Oropharyngeal dysphagia, or OPD, is an impairment of the oral or pharyngeal phases of the swallow. This can impair muscle movements and coordination of the mouth, such as the lips, tongue, jaw, cheeks, palate, and also muscles of the pharynx and the entry to the airway.

Cerebral Palsy affects body movement, muscle control, muscle coordination, muscle tone, reflex, posture and balance. Depending on the part of the brain that is injured depends on how someone’s muscle tone will be effected. For people with spastic CP they have increased muscle tone because of the part of the brain that's injured. If causes very tight muscles which in turn effects the movement of the joints and of the limbs. For others who have dyskinetic CP they lose the ability to have voluntary control over their muscles, and they can have jerky and uncontrolled movement patterns.