Here’s how they teach you to climb the stairs with a non-motorized knee in Physical Therapy. (You need to be doing it for a while to get to where you’re “hands-free” like this woman. She must have the balance of a gymnast.)
Here’s how you do it with the $140,000 motorized knee. (Genium X4) Up the stairs “leg over leg” instead of one step at a time. All of the microprocessor controlled knees allow you to go down the stairs “leg over leg”.
Here’s what I’m currently practicing with a cane. It’s easy to go up and down the stairs if you are holding on to both handrails. It’s harder to do with only one handrail, and the cane gives you less support than the second handrail. It’s necessary to learn to do it with one handrail because many commercial buildings have wider stairs with handrails too far apart to reach with both arms.
What I’m doing in the video (at link below) to go up the stairs is to lean back to lock my knee, then lean forward to ride over the top of the prosthetic leg and place my “good” foot on the step above. I then stand up straight on the good leg, place the prosthetic on the step above that, and repeat.
When I was in Physical Therapy last Monday, I asked them to show me how to get up off the ground if I fall over using the cane. While I was on the ground trying to get up, my leg locked in the full upright position and I couldn’t free the knee. The Physical Therapists don’t have any idea of how to free it either. So I was left with a peg leg and the PT session ended.
I was able to clumsily walk back to the parking garage with my aluminum walker. I then had to take off the leg and put it in the passenger seat for the drive home.
At home I learned that you unlock the leg by plugging in the battery charger (with power), so you need to be within crawling distance of a 110V electrical outlet.
Based on the experience of my double-amputee friend who waited over a day to be discovered after falling, you need to always carry a phone or some way to call for help if you can’t get up independently. Remember that you could suffer shock if you were to fall so your experience when fully under control could be overly optimistic.
Wendy
Went to Physical Therapy today and they gave me a “speed test” to assess my fall risk.
My normal walking speed using an aluminum walker was 1.15 m/sec, fast walking was 1.50 m/sec. That put me in the range for an able bodied 50-yr-old.
I’ve timed myself outside with the 4-wheel rollator on smooth pavement and clocked 1.84 m/sec (about 4/mph).
Physical Therapist said that was “Excellent”.
Me. “I expected to be walking by now.”
Physical Therapist, "You don’t consider this to be walking?
Me. “No. I mean walking with my arms swinging, without an assistive device. I’m still short of that.”
Normative Usual (Comfortable) Pace
Clinical reference data published in large-scale studies (such as the NIH Toolbox norming study) outline these average usual walking speeds and approximate completion times across age groups:
Ages 18–29: ~1.24 to 1.35 m/s (~3.0 to 3.2 seconds)
Ages 30–49: ~1.20 to 1.30 m/s (~3.1 to 3.3 seconds)
Ages 50–59: ~1.15 to 1.25 m/s (~3.2 to 3.5 seconds)
Ages 60–69: ~1.10 to 1.20 m/s (~3.3 to 3.6 seconds)
Ages 70–79: ~1.10 to 1.26 m/s (~3.2 to 3.6 seconds; men average slightly faster than women [1.28, 1.32])
Ages 80–85+: ~0.94 to 0.97 m/s (~4.1 to 4.3 seconds; down to 0.95 m/s for older women) [1, 2]
That doesn’t seem right design-wise (the unlocking part, not necessarily the locking part). Either it’s a bug or a bad design feature. Nobody mobile will always be close enough to an outlet all the time. Heck, what if you’re traveling in Europe where there are no 110-120V outlets? Do you have to carry an adapter with you wherever you go?
Did they give you the full documentation on it? Maybe buried in there is the “trick” needed to unlock it in that case?
Google AI tells me that was an engineering decision. A reset button on the leg could be inadvertently bumped and cause the leg to lock up mid -stride, and perhaps cause a fall.
The German-made charger is rated for 100 to 240 volts, but you’d need an adapter plug for whatever foreign country you were traveling through.
I mentioned above that I didn’t think walking 2.5 mph with an aluminum walker was really walking. The Physical Therapist was disappointed with my answer.
So I asked google AI. "What percent of 70-year-old above knee amputees are able to walk at a 1.2 meter/sec pace without an assistive device?
{{ There is no exact, specific percentage published in scientific literature that directly matches this highly narrow set of criteria (70-year-olds, above-knee amputation, 1.2 m/s gait speed, and zero assistive devices). However, using normative prosthetic mobility datasets and gait speed thresholds, clinical evidence shows that the percentage is extremely low—approaching 0% to less than 5% of that specific population.
This estimate is based on the following established medical and biomechanical findings:
The 1.2 m/s Threshold: A walking speed of 1.2 meters per second is considered the standard pace required to safely cross a typical pedestrian intersection before the light changes. For context, 1.2 m/s to 1.26 m/s is the average self-selected walking speed for a healthy, able-bodied 70-year-old without an amputation. [1, 2, 3]
The Energy Cost of Transfemoral Amputations: Walking with an above-knee (transfemoral) prosthesis requires 60% to 100% more metabolic energy than normal walking. Because two biological joints (the knee and ankle) are missing, muscles in the hip and trunk must compensate entirely to advance and stabilize the limb. [1, 2]
Average Amputee Gait Speeds: In clinical trials, the average self-selected walking speed for a typical above-knee amputee using a standard socket prosthesis ranges between 0.75 m/s and 0.9 m/s. Only highly conditioned, younger individuals or those utilizing advanced osseointegrated (bone-anchored) implants typically achieve or exceed a 1.0 to 1.2 m/s average pace. [1, 2]
Age-Related Decline: According to large-scale mobility studies of prosthetic users, such as the MAAT 7 Normative Mobility Analysis, prosthetic mobility declines steeply with age. By age 70, the vast majority of lower-limb amputations are due to vascular disease or diabetes, which severely limits cardiovascular reserve and further reduces maximum walking speed. [1, 2]
Consequently, while a rare, exceptionally fit 70-year-old traumatic above-knee amputee with a high-tech microprocessor knee might achieve this pace for short distances without a cane or walker, it represents an extreme outlier rather than a statistical norm.
[image]
National Institutes of Health (NIH) | (.gov)
Mobility Analysis of AmpuTees (MAAT 7): Normative Mobility Values for Lower Limb Prosthesis Users of Varying Age, Etiology, and Amputation Level - PMC
Objective: Establish lower limb prosthesis mobility normative values across etiologies, ages, and amputation levels. Design: Cross…
[image]
National Institutes of Health (NIH) | (.gov)
A Comparison of Objectively Measured Free-Living Physical Behaviour in Adults with and without Lower Limb Amputation - PMC
Methods: 57 adults with lower limb amputation (LLA) wore activPAL3 monitors for 8 days, compared to 57 matched controls without LL…
[image]
National Institutes of Health (NIH) | (.gov)
Objectively measured movement behaviors of adult transtibial …
Discussion assessed differences in the percentage of daily dynamic activities, heart rate, heart rate reserve, and body motility d… }}
Well, at least I think I’m still in the hunt. When I was doing my in-patient hospital rehab, they kept telling me there was zero chance I’d be going up and down a 15 step stair case immediately after I left the hospital.
Just to play Debbie Downer for a moment, a story from today’s times:
Ohio Woman Sues Hospital After Wrong Leg Is Amputated
Sharon Jacks, 74, said she went into surgery for the amputation of her lower right leg last year, but her left leg was removed instead. She has accused Selby General Hospital of negligence.
All those seem slow. I average 3.6 mph or 1.6 m/s while rucking with a 40 pound pack. But then again I’ve always been accused of walking like I have somewhere to be.
That makes sense. But while a button would be risky, what about a selection in the app that controls the device? Or even a recessed control (could be something that needs to be rotated 180 degrees, or similar) inside the leg where it connects to the stump? That could never be actuated accidentally while wearing it as it cannot physically be reached at that time. It just seems bad to me that after a fall, or even a brief mishap somewhere out on the street, that it would lock in the extended position and there is NO WAY to release it until you somehow get home where the plug is located.
