June 11
Park Runs are 5 km run/walk/strolls for the family.
For more info, see my May 28 2016 blog about Park Runs.
My favorite nearby one at the Voortrekker monument closed down. It was all on tar roads.
There are usually many baby strollers, and dogs on leads. There are 3 new Park Runs to replace the one that closed down. All three are on rough terrain, and are two lap races. They all say that the terrain is not suitable for strollers, or young children.
Last week I walked one lap of the Bronberrik Park Run venue nearby. It had 3 streams to cross, and a very steep hill. It took me 1 hour 6 minutes to walk the 2.4 km. The up and down slopes slowed me WAY down.
Today I went to another new Park Run venue at Laudium. It is on a large sports ground, and has many 2 meter high berms around the various cricket fields. I zoomed around just one lap.It took me the exact same time, 1 hour 6 minutes and the distance was 2.5 km.
Again, the up and down slopes were the main time killer. Walking up a 2 meter berm, and then back down the other side is so hard for me.
A big reason NOT to run these Park Runs is the fact they are 2 lap races. Most people finish in about 45 minutes, and they usually stop timing after an hour. That means that every single person running the Park Run will lap me. There is no room to pass people in many sections, so I would end up delaying many, many people if I competed in these races.
So I am thinking about doing my own Park Run at these venues, on a Tuesday or Thursday. I need the exercise. I will miss the atmosphere of the real Park Runs though. :-(
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June 12
Today I went to the surgeon to have my stitches removed.
She said all looked great, and the biopsies were good news. Both tumors were benign Basil Cell Carcinoma.
I also chased up why the PET scan is taking so long. The Medical Aid has not given approval yet. Last time it took days. Now so far it has been 2 weeks.
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June 13
I just got news from my Medical Aid. The PET scan is approved.
About 10 minutes later I got a call from, and had a good chat with, the PET scan Ladies. It looks like the morning of June 22 for my PET scan.
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I got a bit of a shock today, while reading an article in a US Army magazine.
They took active duty Soldiers that had lost either :
1 leg below the knee. (BK).
1 leg above the knee (AK).
2 legs below the knee (BBK)
or
2 legs above the knee (BAK)
They also took about 100 un-amputated soldiers.
All of these people were required to walk (no running or jogging) fast in a straight line for 6 minutes.
The military calls this a 6MWT (Six Minute Walking Test).
The total distances walked were measured.
The distance each group averaged for 6 minutes was:
Able body: 761 m
BK: 661 m
BBK: 576 m
AK: 542 m
BAK: 482 m
I am an AK, and last week I was just able to walk 2400 m in 66 minutes. That means a double above the knee amputee can walk over twice as fast as I can. ??? What is my problem?
Of course these are young, fit, soldiers, that have received the very best treatment, training, and rehabilitation possible, and they have the best prosthetics money can buy.
The US Military plans on spending $1.76 million for each above knee amputee.
The best prosthetic knee I own, was bought on eBay.
The Army has done some major work on lower leg prosthetics for soldiers returning to active duty.
These papers are all available for download. It is like sipping water from a fire hose.
AK combat soldiers prefer pure mechanical knees while on combat patrols, but use microprocessor controlled knees once back inside the camps.
In the 6MWT the type of prosthetic knee was statistically irrelevant. Not so with the prosthetic feet used. Most military AK personnel are issued feet like these:
"carbon fiber J-shaped energy storage and return feet with shock absorbers and torque rotators"
Us civilians have to pay house like prices for these things.
Interestingly it seems as if personal preference is the single largest determining factor in the usefulness of a prosthetic foot. Users perceive differences between different foot designs with no evidence to support the differences. One foot just "feels" better than another.
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June 14
I decided to see just how far I could walk in 6 minutes.
This required changing the setup and adjustments for the prosthetic leg.
The knee locks stiff with weight on the heel, and breaks loose as weight shifts to the toe. There are three things that control when the knee breaks loose on a Total Knee 2000 or 2100..
The over center geometry of the leg.
Geometric lock settings.
The angle of the foot in relation to the leg.
The easier the knee breaks, the less energy it takes to walk, but it is far less stable when washing dishes or walking around in the house. Falls are much more likely.
For my walks around the Park Run courses, I had lowered the toe on the foot. This makes it easier to go downhills, but harder to walk up slopes. This lowered toe resulted in less stability.
The area for my 6 minute walk is flat and tared. So I wanted the foot back to level, but also wanted an easier breaking knee. So I adjusted the foot angle and the over center angle on the Total Knee 2000.
Once I was happy that I could go fast, AND not fall, I went to the section of road by my house and walked fast for 6 minutes. Using 2 different GPSs, I went 401 and 403 meters. Far short of even the double amputees tested. :-(
I went home, had lunch, and increased the knee flexion resistance, and decreased the extension resistance. This should make the leg swing forward quicker, and therefore allow more steps in the same amount of time.
Back on the road, and away I zoomed for 6 minutes. 400 meters, and 401 meters on the GPS. The same speed, no change.
I went home and installed the Total Knee 2100 from eBay. It is a much better knee, but also not a 100% knee. It leaks oil, and makes squishy noises. I got it all adjusted as best as I could, and then back to the road.
This time I did 420 and 422 meters in 6 minutes. That is a 5% increase. I didn't feel faster or better, but obviously it was.
I think I agree with the Army's result. Basically....
A good knee is essential for stability and mobility, but the type and cost of the knee is not a significant factor in speed.
A variable angle foot, a shock absorber, and an energy recovery system is more important in gaining speed.
If my goal is a one hour Park Run, then I think a variable angle foot to handle slopes better would benefit me far more than a fancy bionic knee.
Also losing some weight, and getting in better shape wouldn't hurt either. :-)
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