Knee extensor force control as a predictor of dynamic balance in healthy adults

Mear, Emily; Gladwell, Valerie; Pethick, Jamie

doi:10.1016/j.gaitpost.2023.01.004

Cited by 10 publications

(8 citation statements)

References 38 publications

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“…Specifically, low levels of torque complexity reflect a neuromuscular system with reduced number of motor solutions and, therefore, less capable of adapting the motor output to match the task demands. Moreover, Mear et al ( 2023 ) demonstrated that the dynamic balance performance can be explained by changes in torque complexity measures, indicating the capacity of torque complexity to reflect adaptability and providing a parallel with previous research on magnitude-based measures (torque steadiness) and walking performance (Davis et al 2020 ), the risk of falls in older adults (Carville et al 2007 ) and postural sway during upright standing (Davis et al 2020 ). Interestingly, Ravi et al ( 2021 ) demonstrated that the capacity to recover after a perturbation during the locomotion was faster when the individuals walk synchronised to a complex auditory stimulus (i.e.…”

Section: Introductionmentioning

confidence: 52%

Sleep deprivation increases the regularity of isometric torque fluctuations

Oliveira,

Santos,

Pezarat-Correia

et al. 2024

Exp Brain Res

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The regularity of the fluctuations present in torque signals represent the adaptability of the motor control. While previous research showed how it is affected by neuromuscular fatigue and ageing, the underlying mechanisms remain unclear. It is currently under debate whether these changes are explained by central or peripheral neuromuscular mechanisms. Here, we experimentally manipulated the sleep of thirteen young adults through a supervised 24 h-sleep deprivation protocol. This study aimed to investigate the effect of sleep deprivation on the regularity of torque fluctuations, and other standard torque-related outcomes (Peak Torque – PT – and Rate of Torque Development – RTD). The participants were asked to perform knee extension maximal voluntary contractions (MVC) and submaximal knee extensions at 40% of MVC for 30 s. PT and RTD were calculated from the MVC and the regularity of the torque fluctuations was determined on the submaximal task through Sample Entropy (SampEn). In addition, rate of perceived effort (RPE) was collected. We found no significant changes in PT and RTD. The regularity of torque fluctuations significantly increased (i.e., a decrease in SampEn) after 24 h-sleep deprivation (PRE = 1.76 ± 0.268, POS24 = 1.71 ± 0.306; p = 0.044). Importantly, we found a negative correlation between RPE and SampEn relative changes after sleep deprivation. This study brings new insights towards the understanding of the underlying mechanisms that explain changes in torque fluctuations, demonstrating that these changes are not limited to neuromuscular processes but are also likely to be affected by other domains, such as psychological profile, which can indirectly affect the neural drive to the muscles.

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Section: Introductionmentioning

confidence: 52%

Sleep deprivation increases the regularity of isometric torque fluctuations

Oliveira,

Santos,

Pezarat-Correia

et al. 2024

Exp Brain Res

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“…Muscle force CV during submaximal contractions can explain moderate amounts of variance, often more so than maximal strength, in performance of ADLs involving lower limb muscles, such as static (Davis et al ., 2020) and dynamic balance (Mear et al ., 2023), stair climbing power (Seynnes et al ., 2005) and reactive driving (Lodha et al ., 2016). Seemingly few studies have investigated performance of ADLs between Masters athletes and inactive older adults, though there is evidence that static (Sundstrup et al ., 2010; Leightley et al ., 2017), dynamic (Lee et al ., 2021) and reactive balance (Brauer et al ., 2008) are superior in Masters athletes compared to age-matched inactive adults.…”

Section: Discussionmentioning

confidence: 99%

“…This impaired ability to control force is likely to result in a neuromuscular response that is insufficient to withstand a perturbation or adequately compensate when performing a task (Hepple and Rice, 2016). Indeed, decreased force steadiness is predictive of poorer performance in tasks of balance (Davis et al ., 2020; Mear et al ., 2023), chair rise time and stair climbing power (Seynnes et al , 2005), and reactive driving (Lodha et al ., 2016).…”

Section: Introductionmentioning

confidence: 99%

The effect of lifelong physical (in)activity on knee extensor force control

Pethick

2023

Preprint

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It is well-documented that older adults exhibit a greater magnitude and decreased complexity of muscle force fluctuations in comparison to young adults. To date, however, research on this age-related loss of force control has focused on heterogeneous groups of inactive/moderately active older adults, despite accumulating evidence that high levels of lifelong physical activity (such as that exhibited by Masters athletes) has a protective effect on neuromuscular function and morphology. The present study compared healthy young adults (aged < 35; n = 14), healthy but inactive older adults (aged > 55; n = 13) and Masters athletes (aged > 55; n = 14) in order to discern the effects of lifelong physical (in)activity on muscle force control. Force control was assessed during isometric knee extension contractions at 10, 20 and 40% maximal voluntary contraction (MVC) and was quantified according to the magnitude (coefficient of variation [CV]) and complexity (approximate entropy [ApEn]; detrended fluctuation analysis [DFA] α) of force fluctuations. Inactive older adults exhibited significantly greater CV, indicative of poorer force steadiness, than young adults and Masters athletes during contractions at 10, 20 and 40% MVC (allP< 0.001). There were no significant differences in CV between the young adults and Masters athletes. These results indicate that lifelong physical activity has a protective effect against the age-related loss of muscle force control and suggest that, up to this point, our understanding of the age-related loss of muscle force control has been confounded by the effects of physical inactivity.Key pointsAgeing is associated with a decrease in muscle force control (i.e., poorer steadiness and adaptability), though to date this has largely been studied in inactive older adultsLifelong physical activity, such as that exhibited by Masters athletes, has a protective role against many age-related decrements in neuromuscular physiology and functionThis study compared force control, during contractions at intensities typical of the requirements of activities of daily living, in healthy young adults, healthy but inactive older adults and age-matched Masters athletesMasters athletes exhibited significantly better force steadiness than their inactive counterparts and no difference in steadiness compared to young adultsLifelong physical activity appears to modulate the age-related loss of force control, indicating that our current understanding of this loss of force control may be contaminated by the negative effects of inactivity

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“…For example, in the respiratory system, lower complexity of resting airflow patterns in those with asthma is associated with a decreased ability to adjust (increase) airflow relative to greater respiratory task demands (Veiga et al, 2011). In the sensorimotor system, specifically, lower complexity of muscle force control is associated with a decreased ability to respond to (perform) clinical co-ordination tasks in people with (Lodha et al, 2010) and without (Mear et al, 2023) pathology. Lower complexity, subsequently, is associated with decreased adaptability across multiple biological systems (Lipsitz and Goldberger, 1992;Veiga et al, 2011;Lodha et al, 2010;Mear et al, 2023).…”

Section: Clinical Relevancementioning

confidence: 99%

“…In the sensorimotor system, specifically, lower complexity of muscle force control is associated with a decreased ability to respond to (perform) clinical co-ordination tasks in people with (Lodha et al, 2010) and without (Mear et al, 2023) pathology. Lower complexity, subsequently, is associated with decreased adaptability across multiple biological systems (Lipsitz and Goldberger, 1992;Veiga et al, 2011;Lodha et al, 2010;Mear et al, 2023). Therefore, for the musculoskeletal system, decreased sensorimotor system adaptability may result in ongoing vulnerability to injury and a reduced range of situations across which an individual can function effectively.…”

Section: Clinical Relevancementioning

confidence: 99%