Rodolfo A Dellagrana, Fernando Diefenthaeler1, Felipe P Carpes2, Sara G Hernandez3, Wagner de Campos3. 1. Laboratory of Biomechanics, Federal University of Santa Catarina, Florianópolis, SC, Brazil. 2. Laboratory of Neuromechanics, Federal University of Pampa, Uruguaiana, RS, Brazil. 3. Department of Physical Education, Federal University of Paraná, Curitiba, PR, Brazil.
Abstract
PURPOSE/ BACKGROUND: Strength asymmetries are related to knee injuries and such injuries are frequently observed among runners. The purpose of this study was to examine whether long-distance runners have symmetric performance during knee isokinetic testing at two angular velocities. METHODS: Twenty-three healthy and well-trained male long-distance runners performed open-chain isokinetic trials for assessment of concentric quadriceps and hamstrings contractions at velocities of 60 °·s(-1) and 240 °·s(-1). Data were compared between the lower limbs at different velocities. RESULTS: Peak torque and total work were similar between the limbs. Asymmetry was observed for knee flexor power at 240 °·s(-1) (237 ± 45 W and 205 ± 53 W, in the preferred and non-preferred limb, respectively). Asymmetry indexes for flexor power were different between the velocities tested (13.1% and 2.21% for 240 °·s(-1) and 60 °·s(-1), respectively). CONCLUSION: A limb asymmetry was observed among runners for knee flexor power, mainly at higher angular velocities (240 °·s(-1)). In addition, H/Q ratios were observed to be contraction velocity dependent. LEVEL OF EVIDENCE: 3.
PURPOSE/ BACKGROUND: Strength asymmetries are related to knee injuries and such injuries are frequently observed among runners. The purpose of this study was to examine whether long-distance runners have symmetric performance during knee isokinetic testing at two angular velocities. METHODS: Twenty-three healthy and well-trained male long-distance runners performed open-chain isokinetic trials for assessment of concentric quadriceps and hamstrings contractions at velocities of 60 °·s(-1) and 240 °·s(-1). Data were compared between the lower limbs at different velocities. RESULTS: Peak torque and total work were similar between the limbs. Asymmetry was observed for knee flexor power at 240 °·s(-1) (237 ± 45 W and 205 ± 53 W, in the preferred and non-preferred limb, respectively). Asymmetry indexes for flexor power were different between the velocities tested (13.1% and 2.21% for 240 °·s(-1) and 60 °·s(-1), respectively). CONCLUSION: A limb asymmetry was observed among runners for knee flexor power, mainly at higher angular velocities (240 °·s(-1)). In addition, H/Q ratios were observed to be contraction velocity dependent. LEVEL OF EVIDENCE: 3.
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