Prosthetic Orthotics Flashcards

Question

7. Which spinal orthosis is used to prevent thoracic spinal flexion by providing 3-point pressure over the sternum and pubis anteriorly and the upper lumbar spine posteriorly? (a) Custom molded, plastic thoracolumbosacral orthosis (b) Lumbosacral corset with posterior metal stays (c) Jewett orthosis (d) Taylor orthosis

Answer 1

7. (c)Several different types of thoracolumbosacral (TLSO) orthoses are available to control segmental spine motion in this region. A custom molded plastic TLSO provides almost total contact support for uniform pressure distribution and control of motion in all plains. A lumbosacral corset with metal stays provides support circumferentially and helps reduce spine motion primarily in the lumbosacral region. A Taylor orthosis also provides circumferential support with the addition of axillary straps. The Taylor orthosis is primarily designed to resist flexion and extension. A Jewett brace is designed to limit thoracic spine flexion by providing 3-point pressure over the sterum and pubis anteriorally and the upper lumbar spine posteriorally. This type of brace is used most commonly for individuals with thoracic spine anterior compression fractures.

Answer 2

c)High-profile, dynamic elastic response prosthetic feet and ankle components such as the Flex-Foot and Springlite are primarily indicated for individuals who are expected to be community ambulators and are able to ambulate at variable cadences. This class of prosthetic components is also used for individuals participating in running and sports activities. Therefore, this class of components would be most indicated for the individual with a transtibial amputation interested in returning to running. An individual who farms would likely benefit from a prosthetic foot and ankle system which is more accommodative over uneven surfaces.

Answer 3

9. (a)A Syme amputation (A) is ankle disarticulation with tapering of the medial and lateral malleoli and preservation of the heel pad for soft tissue coverage and distal weight bearing. A Boyd hindfoot (B) amputation is a talectomy and calcaneal-tibial arthrodesis after forward translation of the calcaneus. A Chopart level (C) amputation is performed at the mid-tarsal level with sparing of the talus and calcaneus. A tarsal-metatarsal disarticulation (D) is also referred to as a Lisfranc amputation.

Answer 4

10. (b)One advantage of a voluntary-closing hook terminal device is the ability to **adjust the amount of pinch force by adjusting pressure on the cable control.** This improves the ability to manipulate fragile objects. A voluntary opening terminal device uses elastic bands to determine the pinch force and the number of bands would have to be reduced to decrease the pinch force. When carrying objects, voluntary-closing terminal devices require constant cable tension and this can result in quicker fatigue. The ability to visualize the object being manipulated would not be dependent upon whether the terminal device is voluntary closing or voluntary opening.

Answer 5

11. (a)The control cable for opening the terminal device of a standard transradial prosthesis using a voluntary-opening terminal device passes posterior to the elbow joint, along the posterior arm, and attaches to the posterior support strap of a figure-of-8 harness. This arrangement allows glenohumoral flexion to produce tension in the cable and open the terminal device. Glenohumoral extension and biscapular adduction decrease tension on the control cable. Biscapular elevation would not produce cable tension required for terminal device operation.

Answer 6

12. (c)Trauma is the most common cause of upper extremity amputation in adults. Malignancy is a more common cause of amputation in the pediatric population. Upper extremity amputations occur most commonly in the 20- to 40-year-old age group, as a result of trauma and work related accidents. The dominant extremity is affected more commonly and amputations at the transradial level are the most common level of upper extremity amputation. Upper extremity amputations occur much less frequently than lower extremity amputations. Upper extremity amputations account for approximately 20% of all major limb amputations.

Answer 7

13. (d)Small diameter casters on a wheelchair reduce the chair’s turning radius, which gives it greater maneuverability. These casters frequently are mounted on wheelchairs used for sports such as basketball. Smaller diameter casters are less well suited for outdoor activities over rough terrain. The size of the caster does not affect the maintenance required and does not improve wheelchair stability on inclines. Hard, narrow casters are typically recommended for mobility over smooth, level surfaces whereas wider, larger casters are better for mobility over uneven, rough surfaces.

Answer 8

14. (d)All of the shoe modifications listed would be appropriate for an individual with loss of protective sensation except for the use of a solid steel shank built into the sole of the shoe. This modification would decrease the accommodative properties of the shoe and may increase the potential for skin breakdown.

Answer 9

15. (a)With a radial nerve injury at the level described, there is loss of wrist and metacarpal extension because of denervation of the forearm extensor muscles. A dorsal wrist-hand-finger orthosis that holds the wrist, fingers, and thumb in extension and permits flexion of the digits with a low-profile outrigger is used to substitute for this loss of function. This type of orthosis would be inappropriate for the other conditions described.

Answer 10

16. (d)A manual-locking knee is indicated for new unstable amputees and those who need utmost stability because of muscular weakness or poor coordination. The other components are generally used in persons with less risk of falling.

Answer 11

17. (a)Acquired upper limb amputations in adults occur most commonly in males between the ages of 21 and 64 years. These amputations result frequently from work-related accidents or trauma and are most common in the dominant limb at the transradial level. In contrast, congenital upper limb deficiencies occur most commonly on the left side at the transradial level.

Answer 12

18. (c)A resting hand splint is designed to maintain a position of function in a hand that is weak or paralyzed. It is applied on the volar surface and extends from the fingertips to the proximal third of the forearm. The wrist is typically placed in slight extension. The metacarpophalangeal joints are placed in slight flexion and the interphalangeal joints are placed in a neutral position or in slight flexion. The thumb is supported in a position between palmar and radial abduction.

Answer 13

19. (a)Footwear for the person with diabetes and grade 1 skin changes on the plantar aspect of the foot should be designed to relieve pressure over the affected site while evenly distributing pressure over the remaining foot surface to prevent other skin breakdown. A typical prescription would include an extra-depth shoe with a wide toebox and a total-contact, custom-molded insert with pressure relief at the area of skin irritation. Further shoe modifications with a metatarsal bar and rocker bottom sole could also be considered, especially if the patient had grade 2 skin changes or more severe foot deformities. A calcaneal bar or heel lift would not be appropriate considerations in this case.

Answer 14

20. (b)The wrist-driven tenodesis hinge orthosis creates a 3-jaw chuck prehension by stabilizing the interphalangeal joints of digits 2 and 3 and the interphalangeal and metacarpophalangeal joints of the thumb. The extensor carpi radialis muscle activates the wrist extension, which through tenodesis action creates a 3-jaw chuck prehension.

Answer 15

21. (c)Compared with a transfemoral level amputation, a knee disarticulation provides increased ability to bear weight on the distal residual limb. There is no evidence that knee disarticulation amputations have a reduced risk of phantom pain or have improved surgical wound healing. Amputations at the transfemoral level typically have a better cosmetic appearance with prosthetic fittings because the distal prosthetic socket can be tapered to be more symmetric with the opposite side. Knee disarticulation amputations also have a prosthetic knee axis of rotation that is distal compared to the intact knee.

Answer 16

22. (a)The socket of a transtibial prosthesis is typically slightly flexed during the static prosthesis alignment process. Proper flexion of the socket improves weight-bearing characteristics and also reduces knee extension forces during mid-stance and the terminal stance phases of gait. The static alignment also places the socket in 5° of adduction with the foot slightly inset relative to the socket.

Answer 17

23. (b)The metabolic cost of ambulation (mL oxygen consumed per body weight per meter) is a measure of energy consumption per distance. The metabolic cost of ambulation increases following a lower limb amputation and the amount of increase is related to the level of the amputation as well as the amputation’s etiology. Because of this increased metabolic cost, persons will have reduced endurance for ambulation following an amputation. This would be especially true for an individual with bilateral transfemoral amputation(s). The person described, however, should be considered a candidate for prosthetic ambulation and, since he has no prior cardiac history or significant risk factors, cardiac stress testing would not be indicated.

Answer 18

24. (a)Wheelchair recommendations for a person with hemiparesis and limited ambulatory abilities would include a hemi-height chair which is lower to the ground than to a standard height wheelchair. This configuration provides the patient greater advantage to propel the wheelchair with the unaffected lower extremity. It is also important for the leg rests to be removable so that they do not interfere with the patient’s ability to propel the wheelchair.

Answer 19

25. (c)The average range of motion at the ankle during normal human ambulation over level surfaces is from 5° of dorsiflexion to 20° of plantarflexion. This range of motion varies with ambulation over uneven surfaces and with activities such as stair climbing.

Answer 20

27. (d)Midswing is the continuation of the passive pendulum action of the leg. Foot clearance is maintained by activity of the tibialis anterior.

Answer 21

26. (d)SACH is an acronym for solid ankle, cushion heel. The SACH foot has a cushioned heel that compresses during heel strike, stimulating plantar flexion, and has a rigid anterior keel to roll over during late stance. It is light, durable, and inexpensive, and is the orthosis most often prescribed for juvenile and geriatric amputees.

Answer 22

28. (c)This is an elbow-lock control cable. Its proximal end originates at the anterior suspension strap and its distal end engages the elbow-locking mechanism. The principal of the elbow-lock mechanism is pull-and-release to lock, pull-and-release to unlock.

Answer 23

29. (a)The 4-point crutch gait has stability as its primary advantage. At least 3 points are always in contact with the ground. It is more difficult to learn than the other gait patterns and is a relatively slow form of ambulation. The 3-point crutch gait is used by patients with lower limb fractures, amputations, or toe-touch weight-bearing. The 4-point gait pattern enables the crutch user to eliminate all the weight-bearing on the affected lower limb. The 2-point crutch gait is much faster than the 4-point gait and yet still provides some weight-bearing relief to both lower limbs.

Answer 24

30. (d)By Medicare guidelines, to obtain a semi-electric hospital bed for a patient the physician must complete a certificate of medical necessity. Although a full electric bed used in most hospitals may be beneficial for many patients, Medicare guidelines consider the electric powered, variable height feature a convenience and, therefore, Medicare will not cover a full electric bed. A semi-electric hospital bed will be covered if the patient requires frequent changes in body position or has an immediate need for change in body position along with at least 1 of the following conditions: (1) The patient requires positioning of the body in ways not feasible with an ordinary bed. (2) For pain relief, the patient requires positioning of the body in ways not feasible in an ordinary bed. (3) Because of congestive heart failure, pulmonary disease, or aspiration, the patient requires the head of the bed to be elevated more than 30° most of the time. (4) The patient requires traction equipment that can only be attached to a hospital bed.

Answer 25

31. (d)Camber has several advantages. The footprint of the chair is widened creating greater side to side stability; camber allows quicker turning; camber helps to protect the hands by having the bottom of the wheels scruff edges; and camber positions push rims more ergonomically for propulsion. A disadvantage is that the increased width of the wheelchair may make it difficult to maneuver in an environment made for walking (ie, narrow spaces).

Answer 26

32. (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.

Answer 27

33. (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.

Answer 28

34. (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.

Answer 29

35. (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 1⁄2 to 3⁄4 inches beyond the longest toe to accommodate the natural elongation of the foot in ambulation. The arch length is measured at the metatarsal heads.

Answer 30

36. (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.

Answer 31

37. (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.

Answer 32

38. (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.

Answer 33

39. (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%.

Answer 34

40. (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.

Answer 35

41. (b) Transtibial amputees have a lower rate of energy expenditure, heart rate and oxygen consumption when using a prosthesis (vs. non-weight bearing crutch gait). The cardiovascular demand of crutch walking is high, with increased rate of oxygen consumption, increased heart rate, increased energy costs, and respiratory exchange rate in the anaerobic range.

Answer 36

42. (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.

Answer 37

43. (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.

Answer 38

44. (c) An advantage of a single-subject research design (A-B-A design) is that this design can establish cause and effect relationships similar to other true experimental designs. Single subject research designs involve systematic, repeated measurement of a dependent variable over time through 1 or more baseline and intervention phases. The primary limitation with a single-subject research design is that it only establishes the cause and effect relationship for the subject involved in the study. Therefore, these results cannot be assumed to occur in others, because of the variability between subjects. Typically, a single subject research design requires a washout period between medication trials to ensure that the effects of the medication are no longer active. Single subject research designs are especially useful for interventions that do not have extended or prolonged effects. If the intervention has only short-term effects, then a difference in the outcome measured can be clearly demonstrated by comparing results when the intervention is in use against results obtained when it has been removed.

Answer 39

45. (b) When critically evaluating the medical literature, it is important to consider if the results of the study are both clinically and statistically significant. It is also important to consider whether the outcome assessment tools have been validated for both accuracy and reliability. While biases that may impact the outcome of the study also must be considered, it is often impossible to completely eliminate bias from the study.

Answer 40

46. (d) All of the options listed are key aspects of practice-based learning and improvement, with the exception of the ability to advocate for quality patient care and assist patients in dealing with system complexities. This statement is a key aspect of systems-based practice as defined by the Accreditation Council of Graduate Medical Education.

Answer 41

47. (d) Conflicts of interest in biomedical research are becoming more apparent as private companies increasingly develop relationships with academic research scientists. Avoidance of real or perceived conflicts of interest in clinical research is necessary if the medical community is to ensure objectivity and maintain individual and institutional integrity. Financial investments should only transpire outside of the time that the investigator is involved in any research activity and the results of the research are known to the public. If conflicts of interest exist, the investigator is obligated to disclose this involvement in writing to the investigator's medical center, organizations funding the research, and anytime that the research is presented or published.

Answer 42

(c) In patients with diabetes, amputation is a strong possibility, even with ankle pressures higher than 55 mmHg because spuriously high pressures can be present in these patients as a result of calcification of the arterial media. The ankle brachial pressure index (ABPI) is the patient’s brachial pressure compared to the ankle pressure. A resting ABPI greater than 1.0 is considered normal. Patients with intermittent claudication have an ABPI in the range of 0.5 to 0.7, and patients with rest pain or other symptoms of severe ischemia have an ABPI of less than or equal to 0.3. A pressure less than 50 mmHg at the ankle is associated with limb threatening ischemia.

Answer 43

49. (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.

Answer 44

50. (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.

Answer 45

51. (a) Deformity in the spine presents with malalignment of in the pelvis as either contralateral or ipsilateral drop. Two other causes of ipsilateral pelvic drop are contralateral hip abductor weakness and short ipsilateral limb. Weak hip extensors are a cause of backward lean. In stance, a backward lean of the trunk substitutes for weak hip extensors.

Answer 46

52. (d) At least 50% of persons with diabetes and peripheral arterial disease who undergo major limb amputation will die within 5 years of sustaining major lower limb amputation.

Answer 47

53. (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.

Answer 48

54. (b) Disarticulation results in a bulbus distal residual limb, which may complicate prosthetic fitting. Choice of prosthetic knee options for a person with a knee disarticulation, therefore, is limited and potentially excludes the newer, more advanced knee-joint designs. Benefits of a knee disarticulation over a transfemoral approach include greater tolerance to distal limb weight bearing, a longer lever arm to create power during ambulation and running, and improved sitting balance. Of note, functional outcome studies of trauma-related lower extremity amputees concluded that persons with through knee amputations had significantly poorer outcomes. These poorer outcomes are attributed to complications arising from soft tissue failure within the zone of injury.

Answer 49

55. (a) Phantom sensation, phantom pain, and residual limb pain have all been reported about equally in over 70% of amputees 6 months or more after lower limb amputation. This is typically not dependent upon the person's age at the time of amputation, the level of amputation, or surgical technique.

Answer 50

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.

Answer 51

d. Commentary: Moving a wheelchair’s rear axle forward enables the user to propel the chair with less muscle effort and fewer strokes. Because the modification causes more weight to be centered over the rear wheels, it is easier to pop a wheelie, negotiate obstacles and ascend or descend curbs. However, moving the axle forward can also make the wheelchair more “tippy” (likely to tip backwards) and that tendency to tip backwards makes it more difficult to push the chair up a ramp.

Answer 52

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

Answer 53

59. 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.

Answer 54

60. 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.

Answer 55

61. Answer: D Commentary: Medicare Part B pays 80% of the allowed purchase price in one lump sum payment if the patient chooses to purchase the device. The patient is required to pay 20% of the allowed purchase price. If the patient chooses to rent a wheelchair, Medicare part B will pay 80% of the allowed rental price for months 1 through 10 and the patient will pay 20% of the allowed rental charge.

Answer 56

62. 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.

Answer 57

63. 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.

Answer 58

Answer: (b) Commentary: Medial compartment osteoarthritis causes a genu varum deformity. Lateral heel wedges can be used for conservative treatment of medial compartment osteoarthritis. A medial wedge would exacerbate the genu varum. An arch support would help with pes planus (flatfoot) which may be helpful for genu valgum deformity. Rocker bottoms may be used to offload pressure from the metatarsal heads.

Answer 59

65. Answer: (a) Commentary: A straight cane should be used on the unaffected side to lessen the force exerted on the hip with pathology. A Lofstrand crutch is also known as a Lofstrand forearm orthosis. It includes a cuff placed along the lateral aspect of the forearm. Lofstrand crutches are often used bilaterally. Because it does not require the use of the hand or wrist, and does not apply pressure through them, a platform crutch is helpful for patients who need an assistive device and have wrist/ hand pain or weakness.

Answer 60

66. Answer: (d) Commentary: The halo device provides the greatest restriction of cervical motion for flexion/extension, lateral bending and rotation, as shown in the table below:

Answer 61

67. Answer: (b) Commentary: ABI is a noninvasive technique that is used in the assessment of arterial occlusive disease. The ABI is the ratio between the ankle and the brachial systolic pressure. Normal ABI is defined as values greater than 0.9. An ABI below 0.4 tends to carry a poor prognosis. TcPO2 is defined as transcutaneous oxygen, which is in essence a "blood gas" of the skin. Normal TcPO2 is greater than 50mmHg. Values of more than 40mmHg are associated with healing. Ischemia is defined as periwound TcPO2 \< 20mmHg.

Answer 62

68. Answer: (a) Commentary: In addition to a decrease in muscle spasticity, FES decreases the physiologic cost of gait, increases voluntary muscle strength, and increases stride length.

Answer 63

Answer: (d) Commentary: Causes of lateral trunk lean towards the prosthetic side include: prosthesis too short, hip abduction contracture, prosthesis lined in abduction, and short residual limb.

Answer 64

70. 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.

Answer 65

71. Answer: (a) Commentary: Pregnant women frequently develop low back pain, and a sacroiliac belt can be helpful. A cruciform anterior spinal hyperextension (CASH) brace is generally used for osteoporotic compression fractures. A silesian belt is a type of suspension for transfemoral prostheses. The Minerva brace is a cervicothoracic orthosis.

Answer 66

72. Answer: (c) Commentary: A limb board placed underneath the knee will help to prevent knee flexion contractures. Placing a pillow underneath the thigh would encourage the development of a hip flexion and possibly a knee flexion contracture. A pommel between the legs may encourage a hip abduction contracture. A wedge cushion would promote hip flexion contractures.

Answer 67

73. 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. ## Footnote

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Prosthetic Orthotics Flashcards

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