Hence , the psoas assists the gymnasts in maintaining hip flexion , whilst the gluteus maximus helps maintain hip extension in the prone and supine plank positions , respectively .
In contrast , the gluteus maximus is involved in hip extension and works against the hip flexors .
The psoas assists the gymnasts in maintaining hip flexion , whilst the gluteus maximus helps maintain hip extension in the prone and supine plank positions , respectively .
In contrast , the gluteus maximus is involved in hip extension and works against the hip flexors .