Reliability of Ankle⁻Foot Complex Isokinetic Strength Assessment Using the Isomed 2000 Dynamometer.

For quantifying muscle strength in clinical and research practice, establishing the reliability of measurements, specifically to the procedures used, is essential for credible findings. The objective was to establish the reliability of isokinetic measurement of ankle plantar and dorsal flexors (PF/DF) and invertors and evertors (INV/EV) on an IsoMed 2000 dynamometer. Twenty healthy subjects (10 males, 10 females, mean age: 23.1 ± 3.1 years) completed an isokinetic measurement session. The intraclass correlation coefficient (ICC) and standard error of measurement were assessed for peak torque and work of ankle PF/DF (concentric and eccentric) and INV/EV (concentric) for the preferred and nonpreferred limb. Standardized isokinetic measurements of reciprocal PF/DF and INV/EV muscle actions were associated with ICC ranging from 0.77 to 0.98 for the majority of observed parameters. The exception was work in the eccentric mode in the ankle DF and peak torque in the concentric mode in the ankle INV on the preferred limb, where ICC ranged from 0.64 to 0.71. The IsoMed 2000 isokinetic dynamometer can be reliably employed in future studies for reciprocal ankle PF/DF and INV/EV assessment in healthy adult subjects after implementation of a familiarization session.

Assessment of postural stability in stable and unstable conditions.

PURPOSE: The aim of the study was to determine whether it is possible to assess static balance on an unstable surface using center of pressure velocities obtained with a force platform when standing on a wobble board. METHODS: The center of pressure velocities were recorded with a force platform within three days (four trials per day) in thirty young adults in three conditions: standing on a rigid surface, compliant surface, and on a wobble board. Reliability of mean velocities of the center of pressure was examined using intraclass correlation coefficients. Relationships between the three conditions were assessed with Pearson correlation coefficients. RESULTS: Intra-session reliability was excellent for standing on a rigid surface and on a compliant surface and good for standing on a wobble board. Inter-session reliability was good for all parameters in all conditions, except for poor reliability in the anterior-posterior direction in standing on a wobble board. All correlations between the same parameter in different conditions were statistically significant (P < 0.05), except for velocity of the center of pressure in the anterior-posterior direction between stance on a rigid surface and stance on a wobble board. CONCLUSIONS: Centre of pressure velocity parameters obtained with a force plate when standing on a wobble board can provide valuable information about postural stability in unstable conditions.