I don't think

so as even said the title of my project
is no mechanical redundantly for

gay coming station
intensive real amputees.

And I worked with Dr and
he taking on this project.

Their chance to amputees have lost a large
part of the locomotor system which

includes Lemley their ankle joint
their natural joint mobility and

direct muscular control of the ankle
joint and also local pro players that.

Studies that have been done
on joint kinematics and

RAT have shown that they are capable
of returning to limb level goals.

After they've been injured and
so understanding

how kinematics change after something like

an amputation can help us understand how
someone would recover after an injury.

Human locomotion has often been
characterized as a highly redundant system

with more degrees of freedom that are
necessary to actually solve a problem and

are lower limbs have three major joints.

And likely and leg orientation have
been found as goals for locomotion.

Can a magic motor and he says that there
are multiple joint configurations for

I single desired goal.

But with amputees I question becomes
how can you cordon these joint.

To achieve a limb level goal.

If you're missing one.

So a simple way to quantify motor
identity is by looking at the variance

in the joints and comparing it to
the various at the limb level and

what we've seen in the past that
deviations at one joint can be

counteracted by other joints and
this would.

Allow decreased variance
at the limb level.

So important a variance you might wonder
if you have higher variability it

will allow flexibility into the system so
you can make a compensation from just at

the lower variability could cause
increased death on the body.

So the purpose of our study was to
understand the differences in healthy

gait and also try to understand how
the nervous system of an amputee

Courtney's their joint
kinematics to compensate for

the loss of the ankle and
then hopefully in the future.

This would lead to better
gait rehab strategies.

So if you're the type of
person that like has been

getting closer years than I so
I'm going to spoil it for you and

hopefully this will allow you
to follow along a little easier.

So what we found was that
the sound limb of the N.P.T.

is effected by the Concho
lateral amputation.

And that there are main joints
in the limb level goals of

between the legs of the ankle to work
to maintain similarity to one another.

Also we think from this that the return
to preempt Tahsin can imagine it

may not be as important as maintaining
symmetry between the two legs so

from this week can maybe is feeling that
we have should focus on strategies for

the sound limb to prevent overuse injuries
and then also I talked about redundancy we

did find the amputees could use
redundancy destabilised the same

way that an able bodied
subject can back beginning.

We had the size that they mean prosthetics
that limb level goals would be

preserved to able bodied just like we
had seen in the study on rodents and

within the prosthetics and
we thought that the joints would

act to preserve invariant
leg orientation and likely.

So really having the joint level
really low van't at the one level.

Fire method we had five you know.

Lateral traumatic chance to be P.T.S.
and seven able body control

subjects we had them walk for
three thirty second trials on the split.

At one point two meters per second.

And we collected kinematic
data on them using by time and

this just shows a simulation of what
that data looked like that we collected.

So in order to kind of quantify the data
that we collected we chose to metrics

the first being R. squared coefficient
of determination and also variance.

So our squared.

We're using it as an approximated for

determining the similarity
between two kinematic trees so

on its most basic level here I show
the angle angle of the control subjects.

Next I have a prosthetic ankle angle.

And what we're doing is we're just
comparing these two to check trees so

how similar are they.

And if they're really similarities so

I'm comparing here a control ankle able
bodied angle to this down angle of

an amputee we would see an Irish
grid greater than point five.

But when they're not.

There are squared is
less than point five So

here I've got a prosthetic ankle plotted
against a control ankle check three.

And then for our next.

Check a variance we
define that as a measure

of the average variability
from step to step.

So here I'm showing multiple
cycles of a subject and

we just take the variance
over all those so good.

Back to my hypothesis.

Where we said that limb level calls would
be preserved in the prosthetics part

of the N.P.T. gave this shows a graph
of the leg orientation and red.

Used to be the prosthetic
side of the N.P.T.

and in gray we see the control
side here you've got.

The gate cyclic percentage of the gate
cycle in the angle in degrees and

I use are squared to compare the two and

what we found is that they are very
similar with a very high R. squared value.

So from this we can say
that there preserving

back to the able bodied day
on the prosthetic side.

So then we looked at leg length then
we found something totally different.

So again that controlling grey
red is the prosthetic side and

what we found is that they're
not similar at all but

are scared values less than point five So
this kind of went.

Interesting.

So we decided that we would start
looking at the down side of the N.P.T.

and we found again for legs Orient.

OK so here in black I show the down side.

And then again graze the control and
what we found was that.

The sound side was very similar to the
able bodied guys to their preserving on

their sound side for leg orientation but
when you look at leg on the sound side.

They're not similar so.

It's kind of got interested in what was
going on between the legs of the N.P.T.

So what will happen when you make
the comparison between the prosthetic and

the sound side and what we found
is that for Lego orientation.

The two trajectories were very similar.

So this if they were symmetrical for
leg orientation and

then we can compare for leg length.

We found that the prosthetic in-town
thighs were also some I still

remember I showed you before the press
that excited wasn't similar to control and

the sound side wasn't so
much the control for likely but

here we're seeing that they
are symmetrical for likely.

This kind of cool.

So it got to wondering what
are the actual joints doing.

So at the ankle angle we found
kind of what we expected was

that the weren't similar which kind of
makes sense because you're placing a norm.

Human ankle was a prosthetic ankle.

Hell a very when you look
at the knee in the head.

We see that they're really similar.

So between the two legs.

They're symmetrical for these two joints.

So in order to kind of
understand how the amputees

are choosing Islam level goals we
decided to look at the variable.

So here on the Y. axis we have a variance
and then across X. axis are the different

like tag first in the press that
expired in this town in the control and

in blue I show the average
total variance per joint and

then yellow is the variance at the leg for
light orientation.

And what we found is that
the variance at the joint level is

always higher than the variance
at the leg orientation level.

And another thing is that the variance
across the different like type.

Doesn't differ so this says to us that
the N.P.T. on the prosthetic side is

actually achieving the same
level of performance for

a lead orientation as what the control
subject is doing because we don't see

any more or less variance for
like going Taishan.

So we do the same thing for leg length and
we find that there are no differences

between the different leg types for
the variance.

So again even though we found that

the leg trajectory is very different than
what are able bodied subjects are doing.

We don't see them doing it with
any more or less variance so

they're performing at the same
level as the able bodied subjects

are going back to what I just showed you.

We have positive sides first.

Leg orientation and leg length would
be preserved in the prosthetic side of

the N.P.T. and we had to partially
that that because we found

the leg orientation was preserved
to the able bodied state.

However leg.

It was not preserved.

So.

From this we kind of think that the N.P.T.
is probably occupying a different region

of the tax base than what our able bodied
subjects were doing because we found

symmetry at the leg orientation level
the limb level and the joint level and

this may be a type of protective mechanism
that they may be to use in gauging and

because you've seen in the literature that
asymmetry during gait can lead to other

health problems such as low
back pain osteoarthritis and.

Risk of false.

We accepted our help.

This is to say that redundancy would be
used to stabilize them level goals because

we found similar level advances for
leg orientation and likely.

So again the says that even though
these are doing leg differently than

able body controls are there cheering
the same level of performance.

And also in P.C.'s are capable of
cordoning just two joints to stabilize

invariant leg or in Taishan unlikely and
and we've seen this in the a chair with

injured cats who are capable after
an injury of Courtney in their joints to

stabilize invariant brain Taishan and
likely.

The limitations of our study were that we
didn't have a single standardized price

these just for each subject that would
be kind of difficult to do but for

a future where I think it would be really
interesting to look at general amputees

and how they compensate for their loss and
the difference is that we might see

between them in a traumatic M.P.T. because
they've never had the chance to perform as

an able bodied subject and
then also a chance for moral in P.T.S..

How do they achieve a low level goal when
they only have one joint and then Tony

is actually doing some work with this data
right now looking at forces in moments and

how they differ between the legs of
the N.P.T. and also different this.

Between able bodied subjects.

So again.

My take home message is that symmetry and

gait may be more important
than returning to the gate.

And also in P.T. said capable of
ridge using redundancy destabilised

is in my references.

And I like to say thanks to young you my
advisor for all this help and guidance.

On this project and in jest for
for their countless hours

helping me with Matlab and Megan Tony as
well as data collection and a million for

their input and help on this project and
also Susie for help with collection and

data for
his help in recruitment of subjects and

the subjects you generously
produced the question

thank you.

Yes you

are not.

But yeah that would be a good day.

No I did not.

There is a really good point.

In the future.

I think it would be good to try and

tease out what what are the effects
of the dynamic response verses.

I sat on something interesting that I did
notice was that if they had a day and

you had one subject.

No I had more than one but
you could tell like with a dynamic

response that they had
more motion in the ankle.

And someone that had a stiffer ankle but

it would be good to see
that in the future.

Definitely

yes

I mean I

only looked at it briefly I would
say that they were similar across

the subjects that mean it's
representative of each individual that

there

is.
There's definitely a very a delivery and

that was a concern that I had so
it would be good to go back and

analyze those differences but
time was a fact.

Good

thanks.