Purpose: The Iowa Oral Performance Instrument (IOPI) is commonly used to measure tongue strength and endurance. The tongue, however, is reported to periodically move from its intended placement on the IOPI bulb during measurement. This study sought to determine one’s perception of tongue-to-bulb slippage with and without two anti-slip patches (Patch1 – flexible fabric, Patch2 – hypoallergenic micropore fabric) and whether measures of tongue strength and endurance differed across the three IOPI bulb conditions.

Method: 40 healthy adults were randomly assigned to perform tongue strength and endurance procedures by elevating either the anterior (n = 22) or posterior (n = 18) portions of the oral tongue. Three IOPI bulb conditions (bulb alone, bulb+Patch1, bulb+Patch2) were used for tongue strength (5 trials per condition) and endurance (3 trials per condition) assessments. A survey to assess comfort level, stability, and preference followed.

Result: The bulb+Patch1 was perceived to maintain placement and significantly reduce tongue-to-bulb slippage, F (2,76) = 43.557, p < .0001; F (2,76) = 45.451, p < .0001, compared to bulb alone and bulb+Patch2, respectively. Tongue strength [anterior: F (2, 42) = 1.467, p = .242; posterior: F (1.41, 24.004) = 0.374, p = .619] and endurance [anterior: F (2, 42) = 3.738, p = .032; posterior: F (2, 34) = 1.399, p = .261] did not differ across conditions.

Conclusion: The findings suggest that healthy adults preferred using the bulb+Patch1 rather than a bare bulb or the bulb+Patch2 due to perceived stability of tongue-to-bulb contact. Given that lingual assessments of maximal performance did not differ across the IOPI bulb conditions, the use of a flexible fabric patch when adhered to the bulb may be helpful for positional stability without impacting testing validity.


anti-slip patch, IOPI bulb slippage, tongue strength, tongue endurance, assessment