True about pharyngeal diveicula are all excep

Killians dehiscence is a weak pa in the posterior wall of the pharynx which lies at the level of vocal folds or upper border of the cricoid lamina and is limited inferiorly by the thick cricopharyngeal sphincter.Pharyngeal diveicula results due to outpouching of the dehiscenceTwo pas of the inferior constrictor has different nerve supplies, propulsive thyropharyngeus by the pharyngeal plexus and the sphincter cricopharyngeus by the recurrent laryngeal nerve so there is possibility of neuromuscular incoordination. If cricopharyngeus fails to relax and the thyropharyngeus contracts bolus of food may be pushed backwards and tends to produce a diveiculum