This is the first phase in prosthetic design for
patients with lower-limb amputations. During
this phase, the prosthetist asks patients about
such things as their height and weight, their
activities prior to amputation, their potential
goals, and any physical or mental limitations
they have that may make them require a
unique prosthesis (e.g., blindness or the loss
of an upper limb).
Measurement and Casting
During this phase, the prosthetist records
such things as the patients’ foot size, the
length from the residual limb to the knee
center, the length from the knee center to
the floor, and multiple circumferences of the
residual limb. He or she also determines the
best system for holding the prosthesis onto
the residual limb (e.g., suction, a locking pin,
This phase can vary for each patient.
Sometimes, depending on the level of the
patient’s amputation (foot, ankle, below-knee,
etc.), the prosthetist makes a physical cast
of the patient’s residual limb from plaster
or fiberglass to serve as the model from
which the prosthetic socket will be made.
At other times, instead of making a physical
cast of the limb, the prosthetist scans the
limb with a computer and then designs the
prosthetic socket using a computer program.
This technique is faster and less invasive
than the physical casting technique. Once
the socket is designed on the computer, the
prosthetist sends the information to an inhouse Computer Numerical Control (CNC) Mill
- a machine that can perform the functions of
drilling and often turning the prosthesis. This
machine will construct a model to use in the
fabrication of the socket.
Fitting of the Diagnostic
Check Socket (DCS)
In this phase, the prosthetist fits the
patient with a clear plastic diagnostic
check socket (DCS) to determine the
exactness of the socket’s fit. If areas
of the socket need modification, the
prosthetist can modify it to make
it fit properly. Once the socket fit is
appropriate, the prosthetist attaches
the knee unit (if required), the pylon,
and the prosthetic foot.
During this phase, the prosthetist“dials in” the height of the prosthesis
or statically aligns the limb. Then he
or she begins to instruct the patient
on weight-bearing and minimal
walking. As the patient walks, the
prosthetist continues to adjust the
prosthesis to maximize its alignment
for the patient’s gait. During this
visit, the patient typically receives the
Over the course of the patient’s
rehabilitation, he or she will become
stronger, and his or her walking
gait will change. Because of this,
the prosthesis will require constant
During this phase, the prosthetist
discusses the prosthesis in more
depth with the patient so that he or
she will have a better understanding
of it. Patients are also encouraged
to review additional information (on
Web sites, in magazines, etc.) that will
give them a greater knowledge of the
world of prosthetics.
Frequently Asked Questions
When do I get my prosthesis?
This is probably the No. 1 question
that patients ask and rightly so. As
patients begin to heal, they become
anxious and, in many cases, are tired
of being in a wheelchair. The amputee
care team will determine when the
patient is ready for a prosthesis, and
patients should rest assured that this
process will begin as soon as the
patient is deemed ready.
Can I walk right away?
In some cases, depending on the
level of the patient’s amputation, the
patient can begin walking right away.
However, great emphasis is placed on
using proper walking techniques, and
training is provided to ensure that the
patient does so.
Does it hurt?
Although the prosthetic limb is
designed to bear the weight placed
on it, it will take time for the body
to adjust. The amputee care team
will issue the patient a regimented
wearing schedule and will monitor
the residual limb to prevent any
complications. Adherence to the
wearing schedule is a must.
Can I swim or get the
The initial prosthesis is designed
solely to assist the patient in
learning to walk. It is not indicated
for swimming or getting wet in the
shower, but it is durable enough to
handle rain without breaking. Specialty
prostheses, such as swim legs,
shower legs, and running legs, can be
designed at a later date.