Repeated maximal eccentric actions causes long-lasting disturbances in movement control

Abstract

This study examined acute and long-lasting effects of fatigue and muscle damage on fast and accurate elbow flexion and extension target movements (TM) with eight male students. An isokinetic machine was used to perform 100 maximal eccentric and concentric elbow flexions at 4-week intervals. Movement range was 40-170 degrees in eccentric exercise (ECCE) and 170-40 degrees in concentric exercise (CONE), with an angular velocity of 2 rad s(-1). TM was performed in sitting position with the right forearm fixed to lever arm above protractor. Subjects performed TM in horizontal plane (amplitude 60 degrees ) by visual feedback of movement from a television monitor. Surface EMG was recorded from the biceps brachii and triceps brachii muscles. TM measurements and serum creatine kinase (CK) determinations were conducted before, after, 0.5 h, 2 days, and 7 days after both exercises. Blood lactate was taken before, after, and 0.5 h after the exercises. Both ECCE and CONE led to a large decline in maximal voluntary contractions, but the recovery was slower after ECCE when it remained incomplete even until day 7 post-exercise. Lactate increased (P < 0.001) similarly after both exercises. Delayed-onset muscle soreness peaked on day 2 and CK peaked on day 7 after ECCE. Exhaustive eccentric exercise of agonistic muscles impaired the flexion TM performance, and had a long-duration modulation effect on the triphasic EMG activity pattern of flexion and extension TM. In the acute phase, the observed changes in performance and in the EMG patterns are suggested to be related to metabolic changes via III and IV muscle afferents. The delayed recovery, on the other hand, may be related to problems in the proprioceptive feedback caused by muscle damage.

Impact of Loughborough Intermittent Shuttle Test versus soccer match on physiological, biochemical and neuromuscular parameters

“…In fact, both LIST and match induce signiWcant glycogen depletion in skeletal muscle Wbers (Krustrup et al 2006;Nicholas et al 1999), although the eVects of glycogen depletion on high intensity/short duration performance should only occur below critical levels. Alternatively, considering the distinct levels of motor coordination involved in the actions of jumping and sprint running, the repeated eccentric actions performed during the match might cause disturbances in movement control (Bottas et al 2005) aVecting more pronouncedly the running performance, which likely rely to a greater extent on muscular coordination than a single jump or leg curl and extension.…”

Adaptive changes in motor control of rhythmic movement after maximal eccentric actions

“…The rhythmic extension/flexion movement (RM) test was performed with a specific apparatus equipped with a potentiometer constructed in Neuromuscular Research Center of Jyväskylä University (Bottas et al, 2005). RM was performed in a sitting position with the right forearm fixed to the lever arm in the horizontal plane above protractor.…”

“…Our recent study of goal-directed target movement (Bottas et al, 2005) revealed that eccentric fatigue of the elbow flexor muscles affected mostly the flexion movement. On the other hand, the extension movement performance was maintained despite modifications of the triphasic EMG activity pattern up to day 7 post-exercise.…”

Gender Differences after Downhill Running for Voluntary Isometric Contractions of Knee Extensor Muscles using Surface EMG

“…Others showed neuromuscular disturbances following eccentric exercise with elbow flexors (13,14) and quadriceps femoris muscles (15). There is further evidence of selective damage of fast twitch muscle fibers after eccentric exercise in elbow flexors (16) and gastrocnemius muscle (17).…”