Temporal and biomechanical characteristics of oropharyngeal swallow in younger and older men.

As the U.S. population ages, there is increasing need for data on the effects of aging in healthy elderly individuals over age 80. This investigation compared the swallowing ability of 8 healthy younger men between the ages of 21 and 29 and 8 healthy older men between the ages of 80 and 94 during two swallows each of 1 ml and 10 ml liquid. Videofluoroscopic studies of these swallows were analyzed to confirm the absence of swallowing disorders. Biomechanical analysis of each swallow was completed, from which data on temporal, range of motion, and coordination characteristics of the oropharyngeal swallow were taken. Position of the larynx at rest, length of neck, and pattern of hyoid bone movement were also compared between the two groups. None of the younger or older men exhibited any swallowing disorders. The C2 to C4 distance of older men was significantly shorter than that of younger men, and laryngeal position at rest was lower than in younger men but not significantly so. Older men had a significantly longer pharyngeal delay than younger men and significantly faster onset of posterior pharyngeal wall movement in relation to first cricopharyngeal opening. The older men exhibited significantly reduced maximum vertical and anterior hyoid movement as compared to the younger men even when accounting for the difference in C2 to C4 distance in older men. These data support the hypothesis of reduced muscular reserve in the swallows of older men as compared to younger men. Older men also exhibited less width of cricopharyngeal opening than younger men at 10 ml volume, indicating less upper esophageal sphincter flexibility in the swallows of older men. The potential for exercise to improve reserve is discussed. Significant changes in extent of hyoid elevation and duration of cricopharyngeal opening were seen as liquid bolus volume increased.