Increased deep muscle activity with interference low-frequency electrical muscle stimulation: evaluation by positron emission tomography.

BACKGROUND

The effects of electrical muscle stimulation (EMS) devices that efficiently promote deep muscle contraction have not been characterized. The purpose of this study was to clarify using [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) whether interference with low-frequency EMS can promote muscle metabolism in deep.

METHOD: A total of 16 healthy males were randomly assigned to the EMS group (n = 8, age = 29.8 ± 4.1 years) or the control group (n = 8, age = 26.1 ± 5.0 years). Individuals in the EMS group received interference low-frequency EMS for 20 min each day over a span of three consecutive days as part of the pretest phase. On the measurement day, an EMS was conducted for 10 min, followed by an injection of FDG and then another EMS for an additional 10 min. The control group remained in a seated position for 10 min, after which FDG was administered intravenously. Images from PET-computed tomography were acquired in each group 60 min after the injection of FDG. Regions of interest were delineated in each muscle of the lower extremities. We analyzed the metabolism of each skeletal muscle sample by employing a standardized uptake value.

RESULTS

Compared with the control group, the EMS group showed increased glucose metabolism in both superficial and deep muscles of the trunk, pelvis, and lower extremities, as measured by FDG uptake.

CONCLUSION

This exploratory study suggests that low-frequency interference EMS may increase glucose metabolism in deep and superficial muscles of the trunk, pelvis, and lower extremities.