Bottom line: I have been using this unit as part of a doctor-supervised program of physical therapy to reduce lower back pain through exercises, electrical stimulation and cold packs. While over a period of weeks my back pain has in fact been reduced to manageable levels, it is not possible to know if this is because of the exercises, the electrical stimulation or the cold packs, or some combination those treatments.Twelve years ago I had a fall that caused severe pain in my lower back that radiated down into my right leg. The neurologist I consulted diagnosed this as a bulging spinal disk in my lower back (L5/S1) pressing on one or more nerves, and offered to perform spinal surgery right away. I declined his offer and asked about alternatives, the most appealing of which involved several weeks of physical therapy (PT). Over the years, with and without PT, my severe back pain would come and go, usually managed by lying down for hours or a couple of days, and by popping OTC painkillers.Fast forward to late 2015, when the lower back pain began to interfere with my golf. My primary care provider recommended PT and, after consulting with an orthopedist, I began four weeks of PT, which has evolved considerably since 2004, with exercises that are now more varied and are much more closely tailored to my specific spinal issues than in the old days. In addition, a new (to me) technique of electrical stimulation has become common: TENS (Transcutaneous Electrical Nerve Stimulation).Having a doctorate in research psychology I tend to be skeptical of medical treatments that have not been documented by scientific research. Indeed, most of the literature on TENS acknowledges that its effects are highly subjective, hard to measure, and may vary substantially from person to person. Further, while for some people TENS may alleviate pain for short periods, TENS is widely acknowledged not to cure the underlying problem that is causing the pain. I have not found a controlled scientific study that clearly "proves" a causative connection between TENS use and reduction in pain. Further, only some individuals find TENS treatment beneficial, while others report no effect. Finally, some insurance companies will not cover purchase of TENS units or administration of TENS treatments because TENS has not been scientifically proven to stop pain, and especially lower back pain. In such a situation it is hard to say with any certainty that TENS actually works, or even to define with any precision for whom and under what conditions it may work.However, for me and many other people any non-pharmaceutical form of pain management and relief is highly desirable and greatly appreciated, so when my physical therapist recommended it I decided to give it a try as an accompaniment to my regular PT exercises. After several weeks of TENS treatments I find that my back pain is reduced, though some--perhaps most--of that reduction may be due to the exercises as opposed to the TENS.My series of Medicare-paid PT sessions has ended and, while I am able to do almost all of the exercises at home, I was interested to learn that I could get a small, personal version of the large TENS unit my physical therapist uses. Several of the staff in my PT center told me inexpensive units were readily available and that I should consider getting one for my personal use; my PT center does not sell these units, so the staff have no financial or other incentive to recommend purchasing one.After reading the on-line literature about and reviews of TENs units I found that they were available at prices ranging from $25 to several hundred dollars and decided to purchase an inexpensive one so I wouldn't lose much if it broke or failed to work.This TENS unit comes with a handy carrying case that includes the unit, electrodes, connecting wires, battery and instructions. I was actually impressed with the instructions, which were pretty detailed and clear and were written in much better English than is typical for most electronic goods made in China. Some of the controls are digital, which means they can be controlled with relative precision. However, setting the level of electrical stimulation is accomplished via tiny analog knobs, which are not very precise and are a bit difficult to manipulate. The settings on this unit range from 0 to 8; I found that 3 or 4 was the right level for me, and due to other reviewers' comments I have not tried putting the level up to, say, higher than 5. There appear to be substantial individual variations in what is perceived as stimulation as opposed to pain, which is a good reason to have a professional show you how to use the unit and help you establish your own appropriate level of stimulation.The unit's adjustments include several types of stimulation (continuous, pulsing, variable). There is a useful timer and a handy belt clip that allows one to use the unit while walking around the house. One of the staff at my PT center noted that this little $27 unit even has a couple of features that the center's $400 hand-held unit lacks. Of course, the PT center's even larger and much more expensive non-portable TENS machine has more bells and whistles overall than this little unit does. The electrodes that come with the unit are about 1" square, which is suitable for smaller areas of the body like leg or arm or shoulder; upon the advice of my PT staff I purchased electrodes that are about 2" x 4," which are more suitable for larger areas like the back, and are the size of the ones used by the PT staff on my back.Alert: I am not an MD so I cannot offer medical advice. However, I can observe that these units can deliver a pretty hefty jolt of electricity if used improperly, so make sure you learn to use the unit correctly under the supervision of a physician and/or qualified physical therapist. Before using my new unit I took it to one of my PT sessions and had the staff show me how to use it properly. All of these TENS units have lots of warnings in their accompanying product literature, so be sure to follow ALL of these warnings carefully, along with the instructions of your doctor or physical therapist. These personal units are not toys, and should absolutely not be handled or operated by children or physically/mentally compromised adults.After 12 sessions of physical therapy, including exercises and TENS stimulation and ice packs, I am feeling a noticeable reduction in lower back pain and some improvement in flexibility, though it is impossible to say how much improvement is due to TENS vs exercises vs ice packs. Now that my PT sessions have come to an end I plan to continue to do the exercises and to use my little portable TENS unit at home.If, after consulting your doctor and/or a qualified physical therapist you and they think TENS may be helpful to you, I would suggest buying an inexpensive unit like this one to try it out, or trying a TENS treatment from a physical therapist or doctor.I paid for this unit with my own money and I have no personal or business relationship with the vendor, manufacturer or Amazon.So thankful I purchased this. I had experience with a smaller, less powerful unit bought at CVS, but even that was helpful. This TENS unit is a lifesaver for me in helping to manage my pain issues. The best part is that you can set it and then there are safety covers that protect the unit, so you don't have to worry about settings being accidentally changed while wearing. I often wear it on continuous mode for hours, even leaving the house with it all strapped on and hidden under my clothing. It has been a God-send. In my opinion, this device is more effective than pain medications and muscle relaxers (for those of us who have built up a tolerance to medications), and is certainly less toxic to the system.If you're wondering if this is powerful enough, this is one strong little unit that runs on a single 9 volt battery. I never set this higher than about 3.5 and it goes up to 8! You can set it as gentle or strong as you want. You can choose different modes and tweak adjustments. I purchased a set of rechargeable 9 volt batteries with a small recharging unit and I honestly can't believe how long the batteries last. (EBL 840 9V Battery Charger with 4 Pack 600mAh Li-ion Rechargeable 9 Volt Batteries)UPDATE Aug. 2017: I've used this unit for 4 months and it got me through a really horrible time where I was suffering from knotted shoulders and trapezius with terrible trigger points that were so bad I was unable to sleep on either shoulder for nearly 4 full months. The pain radiated down into my upper arms and it felt like I needed rotator cuff surgery due to the muscles all cramping so much. I was seeking chiropractic and massage therapy once a week and taking pain meds around the clock. I finally had to have cortisone injections in 5 major trigger points, but the ONLY thing that truly helped break the cycle of pain and get me through the worst of it before the cortisone was this TENS machine. I can not recommend this unit enough for those suffering from pain.UPDATE Sept. 2017: Well, unfortunately, the unit quit working a few days before I had to travel, so I was forced to buy another one to replace it. The digital display all works, it cycles through everything, but the wires and pads do nothing. I even tried the wires and pads from my new unit, but to no avail. Although I had to wait a month to go through the manufacturer, I was fully refunded for the product and my new one works fine. My original review was 5 stars, dropped to 3 while I waited for a refund, and am leaving it at 4 stars because the seller did take care of the issue and the new unit seems to be working fine (although I did just get it a month ago). I will update if anything changes, but I still stand by the fact that it is a terrific unit when it works!For the four patches that came with it, I was able to move them in several spots and use them for the duration needed for each without even needing to use the ‘electrode gel’ recommended but I bought anyway. Saved the patches for next time and will use with gel if not sticky enough. Slight red marks still present after a few minutes, but skin is not irritated with a rash or texture only color (if that makes sense).I recommend trying it in different locations/ placements SLOWLY turning the knobs because the body/ nerves can be very touchy. One side of mine could go all the way up while the other was never able to, specifically my shoulders and neck area. When it gets to those awkward joints it’s hard to know where to place the patches, and that’s what I mean when you don’t know until you know turning that dial going Ahhhh reaching for it again. But that is not a device error, just how the body works and a suggestion to be mindful about. (-:This Tens Units really helps with my lower back pain and sciatica due to RA, bone spurs, and degenerative disks. Easy to use. The pads have remained sticky through several uses. I always put them back on the plastic after using. Sometimes I use both leads, but one lead is enough to reduce the pain. The effects last over several days. Makes it much easier to do my stretches and range of motion exercises. Also use it on my shoulders to reduce pain. The physical therapist I went to recommended getting a Tens Unit for home use. This one has definitely been a good purchase and given good results.Great material as per usual from crz. Loved that it had pockets too but the waistband, although wide just kept rolling down with any movement. There was no pull cord either so I couldn’t try tightening or anything.The seams are coming apart from the material in different areas after only one wash.The fabric is great (not see-through, not shiny) and so soft! Compared to the butterluxe leggings I actually like this fabric better - it has slightly more structure and better pockets. Yes, they do creep up on your thighs (I'm always pulling them back down) but isn't that part of wearing leggings/bike shorts?Estos pantalones cortos están muy bien. En mi caso, tuve que pedir una talla menos porque son un poquito holgados. La calidad es insuperable. Uso desde hace años esta marca y no la cambiaria por nada, además tiene muchos modelos.Love these shorts for running. I average about 5 miles, and never had to pull them up or adjust. Will be purchasing more.