“Effects of electrical stimulation program on trunk muscle strength, functional capacity, quality of life, and depression in the patients with low back pain: a randomized controlled trial. Rheumatol Int. 2009 Jun;29(8):947-54.”
Right now this is my favorite electric muscle stimulation (EMS) study with regards to low back pain as I read it soon after I came up with my own protocol, which was fairly similar.
The aim of this clinical trial was to evaluate the effects of electrical stimulation (ES) program on trunk muscle strength, functional performance, quality of life (QOL) in the patients with chronic low back pain (CLBP). A total of 41 patients with definite CLBP were included in this study. These patients were randomized into two groups. Group 1 (n = 21) was given an ES program and exercises. Group 2 (n = 20) was accepted as the control group and given only exercises. Both the programs were performed 3 days a week, for 8 weeks in the out-patient department. The patients were evaluated according to pain, disability, functional performance, endurance, quality of life, depression. The muscle strengths were measured with a hand-held dynamometer. There were significant improvements for all the parameters in two groups after the treatment. Except depression and social function, the improvements for all the parameters were better in the ES group than in the control group. We observed that ES program was very effective in improving QOL, functional performance and isometric strength. In conclusion, we can say that ES therapy provides comfortable life functions by improving muscle strength, functional performance and QOL.
They did 4 electrodes on the rectus abdominus region and partial on the obliques for 15 minutes using 50 Hz, 50 ms phase time, and 70-120 mA until “apparent muscle contraction was established”. They used a 10 second on 10 second off pattern, then flipped the patient over and did the same on the lumbar erector spinae muscles. This group of patients was compared to a control group 3 times a week for 8 weeks. The EMS group did exercises as well as electric muscle stimulation, while the control group did only exercise. Researchers conclusions were as follows:
“Both the programs were performed 3 days a week, for 8 weeks in the out-patient department. The patients were evaluated according to pain, disability, functional performance, endurance, quality of life, depression. The muscle strengths were measured with a hand-held dynamometer. There were significant improvements for all the parameters in two groups after the treatment. Except depression and social function, the improvements for all the parameters were better in the ES group than in the control group. We observed that ES program was very effective in improving QOL, functional performance and isometric strength. In conclusion, we can say that ES therapy provides comfortable life functions by improving muscle strength, functional performance and QOL.”
|Exercise & EMS start||Exercise & EMS at 8 weeks||Exercise only start||Exercise only at 8 weeks|
|Pain VAS (out of 10)||8||1||7.7||4|
|Oswestry Disability Index(sec)||36.66||6.57||37.22||19.22|
|Extensor Endurance Test(sec)||35||150||59.9||83.5|
|Abdominal Endurance Test(sec)||98||236||104.5||144.88|
|50 meter walking time(sec)||40.71||23.42||39.22||32.16|
|Pain Disability Index||19||4||22||9.5|
|Back extensor strength(kg)||7||16||7||11|
|Back flexor strength(kg)||6||16||6.5||10.5|
As you can see from the above table, adding EMS to the core muscles of those with low back pain led to reductions in pain and the increases in strength, endurance, and function were substantial. The electrode placement I do is nearly the same. I put 4 electrodes on the rectus abdominus (usually in a diagonal pattern), 2 electrodes more lateral than they do to better target obliques and transversus abdominis, and just 2 on the lumbar region, which feels plenty sufficient at high intensity (as much as is tolerable rather than just what is comfortable). I also use a 4 channel machine so I can stim all the muscles at once rather than having to do the front first and later the back. I do a 10 second on and 50 second off period, 120 Hz and 300 uS pulse width for 12 minutes. [Update to add on a Globus machine I set the pulse width to 450 uS] My combination of parameters closely approximates the “Russian Stim” duty cycle used on olympic athletes and recommended by Charlie Francis as what he used with his sprinters. While perhaps coming across a white noise to patients with low back pain, a therapist understanding the specific EMS parameters is critical to getting an adequate treatment response. EMS performed this way is in fact exercising the muscles very intensely, and the parameters need to be adjusted as you would adjust exercise sets, reps and resistance level when weight training.
My patients report this immediately decreases pain better than classic TENS patterns I used prior and does more to increase abdominal strength than any conventional exercise I have ever tried, all while the spine is kept in a neutral posture with no external load. I think combining the treatment with exercise for extremity strength and spine awareness is certainly ideal, but I find the EMS to significantly boost both pain reduction and strengthening. The best part is that high quality machines are very affordable, so the treatment can be done at home while watching TV. As such, therapy time in the clinic can be maximized with whole body strength, endurance and spine awareness/motor control exercises.
Thanks for reading my blog. If you have any questions or comments (even hostile ones) please don’t hesitate to ask/share. If you’re reading one of my older blogs, perhaps unrelated to neck or back pain, and it helps you, please remember Spinal Flow Yoga for you or someone you know in the future.
Chad Reilly is a Physical Therapist, obtaining his Master’s in Physical Therapy from Northern Arizona University. He graduated Summa Cum Laude with a B.S. Exercise Science also from NAU. He is a Certified Strength and Conditioning Specialist, and holds a USA Weightlifting Club Coach Certification as well as a NASM Personal Training Certificate. Chad completed his Yoga Teacher Training at Sampoorna Yoga in Goa, India.