Technical application and the level of discomfort associated with an intramuscular electromyographic investigation into gluteus minimus and gluteus medius

Our current theoretical understanding of gluteus minimus (GMin) and gluteus medius (GMed) function is primarily based on cadaveric studies and biomechanical modelling. There is an absence of electromyographic (EMG) research that aims to verify this understanding, particularly in relation to the potentially unique functional roles of structurally distinct segments within GMin (anterior and posterior) and GMed (anterior, middle and posterior). The aim of this paper is to provide a comprehensive technical description for inserting intramuscular EMG electrodes into uniquely oriented segments of GMin and GMed; and to report the levels of discomfort associated with gluteal intramuscular electrode insertions. Fifteen healthy volunteers took part in a series of walking trials after intramuscular EMG electrodes were inserted into segments of GMin (×2) and GMed (×3) according to previously verified guidelines. Visual analogue scores following walking trials at comfortable and fast speed indicate that discomfort levels associated with these insertions were low (2.4±1.4 and 1.6±0.7 respectively). The technical descriptions and illustrations provided in this paper will allow trained intramuscular electromyographers to insert electrodes into these muscle segments with confidence.