Relationship between Measures of Isometric and Isotonic Endurance

H Clark, W Barber, W Irwin


Whereas it is commonly accepted in the limb literature that isometric and isotonic contractions utilize different patterns of motor unit recruitment, most of the research examining the relationship between lingual endurance and speech/swallowing function have utilized isometric contractions only. In a series of two experiments, the current study reveals the independence of endurance obtained during isotonic and isometric contractions. Given that many speech and swallowing movements are characterized by isotonic contractions, future research may identify a stronger relationship between isotonic endurance and speech/swallowing function than has been detected by previous studies utilizing measures of isometric endurance.