Sit upright on the exercise ball, centred on it, with your feet firmly planted on the floor. Keep your upper body upright, your chest out and your core muscles firmly engaged. Hold a dumbbell in each hand in front of your chest at collarbone height, with your palms facing inwards and your elbows bent and positioned close to your torso. Now, in one fluid, controlled movement, press the dumbbells vertically upwards over your head, whilst continuously rotating your forearms outwards so that, at the top of the movement, your palms are facing forwards and your arms are straight (upper arms alongside your ears). The core actively compensates for the ball’s wobble throughout the movement, whilst the back remains stable and neutral. Any tendency to arch the lower back is consistently prevented. Then, whilst rotating the wrists in the opposite direction in a controlled manner, slowly lower the weights back to the starting position in front of the chest and repeat the movement smoothly without using momentum.
Attention:
The lower back arches excessively into a hollow back when pressing the dumbbells upwards; the shoulders are passively pulled upwards towards the ears during the lift; the dumbbells move far forwards in front of the head during the lift, rather than being guided in a vertical line above the centre of gravity; in the starting position, the elbows drop too low or splay outwards uncontrollably; the movement is initiated with momentum from the legs or the torso, rather than being performed in a controlled manner using the shoulders and arms; the head is thrust forward or the neck is hyperextended.
Lighten:
Choose a lighter dumbbell weight; position your feet significantly wider apart to create a broader and more stable base on the floor; perform the exercise whilst seated on a stable Swedish bench or a box; omit the rotation and perform a classic, straight-arm shoulder press; press the dumbbells alternately to have more control on each side.
Harden:
Choose heavier dumbbells; place your feet very close together or stand on your heels/toes to drastically reduce your base of support; lift one leg slightly off the floor throughout the entire movement (one-legged sit on the ball); place both feet on an unstable surface (e.g. one balance pad under each foot); deliberately slow down the downward movement (eccentric phase) to take 3–4 seconds.
