Effects of abdominal drawing-in during prone hip extension on the muscle activities of the hamstring,gluteus maximus,and lumbar erector spinae in subjects with lumbar hyperlordosis

[Purpose] The purpose of this study was to compare the effects of an abdominal drawing-inmaneuver (ADIM), measured using a pressure bio-feedback unit, on the activities of thehamstring, gluteus maximus, and erector spinae muscles during prone hip extension.[Subjects and Methods] Thirty healthy adult subjects (14 male, 16 female), were recruited.Subjects’ lumbar lordosis and pelvic tilt angles were measured, and based on the results,the subjects were divided into two groups: a hyperlordotic lumbar angle (HLLA) group(n=15) and a normal lordotic lumbar angle (NLLA) group (n=15). The muscleactivities of the hamstring and gluteus maximus, and of the erector spinae on the rightside of the body, were recorded using surface electromyography. [Results] When performingADIM with prone hip extension, the muscle activity of the gluteus maximus of the HLLAgroup significantly improved compared with that the NLLA group. [Conclusion] This studydemonstrated that ADIM with prone hip extension was more effective at eliciting gluteusmaximus activity in the HLLA group than in the NLLA group. Therefore, ADIM with prone hipextension may be useful for increasing the gluteus maximus activity of individuals withlumbar hyperlordosis.Key words: Abdominal drawing-in maneuver, Hyperlordotic lumbar angle, Prone hip extension