Aug. 11, 2025
Agriculture
Author: Hiral Patel, MHS, CRC
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This two-part blog series will discuss the inclusion of prosthetics in life care plans and the different types of prosthetics. Over 185,000 people in the United States have an amputation each year.[1] The most common causes for amputations are vascular disease, trauma, and cancer.[2] Life care plans usually address future care for amputations due to trauma. Trauma causes 45% of all limb loss.[3] The two main categories of amputations are upper extremity and lower extremity. Part 1 will discuss prosthetics and care for lower extremity amputations. Part 2 will discuss prosthetics and care for upper extremity amputations.
Types of Lower Extremity Amputations
Lower extremity amputations account for 65% of all amputations.[4] Trauma is responsible for only 5.8% of lower-limb amputations.[5] The levels of lower extremity amputations include:
After the amputation, skin closure and infection must be managed. Sometimes a stump revision is necessary for proper healing and prosthetic fit. Sometimes a stump requires a shrinker to mold the stump to the correct size and shape to fit a prosthetic. Proper limb and skin care are essential for health and mobility. Bacterial and fungal infections from sweat can lead to skin irritation, abrasions and skin breakdown could prevent the amputee from using the prosthesis. An amputee should bathe at night as the residual limb tends to swell in hot water or when dangling in the shower. A BKA should never sleep with a pillow under the knee as it can lead to the inability to bend the knee.
Skin care and prosthetic care is necessary to avoid skin breakdown, ulcers, infections and possible reduced sensation in the residual limb. Washing the prosthetic to be sure it is clean for any contact with the skin will prevent the same complications listed above. If the amputee has any problems with the fit or function of the prosthesis, they should immediately contact the prosthetist.
Prosthetic Selection
A prosthesis is an artificial substitute for a missing body part. A lower limb prosthesis refers to a prosthesis that replaces any part of the lower limb to restore the functional and/or cosmetic appearance of the lower limb or both. This may include artificial components that replace the hip, thigh, knee, ankle and foot. The main purpose of a prosthetic is to allow an individual to function at his or her highest level. The most common prosthetics are for AKA and BKA and those are the focus of this blog.
A physician must first determine if a prosthetic is “medically necessary.” “Medical necessity” means that the physician can prove that the service ordered is the appropriate service for the patient. A prosthetic candidate must have a healed amputation site or stump. When the stump is healed, a physician will often refer the patient to a prosthetist. A prosthetist is a specially trained and licensed clinician who evaluates the amputee, determines the appropriate prosthetic, fits the prosthetic, and trains the amputee to use and maintain the prosthetic. One of the first steps in determining the appropriate prosthetic is to determine what level of ambulator the amputee is or will be. This requires determining the K Level.
What is a K-Level?
A K-Level is a rating of amputee’s ability to ambulate based on the Medicare Functional Classification Level,.[7] The rating is from 0 through 4 and indicates a person’s potential to use a prosthetic device, if a device worked well for him or her, and if he or she completed training to use the prosthetic properly.[8] The chart below defines each level:[9]
K-Level Definition 0 Does not have the ability or potential to ambulate or transfer safely with or without assistance and a prosthesis does not enhance their quality of life or mobility. 1 Has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed cadence, typical of the limited and unlimited household ambulator. 2 Has the ability or potential for ambulation with the ability to transverse low level environmental barriers such as curbs, stairs or uneven surfaces. This level is typical of the limited community ambulator. 3 Has the ability or potential for ambulation with variable cadence, typical of the community ambulator who has the ability to transverse most environmental barriers and may have vocational, therapeutic, or exercise activity that demands prosthetic utilization beyond simple locomotion. 4 Has the ability or potential for prosthetic ambulation that exceeds the basic ambulation skills, exhibiting high impact, stress or energy levels typical of the prosthetic demands of the child, active adult, or athlete.The prosthetist completes the initial evaluation with input from the patient and uses the definitions above to determine the appropriate K-Level which is used to determine the appropriate prosthetic.
Above the Knee vs. Below the Knee Prosthetics
The level of amputation determines which components of the lower extremity prosthesis will need to be prescribed. The most common lower extremity amputations are below the knee and above the knee.
Below the Knee (BK) – Transtibial
A BKA prosthetic requires a suspension system to keep the prosthetic in place. The prosthetist will determine which system is best. There are three types of suspension systems:
Above the knee (AK)- Transfemoral
The main difference between a below the knee and an above the knee prosthesis is the AKA requires a knee joint. Functionality depends on selecting the correct knee to fit the person’s age, health, activity level, and lifestyle. Without the knee joint, an amputee would likely have problems with balance and stability and require increased energy to ambulate. The latest or most advanced knee joint is not the best choice for every amputee. For some, safety and stability are the most important consideration. Others who are more active may prefer a knee joint that delivers a higher level of function even if it is more difficult to control.
Types of Prosthetic Knee Joints
Single-axis knee Joints are built with a single hinge point. This type of knee joint is both durable and lightweight, but offers a limited range of adaptability to different gait speeds. Most single-axis knee joints include the ability to lock the knee joint in place for standing or walking when the user needs more security in his prosthesis.
Multi-axis/Polycentric knee Joints bend through multiple hinge points, making it less likely that the knee joint will buckle during standing. In some designs, this mechanism also shortens the prosthesis as it swings beneath the user, reducing the risk of tripping and falling. Polycentric knee joints meet the needs of people for different activities, with simpler versions better for light activity and more advanced versions better suited to heavy activity.
Hydraulic and pneumatic knee joints use air or fluid to adapt to different walking speeds as the wearer swings the leg forward and backward. Some designs allow the user to lock the knee for stability while standing for long periods of time, or when walking in unfamiliar or unsafe environments. Hydraulic and pneumatic knee joints are best for moderately active people who want to vary their walking speeds.
Computerized/Microprocessor knee joints use technology that offers safer walking with less effort, making it easier to navigate hills, ramps, and uneven terrain with greater stability. Microprocessor knee joints are best for people with moderate to active lifestyles who navigate uneven terrain or more basic environmental obstacles like curbs and sloped surfaces. They are especially good for bilateral amputees, as microprocessor knee joints help users feel safer and more confident in daily activities.
Types of Prosthetic Feet
As when selecting a prosthetic leg, several factors must be considered to select the best foot. These include the amputation level, age, weight, foot size, activity level, and occupational needs. Prosthetic feet can be connected to the prosthetic shank with a rigid connection (articulated) or a hinged ankle mechanism (non-articulated).
Solid Ankle Cushioned Heel (SACH) and Elastic (flexible) Keel Foot The simplest non-articulated foot is rigid and provides stability but little lateral movement. It is available in different heights to match individual shoes.
Single-Axis Foot – The articulated single axis foot has an ankle joint that allows the foot to move up and down, enhancing knee stability. The more quickly the full sole of the foot is in contact with the ground, the more stable the prosthesis becomes. This helps users with an amputation anywhere between the knee and hip. The wearer must actively control the prosthesis to prevent the knee from buckling, and the single-axis ankle/foot reduces the effort required to do so. Unfortunately, the single-axis ankle adds weight to the prosthesis, requires periodic servicing, and is slightly more expensive than the more basic SACH foot. A single-axis foot may be more appropriate for individuals where stability is a concern.
Multi-Axis Foot – Similar to the single-axis foot in terms of weight, durability and cost, the multi-axis foot works better on uneven surfaces. The multi-axis foot can also move from side to side.
Dynamic-Response Foot – This foot is best for people with more active lifestyles who vary walking speed, change directions quickly or walk long distances. Dynamic-response feet store and release energy during the walking cycle by absorbing energy in the keel during the “roll-over” phase and then springing back to provide a subjective sense of push-off for the wearer. These have a more normal range of motion and a more symmetrical gait pattern.
Microprocessor Foot – This foot/ankle mechanism has small computer-controlled sensors and adjusts to various needs. Based on input signals, these processors apply an algorithm, or set of rules, to decide how to position the ankle, how to set the damping resistance in the ankle, and how to drive the ankle motor. This foot can react to varying situations with different r alignments to improve the user’s balance and mobility. The goal of this class of prosthetic feet is to mimic the functions of the human foot.
Life Care Planning for Amputees
Life care planners should include all the prosthetics and supplies an amputee needs. They vary based on age, skin integrity, activities, type of prosthetic, length of time used, and other factors. The life care plan should be individualized to meet the individual’s needs.
The Life Care Planning Life Care Planning and Case Management Handbook, Fourth Edition[10] is used in all life care planning courses. Chapter 12, “Life Care Planning for the Amputee,” states the usual and customary charge for a prosthesis is the full, non-discounted, non-Medicare cost, “Almost never is this price paid to the prosthetist for the final prosthetic device. The more appropriate number to use for prosthetic costs is the Medicare allowable reimbursement.”[11] Medicare uses “L codes” to identify specific prosthetics.[12]
A prosthetic device can last anywhere between two to five years. This depends upon the wear and tear from use, age of the amputee and the actual parts. Some parts are easily repaired which allows longer use of the prosthetic.
Most prosthetic devices have warranties ranging from 24 to 36 months after purchase. The life care planner should not include a maintenance cost for the years the device is under warranty.
There are also prosthetic devices designed specifically for showering or swimming which have waterproof parts. There are also “blades” made from carbon for runners. There are prosthetic with flexion and extension movements specifically designed for downhill skiing and snowboarding and similar prosthetics for wakeboarding. BKA can purchase a foot attachment to fit into their prosthetic which then fits into the binding of snow skis. Special feet are also made for rock climbing and there are foot attachments to allow hockey players or skaters to perform on ice.[13]
Conclusion
Prosthetics are constantly being improved with new technology. In the last ten years, lower limb prosthetics have improved:
Related links:With competitive price and timely delivery, Aosuo Medical sincerely hope to be your supplier and partner.
Life care planners need to carefully follow developments in prosthetics so the prosthetics and supplies included in a life care plans best meet the needs of each amputee.
Resources
Centers for Medicare & Medicaid Services Health Technology Assessments. Lower Limb Prosthetic Workgroup Consensus Document. September .
Amputee Coalition Website. Prosthetic Knee Systems. https://www.amputee-coalition.org/resources/prosthetic-knee-systems/
Dillingham TR, Pezzin LE, MacKenzie EJ. Limb amputation and limb deficiency: epidemiology and recent trends in the United States. Southern Medical Journal. ;95(8):875-879.
Hanger clinic https://hangerclinic.com/prosthetics/lower-limb/prosthetic-knees/
Amputee Coalition Website. A Guide to Activity- Specific Prosthetics for Sports
[1] Owings M, Kozak LJ, National Center for Health S. Ambulatory and Inpatient Procedures in the United States, . Hyattsville, Md.: U.S. Dept. of Health and Human Services, Centers for Disease Control and Prevention, National Center for Health Statistics; .
[2] Amputee Coalition Website. Limb Loss Statistics. https://www.amputee-coalition.org/resources/limb-loss-statistics/
[3] Ziegler‐Graham K, MacKenzie EJ, Ephraim PL, Travison TG, Brookmeyer R. Estimating the Prevalence of Limb Loss in the United States: to . Archives of Physical Medicine and Rehabilitation;89(3):422‐9.
[4] Amputee Coalition Website. Limb Loss Statistics. https://www.amputee-coalition.org/resources/limb-loss-statistics/
[5] Dillingham TR, Pezzin LE, MacKenzie EJ. Limb amputation and limb deficiency: epidemiology and recent trends in the United States. Southern Medical Journal. ;95(8):875-879.
[6] Marcovitch H, editor. Black’s Medical Dictionary. London: A&C Black Publishers, .
[7] Crowe et al. Plast Aesthet Res ;6:4 I http://dx.doi.org/10./-..70
[8] inMotion. Volume 23, Issue 5. September-October .
[9] Centers for Medicare & Medicaid Services Health Technology Assessments. Lower Limb Prosthetic Workgroup Consensus Document. September .
[10] Weed, R. and Berens, D. () Life Care Planning and Case Management Handbook. Fourth Edition. CRC Press.
[11] Weed, R. and Berens, D. () Life Care Planning and Case Management Handbook. Fourth Edition. CRC Press. Page 351.
[12] Weed, R. and Berens, D. () Life Care Planning and Case Management Handbook. Fourth Edition. CRC Press.
Updated 08/
Over the past decade, technology and research have greatly expanded the functionality and aesthetics of prosthetic feet. Today, amputees have a wide array of feet from which to choose. Various models are designed for activities ranging from walking, dancing and running to cycling, golfing, swimming and even snow skiing. Heavier wood and steel materials have been replaced over the years by lightweight plastics, metal alloys and carbon-fiber composites. Much like the human foot, many of today’s prosthetic feet can store and return some of the energy generated during walking. Other key attributes included toe and heel springs that allow more natural movement at the ankle, shock absorption, multi-axial rotation, adjustable heel heights, and waterproof materials.
A number of factors must be considered when selecting the right foot/feet for your lifestyle. These factors include your amputation level, age, weight, foot size, activity level, goals and occupational needs.
Structurally, prosthetic feet can be divided into two groups: those with a rigid connection to the prosthetic shank (non-articulated) and those with a hinged ankle mechanism (articulated). In terms of function, prosthetic feet can be categorized into the following groups:
Although not all are discussed in this Fact Sheet, the following are definitions of terms you may hear when discussing various types of prostheses, fitting needs and activity requirements with your prosthetist and physician. This knowledge may help you choose which type of prosthesis is the most appropriate for you and your daily activities and needs. Never hesitate to ask for clarification from your prosthetist or physician if you do not understand something they say. You are an important part of your medical team.
Internal and External Rotation: Internal rotation refers to movement of a joint or body part toward the center of the body, while external rotation refers to the opposite rotation of a joint away from the body.
Dorsiflexion and Plantarflexion: The upward (dorsi) and downward (plantar) movements of the ankle and toes. These movements alternately enable the leg to move forward over the foot, pushing the forefoot to the ground as one takes a step.
Inversion and Eversion: The inward and outward, or side-to-side, motions of the ankle.
The most basic prosthetic feet come in two types: Solid Ankle Cushioned Heel (SACH) and Elastic Keel configurations. These designs consist of crepe neoprene or urethane foam molded over an inner keel and shaped to resemble a human foot. Because they have no hinged parts, these basic feet are relatively inexpensive, durable and virtually maintenance-free. These feet offer cushioning and energy absorption but do not store and return the same amount of energy as dynamic-response feet. SACH and elastic keel feet are generally prescribed for amputees who do a limited amount of walking with little variation in speed.
SACH Foot: The SACH is the simplest type of non-articulated foot. The name refers to a somewhat soft rubber heel wedge that mimics ankle action by compressing under load during the early part of the stance phase of walking. The keel is rigid, which provides midstance stability but little lateral movement. The SACH foot is available in various heel heights to match individual shoes with different heel heights.
Elastic (flexible) Keel Foot: This prosthetic foot allows motion similar to that of SACH feet. In addition, the forefoot is able to conform to uneven terrain but remains supportive and stable during standing and walking.
Articulated prosthetic feet may be single-axis or multi-axis in their design. “Axis” refers to motion in one or more of three different planes, similar to the movement of the natural foot. Prosthetic feet that have movement in two or three axes provide increased mobility at the ankle, which helps stabilize the user while navigating on uneven surfaces.
Single-Axis Foot: The articulated single axis foot contains an ankle joint that allows the foot to move up and down, enhancing knee stability. The more quickly the full sole of the foot is in contact with the ground, the more stable the prosthesis becomes. This is beneficial for users with higher levels of amputation (an amputation anywhere between the knee and hip). The wearer must actively control the prosthesis to prevent the knee from buckling, and the single-axis ankle/foot mechanism reduces the effort required to do so. Unfortunately, the single-axis ankle adds weight to the prosthesis, requires periodic servicing, and is slightly more expensive than the more basic SACH foot. A single-axis foot may be more appropriate for individuals where stability is a concern.
Multi-Axis Foot: Although similar to the single-axis foot in terms of weight, durability and cost, the multi-axis foot conforms better to uneven surfaces. In addition to the up and down mobility of the single-axis foot, a multi-axis foot can also move from side to side. Since the added ankle motion absorbs some of the stresses of walking, this helps protect both the skin and the prosthesis from wear and tear.
People with more active lifestyles typically prefer a more responsive foot. A dynamic-response foot is ideal for those individuals who can vary walking speed, change directions quickly or walk long distances. Dynamic-response feet store and release energy during the walking cycle by absorbing energy in the keel during the “roll-over” phase and then springing back to provide a subjective sense of push-off for the wearer. Additionally, they provide a more normal range of motion and a more symmetric gait. Some dynamic-response feet feature a split-toe design that further increases stability by mimicking the inversion/eversion movements of the human ankle and foot.
The comfort and responsiveness of a dynamic-response foot can also encourage an individual to advance from a more moderate activity level to a higher activity level, given the more natural feel of walking with this type of prosthetic foot. Further, some dynamic-response feet have been shown to reduce impact forces and stress upon the sound side foot and leg.
Microprocessor-controlled (MPC) feet are a fairly new category of prosthetic components. These foot/ankle components have small computer-controlled sensors that process information from both the individual’s limb and the surrounding environment to adjust to various needs. Based on information from input signals, these processors apply an algorithm, or set of rules, to make decisions about how the ankle or foot should respond in any given situation. The microprocessor provides instructions to various parts of the prosthesis in order to produce the desired function of the foot. Current MPC ankles use a variety of sensors, including ankle angle sensors, accelerometers, gyroscopes and torque sensors. The microprocessors in these systems then take the input signals and make decisions as to how to position the ankle, how to set the damping resistance in the ankle, and how to drive an ankle motor during stance phase (1).
The largest potential benefit of an MPC ankle/foot system over other prosthetic feet is the enhanced ability to react to varying environmental situations by providing different mechanical properties or alignments to improve the user’s balance and mobility. For example, non-MPC prosthetic feet work nicely on smooth, level terrain; however, they have a more limited ability to alter their mechanical properties or alignment when walking on slopes or other uneven surfaces. Powered feet provide propulsion during ambulation to enhance walking capabilities in real-time. Some specific models include software as well as options for connectivity to mobile devices through smart or computer apps. This allows the prosthetist and user to match the performance of the ankle/foot to various activities, allow for adjustments to the input gains and timing, and turn on or off certain features. All of these functions provide a more individualized experience by the user.
The ultimate goal of this class of prosthetic feet is to mimic the functions of the human foot. However, devices differ in their ability to accommodate for all environments and thus to the extent in which that accommodation can be achieved (2). Although these types of feet can coordinate the movements of the foot and ankle automatically, they do not directly communicate with the body. Microprocessor or powered prosthetic feet require batteries to power the chip, sensors, motors and actuators. Additionally, electronic parts associated with microprocessor systems make them more delicate than their passive counterparts. Many should not be used in water or in highly dusty or dirty environments. Due to the extra parts required by the addition of the microprocessor, they often weigh more than other prosthetic feet. Users may notice the mechanical clicks and sounds coming from the prosthesis as the microprocessor extrapolates information and adjusts various aspects of the ankle or foot. Finally, the higher level of technology and more intricate design of this class of prosthetic feet mean they may likely be the more expensive options on the market.
Just as there is no single tool perfectly suited for every job, there is no single foot that is perfect for every amputee. Knowing the available options will enable you to discuss this issue clearly with your prosthetist. Evaluate the pros and cons of different feet so you can make the best choice for your individual aspirations and abilities. In comparing the potential benefits of microprocessor-controlled systems over other systems, physicians and prosthetists should focus on the functional aspects of the prosthetic foot and its level of appropriateness, given the user’s individualized needs and goals.
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