1. Slouching while sitting. Slouching typically consists of rounding the spine into flexion. When sitting this usually involves tipping the pelvic posteriorly, losing the normal lumbar extension, creating thoracic kyphosis, rounding the shoulders, and jutting the head forward.
The fix: Focus on sitting up straight with a small arch in your lower back, shoulders back, and head upright. Take frequent breaks from sitting to stand, walk, stretch, and move. Here are some easy stretches that can help and here is a video of some other ones.