--- title: "The Secret to Understanding Mysterious Pain" entity: "blog" canonical_url: "https://www.betterknees.com/blog/the-secret-to-understanding-mysterious-pain" markdown_url: "https://www.betterknees.com/llms/blog/the-secret-to-understanding-mysterious-pain" lastmod: "2016-08-17T21:21:00.000Z" --- [read time ~ 5 minutes] Paul sat across the table from me at our favorite restaurant. He slumped to one side, gazing down at his empty appetizer plate and moved a few remaining crumbs around with his fork. It seemed obvious that something was bothering him, so I asked if anything was on his mind. “Yeah, my knees hurt; they really hurt. And I don’t know [why](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638628/) .” Paul was semi-retired. He worked as a consultant and loved to travel. He recently returned from a two week backpacking trip that included both camping and fishing--two activities that he loved. My immediate reaction was empathy. “Oh, man, I’m sorry… When did that start?” “Yesterday,” Paul responded, sitting up a bit. “I don’t get it. I was fine on my last trip and I’ve felt fine landscaping my yard since I’ve been back.” “Oh, that’s right,” I said, as I remembered he was having a load of mulch and some small limestone boulders delivered last Saturday. “How does your yard look?” Paul brightened up a bit: “It looks fantastic. Just in time for this great weather we’re having. It’s so nice to sit out there in the evenings. But now, my knees are aching so much….” He looked down again with disgust. “So you felt fine on your trip, and you felt fine last weekend when you were weeding, mulching, and arranging the rocks?” “Yep,” Paul agreed. “I was really careful not to [bend](http://www.kertzcoaching.com/single-post/2019/04/23/What-Do-Knee-Back-Pain-Have-in-Common) over too much when I was [lifting](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.37.8932&rep=rep1&type=pdf) the stones. I didn’t want to hurt my back.” I felt myself shifting into detective mode. “So when exactly did your knees start hurting?” A little anger crept into his voice. “Monday evening when I was doing nothing! My wife and I were just sitting outside on the patio...” Paul paused, shaking his head. His knee pain seemed rather mysterious. One of the most frustrating things about hurting is not knowing [why you hurt](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638628/) . If you step on something sharp while walking barefoot, the pain causes you to spontaneously lift your foot away from the sharp object. This is because there are a lot of sensors in skin. And [these sensors are connected to pathways called nerves](http://www.ncbi.nlm.nih.gov/pubmed/18424369) --the structures that serve as the information superhighways of our bodies-- delivering messages to the brain. Nerves also deliver messages from [muscles](http://www.ncbi.nlm.nih.gov/pubmed/20591707) and from [bones](http://www.ncbi.nlm.nih.gov/pubmed/22396082) . Pain is felt when messages from the sensors within various body parts travel via nerves to the brain. But some body parts can be harmed without immediate pain because some body parts don’t have nerves. Without nerves, there is no way to immediately tell the brain that harm is happening. [Cartilage](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445147/) is an example of a body part without nerves. Cartilage is a tough substance that covers the end of the bones in your body—found in your hip, shoulder, knee, and other joints. So you can be hurting your cartilage [without knowing it](http://www.kertzcoaching.com/single-post/2018/09/12/Making-Good-Choices-Stairs-vs-Elevator) --at least for a while. When harm happens to the cartilage incredibly [tiny particles of cartilage](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638628/) shear off. They are microscopic and too small to initially be seen on imaging studies like X-rays or MRIs. These tiny particles of cartilage float around inside the joint until they eventually contact the joint lining. It may take several hours or as long as a couple of days for this to happen. When the tiny particles of sheared-off cartilage contact the joint lining, they cause irritation and inflammation. Since the joint lining has access to nerves, messages about this irritation and inflammation are sent to the brain, and [pain is finally felt](http://www.ncbi.nlm.nih.gov/pubmed/24938198) . When cartilage is damaged, pain results, but not necessarily right away. (That’s why it often feels mysterious.) Paul probably harmed the cartilage in his knees during his weekend landscaping project. What likely happened is microscopic particles of cartilage inside his knee sheared off as he was [squatting](http://www.kertzcoaching.com/single-post/Should-You-Stop-Squatting) and lifting heavy rocks. He didn’t immediately feel pain because cartilage doesn’t have nerves to deliver pain messages to the brain. However, a day or two later, the tiny particles of cartilage that sheared off contacted the joint lining--a body part that does have nerves. And by Monday evening, the nerves from the joint lining delivered pain messages to the brain at a moment when he wasn’t doing anything harmful--when he was simply relaxing in his backyard. The Mystery of Delayed Pain, Explained: - Pain is felt immediately when the body part being harmed has access to nerves (the superhighways that deliver pain messages to the brain). - Body parts that don’t have nerves--like cartilage--can be hurt without immediately knowing it. - When cartilage is harmed, eventually sheared-off microscopic pieces of the cartilage irritate the nearby joint lining, and this joint lining sends pain messages to the brain via nerves. My colleague, [Doug Kelsey](https://shoutout.wix.com/so/30NmEiUHD/c?w=60sMInP5EQMB1X9PMveMRGtfyJ-AWPouaE4ZOLVCOV4.eyJ1IjoiaHR0cHM6Ly93d3cuZG91Z2tlbHNleS5jb20vZGQta2Vsc2V5LyIsInIiOiIzMjUwMGUwNy01YmUwLTRhM2UtYzI1Zi0yYmQ0NTUzNjJhYmIiLCJtIjoibHAifQ) , PT, PhD, and I have developed [Better Knees for Life](https://kelsey-group.teachable.com/p/better-knees-for-life) , a program for people with tolerable knee pain. Better Knees for Life offers step-by-step instructions that can be performed at home with very little equipment. What people are saying about [Better Knees for Life](https://kelsey-group.teachable.com/p/better-knees-for-life) : "...well thought out, easy to understand and implement." "It is almost like a computer algorithm. (That's how clear it is!)" "BKL (Better Knees for Life) is an outstanding program -- with graded exercise programs and guidelines for advancing, and outstanding support with the Zoom sessions." "I've already recommended BKL to 2-3 friends because of the noticeable difference in reducing pain in my left knee." [Better Knees for Life](https://kelsey-group.teachable.com/p/better-knees-for-life) helps you get stronger, feel better and maybe best of all, feel more in control of your life. To learn how my clients overcome knee pain , click [here](http://www.kertzcoaching.com/single-post/Too-Busy-for-Knee-Pain) , [here](http://www.kertzcoaching.com/single-post/2019/05/07/Is-Yoga-Good-for-My-Knees) , [here](http://www.kertzcoaching.com/single-post/2019/04/23/What-Do-Knee-Back-Pain-Have-in-Common) , [here](https://www.kertzcoaching.com/post/from-knee-pain-to-crossfit-squats) , or [here](https://www.youtube.com/watch?v=O4u2CjH-F_Q) . For more information on safely strengthening your knees, read [How to Grow Strong Knee Joints](https://www.kertzcoaching.com/post/how-to-grow-strong-knee-joints) and [Can You Rebuild Knee Cartilage?](https://www.kertzcoaching.com/post/can-you-rebuild-knee-cartilage) Read more about delayed knee pain: [The 90 Day Knee Arthritis Remedy](http://www.amazon.com/Day-Knee-Arthritis-Remedy-Switching-ebook/dp/B07MD3C8V6) . For a detective to help you solve your mysterious or delayed pain problems, work with me. To learn if working together is a [good fit](https://www.youtube.com/watch?v=O4u2CjH-F_Q) for you, schedule a [Strategy Session](http://www.kertzcoaching.com/services) , by clicking [here](http://www.kertzcoaching.com/services) . [#pain](https://www.kertzcoaching.com/blog-1/hashtags/pain) [#jointpain](https://www.kertzcoaching.com/blog-1/hashtags/jointpain) [#cartilage](https://www.kertzcoaching.com/blog-1/hashtags/cartilage) [#nerves](https://www.kertzcoaching.com/blog-1/hashtags/nerves) [#jointlining](https://www.kertzcoaching.com/blog-1/hashtags/jointlining) [#delayedpain](https://www.kertzcoaching.com/blog-1/hashtags/delayedpain) [#kneepain](https://www.kertzcoaching.com/blog-1/hashtags/kneepain) As I was cleaning out my closet, I found something from roughly 18 years ago. A cycling jersey. (It’s pictured below.) But I’ve never been a competitive cyclist. When I moved to Austin almost two decades ago, I was looking to meet people in my new city. So I attended a Saturday cycling workshop. We learned bike maintenance, and then we went on a hilly group ride. I had such a great time! But the following day, I had burning, achy pain on the front of my knees. And it didn’t just go away on its own. At the time, I was struck by how something that I was told in physical therapy school – that biking is good for your knees – had somehow caused my painful knees. What was going on? When I stopped to think about the people whom I had helped in my initial years as a physical therapist, I recognized that: - Some of them reported that biking made their knees feel better. - But others who rode a stationary bike for several minutes in the clinic reported that their knees felt worse. - And sometimes they didn’t feel this increase in knee pain until the next day. Fast forward to today: My knees feel great. I enjoy rigorous hikes, weight lifting, yoga, pickleball, and yes, even hilly bike rides! And I’m frequently asked this question: Will biking make your knees stronger? When you’re biking, you’re using your leg muscles. The muscles on the front of your thighs (your quadriceps) straighten your knees. Your quadriceps start from the front of your hip and the upper part of your thigh bone. And they attach onto your shin bone, via the patellar tendon / ligament, pictured here: The hamstring muscles , on the back of your thighs, bend your knees. Your hamstrings (highlighted in teal, below) start from the bones that you sit on (ischial tuberosities) and attach on the back of your shin bones (tibia and fibula). When your quadriceps or your hamstring muscles contract , they pull your shin and thigh bones together, and this "squishes" everything in between your bones . This includes both the cartilage on the ends of your bones (labelled below as “articular cartilage”) and the synovial fluid (pictured below in yellow). When it’s strong, your cartilage is a firm substance. And when it’s healthy, your synovial fluid is thick. Stronger, healthier knees – your cartilage and your synovial fluid – are able to withstand more force (more "squishing") without pain. If your knees are not strong and healthy enough to withstand the forces from your activities, your knees will likely become sore, achy, stiff, or swollen. 4 ways that force affects your knees > If you don’t place enough force on your knees, your knees will weaken . This occurs when someone is more sedentary for a season or an extended period of time. > If you place too much force on your knees, your knees will weaken . Force that exceeds what your knees can withstand occur with: - high force applied quickly (during a single impact, such as a fall or a car accident), - low force applied over a longer period of time (staying in a certain position, like sitting or standing), or - repetitive forces (movements, including hiking, running, squatting, biking, and pickleball). > If you place the right amount of force on your knees – not too little and not too much – you’ll maintain your knee strength. This means, if you're experiencing either constant or periodic knee pain, those sore, achy, stiff, sharp, or swollen sensations don't go away. > And if you start with the right amount of force on your knees, and then gradually place more and more force on your knees, your knees will get stronger . ## The 5 step process to strengthen your knees with a bike: Step 1. Identify your biking tolerance. This involves determining the type, duration, and intensity of biking that feels good or neutral for your knees. - The type of biking you choose may be a stationary bike, a road bike, or a mountain bike. - The duration refers to how long you ride your bike. - The intensity of biking is determined by factors including how fast you pedal and the resistance you’re using. (Resistance may be set on a stationary bike. On a road/mountain bike, the resistance will depend on elevation changes and on the gears you choose.) If you get knee pain, stiffness, or swelling during or after biking, you have exceeded your knees’ tolerance for biking. Allow those symptoms to resolve before your next bike ride. (If you’d like some additional guidance with this step, watch this [video](https://www.youtube.com/watch?v=ewq722Bff2k).) Step 2. Establish your biking baseline. Using the type, duration, and intensity that you identified in step one, ride your bike 3 times per week on non-consecutive days. Repeat this during a second week. IF you experience any knee soreness, stiffness, swelling, or pain, adjust at least one biking variables (the type, duration, and/or intensity of your biking) until you can complete step two without causing knee symptoms. You’re ready to move on to step three when you have found a type, duration, and intensity of biking that you can perform three times per week for 2 weeks – without causing knee symptoms. Step 3. Advance your biking. Option A: Increase your biking duration by roughly 10 - 20%. Let’s say your baseline for biking was 20 minutes on Tuesday, Thursday, and Saturday. In this case, advance to 24 minutes on three non-consecutive days the following week. - IF your knees feel good or neutral during and after these 24-minute rides, continue advancing your biking duration by 10 - 20% in the subsequent week. - IF you experience knee pain, swelling, or discomfort following these 24-minute rides & these knee symptoms resolve completely within 36 hours, continue with three 24-minute rides the subsequent week. - IF you experience knee pain, swelling, or discomfort following these 24-minute rides & these knee symptoms persist for longer than 36 hours, do two things: (1) allow your symptoms to resolve before continuing, & (2) drop your duration by at least 10% during the subsequent week. (For example, instead of three 24-minute rides, bike for 21 minutes on three non-consecutive days.) Option B: Gradually increase the resistance while you’re biking. So if your baseline for biking was 20 minutes on Tuesday, Thursday, and Saturday, you’ll continue to ride for 20 minutes on three non-consecutive days, and you’ll gradually increase the resistance. Resistance is measured and adjusted most easily on a stationary bike. It’s possible to increase resistance while riding a bike outside by starting on a flat road, then one with some rolling hills, and progressing to steeper or more frequent elevation changes. During the week that you make a small increase in your bike’s resistance: - IF your knees feel good or neutral, continue advancing the resistance during 20-minute bike rides the subsequent week. - IF you experience knee pain, swelling, or discomfort & these knee symptoms resolve completely within 36 hours, continue with that same small increase in resistance the following week. (Hold off on increasing the resistance additionally.) - IF you experience knee pain, swelling, or discomfort & these knee symptoms persist for longer than 36 hours, do two things: (1) allow your symptoms to resolve before continuing, & (2) decrease your resistance during the subsequent week. Pro Tip: Choose either Option A or Option B – not both. My clients know this is what I frequently refer to as “limiting the variables.” If you experience an increase in symptoms after simultaneously making two types of changes, such as increasing duration and resistance, it’s difficult to interpret what your knees are saying. Are your knees saying they didn’t like how long you biked? Are your knees saying they didn’t like how hard you biked? Or are your knees saying that the duration and the resistance were fine, but both increases together were too much? Having this level of insight gives you greater clarity on how to proceed. Step 4. After three weeks of advancing your biking, repeat steps one through three. When you’re able to advance your biking (duration or resistance) during three separate weeks – without experiencing an aggravation in knee symptoms – reassess your bike tolerance (step one ). This involves determining the type, duration, and resistance of biking you can do while your knees feel good or neutral, during and afterwards. (Review how to do this within step one above.) Using your newly determined bike tolerance, ride your bike 3 times per week on non-consecutive days. Repeat this during a second week. When you’re able to complete two weeks of biking three times per week – without causing knee symptoms – you’re ready to move on to step three. (For additional guidance, review step two above.) Finally, repeat step three (above). Step 5. When you’ve achieved your desired strength gains, celebrate your results! Steps to Strengthen Your Knees with a Bike - Identify your biking tolerance. - Establish your biking baseline. - Advance your biking. - Repeat steps one through three. - Celebrate your results. Takeaways: - When you’re using your quadriceps or hamstrings, these leg muscles pull your thigh bones and shin bones together. - This “squishes” everything in between – in particular, the cartilage and the synovial fluid in your knees. - When these parts of your knees aren’t strong enough to withstand the forces from your activities, knee pain, swelling, or stiffness results. - By placing the right amount of force on your knees and gradually increasing these forces, your knees will get stronger. - Stronger knees will allow you to be more active without knee pain. Let's build Better Knees together! Laurie Kertz Kelly When you’re ready to build [Better Knees](https://betterknees.patientbase.io/services) – with personal guidance : Schedule a free 20-minute [Strategy Session](https://TheKelseyGroup.as.me/) . (Find your best time [here](https://TheKelseyGroup.as.me/) .) [Learn more about Laurie Kertz Kelly](/about) Disclaimer: The information in this blog post is for educational and informational purposes only and is not intended as medical advice. It should not be used to diagnose, treat, or prevent any health issue or disease without consulting with a qualified healthcare professional. The author of this blog and the website do not bear any responsibility for any actions taken based on the information provided in this blog.