Affiliations: Department of Biomedical Sciences, University of Sassari, Sassari, Italy
Correspondence:
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Corresponding author: Franca Deriu, Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari, Italy. Tel.: +39 079228294; Fax: +39 079228156; E-mail: deriuf@uniss.it
Abstract:
BACKGROUND: Peak torque (PT) is considered the most
representative parameter of muscle performance in isokinetic dynamometry
while other computable parameters such as mean peak torque (MPT), maximal
work (maxW) and mean work (meanW) are generally neglected. OBJECTIVES: This cross-sectional study reassessed whether
PT is the only necessary parameter in isokinetic testing and weighed the
contribution of each variable to muscle performance. METHODS: Thirty apparently healthy volunteers underwent
isokinetic assessment of the ankle dorsiflexors of both legs at 45 and 90°/s. Bivariate relationships and multivariate associations between PT, MPT,
maxW and meanW were examined employing Pearson's analysis and principal
component analysis (PCA), respectively. RESULTS: At both velocities, Pearson's coefficients were
very high between PT and MPT as well as between maxW and meanW (r > 0.9;
p< 0.0001) and fair-to-good (r= 0.65-0.73; p < 0.0001) between torque and work
measures. At 90°/s the PT and MPT mostly contributed to muscle
performance while at 45°/s, MPT and meanW exhibited the highest
component loadings, whereas PT performed poorly. CONCLUSIONS: Isokinetic variables contributed with
different loadings to muscle performance of ankle dorsiflexors, depending on
the angular velocity employed. In particular, work measures may usefully
complement the conventional PT-only analysis, especially in rehabilitative
settings where low speeds are recommended.
