What can cause impaired bladder contractility? antibiotics, nsaids, poor posture or being sedentary for over a year?

I don't see any of these causing weak bladder contractility which can lead to urinary retention. Diabetes & chronic overdistension from prostate enlargement or pelvic floor weakness leading to bladder prolapse in women are common causes. Spinal cord problems are less common causes. Medications like sudafed causes temporary urinary retention, especially in men with prostate enlargement.