Exercise number 2 is single leg squats. In strength training, the squat is an exercise that trains primarily the muscles of the thighs, hips and buttocks, hamstrings as well as strengthening the bones, ligaments and insertion of the tendons throughout the lower body. Squats are considered a vital exercise for increasing the strength and size of the legs and buttocks. Video taken from Sagittal plane(20) view. Use a superior limb(19) for stability. Keep your toes pointed straight ahead and avoid any inversion(18) or eversion(17).