Effects of Strenuous Exercise with Eccentric Muscle Contraction: Physiological and Functional Aspects of Human Skeletal Muscle

Abstract

Purpose: We used magnetic resonance (MR) imaging and ultrasonography in combination with a dynamometer to assess physiological and functional aspects of the skeletal muscles after strenuous exercise that included eccentric contraction.Methods: Seven male subjects (mean age, 21.7 years) performed ankle plantar ‰exion that included eccentric contraction and underwent diŠusion-weighted MR imaging for calculation of the apparent diŠusion coe‹cient (ADC) of the triceps surae muscles. We used ultrasonography combined with a dynamometer to measure the displacement of the myotendinous junction (MTJ) of the medial gastrocnemius and maximal isometric force during ankle plantar ‰exion. We also assessed the level of muscle soreness of the calf using a visual analogue scale. We measured these parameters before exercise and one, 2, 3, 5, and 8 days after exercise and examined signiˆcant changes from the pre-exercise value using repeated-measures analysis of variance with Dunnett's test for each measurement parameter.Results: One day after exercise, we observed increased muscle soreness (Pº0.001) and decreased MTJ displacement (Pº0.05); isometric force generation tended to decrease, but the change was not signiˆcant. Muscle soreness peaked 2 days after exercise (Pº0.001) and remained signiˆcantly increased until 5 days after exercise (Pº0.005). The medial gastrocnemius exhibited increased ADC value 3 days after exercise (Pº0.005), but the lateral gastrocnemius and the soleus showed no signiˆcant changes throughout this study.Conclusion: Ourˆndings suggest that muscle damage induced by eccentric contraction manifests as muscle soreness and dysfunction early after exercise and later increases water diŠusion within damaged muscle.

Techniques and applications of skeletal muscle diffusion tensor imaging: A review

“…Studies on muscle damage due to eccentric contractions or muscle tears support the in vitro results and reported an increased MD together with decreased FA in comparison to healthy controls . Using tractography the architecture was found to be disorganized .…”

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“…90 Similar results were found in the study of femoral artery ligation. However, after 10 days in that setting diffusion values were lower than the initial " (89) " (89,90,114) 5 (89) " (89,90,114) 5 (89) Stimulated # (90) " (90) " (90) Denervation of muscles # (115,116) " (116,117,118) " (115,116) # (116,117,118) " (116) " (116) Acute: Cell swelling and increased extracellular fluid due to inflammatory response Chronic: Reduced fiber diameters due to atrophy Trauma Acute: Cell swelling and increased extracellular fluid due to inflammatory response Chemical induced # (2,88,91) " (88) " (2,88,91) # (88) " (2,88,91) " (88) Chronic: Reduced fiber diameters due to atrophy Overuse 5 (120) " (123,124) 5 (120) 5 (120) Overuse in dystrophic muscles " (120) " (120) " (120) Inflammation in polymyosit...…”

“…Studies on muscle damage due to eccentric contractions or muscle tears support the in vitro results and reported an increased MD together with decreased FA in comparison to healthy controls. 123,124 Using tractography the architecture was found to be disorganized. 123 For assessing the use of DTI as a potential readout of overuse injuries Froeling et al 5 performed a longitudinal study in marathon runners in which they found an elevated MD in the biceps femoris up to 3 weeks after the marathon.…”

Ultrastructural study of myotendinous junction plasticity: from disuse to exercise

“…In fact, anatomical regions close to distal and proximal myotendinous junctions of human quadriceps femoris are the most sensitive to pain after eccentric exercise, and increased muscle soreness and decreased MTJ displacement has been observed in human gastrocnemius the day after training [52,53]. Recently, Lau and coauthors have observed how the magnitude of MTJ displacement of human biceps brachii increases from set 1 to set 10 during the first eccentric exercise bout, but no significant changes over sets were evident during a second bout.…”