The mechanism for urinary continence is not obstructive. Ultrasound and video data indicate that 3 striated muscle forces contract in opposite directions around a competent pubourethral ligament (PUL) to close the distal urethra and bladder neck. If PUL is loose, both mechanisms are invalidated, because striated muscles need a firm insertion point to function efficiently. The patient now loses urine on effort. Referring back to original research, the various steps involved in a midurethral sling operation are analysed with a view to optimizing surgical results. These include an analysis of what causes postoperative urinary retention, why the components of the distal closure mechanism need repair and simple steps to avoid nerve and blood vessel injury.