ORIGINAL ARTICLES   

Gazzetta Medica Italiana Archivio per le Scienze Mediche 2009 August;168(4):233-40

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: English

Influence of force output intervals and instruction conditions on repeated muscular endurance evaluation

Demura S. ¹, Miyaguchi K. ², Aoki H. ³

¹ Kanazawa University, Ishikawa-Ken, Japan. 2 Ishikawa Prefectural University, Ishikawa-Ken, Japan 3 Graduate School, Kanazawa University Ishikawa-Ken, Japan

Aim. This study aimed to examine the influence of output intervals and instruction conditions on the evaluation of repeated rhythmic muscular endurance.
Methods. Fifteen healthy young male adults performed maximal repeated rhythmic grips for 6 min under the following two instruction conditions with two and three sec intervals: 1) “Squeeze as hard as you can freely (Ex1)” and 2) “Squeeze as hard as you can quickly at the cue of a beep (Ex2)”.
Results. The two sec interval showed a more marked decline of exertion forces than the three sec interval in the first half of the measurement period. The decline rate in Ex2 was small in the three sec interval, and more than half of the subjects could continue gripping at 80% MVC for more than 1 min. In the two sec interval, correlations between instruction conditions were high for the decline rate and the final force value. It may be difficult to evaluate a declining tendency of force output just after the start of measurements for the three sec interval. On the other hand, the influence of the instruction condition on evaluation parameters was smaller in the two sec interval than in the three sec interval.
Conclusion. When evaluating muscular endurance by repeated rhythmic gripping, the following instruction may be effective: “Squeeze as hard as you can quickly at the cue of a beep every two sec”. Therapists should understand that in various physical function tests, not only the grip test, appropriate instructions are essential to obtain accurate measurements.