Knickerbocker's theory does not explain why the first firm in an oligopoly decides to undertake FDI rather than to export or license. (Hills, 2008) also suggested that the imitative theory does not address the issue of whether FDI is more efficient than exporting or licensing for expanding abroad.
Isometrically, the lower back, the upper back, the abdominals, the trunk muscles, the costal muscles, and the shoulders and arms are all essential to the exercise and thus are trained when squatting with the proper form.
Erector Spinae. Although you may not think of the squat as a back exercise, the erector spinae muscle group contracts isometrically -- without shortening and lengthening -- during both the downward-movement and upward-movement phases of the exercise.