Summary of Responses to AK Hip Flexion Impairment
Custom Prosthetic Services Ltd.
Description
Collection
Title:
Summary of Responses to AK Hip Flexion Impairment
Creator:
Custom Prosthetic Services Ltd.
Date:
7/3/2002
Text:
Thank you to all who responded to my original post. It is repeated below, with summarized responses following it:
I have a middle age trans femoral amputee client who has been using a prosthesis for about ten years now. Surgeons have detected a metastatic liposarcoma mass around his psoas major muscle on the affected side, and
to remove it the muscle must go also.
He has been counseled that this will significantly reduce his hip flexion power, however, post surgical physiotherapy will help to some extent.
I am looking for some suggestions regarding any prosthetic design or componentry that may help offset or mitigate this probable hip flexor
impairment. I will summarize and post any replies.
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I heard about this at an orthotic course, but it might work: What about creating a waist belt with elastic webbing from the waist belt to the near distal end of the socket? That way, it could act as an assist to hip flexors. There is a fancy name for the orthotic version, and someone sells
it, but I can't remember. Contact Horton if you want more information.
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You may have to consider two ways to initiate hip flexion:
A: Hyperlordosis in late stance; initiation of hip flexion similar as in a HD, a side joint (hip) with an extension (or hyperextension-) stop, a pelvic crest pad (in order to make good contact between the hyper-extended pelvis and the side joint) may serve to initiate flexion.
If this is not enough:
B. Equip that side joint with a spiral spring being loaded in extension/hyperxtension, releasing energy for swing (hip flexion) initiation after toe off.
Do I know a specific component? Sorry : No, you might have to design one yourself.
I am surprised, however, that removal of the iliopsoas seems to be a sufficient clinical solution. Would have assumed that the surgeons are much more radical, once they find metastatic tissue. You may end up with a HD, I am afraid.
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What kind of knee units are you using?
You don't need hip flexors to ambulate. Try it. Put an AK at toe off orientation, and then just hold the anterior brim and pick it up (superiorly) off the floor. It automatically flexes.
Where you will run into trouble though is if you have knee flexion resistance (usually hydraulic or a really stable knee alignment). Then you will not be able to accelerate the shin fast enough to clear the ground in swing phase. constant friction will work great though with minimal friction.
Since you are a Canadian CP, I am assuming you learned orthotics also in school, so you can imagine how a para ambulates without hip flexors. They just use the pendulum effect of the weight of their lower extremity in an
open kinetic chain.
The gait training way of using stiffer knees is to have the patient sit down on the ischial seat to initiate knee flexion prior to swing phase. What this does is use posterior pelvic tilt to load the socket posterior to the knee and also to use the hip Y ligaments to cause the knee to initiate flexion of the knee. This is more tricky than the hip hiking described above.
Oh, he would have a hard time running though because he cannot forcefully flex for quick cadence. Walking would be no problem though since small accelerations of the rectus as a knee flexor would be adequate for
walking.
Also remember he still has rectus femorus and sartorius. He only needs to assist gravity in initiating the hip flexion. you don't need a lot of hip power. To take the first step, he should use his sound side rather than starting with the ipsilateral side as some of the gait training texts teach. This requires a bit more balance. Pelvic thrust and lumbar
flexion also can accelerate the limb (how HDs ambulate).
Making the limb lightweight works against him so such a heavy knee will make the pendulum affect better.
----------------------------------------------------------
I have a middle age trans femoral amputee client who has been using a prosthesis for about ten years now. Surgeons have detected a metastatic liposarcoma mass around his psoas major muscle on the affected side, and
to remove it the muscle must go also.
He has been counseled that this will significantly reduce his hip flexion power, however, post surgical physiotherapy will help to some extent.
I am looking for some suggestions regarding any prosthetic design or componentry that may help offset or mitigate this probable hip flexor
impairment. I will summarize and post any replies.
---------------------------------------------------------------------------------------
I heard about this at an orthotic course, but it might work: What about creating a waist belt with elastic webbing from the waist belt to the near distal end of the socket? That way, it could act as an assist to hip flexors. There is a fancy name for the orthotic version, and someone sells
it, but I can't remember. Contact Horton if you want more information.
--------------------------------------------------------------------------------------
You may have to consider two ways to initiate hip flexion:
A: Hyperlordosis in late stance; initiation of hip flexion similar as in a HD, a side joint (hip) with an extension (or hyperextension-) stop, a pelvic crest pad (in order to make good contact between the hyper-extended pelvis and the side joint) may serve to initiate flexion.
If this is not enough:
B. Equip that side joint with a spiral spring being loaded in extension/hyperxtension, releasing energy for swing (hip flexion) initiation after toe off.
Do I know a specific component? Sorry : No, you might have to design one yourself.
I am surprised, however, that removal of the iliopsoas seems to be a sufficient clinical solution. Would have assumed that the surgeons are much more radical, once they find metastatic tissue. You may end up with a HD, I am afraid.
--------------------------------------------------------------------------------------
What kind of knee units are you using?
You don't need hip flexors to ambulate. Try it. Put an AK at toe off orientation, and then just hold the anterior brim and pick it up (superiorly) off the floor. It automatically flexes.
Where you will run into trouble though is if you have knee flexion resistance (usually hydraulic or a really stable knee alignment). Then you will not be able to accelerate the shin fast enough to clear the ground in swing phase. constant friction will work great though with minimal friction.
Since you are a Canadian CP, I am assuming you learned orthotics also in school, so you can imagine how a para ambulates without hip flexors. They just use the pendulum effect of the weight of their lower extremity in an
open kinetic chain.
The gait training way of using stiffer knees is to have the patient sit down on the ischial seat to initiate knee flexion prior to swing phase. What this does is use posterior pelvic tilt to load the socket posterior to the knee and also to use the hip Y ligaments to cause the knee to initiate flexion of the knee. This is more tricky than the hip hiking described above.
Oh, he would have a hard time running though because he cannot forcefully flex for quick cadence. Walking would be no problem though since small accelerations of the rectus as a knee flexor would be adequate for
walking.
Also remember he still has rectus femorus and sartorius. He only needs to assist gravity in initiating the hip flexion. you don't need a lot of hip power. To take the first step, he should use his sound side rather than starting with the ipsilateral side as some of the gait training texts teach. This requires a bit more balance. Pelvic thrust and lumbar
flexion also can accelerate the limb (how HDs ambulate).
Making the limb lightweight works against him so such a heavy knee will make the pendulum affect better.
----------------------------------------------------------
Citation
Custom Prosthetic Services Ltd., “Summary of Responses to AK Hip Flexion Impairment,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 5, 2024, https://library.drfop.org/items/show/219353.
