabricated diabetic shoe
and custom orthotic would be clinically appropriate and more cost-effective. A patella tendon
bearing ankle-foot-orthosis is not indicated and would not effectively offload the metatarsal
heads. A metatarsal bar or pad placed proximal to the metatarsal head is an effective way to
offload the metatarsal head.

2012

9

The primary stabilizing effect of the flexible lumbosacral orthosis is its ability to

(a) restrict spinal extension.
(b) prevent atrophy of trunk muscles.
(c) elevate intra-abdominal pressure.
(d) enhance kinesthetic feedback

Answer: C
Commentary: Although they do not effectively restrict motion to a significant degree, flexible
lumbosacral orthoses elevate intra-abdominal pressure, thereby unloading the spine and
supporting structures. This action also provides inhibitory kinesthetic feedback and warmth.
Long-term use of binders and other flexible lumbosacral orthoses may, unfortunately, result in
atrophy of trunk muscles

2009

10

What is the minimal number of points of contact that an orthosis must have in order to exert
rotational control?

(a) One
(b) Two
(c) Three
(d) Four

Answer: C
Commentary: Rotational control forces or moments across a joint are not effective unless there
are at least 3 points of contact between the device and the limb segment

2009

11

What is the primary advantage of a body powered upper limb prosthesis compared to a
myoelectric prosthesis?

(a) Greater sensory feedback
(b) Moderate or no harnessing
(c) Less body movement to operate
(d) Enhanced cosmesis

Answer: A
Commentary: The advantages of body powered upper limb prostheses include the following
factors: moderate cost, most durability, highest sensory feedback, and a variety of prehensors
available for various activities. Their disadvantages are that they require the most body
movement to operate, have the most harnessing and require increased energy expenditure to use.
Myoelectric and/or switch controlled upper limb prostheses have the following advantages: they
require moderate to no harnessing, require fewer body movements to operate, have moderate
cosmesis, provide more function in proximal areas and, in some cases, provide a stronger grasp.
Battery powered prostheses are the heaviest and most expensive prostheses. They also require the
most maintenance, provide limited sensory feedback and require extended therapy time.

2009

12

What advantage does a suspension system that features a gel liner pin have over a sleeve suspension system in a transtibial amputee?

a.Better heat dissipation and reduced sweating
b. Improved cushioning and reduction in shear forces
c. Ease of donning and doffing
d. Ease of liner care and cleaning

b is correct

Because they transmit good control of the prosthesis, offer better cushioning and reduce shear forces on the residual limb, gel liner suspension systems are very popular. They do not provide better heat dissipation, and excessive heat retention and sweating are often major disadvantages. The donning can be difficult, since a gel liner must be positioned correctly on the residual limb to ensure that the pin engages correctly. Lastly, the gel liners require daily cleaning to avoid skin rashes and skin infections.


2014

13

A 68-year-old woman with well controlled diabetes is asking your opinion on specialized footwear. She has good pedal pulses, intact sensation and no foot deformity. She has no prior history of ulcers. In addition to frequent foot inspections, you recommend

a. custom molded diabetic shoes.
b. well fitting breathable shoes.
c. off-the-shelf diabetic shoes with wide toe box.
d. custom insert with metatarsal pad.

Option b is correct.

Because she has well controlled diabetes (DM), intact pulses, intact sensation and no obvious foot deformity, this patient is at lower risk. Based on her risk profile, specialized footwear is not recommended. Patients with DM without risk factors for ulcer could be counseled and educated regarding the use of well fitting tennis shoes and sneakers. Other interventions listed could be considered, if ulcer risk factors change.

2014

14

The most appropriate cervical orthosis for an unstable cervical spine fracture is

a. Philadelphia/Miami J orthosis
b. Sternal occipital mandibular immobilizer (SOMI) orthosis
c. Halo orthosis
d. Milwaukee orthosis

Option c is correct.

For an unstable fracture, a Halo orthosis provides the best limitation in range of motion to protect the spinal cord from further injury. A Philadelphia/Miami J orthosis is not appropriate for unstable fractures. A SOMI device is primarily used in cervical sprains or stable fractures with intact ligaments. A Milwaukee brace/orthosis is a cervicothoracolumbosacral orthosis primarily indicated for scoliotic management of high thoracic curves

2014

15

In a body-powered upper extremity prosthesis, which feature is an advantage of a voluntary opening device over a voluntary closing device?

a. It provides larger prehensile forces.
b. Variable prehensile force is transmitted through the control cable.
c. There is no need for constant pull on the control cable during grasp.
d. It provides indirect sensory feedback.

Option c is correct.

Closing forces in the voluntary opening terminal device rely on springs or rubber bands to provide prehensile force. Typical closing forces range from 5 lbs to 10 lbs. Voluntary closing devices are capable of providing prehensile forces up to 20-25 lbs and provide indirect sensory feedback through the force exerted on the control cable. A disadvantage of the voluntary closing device is the need for a constant pull on the control cable during prolonged grasping.

2014

16

At mid stance, where is the ground reaction force vector located?

(a) Anterior to ankle, posterior to knee
(b) Anterior to ankle, anterior to knee
(c) Anterior to knee, anterior to hip
(d) Posterior to knee, posterior to hip

Answer: B
Commentary: In mid stance, the ground reaction vector lies anterior to the ankle, anterior to or through the knee axis, and posterior to the hip center. The passive torques created by this vector alignment are ankle dorsiflexion, knee extension and hip extension

2009

17

The primary advantage of a soft insert fitted into the socket of a transtibial prosthesis is that it is

(a) perspiration resistant.
(b) easy to keep clean.
(c) easily modified.
(d) very durable

Answer: C
Commentary: Soft inserts are fabricated to fit inside the socket. They are recommended for
patients with thin, sensitive, or scarred skin, or peripheral vascular disease (PVD). They are
easily modified. Hard sockets also have their advantages. They are perspiration resistant, less
bulky than sockets fitted with a soft insert, easy to keep clean, and durable. Further, reliefs or
modifications can be located with precision in the hard socket.

2009

18

Which factor promotes knee stability during the gait cycle of a person with transfemoral
amputation?

(a) Knee component placed anterior to the socket
(b) Hard heel in the prosthetic foot
(c) Polycentric 4-bar linkage prosthetic knee
(d) Anterior position of the shank on the prosthetic foot

Answer: C
Commentary: Flexion moment at the hip, a rigid heel in the solid ankle, cushion heel foot and the
anterior position of the shank all shift the ground reaction force behind the knee joint to produce a
knee flexion moment. The 4-bar linkage with instantaneous center of rotation and the posterior
location of instant center in extension creates knee stability, especially at heel strike.


2009

19

In prosthetics, K levels are used to describe or define

(a) activity levels.
(b) prosthetic feet.
(c) funding levels for prosthesis.
(d) etiology of amputation

Answer: A
Commentary: K levels are used to describe activity levels These K0-K4 designations are
guidelines for prosthetic components covered by Medicare

2009

20

A weight-activated stance-control knee unit would be indicated in a transfemoral amputee who

(a) has cognitive deficits.
(b) has a contralateral weak limb.
(c) is an unlimited ambulator.
(d) is a new amputee.

Answer: D
Commentary: Weight-activated stance-controlled knees are often used for individuals with a
transfemoral amputation. They are especially useful as a preparatory prosthesis in a new amputee, because their simplicity and safety help new amputees learn to walk with a prosthesis. To flex the knee, the amputee must shift weight onto the opposite leg, which requires the opposite limb to accept increased weight. Additionally, the amputee must have the cognitive ability to learn to weight shift. The requirement to shift weight off of the prosthesis to allow knee flexion presents few problems at slow cadences, but if the amputee attempts to walk at a more normal speed, the gait pattern is disrupted by the premature weight shift.

2009

21

The most common reason for prescribing a plastic leaf-spring ankle-foot orthosis is to
(a) overcome ankle spasticity.
(b) reduce lower-extremity edema.
(c) prevent plantar flexion deformity.
(d) support weak ankle dorsiflexors.

(d)
A plastic leaf-spring orthosis (PLSO) is probably the most commonly prescribed type of ankle-foot orthosis (AFO). It substitutes for weak ankle dorsiflexors and provides some medial lateral stability. Severe spasticity of the ankle may require prescription of a solid AFO. A plastic spiral AFO may be prescribed for concomitant weakness of both the ankle dorsiflexors and plantar flexors when spasticity is absent.

2008

22

The gluteus maximus is primarily active during which part of the gait cycle?
(a) Pre swing
(b) Loading response
(c) Midstance
(d) Terminal stance

(b)
The gluteus maximus is primarily active from terminal swing through initial contact and loading response. During midstance, terminal stance, and pre swing the gluteus maximus is actually silent.

2008

23

For a patient with hemiplegia who prefers to use his legs and push his wheelchair backwards, the wheelchair should be configured with
(a) the back edge of the seat lower than the front edge.
(b) a single arm drive mechanism on the non-hemiplegic side.
(c) the large wheel axle plate moved to a more anterior position.
(d) large wheels in the front and casters in the back.

(d)
The casters should lead the rear wheels for the most common direction of travel. This will help reduce the possibility of the user flipping over when hitting an obstacle and will make the chair more directionally stable.

2008

24

A potential benefit of osseointegration (the direct skeletal attachment of the prosthesis to bone) is
(a) elimination of poor prosthetic socket fit.
(b) ability to return to running activities.
(c) early prosthetic fitting.
(d) ability to perform heavy manual work.

(a)
The primary benefits of attaching a prosthesis directly to the skeleton are comfort, elimination of poor prosthetic socket fit, and elimination of skin problems. Recipients report improved sensory feedback from the skeletally attached limb. Limitations include a 2-stage procedure, which results in an extended time of non-weight bearing, and extended rehabilitation (up to 2 years). The procedure poses a significant risk of infection, and the recipient must limit running, jumping, and heavy manual work in order to minimize loosening of the prosthesis.

2008

25

Your adult patient with a spinal cord injury needs to access his bathroom in his standard-width
wheelchair. If no turn is required following entry into the bathroom, the minimal width of the
doorway should be

(a) 26 inches.
(b) 32 inches.
(c) 36 inches.
(d) 40 inches.

(b) The proper minimum width of a doorway for a wheelchair without a turn is 32 inches. If a turn is
involved, then the doorway width should be at least 36 inches.

2008

26

0. Which K level best describes an individual who is able to ambulate within the household, but not
out in the community?

(a) K 1
(b) K 2
(c) K 3
(d) K 4

(a) The K level of 1 represents that of a household ambulator; K 2 limited community ambulator; K 3
unlimited community ambulator; K4 a very active community ambulator. The household exception FIM
score of 5 indicates a "modified independent" ambulator who can handle household distances (i.e., less
than 50 feet) inside or out.

2008

27

Which wheelchair component is appropriate for a patient with T10 spinal cord injury?
(a) Quick release axle
(b) Projection rims
(c) Arm trough
(d) Tilt-in-space system

Answer: (a)
Commentary: Quick release axles allow persons with spinal cord injury who drive to load their wheelchairs into the car more easily. Projection rims assist with wheelchair propulsion in patients who have insufficient hand function. The tilt-in-space recline system offers independent pressure
relief in patients with tetraparesis. Arm troughs support the arms and forearms of persons with limited upper limb strength. A patient with T10 spinal cord injury has sufficient upper limb and trunk control so that projection rims, arm trough, and tilt-in-space features are not necessary.

2011

28

What shoe modification can be used to treat medial compartment knee osteoarthritis?
(a) Rocker bottom sole
(b) Solid ankle cushioned heel
(c) Medial wedge
(d) Lateral wedge

Answer: (d)
Commentary: Medial compartment osteoarthritis results in genu varum. A lateral wedge can help
relieve pain by placing a valgus force at the knee. A medial wedge would exacerbate the problem.
Solid ankle cushioned heel is a type of prosthetic foot. A rocker bottom sole is helpful for other
conditions such as forefoot fractures, hallux rigidus, foot arthritis, and insensitive feet.

2011

29

When should upper extremity prosthesis fitting be initiated in the adult?
(a) Within the first month after amputation
(b) When residual limb strength is full.
(c) When the patient requests a prosthesis
(d) When residual limb volume has stabilized

(a) The first month after upper limb amputation is the optimal period for prosthesis fitting. Fitting should be initiated during this time to maximize the level of acceptance and use of the prosthesis

2007

30

Your 5-year-old patient with spastic tetraplegic cerebral palsy needs a wheelchair prescription. He is dependent for transfers, but cognitively normal. He is able to feed himself and uses a communication device. His family transports him in their car in an adapted car seat. On examination, he is unable to sit unsupported, but sits well with minimal support; he has no scoliosis, and his passive range of motion is full. Which elements would be best to include in his wheelchair prescription?
(a) Folding frame, sling seating
(b) Adaptive stroller, linear seating
(c) Tilt in space frame, custom seating
(d) Rigid frame, contoured seating

(d) While this child is totally dependent for transfers, he only requires minimal support to sit upright and has no fixed deformities. Custom seating should be used for those with fixed deformities. A tilt-in-space frame should be used when children need to have their position in space changed frequently because of deformities or medical problems. While it is tempting to prescribe a wheelchair with a folding frame for a family who transports a child in a car rather than a van, the child will be better positioned using contoured seating and a rigid frame. At age 5 years, the size of frame needed will be able to be transported in a car even without folding. Adaptive strollers usually position the child in a reclined position and should be used as a backup to a wheelchair, which is not easily transported in an automobile, or for a child who can walk but periodically needs dependent mobility for fatigue or following seizures or for similar reasons

2007

31

Double limb stance is what percent of the entire gait cycle?
(a) 5%
(b) 10%
(c) 20%
(d) 30%

(c) The average double limb support is 20% and single limb support is 40% of the entire gait cycle. Stance phase accounts for 60% of the gait cycle and swing phase accounts for 40%.

2007

32

What is a possible cause for circumduction during mid swing in the transfemoral amputee?
(a) Insufficient knee friction
(b) Prosthesis too short
(c) Excessive medial brim pressures
(d) Inadequate hip extension

(c) Possible causes for circumduction in the gait of a transfemoral amputee include excessive mechanical resistance to knee flexion, prosthesis aligned with too much stability, prosthesis too long, increased medial brim pressures, inadequate suspension, patient lacks confidence or has inadequate hip flexion

2007

33

To allow pronation of the foot, which 2 joints must have their axis of rotation in parallel?
(a) Lisfranc and talonavicular
(b) Subtalar and calcanocuboid
(c) Talocrural and subtalar
(d) Talonavicular and calcaneocuboid

(d) The transverse tarsal joint, namely the talonavicular and calcaneocuboid joints, must have their joint axes in parallel to allow for a flexible midfoot and pronation. If the axes intersect, the midfoot becomes rigid, which enables proper supination.

2007

34

The primary goal of a knee orthosis is to
(a) prevent knee injury in athletes.
(b) control knee instability in the anterior direction.
(c) prevent recurvatum.
(d) decrease the quadriceps force across the knee.

(c) Knee orthoses are prescribed to prevent genu recurvatum and provide mediolateral stability. They may be used during sports and other activities to provide functional support for an unstable knee or during the rehabilitation phase following injury or surgery on the knee. The use of knee orthoses for the prevention of knee injury in athletes is controversial. The Swedish knee cage prevents recurvatum but permits flexion. The three way knee stabilizer gives good control of structural knee instability in the lateral, medial, and posterior directions.

2007

35

The primary advantage of mag wheels over spoked wheels in the performance of a wheelchair is
(a) lighter weight.
(b) reduced maintenance.
(c) more maneuverability.
(d) general preference by active wheelchair users.

(b) Although MAG wheels require minimum maintenance and wear well, spoked wheels are substantially lighter, more responsive, and are generally preferred by active wheelchair users.

2007

36

For an individual who has C5 tetraplegia, orthotic splinting attempts to maintain the functional position of the hand. This usually includes
(a) closing the thumb web space.
(b) 30º to 40º of metacarpophalangeal flexion.
(c) promoting flattening of the palmar arch.
(d) supporting the wrist in 20º to 30º of extension.

(d) The functional position of the hand includes supporting the wrist in 20º to 30º of extension, supporting the palmar arch with the 4th and 5th metacarpals slightly anterior to the second and third digits. Metacarpophalangeal flexion of 30° to 40° would be excessive. The thumb web space should be preserved.

2007

37

Performing a leg press exercise is an example of an
(a) open kinetic chain exercise.
(b) closed kinetic chain exercise.
(c) isokinetic exercise.
(d) isometric exercise

(b) Open kinetic chain exercise occurs when the most distal segment is not in contact with a surface (eg, leg extensions). Closed kinetic chain exercise occurs when the most distal segment is in contact with a surface (eg, a leg press). In isokinetic exercise a muscle contracts with a constant angular velocity and variable resistance. In isometric exercise a muscle contracts against an immovable object and there is no joint angular movement.

2007

38

An athlete is found to have a high-arched (pes cavus) foot in supinated weight bearing. Which
motion is associated with this finding?
(a) Tibial external rotation
(b) Forefoot abduction
(c) Ankle dorsiflexion
(d) Talus internal rotation

(a) Supination in weight bearing is a triplanar motion involving multiple joints of the foot and ankle.
Supination incorporates ankle plantar flexion, talus external rotation, and forefoot adduction.
Obligate tibial and femoral external rotation occurs with supination

2006

39

In a patient with a transfemoral amputation, what is the most likely cause of excessive knee flexion
during ambulation?
(a) Hip flexion contracture
(b) Prosthetic knee alignment in an excessively posterior position
(c) Excessive socket extension
(d) Too soft a plantar flexion bumper in the heel

(a) One of the most common gait deviations in patients with transfemoral amputations is abrupt or
excessive knee flexion during ambulation. The prosthetic knee joint should normally be stable in
extension in stance phase from heel contact to foot flat. This stability is accomplished by aligning
the prosthetic knee axis posterior to the trochanteric knee ankle line. Adequate strength and range
of motion in hip extension are critical to maintaining this alignment. Thus, weak hip extensors and
hip flexion contractures can cause knee instability. Two prosthetic causes of knee instability are (1)
knee malalignment in an excessively anterior position relative to the hip and ankle joints, and (2)
excessive socket flexion. A plantar flexion bumper that is too stiff, extensive foot dorsiflexion, or a
change in shoe heel height from low to high may all promote knee flexion

2006

40

During which phase of the gait cycle are the ankle plantarflexor muscles (gastrocnemius and soleus)
most active?
(a) Initial contact
(b) Loading response
(c) Midstance
(d) Terminal stance

(d) During the gait cycle, the ankle plantarflexors become active during the midstance phase when they
contract eccentrically to control forward progression of the tibia and ankle dorsiflexion. These
muscles become most active during the terminal stance phase when they contract concentrically to
produce ankle plantarflexion and accelerate the trunk forward. The ankle plantarflexors are
minimally active during the initial contact and loading response phases of the gait cycle.

2006

41

A circumducted gait in a man with an above knee amputation is most likely due to
(a) a rigid heel in his solid ankle, cushioned heel (SACH) foot.
(b) inadequate friction in his prosthetic knee unit.
(c) his prosthetic foot being set in dorsiflexion.
(d) inadequate socket suspension.

(d) Inadequate socket suspension causes the prosthesis to be functionally too long. A rigid heel and
foot set in dorsiflexion would increase knee flexion movement. Inadequate friction would cause the leg to “snap” into terminal extension

2006

42

Which modification will make a rocker bottom sole most effective?
(a) Increase sole thickness with apex at the metatarsal heads.
(b) Provide a rigid sole with no shock absorption.
(c) Extend the length of the shoe to ½ inch beyond the longest toe.
(d) Ensure that arch length is measured 2cm proximal to metatarsal heads

(c) The sole of a shoe for an individual with a neuropathic foot should be shock absorbing. The rocker
sole allows ambulation with reduced pressures on the forefoot. This requires an addition to the sole
thickness with an apex 1cm proximal to the metatarsal heads for the sole to roll over the forefoot.
The length of the shoe must be ½ to ¾ inches beyond the longest toe to accommodate the natural
elongation of the foot in ambulation. The arch length is measured at the metatarsal heads

2006

43

A prescription for side joints and corset in a below knee prosthesis would be indicated in a patient
with
(a) a short residual limb.
(b) a slight degree of knee joint laxity.
(c) fluctuating limb volume.
(d) fragile skin.

(a) Side joints and corset are indicated for persons with short or damaged residual limbs, or those with a high degree of limb laxity. Long-term users may also prefer to continue side joints and a corset even without the aforementioned indications.

2006

44

The primary advantage of a sterno-occipital-mandibular immobilizer orthosis is its
(a) excellent limitation of cervical extension.
(b) ease of donning while the patient is supine.
(c) high level of patient comfort.
(d) excellent limitation of atlantoaxial motion.

(b) The sternal-occipital mandibular immobilizer (SOMI) is effective at limiting flexion, whereas the 4-post orthosis restrains extension better. The SOMI can be applied to the supine patient without having to rotate the individual. The SOMI is not comfortable. Overall, control of atlantoaxial
subluxation is difficult to achieve with orthoses

2006

45

Which anatomical configuration is associated with an anterior pelvic tilt when the patient is
standing?
(a) Short abdominal muscles
(b) Increased lumbar lordosis
(c) Elongated hip flexors
(d) Short and strong gluteal muscles

(b) An anterior pelvic tilt is caused by one of several anatomic factors. These include tight hip flexors,
weak lower abdominals, and weak gluteal muscles. Compensatory lumbar extension through
lumbar lordosis results in individuals with excessive anterior pelvic tilt

2006

46

The proper width of a doorway to allow transit of a power wheelchair without turning is at least
(a) 26 inches.
(b) 30 inches.
(c) 36 inches.
(d) 40 inches

(c) The proper width of a doorway for a power wheelchair is at least 34 inches. Base would increase to
36 inches if a turn is involved. A manual wheelchair requires a 32-inch doorway. The minimum
turning space is a 5-foot radius for a manual wheelchair and a 6-foot radius for a power chair

2006