Department of Exercise, Sport and Lifestyle Medicine

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Browsing Department of Exercise, Sport and Lifestyle Medicine by browse.metadata.advisor "Arnold, Sarah"

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    The change in postural control in highly trained trail runners following a short, competitive, off-road time trial
    (Stellenbosch : Stellenbosch University, 2023-03 ) Price, Nicholas; De Waal, Simon; Arnold, Sarah; Stellenbosch University. Faculty of Medical and Health Sciences. Dept. of Exercise, Sport and Lifestyle Medication.
    ENGLISH ABSTRACT: Research on acute effects of trail running (TR) induced fatigue and postural control (PC) in highly trained trail runners is scarce. Therefore, the aim of this study was to measure the change in select postural control variables following a short, real-world, trail run time trail (26km; +900m) in a sample of highly trained trail runners. Thirteen (N=13) male, highly trained trail runners (age: 30.00  5.58 years old; weekly running: 65.00  6.45 kilometres) participated in this study. Participants completed five postural control system (PCS) tests before and after a short, real-world, TR time trial (26km +900m ascent). Balance tests included a Modified Clinical Test of Sensory Interaction of Balance (MCTSIB), Single Leg Modified Clinical Test of Sensory Interaction of Balance (SLMCTSIB) and a Star Excursion Balance Test (SEBT). Postural sway and sway frequencies were measured via a Gyko Inertial Measurement Unit (Microgate, Italy) during four different stance conditions; firm surface with eyes open (FO), firm surface with eyes closed (FC), compliant surface with eyes open (CO), and compliant surface with eyes closed (CC). Jump tests included a Countermovement Jump Test (CMJ) and Single-Leg Countermovement Jump test (SLCMJ). Jump height and flight time were measured using OptoJump (Microgate, Italy) and two Logitech web cameras (30 fps). Tests for normality were performed using the Shapiro-Wilk test. A combination of paired samples t-tests and Wilcoxon signed-rank tests were used to identify differences in mean scoresbefore and after the time trial (significance flagged as p<0.05). Statistically significant increases (p<0.05) in mediolateral sway were observed in stance conditions FO, FC and CC while anteroposterior sway showed significant increases (p<0.05) for stance conditions FO, and CO during the MCTSIB. A statistically significant increase (p<0.05) in mediolateral sway was observed in the SLMCTSIB for the FO stance condition. A significant decrease in reach length was observed during the SEBT in the anterior movement only (p<0.05) and only on the right foot. No statistically significant changes (p>0.05) were observed for maximal and mean jump height and time for CMJ. However, statistically significant decrements (p<0.05) were found for all variables during the SLCMJ test. This study's key finding was that significant changes in select PC variables were observed following a short TR time trial. In conclusion, it appears general TR-induced fatigue negatively impacts PC regulation following a 26km (+900m) trail run time trial. However, a combination of training status, task experience and compensatory strategies appear to limit the magnitude that general neuromuscular fatigue can have on PC regulation. A greater contribution from cognitive resources such as increased awareness and attentional demand could improve sensory detection capabilities needed to identify optimal balance demands via proprioceptive sensory sources. Future studies should measure trail runners of varying training statuses to better understand this phenomenon.