2. Objectives
• Stubbies: precise introduction
• Design criteria
• Design and components
• Procedure to increase prosthetic height to the full length prosthesis
• Advantages and drawbacks of stubbies
3. Stubbies
• Stubby (adjective): short and thick
• The Stubbies are the short prosthesis that uses the rocker-bottom
platform attached directly to the end of socket or the extension/pylon
with foot attached directly to the end of the socket.
• Indication: bilateral Transfemoral amputation
4. Stubbies: Design criteria
• Bilateral amputees purely depend mostly upon the prosthesis for their
basic ADLs, the socket should be comfortable, easy to don and off with
proper suspension.
• Prosthesis should be light in weight yet robust.
• Upper extremity condition will very much affect the design of the
prosthesis specially the socket and suspension type.
• Height of the stubbies prosthesis kept as short as seat height of standard
chair measuring from ischial tuberosity to reduce energy intake of waking.
• Further, better shock absorbing material are required in the foot/pylon to
control pulmonary exchange.
• Easy ground clearance is also important hence foot design and alignment
are also required to be considered .
5. Stubbies: Design and components
• Prosthesis design: Exoskeleton or Endoskeleton
• Socket design: both Sub-ischial or Ischial –
containment socket are feasible.
• Suspension type: Simple Suspension like Silesian Band
(integrated for right and left side socket for simplicity)
or other vacuum or mechanical if desired.
• Design of feet: Wooden Rocker pattern (used in
exoskeleton design) or Prosthetic foot or TD units
(used in endoskeleton design)
• Arc of wooden rocker pattern is determined by
keeping anatomical hip joint as center. They gives
better ground clearance during swing.
• While length of the wooden rocker depends upon the
effective length (from heel to MT head) of the natural
foot length of the patient.
• Initial length of prosthesis: height measured from the
ischial tuberosity or Greater Trochanter to the floor
should not be less than 18 inches (i.e seat height of
standard chair)
Exoskeleton Stubbies
with wooden rocker
pattern
6. Suspension: mainly TES/ Silesian band/ hip joint and pelvic
band
Silesian band
AK strap suspension: Jaipur foot
technology
7. Stubbies management: step by step
procedure till full length Prosthesis
• Basic requirements:
A. Tilt table: for graded weight
bearing
B. Parallel bar
C. Crutches and Canes
• Gradual increase in the height is done
from minimum height of 18 inches
(measured from Ischial seat) to the
full length Prosthesis
8. Stubbies management: step by step
procedure till full length Prosthesis
• In case where bilateral prosthetic feet are
used instead of wooden rocker pattern,
initially the feet are kept in reverse way,
as most of the weight in the Stubbies
passes through Ischial tuberocity, hence
posterior falling tendency exist.
• When patient feel sufficiently balanced
and has minimal or no backward falling
tendancy, the feet therefore can be
rotated to normal position
• Usually every three months to six months
duration, the height of the prosthesis
(pylon length) is increased by two to
three inches.
9. Stubbies management: step by step
procedure till full length Prosthesis
• The knee is included when seating on the w/c seat or opening a door-
lock becomes problem
• Gradually the pre-dominant side provide with single/polycentric knee
joint, while the non-dominant side provided with mostly weight
activated knee/polycentric knee
• Bilateral weight activated Prosthetic knee are seldom given.
• Walking stick/elbow crutches required when walking on uneven or
inclined terrain
10. Stubbies advantages and drawbacks
Advantages
• Safety: mostly used by adult
amputee than child
• Stability
• Decreased energy cost
• Upright posture
• Confidence
• ADL facility
• Preparing for full length prosthesis
Drawbacks
• Increased intrathoracic pressure
thereby increased altered
pulmonary ventilation
• Body image loss
• Social stigma
• Surrounding modification required
