Knee position sense and knee flexor neuromuscular function are similarly altered after two submaximal eccentric bouts

Abstract

Purpose This study examined eccentric-induced fatigue effects on knee flexor (KF) neuromuscular function and on knee position sense. This design was repeated across two experimental sessions performed 1 week apart to investigate potential repeated bout effects. MethodsSixteen participants performed two submaximal bouts of KF unilateral eccentric contractions until reaching a 20% decrease in maximal voluntary isometric contraction force. Knee position sense was evaluated with position-matching tasks in seated and prone positions at 40° and 70° of knee flexion so that KF were either antagonistic or agonistic during the positioning movement. The twitch interpolation technique was used to assess KF neuromuscular fatigue. Perceived muscle soreness was also assessed. Measurements were performed before, immediately (POST) and 24 hours after (POST24) each eccentric bout. ResultsNo repeated bout effect on neuromuscular function and proprioceptive parameters was observed. At POST, central and peripheral factors contributed to the force decrement as shown by significant decreases in voluntary activation level (-3.8 ± 4.8%, p < .01) and potentiated doublet torque at 100 Hz (-10 ± 15.8%, p < .01). At this time point, position-matching errors significantly increased by 1.7 ± 1.9° in seated position at 40° (p < .01). At POST24, in presence of muscle soreness (p < .05), although KF neuromuscular function had recovered, positionmatching errors increased by 0.6 ± 2.6° in prone position at 40° (p < .01). ConclusionThese results provide evidence that eccentric-induced position sense alterations may arise from central and/or peripheral mechanisms depending on the testing position.

Contralateral versus ipsilateral protective effect against muscle damage of the elbow flexors and knee extensors induced by maximal eccentric exercise

“…8 Some studies reported that proprioception, such as position sense (PS), was impaired following eccentric exercise that induced muscle damage. [8][9][10][11] Only three studies have investigated the IL-RBE on proprioception. 8,10,11 For example, Paschalis et al 8 reported that changes in PS and joint reaction angle (JRA) after maximal eccentric exercise of the KF were significantly smaller and recovered faster after the second bout compared to the first bout that was performed by the same muscle 4 weeks earlier.…”

“…[8][9][10][11] Only three studies have investigated the IL-RBE on proprioception. 8,10,11 For example, Paschalis et al 8 reported that changes in PS and joint reaction angle (JRA) after maximal eccentric exercise of the KF were significantly smaller and recovered faster after the second bout compared to the first bout that was performed by the same muscle 4 weeks earlier. In contrast, Da Silva et al 11 found no significant difference in PS of knee joint between the first and second bouts of submaximal eccentric exercise of the same KF separated by 1 week.…”

“…Impairment of proprioception affects motor control, leading to injuries during exercise or everyday life activities 8 . Some studies reported that proprioception, such as position sense (PS), was impaired following eccentric exercise that induced muscle damage 8–11 . Only three studies have investigated the IL‐RBE on proprioception 8,10,11 .…”

Submaximal fatiguing eccentric contractions of knee flexors alter leg extrapersonal representation

“…These observations led the authors to suggest that the increase in position-matching errors following fatiguing eccentric protocols was due to exercise-induced alterations in the central nervous system [ 22 , 26 ]. Specifically, in a recent experiment, our group concurrently examined the effects of a submaximal fatiguing eccentric protocol of knee flexors (KF) on neuromuscular function and position sense at the knee using bilateral position-matching tasks [ 27 ]. During such tasks performed in seated position, errors increased in the presence of central fatigue immediately following the fatiguing eccentric protocol, but reverted to baseline levels 24 h post-exercise [ 27 ].…”

“…Specifically, in a recent experiment, our group concurrently examined the effects of a submaximal fatiguing eccentric protocol of knee flexors (KF) on neuromuscular function and position sense at the knee using bilateral position-matching tasks [ 27 ]. During such tasks performed in seated position, errors increased in the presence of central fatigue immediately following the fatiguing eccentric protocol, but reverted to baseline levels 24 h post-exercise [ 27 ]. Acute eccentric-induced position sense alterations were attributed to disturbances in the integration and/or processing of positional signals at the somatosensory cortex level due to the actions from group III-IV afferents.…”