Muscle Stimulation for Aesthetic Body Shaping: A Comprehensive and Critical Review

Abstract

BACKGROUND Aesthetic muscle stimulation (AMS) using high-intensity electromagnetic field (HIFEM) targets skeletal muscle neurons, causing muscle hypertrophy and loss of adipose tissue, thereby cultivating a sculpted physique. Many studies have evaluated AMS for noninvasive body contouring; however, the efficacy, safety, and long-term data remain unclear. OBJECTIVE To critically evaluate the current literature on the use of electromagnetic muscle stimulation for body contouring and provide a consensus on patient selection and long-term efficacy of AMS. MATERIALS AND METHODS PubMed and Embase were searched using the terms: "HIFEM," "Electromagnetic therapy," and "muscle" or "Electrical stimulation muscle treatments" and "aesthetics." Studies involving the use of muscle stimulation for nonaesthetic/dermatologic, in vitro studies or studies involving animals were excluded. RESULTS Twenty studies in total were included [9 moderate-quality, 8 low-quality, and 3 very low-quality studies] based on the Grading of Recommendations, Assessment, Development, and Evaluation scale, representing 521 patients. Body sites evaluated included the abdomen (378 patients), buttock (156 patients), arms (22 patients), and calves (15 patients). CONCLUSION Electromagnetic muscle stimulation represents an effective therapeutic intervention for abdominal contouring that yields increased muscle thickness, and reduced abdominal fat thickness, for up to 1 year after treatment. Larger, controlled studies are needed to determine the efficacy of electromagnetic muscle stimulation alone for contouring of buttocks, thighs, arms, and calves.

Prospective study to assess the efficacy and safety of a noninvasive electro‐muscular stimulation for improvement of muscle strength and muscle toning of the extremities

“…7 More recently, toned and sculpted arms have increasingly been of interest in aesthetics, however, there are few studies evaluating the efficacy of muscle stimulation for toning and strengthening of the upper arms. 6,13,14 HIFEM was previously demonstrated to be of benefit in toning arms of 18 HIFEM-treated patients, with a mean 15% increase in biceps brachii muscle thickness 1 month following treatment and sustained at 6-month follow-up according to ultrasound measurements. This study also demonstrated a 13% and 15% decrease in adipose tissue overlying biceps brachii muscle at 1 and 6-month follow-up, respectively.…”

“…The design of this bioelectrical muscle stimulator system has revolutionized EMS technology, in that it can maximize targeted muscle contraction while minimizing energy dispersion to surrounding epidermis and dermis, thus significantly reducing the risk of burn and discomfort that have been reported to occur with conventional EMS-based devices. 6,[9][10][11][12] Furthermore, this system can target multiple muscle groups (i.e., biceps and triceps) in the same 30-min treatment period, compared to HIFEM-based systems that are only able to target one muscle group at a time thereby maximizing treatment efficiency. 7,12,16,17 The data presented herein also demonstrates efficacy for patients regardless of assigned gender and age.…”

“…1 Muscle stimulation devices such as high-intensity focused electromagnetic field (HIFEM) and electrical muscle stimulation (EMS) have become increasingly popular amongst patients interested in targeting underlying musculature to achieve their aesthetic and fitness goals. [2][3][4][5][6] EMS devices function by transmitting dense electrical currents via cutaneous electrodes that emit energy to surrounding tissue including skin receptors. 4,5,7 Prior studies have reported a risk of thermal burns and discomfort related to earlier generation EMS devices, potentially related to an inadequate dispersion of electrical current that concentrates in focal areas that eventuates in cutaneous burn injury.…”

“…4,5,7 Prior studies have reported a risk of thermal burns and discomfort related to earlier generation EMS devices, potentially related to an inadequate dispersion of electrical current that concentrates in focal areas that eventuates in cutaneous burn injury. 6,[8][9][10][11][12] More recently however, a bio-electrical muscle stimulator, which combines both magnetic and EMS technology, was cleared by the US Food and Drug Administration and contains a modified applicator design to mitigate discomfort/pain and burn risk associated with EMS alone. This device discharges direct current to produce multiple different exercise movements targeting more than one muscle group at a time.…”

“…In 2019, it is estimated that over one million body contouring treatments were performed in the United States by dermatologists, an increase of 60% from the prior year 1 . Muscle stimulation devices such as high‐intensity focused electromagnetic field (HIFEM) and electrical muscle stimulation (EMS) have become increasingly popular amongst patients interested in targeting underlying musculature to achieve their aesthetic and fitness goals 2–6 . EMS devices function by transmitting dense electrical currents via cutaneous electrodes that emit energy to surrounding tissue including skin receptors 4,5,7 .…”