Comparison of gluteus maximus and hamstring electromyographic activity and lumbopelvic motion during three different prone hip extension exercises in healthy volunteers

• Muscle activity of the gluteus maximus (GM) was measured during three different PHE exercises.
• The kinematic data for rotation or anterior tilting angle of the pelvis were measured.
• Prone table hip extension with 90° knee flexion (PTHEK) was an effectively modified exercise.
• Finding suggested that the PTHEK can be recommended as an effective method to strengthen GM.

ObjectiveTo compare the surface electromyography (EMG) amplitude of the hip joint, including the gluteus maximus (GM), biceps femoris (BF), and semitendinosus (ST) muscles generated by three different exercises: prone hip extension (PHE), prone table hip extension (PTHE), and prone table hip extension with 90° knee flexion (PTHEK), with compensatory pelvic motions.DesignRepeated-measure within-subject intervention.ParticipantsSixteen-healthy males (mean age = 23.4 ± 2.2 years).Main outcome measuresEMG was used to collect EMG signals from the GM, erector spinae (ES), BF, and ST muscles. Furthermore an electromagnetic tracking motion analysis was also performed to measure the compensations.ResultsEMG amplitude differed significantly among the three conditions (PHE vs. PTHE vs. PTHEK) (p < 0.05). The mean GM muscle activity increased significantly during the PTHEK (70.93% and 13.75% increases in %MVIC compared with the PHE and PTHE, respectively) (p < 0.01). However, there was no significant difference in the kinematic data for rotation or anterior tilting angle of the pelvis among the three conditions (p > 0.05).ConclusionsThese results suggest that the PTHEK can be recommended as an effective method to strengthen the GM muscle without increased BF or ES muscle activities and without compensatory pelvic motions.