2015 ISAKOS Biennial Congress ePoster #2612

Evaluation of the Belt Electrode Skeletal Muscle Electrical Stimulation System Using Positron Emission Tomography

Hitoaki Numata, MD, Kanazawa, Ishikawa JAPAN
Junsuke Nakase, MD, PhD, Kanazawa, Ishikawa JAPAN
Takeshi Oshima, MD, PhD, Kanazawa, Ishikawa JAPAN
Hiroyuki Tsuchiya, Kanazawa, Ishikawa JAPAN
Kanazawa Univercity, Kanazawa, Ishikawa, JAPAN

FDA Status Cleared

Summary: We evaluated the effectiveness of the belt electrode skeletal muscle electrical stimulation (B-SES) system using positron emission tomography (PET). PET demonstrated that exercise with B-SES increased skeletal muscle activity of hip abductor, flexor, and extensor muscles as well as the knee flexor and extensor muscles.

Abstract:

Objectives:
Lower extremity muscle weakness in athletes after lower limb trauma or surgery can hinder return to sports. The associated muscle atrophy may lead to deterioration in performance after return to sports, and rehabilitation after trauma or surgery is a key determinant affecting patient return to prior activity levels. In recent years, the belt electrode skeletal muscle electrical stimulation (B-SES) has been developed, and is capable of inducing all lower limb skeletal muscles to contract simultaneously. However, few studies have evaluated skeletal muscle activity with B-SES. Conventionally, muscle activity during various types of sports has been studied using electromyography (EMG), but only superficial muscles as well as a limited number of muscles can be investigated by EMG because the equipment needs to be attached to the body for measurement. Therefore, we investigated whether positron emission tomography (PET) could evaluate all activity of all skeletal muscles in the body simultaneously. Recently, muscle activity during exercise has also been examined using PET with 18F-fluorodeoxyglucose (FDG), since FDG accumulation in the muscle can be used as a surrogate marker for glucose uptake and muscle activity level. The purpose of this study was to evaluate the effectiveness of the B-SES system using PET.

Methods

Ten healthy males (mean age, 26.0 years) were divided into 2 groups, a control group and an exercise group. The subjects in the control group were kept in a sitting position for 10 min and FDG (37 MBq) was intravenously injected. After the injection, the subjects remained seated for another 10 min. In the exercise group, subjects exercised using the B-SES system for 20 min daily for three consecutive days. On the measurement day, they exercised for 10 min, received an injection of FDG, and exercised for another 10 min. PET-computed tomography images were obtained in each group 60 min after the FDG injection. Regions of interest (ROI) were drawn in each lower extremity muscle. We compared skeletal muscle metabolism in the two groups using the standardized uptake value (SUV), which was calculated to quantitate the FDG uptake per unit volume of the muscle tissue. The Student’s t-test was used to evaluate differences in muscle volumes and SUVs for all ROIs between the control and exercise groups. The minimum level of significance was set at P < 0.05.

Results

FDG accumulation in the gluteus maximus, gluteus medius, gluteus minimus, rectus femoris, vastus lateralis, vastus medialis, vastus intermedius, sartorius, semitendinosus, semimembranosus, and biceps femoris in the exercise group was significantly higher than that in the control group (P < 0.05). However, there were no significant differences in FDG accumulation in the iliopsoas, tibialis anterior, soleus, and gastrocnemius between the two groups.

Conclusions

Unlike previous evaluations of skeletal muscle activity using EMG, our evaluation using PET allowed concurrent assessment of the effect of B-SES on all lower leg muscles, including the deep muscle. In this study, we demonstrated that exercise with B-SES increased skeletal muscle activity of hip abductor, flexor, and extensor muscles as well as the knee flexor and extensor muscles.