Illustrations by Frank Angulo
Illustrations reproduced with permission from Advanced
Rehabilitation Therapy Inc., Miami, Florida
Much has been written and discussed about
establishing stability in the socket by means of surgery with
either myoplasty or myodesis procedures, in which the muscles are
stabilized by suturing muscle to muscle or muscle to bone. In
addition to creating stability anatomically, prosthetic socket
designs have been focused on maintaining bony alignment and placing
the residual muscle in a functionally optimal position to
facilitate a maximal contraction to aid the amputee with everyday
activities and prosthetic control.
While the actual benefits of surgical procedures and socket
designs are frequently debated, most authorities concede that a
sound surgery and well-constructed socket will be of some advantage
to the amputee. However, both surgery and socket design are passive
measures. Regardless of the proficiency of the surgeon and
prosthetist, unless the amputee learns to effectively utilize the
muscle within the socket dynamically, benefits from surgery and
socket design will be of little avail.
Stability within the socket is essential to
quality performance. Stability requires not only strength, but also
the ability to control movement in all directions and at varying
speeds. Achieving the capability to utilize the remaining muscles
within the socket to control forces placed on the prosthetic limb
from any direction will assist tremendously in activities requiring
speed, power, and agility. A training program designed to improve
stability within the socket should focus on joint proprioception,
in which the speed of contraction–not the maximal force of the
contraction–becomes the emphasis of the exercises.
The following selected exercises, with instructions for the
amputee, are designed to build both strength and power in multiple
directions in a low-impact fashion, thus reducing the stress to the
residual limb and the chance of injury. When these exercises are
incorporated into a training program, amputees of any functional
level will realize benefits in their overall ability. Moreover,
multidirectional exercises allow the amputee to derive maximal
benefits from the surgical procedure and socket design.
Side Walking
Side walking is performed to help learn the
movement strategies necessary for walking in different directions.
Simply move sideways for a predetermined distance, picking up speed
as the movement becomes easier. The use of walking aids, such as
canes, crutches, and walkers, is acceptable.
Crossing one leg in front of the other also helps in learning
movement strategies in multiple directions. Additionally, these
patterns of movement can assist in fall prevention as you learn to
quickly move one leg in front of the other and return to the
starting position. Moving one leg behind the other is more
difficult, but has the same benefits of the previous exercises.
Care must be given not to bump the prosthetic knee with the sound
limb, which will cause it to collapse. Maintaining a backward force
within the socket with hip musculature will help to maintain
stability. Once each individual movement is learned, braiding or
placing one leg in front of the other and then behind the leg
during the subsequent step, may be practiced. Becoming comfortable
with this skill will allow for movements in any direction with
confidence.
To improve balance and assist with improved trunk
rotation during straightforward walking, perform braiding with
trunk rotation, in which the trunk moves in opposition to the
pelvic motion. Repeat this pattern several times and then walk in a
straight line. You will notice that trunk rotation during walking
is now easier. As coordination and skill begin to improve, increase
your speed during the braiding exercises. This sequence will assist
tremendously in improving your prosthetic control in multiple
directions and on different terrains.
Cup Walking Introduction
Cup walking exercises have been extremely beneficial in helping
amputees learn to control their prosthesis. Cup walking is one of
the more challenging–yet worthwhile–exercises that can be
performed.
Place five to ten plastic cups approximately 12 to
18 inches apart. Starting at one end of the row of cups, slowly
raise the leg when stepping forward so that the knee is waist high,
or so that a 90-degree angle is formed at the hip, and then slowly
return the foot to the floor as you step over the cup. Paper cups
are also a good choice to use instead of plastic, since they crush
more easily if stepped on.
There are three key elements to focus on when balancing over the
prosthetic limb as you advance the sound limb. First, contract the
muscles within the socket by tightening the buttocks and thigh
muscles on the prosthetic side only. Second, exert a downward force
through the socket. In other words, imagine that you are pushing
your prosthetic foot down through the floor. Third, feel the weight
of your body pass over your prosthetic foot, attempting to maintain
weight over the great toe of the prosthetic foot.
One of the major benefits of this exercise is the heightened
awareness of the prosthetic foot. Feeling the bodyweight over the
foot and learning how to control your balance over the foot will
enhance your prosthetic control in a variety of activities. Don’t
get frustrated. This can be a difficult exercise.
As stated earlier, multidirectional movements are
extremely important when attempting to strengthen all the muscles
around the hip. Performing each of the Cup Walking activities
promotes different movement strategies while concentrating on other
groups of muscles. To achieve success with the prosthetic
single-limb balance necessary for this exercise, you must focus on
the three key elements: muscle contractions within the socket,
weight down through the socket, and feeling the weight progress
over the prosthetic foot. Taking your time and slowly advancing
through the cups will produce the greatest benefits from this
exercise.
Backward walking is another skill that will assist in developing
prosthetic control. Focus on the same key elements, contracting the
muscles, exerting a downward and backward force within the socket.
Additionally, limiting any unnecessary movement from the trunk will
help.
There are a number of variations that can be introduced into the
cup walking exercises. For instance, walking on a compliant or foam
surface increases the need for stability within the socket in order
to execute the exercise exactly the same way as it is performed on
a solid floor. The foam creates the need to maintain knee stability
in all directions and therefore, requires the muscles of the knee
and hip to react faster in order to maintain balance.
To further challenge the prosthetic limb musculature and to
improve balance, sideways walking will facilitate the use of
different muscle groups. With side walking, it is important to
contract the muscles about the buttocks as well as the thigh
muscles.
The Functional Training Series for Transfemoral and Transtibial
Amputees video and book series can assist clinicians and amputees
in learning more about these exercises and many others.
Robert Gailey, PhD, PT, has specialized in the
rehabilitation of lower-extremity amputees for about 20 years. He
has done extensive research, writing, and lecturing. In addition to
teaching at the University of Miami, Florida, he also operates
Advanced Rehabilitation Clinical Services and Seminars in Miami
(www.advancedrehabtherapy.com).
University of Miami School of Medicine Department of Orthopaedics Division of Physical Therapy