The Effect of Vertical Dimension on Muscular Strength

Abstract

The purposes of this investigation were to determine 1) if there was a difference in systemic muscular strength as mandibular position was varied in apparently normal subjects, and 2) if muscle strength changed, were these changes related to a history of pain or discomfort associated with the temporomandibular joint or to a clinical examination of certain muscles at the head or neck. Twenty-seven subjects filled out a screening questionnaire designed to determine a history of pain or discomfort associated with the head and neck. All subjects were examined for muscle tenderness to palpation and occlusal discrepancies. Each subject was tested for muscular strength on the Cybex II-Data Acquisition System while their vertical dimension of occlusion was altered. The data did not support either research hypothesis. Twenty-three of 2 7 (85%) subjects had medial pterygoid tenderness and 25 of 2 7 (93%) subjects had lateral pterygoid tenderness. Only one subject was asymptomatic to muscle palpation. It appears that many apparently normal individuals are symptomatic to muscle palpation. J Orthop Sports Phys Ther 1981;3(2):57-61.