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. 2025 Jan 13:15:1520578.
doi: 10.3389/fphys.2024.1520578. eCollection 2024.

Impact of muscle fatigue on anticipatory postural adjustments during gait initiation

Jorge L Storniolo  1   2 , Veronica Farinelli  1 , Roberto Esposti  1 , Paolo Cavallari  1   2
Affiliations

Impact of muscle fatigue on anticipatory postural adjustments during gait initiation

Jorge L Storniolo et al. Front Physiol. .

Abstract

Introduction: Prolonged or strenuous exercise leads to a temporary decrease in muscle function and performance, which interferes with activity of both prime movers and postural muscles. This effect of fatigue has been reported both for single segment movements and for locomotion. However, little is known regarding the effects of fatigue on anticipatory postural adjustments (APAs) during gait initiation, a task in which the control of focal movement should be strictly coupled to a feedforward control of posture.

Methods: We studied APAs during gait initiation in 16 healthy well-trained adult males, searching for muscle activities that precede the backward shift of the Center of Pressure (CoP). Participants stood on a force plate for about 10 s and then started walking at their natural speed. APAs were evaluated before and after a 1 min exhausting sequence of countermovement jumps. An optoelectronic system captured the heel-off events while a force plate measured the CoP position and vertical ground reaction force. Wireless probes recorded the electromyogram of trunk and leg muscles from both sides.

Results: It was observed that muscle fatigue delayed excitatory and inhibitory APAs, of about 40 and 80 ms, respectively, and a parallel delay was induced on prime movers; moreover, velocity and amplitude of backward CoP shift were reduced. Regarding APAs sign and occurrence, most of the participants showed bilateral inhibition in dorsal muscles and excitation in the ventral ones, displaying a forward "diving" strategy that was almost unaffected by fatigue. However, after fatigue, three of the "diving" participants switched to a "turning" strategy, i.e., they displayed a reciprocal activation/inhibition pattern in the dorsal muscles, compatible with a trunk rotation.

Discussion: The "turning" strategy has been previously described in untrained individuals and in a toes-amputee mountain climber, who showed a "diving" approach to gait initiation when wearing his prosthetic shoes and switched to the "turning" approach when barefoot. Altogether, these results support the idea that one and the same person may develop a repertoire of postural strategies among which the central nervous system will choose, according to the personal fitness and the constraints in which the action is performed.

Keywords: APAs; exhausting exercise; human; postural strategies; trunk muscles.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.

Figures

FIGURE 1
FIGURE 1
Starting the countermovement jump sequence: 1: standing position; 2: knees flexion to squat; 3: jump and take off from the force plate; 4: landing on the force platform; 5: pushing to jump again.
FIGURE 2
FIGURE 2
Comparison of raw (grey) and integrated (blue) EMG activity in control (left) and fatigue (right) condition on the leading side. One participant in which all muscular activities kept the same sign before and after fatigue. From the top: Erector Spinae (ES), Obliquus Abdominis (OA), Biceps Femoris (BF), Vastus Medialis (VM) and prime movers Soleus (Sol) and Tibialis Anterior (TA). Arrows mark the onset of excitation (upward arrow) or inhibition (downward arrow). Black dashed lines at time 0 mark the onset of the backward whole-body CoP shift while the horizontal lines represent the average muscle activity at baseline. The lowermost plot shows the anteroposterior CoP displacement (red) as well as the heel vertical displacement (black).
FIGURE 3
FIGURE 3
Comparison of raw (grey) and integrated (blue) EMG activity in control (left) and fatigue (right) condition on the trailing side. Same participant and graphic conventions as in Figure 2.
See this image and copyright information in PMC

References

    1. Allison G. T., Henry S. M. (2002). The influence of fatigue on trunk muscle responses to sudden arm movements, a pilot study. Clin. Biomech. (Bristol, Avon) 17 (5), 414–417. 10.1016/s0268-0033(02)00029-3 - DOI - PubMed
    1. Assaiante C., Woollacott M., Amblard B. (2000). Development of postural adjustment during gait initiation: kinematic and EMG analysis. J. Mot. Behav. 32 (3), 211–226. 10.1080/00222890009601373 - DOI - PubMed
    1. Baldissera F., Borroni P., Cavallari P., Cerri G. (2002). Excitability changes in human corticospinal projections to forearm muscles during voluntary movement of ipsilateral foot. J. Physiol. 539 (Pt 3), 903–911. 10.1113/jphysiol.2001.013282 - DOI - PMC - PubMed
    1. Baldissera F., Esposti R. (2005). Postural constraints to coupling of ipsilateral hand-foot movements. Neuroreport 16 (15), 1615–1619. 10.1097/01.wnr.0000181586.49130.48 - DOI - PubMed
    1. Behrens M., Gube M., Chaabene H., Prieske O., Zenon A., Broscheid K. C., et al. (2023). Fatigue and human performance: an updated framework. Sports Med. 53 (1), 7–31. 10.1007/s40279-022-01748-2 - DOI - PMC - PubMed