A bike leaning against a wall. A person moving their legs back and forth sitting on a chair.

Any Similarity Between Synovial Fluid and My Bike’s Hydraulic Brake System?

This morning as I was slowly rotating my wrists, gently flexing and extending my fingers, bending my elbows — basically waking up my hands and arms to get ready to do some typing — I noticed how my knees, ankles, and toes needed the same amount of joint-movement love.

Getting a range of motion in my joints

So I sat in a position where I could swing my legs freely, starting with small movements and gradually increasing the range of motion. By the time I had reached full range of motion, I probably looked like a little kid being all fidgety and unable to stay still. Sometimes I think fidgety is good.

Then I rotated my ankles which at first produced quite a bit of popping and clicking noises. Finally came the part that felt more satisfying — I flexed and extended my toes up and down, up and down.

None of this took much time, but it certainly felt good!

Connective tissues in my legs

While I was swinging my legs back and forth, I could feel the tendons and/or ligaments around my knee loosen up a bit. These are important structures that attach muscle to bone or bone to bone. They keep everything stable and functioning well. Inflammation in any of these connective tissues can cause pain and reduce mobility.

It felt good to swing my legs but reminded me that I really need to take some time to stretch my quadriceps, hamstrings, and calves to reduce the tensions pulling on my kneecap and knee joint overall.

Peaking inside my knees: bones and cartilage

All of this got me thinking about my knees in general. In addition to rheumatoid arthritis, I have osteoarthritis. It’s a double whammy for the knees.

I’ve seen the curly bone spurs that have grown on the edges of the bones that meet at the knee on x-ray films. I’ve seen the thinned cartilage inside the knee and reduced joint space on MRI scans too.

Someday I know that I will require total knee replacements, but in the meantime, I’m working to extend the life of my original knee joints.

Synovial fluid and hyaluronic acid

On different occasions, I've had hyaluronic acid viscosupplementation injected in both knees. The thick gel-like substance that, once injected, functions like extra synovial fluid in the joint. For me, this procedure has been effective and long-lasting.

Viscosupplementation was helped my knee pain

Before viscosupplementation, my knees were very painful. So painful that I couldn’t sleep in bed and had to be propped up very carefully in a recliner to find some relief from the pain. My knees seemed a bit loose, particularly when the orthopedic doctor manipulated them. And putting direct pressure on my knees — such as doing something as simple as standing still for any length of time — was excruciating.

Cycling for knee rehabilitation

In addition to first steroid injections and later hyaluronic acid injections, I started riding an indoor exercise bike to rehab my knees. At first, it wasn’t easy and I wondered if it would really help. But it didn’t take long to start to feel the benefit.

My tendons and ligaments became more supple, my muscles gained strength, and my joint felt more fluid. I even pictured the enhanced synovial fluid bathing my knees in slippery, lubricating goodness. The condition of my knees improved so much that I purchased an outdoor bike to continue the cycling, but now for fun.

Maintenance is essential: bikes and bodies

Everything I learned about my knees from the orthopedic specialist and a physical therapist has helped me to take better care of myself and prevent the need for a major overhaul (knee replacement surgery) in the near future.

Now that I’ve become an outdoor cyclist, I’ve spent time learning how to maintain my bike so that I can avoid the need for major repairs. Yesterday, I was watching a video on how to properly maintain the hydraulic disc brake system on the bike.

Similarties between synovial fluid and the hydraulic brake system

The hydraulic brake system is filled with mineral oil and if air gets into the system, the brakes will first get squishy and eventually fail to function. In my imagination, this type of squishiness and unreliability might resemble the wobbliness in my knees that my ortho doc detected years ago. In both cases, more fluid in the system would be helpful, if not absolutely necessary.

So as I was swinging my knees this morning, I was picturing the synovial fluid getting squeezed in and out of the joint, lubricating the knee, in a similar way that the hydraulic fluid gets pushed through the brake hoses on my bike. Fluidity is important to the proper function of my knees and of my bike.

Mind your ABCs and stay fluid

As a cyclist, it’s important to check the ABCs before any ride — air up the tires, brakes are working, chain is clean and lubricated. Of course, there are other necessary items — helmet, water, lights, tool kit, ID, insurance card, phone, etc — to have on the ride.

Living with RA and/or OA, it’s equally important that we check our ABCs each day — gently move those articulating joints, breathe deeply into every corner of the body, and gently stretch and strengthen the important connective tissues helping to keep our body parts connected.

Be well,

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