Welcome to another study review. This one is about back pain and positive outcomes using WB-EMS. A recent multicenter study published in the Scientific Journal of Sport and Performance (Berger et al., 2025) sheds light on the promising potential of whole-body electro-muscle stimulation (WB-EMS). 

Muscle Endurance and Back Pain

Muscle endurance is the ability of your muscles to exert force over time repeatedly. It is crucial for everyday activities and overall musculoskeletal health. An endurant core, in particular, plays a vital role in spinal stability and preventing back pain – a prevalent issue affecting many people.

The Study: Impact of WB-EMS on Low Back Pain

Researchers aimed to determine the effects of a 6-week WB-EMS intervention on muscle endurance parameters, particularly of the trunk, and on subjectively perceived back pain. The study involved 81 males, 67 females with an average age of 35. These individuals were divided into two groups:

• WB-EMS Group: Participated in a 6-week WB-EMS program in commercial fitness facilities.
• Control Group: Remained inactive during the study period.

EMS Protocol:

The WB-EMS group underwent one training session per week utilizing the following specific parameters:

• Frequency: 85 Hz. This higher frequency is known to effectively recruit muscle fibers for strength and endurance gains.
• Pulse Width: 350 microseconds. This duration of the electrical impulse is sufficient to stimulate muscle contractions.
• On/Off Cycle: 4 seconds ON, 4 seconds OFF. This intermittent stimulation pattern allows for muscle activation followed by brief recovery periods.

While wearing the EMS suit, participants performed about 12 repetitions f squats, diagonal trunk flexion, standing rows, back extensions, trunk rotations, lunges, standing crunches, reverse flys, and tricep extensions.

Measuring the Outcomes: Strength and Pain Levels

Before and after the 6-week intervention, participants underwent a series of tests:

• Trunk muscle endurance (McGill Test): This gold-standard test assessed the maximum time participants could hold four isometric positions targeting different core muscle groups:
  
  • Trunk Flexion (holding a sit-up position)
  • Trunk Extension (holding a prone hyperextension position)
  • Lateral Flexion (holding a side plank position on both sides)
• Plank Test: Measured the duration participants could hold a standard plank position with alternating leg raises.
• Subjective Back Pain (VAS): Participants rated their average back pain intensity over the last 24 hours (VAS 24) and the last 7 days (VAS 7) on a 10 cm visual scale.

Results: Significant Improvements with WB-EMS

• Enhanced Trunk Strength Endurance: The WB-EMS group showed significant increases in the holding times for all four components of the McGill Strength Endurance Test. For instance, trunk flexion holding time improved from 84.0 seconds to 111.3 seconds, and trunk extension from 97.1 seconds to 119.6 seconds. The control group showed no significant changes.
• Improved Plank Performance: Participants in the WB-EMS group held the plank with alternating leg raises for significantly longer after the intervention (52.8 seconds to 67.8 seconds), indicating improved overall core endurance.
• Reduced Back Pain: Notably, the WB-EMS group experienced a substantial decrease in reported back pain. VAS 24 scores reduced from 22.5 mm to 11.2 mm, and VAS 7 scores decreased from 25.3 mm to 13.7 mm. The control group reported no significant changes in pain levels.

Statistical analysis confirmed that these improvements in the WB-EMS group were significantly greater than those in the control group.

This study provides strong evidence that a 6-week WB-EMS intervention, utilizing specific parameters of 85 Hz frequency and 350-microsecond pulse width with a 4-second on/4-second off cycle, can effectively:

• Significantly enhance strength endurance of the trunk muscles.
• Lead to a meaningful reduction in subjectively perceived back pain.

These findings highlight WB-EMS as a promising and time-efficient training method for individuals looking to improve core strength, enhance overall strength endurance, and potentially alleviate back discomfort. 

My Thoughts on the Study:

It is great to see positive outcomes using EMS. We already know that strengthening the core can help with back pain. In addition, the actual stimulation can help reduce the sensation of pain in muscles. The nature of WB-EMS being as low-impact as needed also helps prevent any further aggravation to joints.

The study, however, has many limitations. It was pretty short and was not conducted in the same center, so there could have been a variation in training protocols. Researchers did not measure any other activities outside of performing EMS. Participants did not have the same type of lower back pain. It would have been nice to have another intervention group performing well-known lower back pain exercises to see the difference. We know that doing nothing, as in the control group, will typically not help with pain and will not improve strength.

If you're interested in EMS training with me and live near Santa Monica, Brentwood, Palms, Beverly Hills, or Bel-Air, please send me an email at conradfitness@gmail.com or book a 15 min call with me.

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