Reliability of concentric ankle dorsiflexion fatigue testing

Area of Science:

• Biomechanics
• Exercise Physiology
• Sports Medicine

Background:

• Assessing muscle fatigue is crucial in sports science and rehabilitation.
• Isokinetic dynamometry is a common tool for evaluating muscle function.
• Reliability of fatigue assessment protocols needs to be established.

Purpose of the Study:

• To determine the reliability of an isokinetic test for ankle dorsiflexion fatigue.
• To evaluate the Biodex dynamometer's utility in fatigue testing.
• To compare the reliability of different fatigue metrics.

Main Methods:

• Recruited 20 recreationally active young adults (10 men, 10 women).
• Utilized a Biodex dynamometer for concentric ankle dorsiflexion contractions (60°/s).
• Participants performed 50 contractions on two separate occasions, measuring total work (TW) and work fatigue (WF).
• Analyzed reliability using intra-class correlation coefficients (ICC2.1), coefficients of variation (CV), and Bland-Altman plots.
• Compared peak torque variables (e.g., 3-3 repetitions) and WF for reliability.

Main Results:

• Peak torque variables and total work (TW) showed higher reliability than work fatigue (WF).
• The "3-3" peak torque variable exhibited a low coefficient of variation (CV) of 5.6%.
• Work fatigue (WF) had a higher CV of 11.3%, indicating lower reliability.
• Bland-Altman analyses supported the reliability of peak torque and TW measures.

Conclusions:

• Isokinetic testing using a Biodex dynamometer provides a reliable method for assessing ankle dorsiflexion fatigue.
• Peak torque measurements are more reliable indicators of fatigue than work fatigue metrics in this context.
• This protocol can be confidently used in research and clinical settings for evaluating ankle muscle fatigue.