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Test-retest reliability of biodex system 4 pro for isometric ankle-eversion and -inversion measurement
Gediminas Tankevicius1, Doanata Lankaite, Aleksandras Krisciunas
1Lithuanian University of Health Sciences, Kaunas, Lithuania.
Context:
The lack of knowledge about isometric ankle testing indicates the need for research in this area.
Objective:
to assess test-retest reliability and to determine the optimal position for isometric ankle-eversion and -inversion testing.
Design:
Test-retest reliability study. Isometric ankle eversion and inversion were assessed in 3 different dynamometer foot-plate positions: 0°, 7°, and 14° of inversion. Two maximal repetitions were performed at each angle. Both limbs were tested (40 ankles in total). The test was performed 2 times with a period of 7 d between the tests.
Setting:
University hospital.
Participants:
The study was carried out on 20 healthy athletes with no history of ankle sprains.
Main Outcome Measures:
Reliability was assessed using intraclass correlation coefficient (ICC2,1); minimal detectable change (MDC) was calculated using a 95% confidence interval. Paired t test was used to measure statistically significant changes, and P <.05 was considered statistically significant.
Results:
Eversion and inversion peak torques showed high ICCs in all 3 angles (ICC values .87-.96, MDC values 3.09-6.81 Nm). Eversion peak torque was the smallest when testing at the 0° angle and gradually increased, reaching maximum values at 14° angle. The increase of eversion peak torque was statistically significant at 7 ° and 14° of inversion. Inversion peak torque showed an opposite pattern-it was the smallest when measured at the 14° angle and increased at the other 2 angles; statistically significant changes were seen only between measures taken at 0° and 14°.
Conclusions:
Isometric eversion and inversion testing using the Biodex 4 Pro system is a reliable method. The authors suggest that the angle of 7° of inversion is the best for isometric eversion and inversion testing.
