Static and Dynamic Postural Changes after a Mountain Ultra-Marathon of 80 km and 5500 D+

Abstract

The study aimed to investigate the effect of fatigue on static and dynamic postural stability after completing a mountain ultra-marathon. Twelve male athletes participated in the study. Postural stability was assessed before and immediately after the race. Static postural stability was evaluated on a dynamometric platform with eyes opened (OE) and closed (CE). Dynamic postural stability was assessed with OE on an instrumented plate which allowed medio-lateral oscillations. Stabilometric data were affected by fatigue in the OE condition, concerning sway path velocity (p = 0.0006), sway area velocity (p = 0.0006), area of the confidence ellipse (p = 0.0016), maximal anterior-posterior (AP) (p = 0.0017) and medio-lateral (ML) (p = 0.0039) oscillations. In the CE condition the sway path velocity (p = 0.0334), the maximal ML oscillations (p = 0.0161) and the area of the confident ellipse (p = 0.0180) were also negatively influenced. Stabilogram diffusion analysis showed in the OE condition an increase of short-term diffusion coefficients considering the anterior-posterior direction (Dfys; p = 0.0023) and the combination of the two (Dfr2s; p = 0.0032). Equally, long term diffusion coefficients increased considering the anterior-posterior direction (Dfyl; p = 0.0093) and the combination of the two (Dfr2l; p = 0.0086). In CE condition greater values were detected for medio-lateral direction (Dfxl; p = 0.033), anterior-posterior direction (Dfyl; p = 0.0459) and the combination of the two (Dfr2l; p = 0.0048). The dynamic postural stability test showed an increase of the time spent with the edges of the plate on the floor (p = 0.0152). Our results showed that mountain ultra-marathon altered static stability more than dynamic stability. An involvement of cognitive resources to monitor postural stability after fatiguing could be the explanation of the worsening in the automatic task (quiet standing) and of the positive compensation in the less automatic task (dynamic standing on the instrumented plate).

Devices and tasks involved in the objective assessment of standing dynamic balancing – A systematic literature review

“…Sagittal axis balance board (‘stabilometer’): The participant has to stand on an unstable board that has a sagittal (AP) axis ( Fig 5A ). The task is to keep the platform horizontal by balancing the weight distribution between legs [ 28 – 30 ].…”

“…The included balance board studies that focused on a single (either sagittal or frontal) axis of motion investigated only single groups. Sagittal axis balance board studies [ 28 – 30 ] had distinct clinical conclusions: a concurrent verbal task can improve balancing performance on a board [ 29 ]; significant learning occurs during six consecutive days of training on a board [ 28 ]; fatigue affects static and dynamic stability differently, static balancing decreasing significantly more [ 30 ]. Utilizing frontal axis balance boards [ 31 , 32 ], a proof of concept article provides insight into postural control changes with changing board stiffness [ 32 ].…”

Short-Term Modifications of Postural Balance Control in Young Healthy Subjects After Moderate Aquatic and Land Treadmill Running

“…CoP trajectory was collected at 100 Hz. The classical stabilometric parameters calculated from the CoP were: the area of the confidence ellipse [mm 2 ], the sway path [mm/sec], the sway area [mm 2 /sec], the maximal oscillation in the ML and AP direction [mm], (Marcolin et al, 2016 ). The analysis was performed for each subject, extracting data from each trial concerning both OE and CE in the ATM and LTM conditions.…”

“…Moreover, CoP trajectory can be modeled as a fractional Brownian motion by means of the stabilogram diffusion analysis (SDA) revealing open loop and closed loop control mechanisms of posture (Collins and De Luca, 1993 ). Different studies considered SDA as a reliable method to rigorously explore postural balance control (Collins and De Luca, 1993 ; Doyle et al, 2008 ), thus it has extensively been employed over the last 25 years (Collins and De Luca, 1995 ; Derave et al, 2002 ; Laughton et al, 2003 ; Raymakers et al, 2005 ; Marcolin et al, 2016 ). Also, the time-development of the subsequent CoP trajectories is frequently considered as an indirect outcome of random and non-stationary fluctuations in the postural balance control throughout the employment of the sample entropy algorithm (SampEn) (Roerdink et al, 2006 ).…”

“…Moreover, it has been proposed that exercise intensity affected postural balance control both when running is performed above (Nardone et al, 1997 ) and below (Derave et al, 2002 ) the anaerobic threshold. Also, prolonged running exercise influenced postural balance performance (Lepers et al, 1997 ; Degache et al, 2014 ; Marcolin et al, 2016 ). Recently, aquatic running has been considered as a surrogate to land running (Bressel et al, 2017 ).…”