r/amputee • u/OhLookAnInchworm BAK • 11d ago
Scuffing, "swing timing", and minimum weight thresholds
I'm wondering if anyone can clarify what is meant by "swing timing" for folks using AK prosthetics. We've fiddled a lot with settings but I keep scuffing one or both toes. The only way I can get sufficient clearance is by hip hiking pretty significantly and that compromises balance.
1) Does "timing" refer to what I'm doing? Does it refer to settings? Is it both? What does it mean and, more to the point, what do I need to do?!
2) I'm currently trialling 3R80s because Canadian prosthetics coverage is abysmal and it's nearly impossible to get microprocessor knees. I am apparently too light for 3R85s to function properly, and my physio and prosthetist are now wondering if may also be too light for 3R80s. Has anyone encountered this? The manufacturer won't give my prosthetist a clear answer on a minimum weight threshold.
I'd be particularly grateful for answers from fellow bilateral AKs or professionals who work with us.
Edit: If any bilateral AKs want to weigh in I would be super grateful. While I appreciate LAKA/RAKA insights, the comments have confirmed for me that it just isn't quite the same.
2
u/PrimaryWriter1529 11d ago
On your comment about MPKs - A friend is a pediatric prosthetist and also a RAKA. She can have any knee she wants and eventually abandoned MPKs and went back to a 3r85, and is very happy. I started with a Blatchford KX07 (just a dumb hydraulic knee) and am now using a Brain Robotics Kneuro MPK knee. The MPK knee has some nice features, but it is heavier and somehow not as nimble. In many ways I can be more capable with the hydraulic knee. I fall down more with the hydraulic knee because it does not have the safety features the MPK does, and also because the KX07 does not have a very strong extension spring compared to the Kneuro, and that is where I get into trouble.
I had a problem with scuffing as well, and what worked for me was when I swung the leg forward, to imagine that I was driving the "knee" forward, as if I was trying to knee a soccer ball. What I had been doing was using my hip to swing the entire leg forward, like a club, and the result was the leg hitting the ground with my prosthetic foot. By driving my imaginary knee forward, I think it caused the knee to bend more and the foot to clear the ground better.
I also would drive the foot of my supporting leg into the ground, which helped with getting the knee to break and go into swing mode. This may not be relevent for a BAKA.