Effects of local and widespread muscle fatigue on movement timing

Abstract

Repetitive movements can cause muscle fatigue, leading to motor reorganization, performance deficits, and/or possible injury. The effects of fatigue may depend on the type of fatigue task employed, however. The purpose of this study was to determine how local fatigue of a specific muscle group versus widespread fatigue of various muscle groups affected the control of movement timing. Twenty healthy subjects performed an upper-extremity low-load work task similar to sawing for 5 continuous minutes both before and after completing a protocol that either fatigued all the muscles used in the task (widespread fatigue) or a protocol that selectively fatigued the primary muscles used to execute the pushing stroke of the sawing task (localized fatigue). Subjects were instructed to time their movements with a metronome. Timing error, movement distance, and speed were calculated for each movement. Data were then analyzed using a goal-equivalent manifold (GEM) approach to quantify changes in goal-relevant and non-goal-relevant variability. We applied detrended fluctuation analysis to each time series to quantify changes in fluctuation dynamics that reflected changes in the control strategies used. After localized fatigue, subjects made shorter, slower movements and exerted greater control over non-goal-relevant variability. After widespread fatigue, subjects exerted less control over non-goal-relevant variability and did not change movement patterns. Thus, localized and widespread muscle fatigue affected movement differently. Local fatigue may reduce the available motor solutions and therefore cause greater movement reorganization than widespread muscle fatigue. Subjects altered their control strategies but continued to achieve the timing goal after both fatigue tasks.

Sex-Specific Links in Motor and Sensory Adaptations to Repetitive Motion–Induced Fatigue

“…Mean shoulder horizontal abductionadduction angles were significantly greater in the final minute of the task (End) than in the first minute (Start), whereas mean shoulder-elbow relative phase was significantly decreased as a function of time. These results are consistent with results from previous studies that used repetitive upper-limb tasks and that demonstrated shifts in posture and compensatory changes in coordination, interpreted as strategies to decrease the load on fatiguing muscles (Côté et al, 2002(Côté et al, , 2005Cowley et al, 2014;Forestier & Nougier, 1998;Gates & Dingwell, 2011). However, this is the first time that upper-limb coordination changes have been quantified using the continuous relative phase approach.…”

“…Moreover, different kinds of fatigue protocols have led to increases in motor variability (Cowley, Dingwell, & Gates, 2014;Fuller et al, 2009;Gates & Dingwell, 2011;Qin, Lin, Faber, Buchholz, & Xu, 2014). Motor variability, defined as the intrinsic variability in actions controlled by the sensorimotor system (Madeleine, 2010;Mathiassen, Möller, & Forsman, 2003), has evolved into an important concept in the field of biomechanics because of the proposed benefit of variability toward decreasing the rate of fatigue development and the relative risk of injury (Côté, 2014;Madeleine, 2010;Srinivasan & Mathiassen, 2012).…”

Muscular and Vascular Issues Induced by Prolonged Standing With Different Work–Rest Cycles With Active or Passive Breaks

“…However, a significant degradation was observed immediately after 5 hr, but this performance decrement was no longer present after the recovery period. Several studies have illustrated motor control impairments induced by muscle fatigue (Cowley, Dingwell, & Gates, 2014; Johnston, Howard, Cawley, & Losse, 1998; Selen, Beek, & van Dieen, 2007). However, these effects were measured only immediately after a rather severe fatiguing task regimen (at least 7 on a 10-point subjective rating scale).…”

Proximal and distal muscle fatigue differentially affect movement coordination

“…The mean IMPF value was obtained for each movement cycle of the fatigue protocol. The rate of decrease in frequency was calculated using the average IMPF from each cycle [ 6 ]. The IMPF was expected to decrease because muscle fatigue causes motor units to contract more synchronously leading to a decrease in high frequencies in the EMG signal [ 27 , 28 ].…”

“…Many factors influence the way that people change their movement patterns after fatigue. In particular, fatigue that is localized in a specific muscle group causes greater changes in muscle coordination [ 5 ] and movement amplitude and speed [ 6 ] compared to fatigue that is widespread over several muscles. The direct relationship between muscle fatigue, movement, and injury is difficult to discern because the conditions that lead to fatigue and the activities performed while fatigued vary across worksites.…”