How to Use a TENS Unit on a Sore Knee After a Long Day

By 7 p.m. on a day when I have been on my feet, my left knee is the loudest thing in the room. I am 63, retired after 31 years as a union pipefitter, and the orthopedist who diagnosed the osteoarthritis at 58 did not tell me it would get easier after supper. It does not. The knee stiffens on the stairs in our split-level house, aches when I stand up from the recliner, and lets me know about it after Tater and I finish our evening walk. Tater is my 9-year-old yellow Lab mix, about 70 pounds, and he still wants two walks a day. That daily walk is the reason I care about this at all.

I am not a doctor. I am a guy who has tried the heating pad, the ice pack, the compression sleeve and a pile of advice from people who meant well. About nine months ago, my orthopedist said a TENS unit was reasonable to try, and my physical therapist showed me where to put the pads. I bought the AUVON 24 Modes TENS Unit. I use it in the evening, in the recliner, for 20 to 30 minutes, a few nights a week. This is how I do it, what it feels like, and where it falls short.

Step 1: Get cleared before you get clever.

Before I put a pad on my skin, I asked my orthopedist and my physical therapist. That is not a disclaimer I am tacking on. It is the first step. I have osteoarthritis in my left knee. My right knee had a meniscus trimmed back when I was 47, and it is the good one now. I have never had a knee replacement and I am not scheduled for one. My situation is mine, not yours.

A TENS unit is not for everyone. If you have a pacemaker or another implanted device, if you are pregnant, or if you have heart trouble, ask your doctor before you buy one. I am not qualified to clear you. My orthopedist knew what was going on with my knee and said it was reasonable to try. My PT showed me pad placement around the kneecap, never directly over it. That handoff mattered more than any listing on Amazon. If your doctor says no, the answer is no.

Step 2: Set up before you sit down.

The AUVON has 24 pre-programmed modes. I have tried maybe four. I am not a guy who needs all 24, and I do not think you need to be either. The unit runs on a rechargeable lithium battery, so I am not hunting AA batteries at 8 p.m. There is a power indicator, and I check it before I settle in. If it is low, I plug it in behind the end table and use it the next night. That is the whole charging routine.

I wash my hands and dry the skin around my left knee. Lotions and oils do not help the pads stick, and a pad that lifts off is a pad that is not doing its job. The AUVON pads are the upgraded gel type and they have held up well for me when I keep the skin clean and put them back after use. I do not stretch them or fold them over on themselves. I also check for cuts, scratches or a rash. If the skin is broken, I skip that night. A TENS pad is not a bandage.

Step 3: Put the pads around the kneecap, not on it.

My PT showed me this with a dry erase marker on a piece of paper, and I still do it the same way. One pad goes above the kneecap. One goes below, or one on each side, depending on where the ache sits that night. The important part is that the pads surround the kneecap. They do not sit on the kneecap itself. I keep them on clean, dry skin and press them down flat.

I do not move the pads while the unit is running. If I need to shift one, I turn the unit off first. That sounds obvious until you are in a recliner with a dog barking at the mail truck and you try to adjust a pad without looking. I learned to slow down. The pads are sticky enough when they are clean, but they are not going to stay put if I am twisting around.

Carol, my wife, is the one who notices when a pad is curling at the edge. She is a retired school office administrator and has no knee trouble of her own, but she has a good eye for a pad that is about to quit. If the pad will not lie flat or the gel is dirty, I replace it. A weak pad makes the whole session feel like a mosquito with a battery. That is not the point.

Step 4: Keep it gentle and give it 20 to 30 minutes.

I start gentle and stay gentle. The AUVON has 24 modes, but I do not chase a strong sensation. I want a gentle buzz that I can feel without my leg jumping. If it stings, bites or makes me tense up, I shut it off and try again another night. More is not better here. I have had nights when the knee was angry after fishing at Mark Twain Lake, and I still did not push it. I would rather do 20 quiet minutes than 10 minutes of gritting my teeth.

Twenty to thirty minutes is my window. I set it up in the recliner, put my feet up, and let it run while the evening news is on. I do not walk around, I do not go up and down the stairs, and I do not take it into the bathroom. I have never used it in the pool, the shower, the boat or in bed. Water and a TENS unit do not mix in my house. Neither does falling asleep with it on. Carol has caught me close to dozing more than once and made me shut it off.

I use it a few nights a week, not every night. If I have had a long day on the stairs or a fishing day where I stood on the dock too long, that is when I reach for it. On a normal Tuesday, I might skip it. The point is not to rack up sessions. The point is to take the edge off so I can get through the evening and get some sleep.

Twenty to thirty minutes in the recliner, a few nights a week, is what I actually kept doing. The rest was noise.

Step 5: Shut it down, check your skin, and write down what happened.

When the time is up, I turn the unit off before I peel the pads. I remove them slowly and look at the skin. If it is red in a pattern that matches the pad, I leave that spot alone for a day. If it is itchy or raised, I do not use the unit again until I talk to my PT. I have not had a bad reaction, but I have had a little redness after a long session. That is my cue to shorten the next one.

I put the pads back where they belong, plug the charger in behind the end table, and leave the unit there. If I put it in a drawer, I forget about it. The AUVON lives next to the recliner because that is where I use it. The charger stays plugged in. Boring, but it works.

I keep a small note on the calendar. Not a diary. Just a line: date, how long, and whether the knee felt better, the same or worse the next morning. After a couple of weeks, I could see a pattern. The nights after Tater's long walk were the ones where I used it. The nights after I sat too long were the ones where the ice pack did more. That note is how I stopped expecting the TENS unit to do a job it was never going to do. It is one tool in the evening, not a switch that turns off arthritis.

What Else Helps

The TENS unit is not the only thing I use, and it is not the first thing I reach for every night. If my knee is puffy after fishing or a long walk, I use the Vive knee ice pack wrap cold for 15 to 20 minutes. If it is stiff in the morning before the first walk with Tater, I warm it in the microwave and use it warm. The gel packs live in the kitchen freezer and the wrap hangs on a hook in the laundry room. That is a separate routine from the TENS unit, and I do not use them at the same time.

For walks, I wear a Modvel compression sleeve on my left knee. My PT suggested trying light compression, and I have used one for about 18 months. It is a slip-on sleeve, no straps and no hinges. It is not heavy support. It is just a layer that makes the knee feel less loose on the sidewalk. On fishing days, when I am getting in and out of the jon boat or standing on the dock, I wear the DR. BRACE ELITE for the side stabilizers and the straps. That one stays in my tackle bag. I do not wear it to bed and I do not wear it in the pool.

At night, I sleep with the Contour Legacy foam pillow between my knees. Carol found it after I kept waking up at 3 a.m. with the knee aching from my knees pressing together. I have used it for about two years. It travels with me on overnight fishing trips. None of this is fancy. The combination is what lets me do the things I want to do, which is walk Tater, get in and out of the boat, and take the stairs in my own house without planning every step.

Who This Is For

This is for the person who has a sore knee at the end of the day and has already tried the obvious stuff. You have a heating pad. You have an ice pack. You have a sleeve in the drawer that you forget to wear. You are not looking for a lecture. You are looking for one more thing to try in the evening, after the day is done and before bed. If your doctor has cleared you, the AUVON is a reasonable option to look at.

It is also for the person who wants a simple device with 24 pre-programmed modes and a rechargeable battery, not another screen to fool with. I am 63. I do not want a setup that requires a phone and an account. I want to sit down, put the pads on, and turn it on. That is what I do. It is not for someone who wants a cure. I have osteoarthritis. It does not go away because I put pads on my knee for 20 minutes. The AUVON makes the evening easier some nights. That is the claim I am making, and it is the only one I can back up.

Who Should Skip It

If you have a pacemaker or another implanted device, or you are pregnant, or you have heart trouble, skip it until your doctor says otherwise. If you have broken skin, a rash or an open cut around the knee, skip it that night. If you cannot feel your feet or you have nerve damage, do not start without your doctor and PT. I am not the person to clear you.

If you want a device that works while you walk the dog or clean the gutters, skip this one. It is a sit-down tool. If you are not willing to keep the pads clean and replace them when they stop sticking, skip it. If you think 24 modes means 24 different fixes, skip it. I use maybe four modes, and I could probably get by with two. The unit is only as good as the routine around it.