The participants performed BE in the supine position.
The hip joint was maintained in neutral rotation using the
procedure recommended by Hölmich et al15). For the 45°
hip flexion position, the knee joint was maintained in 60°
of flexion with the feet on the floor, toes pointed forward,
and hands on the floor by the subjects’ sides, palms down.
The subjects lifted their pelvis until 0° of hip flexion was
reached with the pelvis in neutral alignment. The position
was held for 5 s.
Participants performed the BEHA using a pressure biofeedback
unit (Stabilizer, USA) to control the force of hip
adduction. The biofeedback cuff was placed between the
knees. The participant was instructed to perform hip adduction
to maintain a pressure of 60 mmHg. Then, with the
hip joint in full extension and a neutral position, the EMG
was recorded for 5 s.
Data of each muscle were normalized as percentages of
MVIC. Statistical analysis was performed using SPSS ver.
18.0 for Windows (SPSS, Chicago, IL). The paired t-test
was used to evaluate differences in EMG activities between
BE and BEHA. All statistical tests were performed at the
5% level of significance.