Your obliques are the muscles on the side of your waist and it is important to strengthen them in order to prevent injuries and pain especially associated with the lower back and shoulders. Our internal and external obliques enable the rotation and flexion of the trunk, whilst also stabilising the spine and preventing it from hyperextending (arching). One of the most important roles of the obliques is anti-rotation. The ability to decelerate and stabilise the spine against forces that twist it is critical to preventing spinal injury.
Spending a lot of time seated can cause these muscles to become tight and weak as when we sit poorly (rounded forwards) our spines are in flexion which shortens these muscles. If you have an anterior tilt (more of an arched back) then these muscles are forced into a stretched position which makes it harder for them to do their job.
To strengthen your obliques, here are my favourite exercises:
Toe Taps with Contralateral Press
Lying on your back, legs in tabletop, press one hand into the opposite thigh and maintain a constant pressure. Bracing your stomach muscles and making sure your back doesn't arch, extend the other leg towards the floor.
Flexing your head and shoulders off the floor, legs in tabletop, twist your torso to the opposite knee as extend the other leg. Try to keep both shoulders lifted from the floor.
Side Plank Oblique Squeeze
Lying on one side, place your elbow under your shoulder and lift hips off the ground, bring your bottom leg forwards. Inhale extend arm, as exhale bring knee to your elbow.
Lying on your back, bring yourself on one bum cheek and cross the top leg over the bottom. Pressing into your bottom arm, lift body up and try to touch your toes.
I hope you find these useful, any questions please get in touch.