EMG Activation of Gluteal Musculature During Exercises With and Without Resistance

The gluteus medius (Gmed) and gluteus maximus (Gmax) muscles are important components in the
treatment of many lower limb injuries. Recent studies have evaluated a myriad of exercises
which activate the Gmed and Gmax, but limited research remains on exercises involving
resistance and the role of the TFL. The purpose of this study is to evaluate Gmed, Gmax, and
TFL percent maximal voluntary isometric contraction (%MVIC) and perceived exertion in
healthy and low back pain patients while performing exercises with and without resistance.
Methods: A convenience sample of healthy subjects and patients diagnosed with non-radicular
low back pain will be recruited. Exclusionary criteria will include: current low back or
lower extremity injury (healthy group), pregnancy, history of hip surgery, and radicular
symptoms. Surface electromyography will be used to quantify the activity level of the
gluteal muscles and TFL while performing a series of 8 exercises with and without
Thera-Band® Resistance Tubing and Stability Trainer. The maximal voluntary isometric
contraction (MVIC) will be established for each muscle group and the order of exercises
performed will be randomized to minimize the effect of fatigue. Following the completion of
each exercise, the patient will rate their perceived exertion level on the Thera-Band®
Resistance Intensity Scale for Exercise (RISE). The EMG signals will be smoothed and
rectified and analyzed using a root-mean-square algorithm. Clinical Relevance: The results
of this study will allow clinicians to better prescribe exercises, proven to activate the
gluteal muscles and limit the TFL involvement, in the treatment of low back pain.