Week 5 Flashcards
What are the causes and their percentages of amputations?
- 54% Vascular disease
- 45% trauma
- > 2% cancer related
- Military Trauma
What is the association created to increase awareness on diabetes and vascular disease called?
Preservation Amputation Care
and Treatment program (VA PACT program)
What should the shape of the prosthetic of the transtibial limb be?
Should be a contour, like a smiley face to cradle the patella tendon in it
What kind of support does the weightbearing region of the transtibial limb: medial tibial flare provide?
Horizontal and vertical support
What is the weightbearing characteristics of the pre-tibial region?
Can be compressed for anterior stabilization of the tibia during gait
- Area where the remaining dorsiflexor musculature remains
What is the characteristics of the weightbearing region of the transtibial limb: fibular shaft?
- Major contributor to the lateral stabilization of the residual limb within the socket in the stance phase of gait.
- Can be flattened for the stabilization of the fibula, but the fibula must be adequately long in relation to the tibia to do so
- Important that the modification does not impinge on the distal aspect of the fibula head, where the peroneal nerve is located
What is the characteristics of the weightbearing region of the transtibial limb: popliteal fossa?
- May be utilized when a counter pressure to the patella tendon modification is needed
- Can be used with a broad and diffused pressure distribution from the prosthetic socket
- Curve shape
What is the characteristics of the weightbearing region of the transtibial limb: Gastroc-Soleus Muscle Belly?
Utilized for soft tissue compression in aiding a hydrostatic support mechanism within the socket.
- This is where most soft tissue atrophy occur
What is the originating point of the ground reaction force vector?
The CoP
What is an induced moment?
The force that moves towards the knee, causing the knee to move toward flexion or extension
What is a reactionary moment?
How the patient must react in muscle contraction and joint motion to overcome the induced moment being placed upon the prosthesis
What is a concentric muscle contraction?
Muscle activation that increases tension on the muscle as it shortens
What is an eccentric contraction?
The motion of an active muscle while it is lengthening under load
Where is CoP at initial contact?
At the corner of the heel on the foot. GRFV has little consequence on the knee during this period
Where is CoP at loading response?
Slightly anterior to where it was before, as the prosthetic heel compresses
Where is the GRFV during loading response?
Posterior to the knee, thus inducing a knee flexion moment to the prosthesis
What are the muscle actions going on during loading response of a prosthetic limb?
Concentric contraction of the quads extends the tibia within the socket in an attempt to slow the progression of the shank of the prosthesis.
Why would the tibia in the prosthetic limb migrate anteriorly during loading response?
The tibia is not completely stabilized within the soft tissue of the residual limb, it will migrate anteriorly towards the surface of the socket, yet must be stabilized as much as possible by the design of the socket
___ should be the most stable position in gait when using a prosthesis
Mid stance should be the most stable position in gait when using a prosthesis
Where is the CoP during mid-stance with a prosthetic?
Anteriorly toward the center of the foot, while it is flat on the floor
Where is the GRFV during mid-stance with a prosthetic?
Should move through or slightly anterior to the knee and not produce unwanted flexion or extension moments
What should the tibia be like during mid-stance with a prosthetic?
In a neutral position within the socket and full vertical axial weight bearing support of the residual limb occuring
Where is the CoP during terminal stance with a prosthetic?
It moves anteriorly toward the meta-tarsal are and toe region of the foot
Where is the GRFV during terminal stance with a prosthetic?
Anterior to the knee, which will cause a posteriorly directed knee extension moment
What muscle actions are happening during terminal stance with a prosthetic?
Hamstrings are activated and flexes the residual limb in the socket. This motion will pull the body over the foot and overcomes the knee extension moment as the “sound” foot reaches the floor
Where is body weight transferred to during pre-swing with a prosthetic?
The “sound” foot
Where is the CoP during pre-swing with a prosthetic?
Continues to move anteriorly to whatever portion of the foot is still on the ground
Where is the GRFV during pre-swing with a prosthetic?
Moves posterior to the knee joint and will cause a significant knee flexion moment
What muscle actions are happening during pre-swing with a prosthetic?
To keep from dropping off the end of the toe, the patient will contract their quads and extend their limb within the socket.
What should the tibia be like during pre-swing with a prosthetic?
Anterior
What assist in moving the limb forward during pre-swing?
Pelvic rotation and hip flexion
___ is the most weight tolerant region of the transfemoral limb
The ischial tuberosity is the most weight tolerant region of the transfemoral limb
What are the characteristics of weight bearing region of the
transfemoral limb: femoral triangle?
- Anterior
- Can be lightly used as a stabilization point of the limb within the socket
- Pressure must be widely distributed, so as not to impinge on the neurovascular region
What are the characteristics of weight bearing region of the
transfemoral limb: lateral shaft of the femur?
- Primary region used to establish coronal stability of the residual limb within the socket
- Pressure is applied beginning distal to the greater trochanter, all along the shaft, and stops just proximal to the distal lateral femur
How is the significant portion of the weight support in a transfemoral limb achieved?
Soft tissue circumference compression, in conjunction with proximal distractions, that naturally occurs when weight bearing is applied in the prosthesis
What is used to control limb progression and placement during initial contact with a transfemoral prosthesis?
Hip extension
What attains knee stability in patients with a transfemoral prosthesis during loading response?
- Hip activation
- Alignment stability
- Knee component
How do you add more stability during stance with a transfemoral prosthesis?
The knee unit can be positioned slightly more posterior
What is one of the most common deviations seen in a transfemoral prosthesis during mid-stance?
Lateral trunk lean during mid stance of the prosthetic side.
What are the possible causes of the most common deviation seen in a transfemoral prosthesis during mid-stance?
- Short limb length
- Poorly fitting socket
- Hip abductor weakness
What is needed to prevent the the most common deviation seen in a transfemoral prosthesis during mid-stance?
Hip abductor strength and femoral adduction in socket
needed to prevent lateral trunk lean
What initiates knee flexion durinf pre-swing of transfemoral prosthesis?
Knee flexion initiated with hip flexion and PELVIC ROTATION
Following early gait training, a patient with a transtibial prosthesis is instructed in skin inspection of the residual limb. Over which anatomical structure is it most acceptable for the patient to observe some mild redness?
Shaft of fibula
A wound is most likely to occur at which anatomic location if a transtibial amputee using a prosthetic is encountering excessive compression and shear forces in Loading Response?
Anterior distal tibia
In the transtibial amputee utilizing a prosthesis, what acts to overcome the induced knee extension moment in Terminal Stance aiding in pulling the body over the foot of their prosthetic limb?
Hamstrings
In the transtibial amputee utilizing a prosthesis, which of the muscles act to overcome the induced knee flexion moment to keep the patient from dropping off the end of the toe in Pre-Swing?
Quadriceps
For the transtibial amputee ambulating with a prosthesis, which is crucial for achieving clearance of the prosthetic foot in Initial Swing?
Hamstring contraction to achieve adequate knee flexion
For transfemoral amputee utilizing a prosthesis, which muscles act most significantly to control the prosthetic knee against the induced knee flexion moment that occurs during Loading Response?q
Gluteus maximus
What applies to Pre-Swing in the transfemoral amputee utilizing a prosthesis?
Hip flexion occurs to facilitate knee flexion
For the transfemoral amputee ambulating with a prosthesis, a force couple occurs which leads to proximal medial and distal lateral pressures upon the residual limb during Mid-Stance. This force couple is crucial for maintaining frontal plane stability. Which muscle group serves to generate this force couple within the socket?
Hip abductors
For the transfemoral amputee utilizing a prosthesis, what typically serves to facilitate knee extension in Terminal Swing?
Eccentric contraction of hip extensors
What are the critical phases where the limb is stressed with a transtibial prosthesis?
- Loading response
- Terminal stance
- Pre-swing
What are the things to do toreduce pressure during loading response in a prosthesis?
- Reduce flexion moment
- Move CoP anteriorly
What are the critical phases where the limb is stressed with a transfemoral prosthesis?
- Loading response
- Mid stance
- Terminal stance
