Metabolic and Attentional Energy Costs of Interlimb Coordination (original) (raw)
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The metabolic and cognitive energy costs of stabilising a high-energy interlimb coordination task
Human Movement Science, 2005
Kinematic (relative phase error), metabolic (oxygen consumption, heart rate) and attentional (baseline and cycling reaction times) variables were measured while participants practised a high energy-demanding, intrinsically unstable 90° relative phase coordination pattern on independent bicycle ergometers. The variables were found to be strongly inter-correlated, suggesting a link between emerging performance stability with practice and minimal metabolic and attentional cost. The eVects of practice of 90° relative phase coordination on the performance of in-phase (0°-phase) and antiphase (180°-phase) coordination were investigated by measuring the relative phase attractor layouts and recording the metabolic and attentional cost of the three coordination patterns before and after practice. The attentional variables did not diVer signiWcantly between coordination patterns and did not change with practice. Before practice, the coordination performance was most accurate and stable for in-phase cycling, with antiphase next and 90°-phase the poorest. However, metabolic cost was lower for antiphase than either in-phase or 90°-phase cycling, and the pre-practice attractor layout deviated from that predicted on the basis of dynamic stability as an attractor state, revealing an attraction to antiphase cycling. After practice of 90°-phase cycling, in-phase cycling remained the most accurate and stable, with 90°-phase next and antiphase the poorest, but antiphase retained the lowest metabolic energy cost. The attractor layout had changed, with new attractors formed at the practised 90°-phase pattern and its symmetrical partner of 270°-phase. Considering both the pre-and post-practice results, attractors were formed at either a low metabolic energy cost but less stable (antiphase) pattern or at a more stable but higher metabolic energy cost (90°-phase) pattern, but in neither case at the most stable and accurate (in-phase) pattern. The results suggest that energetic factors aVect coordination (B.S. Lay). 834 B.S. Lay et al. / Human Movement Science 24 (2005) [833][834][835][836][837][838][839][840][841][842][843][844][845][846][847][848] dynamics and that coordination modes lower in metabolic energy expenditure may compete with dynamically stable modes.
The Influence of Work Rate and Cadence on Movement Coordination in Cycling
ISBS - Conference Proceedings Archive, 2010
This study investigated the effect of cycling cadence and work rate on coupling motion in trained male cyclists. Subjects undertook 9 pedalling bouts at various work rates and cadences (120, 210, 300 W at 60, 90, 120 rpm) and intra-limb joint coupling motions were examined using a continuous relative phase (CRP) analysis. The hip/knee (HK) coupling motion was significantly more in-phase during the 90 and 120 RPM trials compared with the 60 RPM trial (recovery phase). Similarly the knee/ankle (KA) coupling motion was significantly more in-phase in the 120 RPM trials than the 60 or 90 RPM trials (propulsive phase). No differences were found between work rate conditions. The results suggest for higher cadences the resulting movement patterns are more stable and consequently more economical. Cyclists should therefore seek to maintain a higher cadence.
Analysis of muscle coordination strategies in cycling
IEEE Transactions on Rehabilitation Engineering, 2000
The functional significance of the stereotypical muscle activation patterns used in skilled multi-joint tasks is not well understood. Optimization methods could provide insight into the functional significance of muscle coordination. The purpose of this study was to predict muscle force patterns during cycling by pushing and pulling the pedal using different optimization criteria and compare the predictions with electromyographic (EMG) patterns. To address the purpose of the study, 1) the contribution of muscle length and velocity changes to EMG-muscle force relationships during cycling was examined by comparing joint moments calculated from EMG and inverse dynamics, 2) patterns of individual muscle forces during cycling of five subjects were predicted using 13 different optimization criteria, and 3) the properties of the criterion with the best performance in predicting the normalized EMG were used to explain the features and functional significance of muscle coordination in cycling. It was shown that the criterion that minimizes the sum of muscle stresses cubed demonstrated the best performance in predicting the relative magnitude and patterns of muscle activation. Based on this criterion, it was suggested that the functional significance of muscle coordination strategy in cycling may be minimization of fatigue and/or perceived effort.
Intra-Segment Coordination Variability in Road Cyclists during Pedaling at Different Intensities
Applied Sciences
Background: The purpose of this study is to examine the lower extremity intra-segment coordination and variability of road cyclists during pedaling at different intensities. Methods: Eleven semi-professional road cyclists perform four trials at workloads of 50%, 75%, 100%, and 125% of their maximum power output in a randomized order. Thigh, shank, and foot range of motions (ROM) and the coordination and variability of these segments are compared across different pedaling intensities. Results: Foot ROM in the sagittal plane and shank ROM in the transverse plane are significantly different between different pedaling intensities. Moreover, specific coupling patterns and variabilities are observed across the pedaling cycle; however, they were not significantly different across different pedaling intensities in four pedaling phases. Conclusion: The results highlight the role of knee extensors and plantar flexors during the first and second half of the propulsion phase of pedaling, respec...
Intra-limb coordinative adaptations in cycling
Sports Biomechanics, 2012
This study aimed to establish the nature of lower extremity intra-limb coordination variability in cycling and investigate the coordinative adaptations that occur in response to changes in cadence and work rate. Six trained and six untrained males performed nine pedalling bouts on a cycle ergometer at various cadences and work rates (60,90,120 rpm at 120,210,300 W). Three dimensional kinematic data were collected and flexion/extension angles of the ankle, knee and hip were subsequently calculated. These data were used to determine two intra-limb joint couplings (hip flexion/extension-knee flexion/extension [HK], knee flexion/extension-ankle plantarflexion/dorsi-flexion [KA]) which were analysed using continuous relative phase analysis. Trained participants displayed significantly (p<0.05) lower coordination variability (6.6±4.0°) than untrained participants (9.2±4.7°). For the trained subjects, the KA coupling displayed significantly more in phase motion in the 120 rpm (19.2±12.3°) than the 60 (30±7.4°) or 90 rpm (33.1±7.4°) trials and the HK coupling displayed significantly more in phase motion in the 90 (33.3±3.4°) and 120 rpm (27.9±13.6°) than in the 60 rpm trial (36.4±3.5°). The results of this study suggest that variability may be detrimental to performance and that a higher cadence is beneficial. However, further study of on-road cycling is necessary before any recommendations can be made.
Frontiers in Physiology, 2021
Although exercise-induced fatigue has been mostly studied from a reductionist and component-dominant approach, some authors have started to test the general predictions of theories of self-organized change during exercises performed until exhaustion. However, little is known about the effects of fatigue on interlimb coordination in quasi-isometric actions. The aim of this study was to investigate the effect of exerciseinduced fatigue on upper interlimb coordination during a quasi-isometric exercise performed until exhaustion. In order to do this, we hypothesized an order parameter that governs the interlimb coordination as an interlimb correlation measure. In line with general predictions of theory of phase transitions, we expected that the locally averaged values of the order parameter will increase as the fatigue driven system approaches the point of spontaneous task disengagement. Seven participants performed a quasiisometric task holding an Olympic bar maintaining an initial elbow flexion of 90 degrees until fatigue induced spontaneous task disengagement. The variability of the elbow angle was recorded through electrogoniometry and the obtained time series were divided into three segments for further analysis. Running correlation function (RCF) and adopted bivariate phase rectified signal averaging (BPRSA) were applied to the corresponding initial (30%) and last (30%) segments of the time series. The results of both analyses showed that the interlimb correlation increased between the initial and the final segments of the performed task. Hence, the hypothesis of the research was supported by evidence. The enhancement of the correlation in the last part means a less flexible coordination among limbs. Our results also show that the high magnitude correlation (%RCF > 0.8) and the %Range (END-BEG) may prove to be useful markers to detect the effects of effort accumulation on interlimb coordination. These results may provide information about the loss of adaptability during exercises performed until exhaustion. Finally, we briefly discuss the hypothesis of the inhibitory percolation process being the general explanation of the spontaneous task disengagement phenomenon.
Training With Independent Cranks Alters Muscle Coordination Pattern in Cyclists
Journal of Strength and Conditioning Research, 2009
Ferná ndez-Peñ a, E, Lucertini, F, and Ditroilo, M. Traning with independent cranks alters muscle coordination pattern in cyclists. J Strength Cond Res 23(6): 1764-1772, 2009-In cycling, a circular pedaling action makes the most useful contribution to forward propulsion. Training with independent cranks (IC) has been proposed to improve the pedaling action. The aims of this study were, first, to assess whether the intermuscular coordination pattern of the pedaling action with normal cranks (NC) is modified after a training period with IC and, second, to determine if the new coordination pattern is maintained after a washing-out period. Eighteen cyclists, divided into a control (CG) and an experimental (EG) group, underwent 2 test sessions (T1 and T2) separated by 2 weeks of training (18 hours). The electromyographic (EMG) activity of 4 lower limbs' muscles was recorded while the athletes pedaled at 80 rpm for 60 seconds at 30 and 50% of the maximal power output determined during a maximal pedaling test. The tasks were performed with IC (EG) and NC (EG and CG). The EG underwent a retention test session (T3) after another 18-hour training with NC. EG showed a significant (45.8 6 8.8 vs. 36.0 6 6.1%, p , 0.01 at 30% intensity) and a quasi-significant (62.7 6 10.3 vs. 54.2 6 8.7%, p = 0.09 at 50% intensity) decrease in vastus lateralis EMG activity and a quasi-significant (36.4 6 13.4 vs. 43.5 6 10.9%, p = 0.09 at 30% intensity) and a significant (54.5 6 12.1 vs. 65.5 6 16.1%, p , 0.05 at 50% intensity) increase in biceps femoris EMG activity between T1-NC and T2-NC. By T3, EMG activity returned to initial levels (T1). On the contrary, CG did not reveal any significant variation. The results provide scientific support for muscle coordination pattern alteration from the use of IC, potentially achieving a more effective pedaling action. IC training reduces quadriceps exertion, thus preserving it for important moments during competition.
Neuroscience Letters, 2008
The present study investigated the influence of a bilateral exhaustive exercise on the stability of bimanual anti-phase coordination pattern and attentional demands. Eight subjects performed the anti-phase coordination pattern in two sessions: an Exhausting Session and a Control Session. During the Exhausting Session, subjects performed the bimanual coordination after exhaustion of forearms muscles (i.e. endurance time test). For the Control Session, no endurance time test was previously designed before the performance of anti-phase coordination. Within these experimental sessions, two levels of load (loaded and unload) and two frequencies (1.75 and 2.25 Hz) were also manipulated during the bimanual task. Attentional demands associated with performing the anti-phase coordination pattern was measured via a probe reaction time task (RT). The results showed that relative phase variability was higher for the fastest frequency after the exhaustive exercise. Moreover, as a result of the previous muscle exercise, the observed phase coupling was less accurate. No significant effect was found concerning the attentional demands as assessed through RT. The present findings suggest that the muscle exhaustion affects bimanual performance at a more peripheral level.
Cilj študije primera je bil predstaviti učinke kolesarjenja v klanec na vzorce mišične aktivnosti in istočasno praktično preizkusiti metodološki pristop za glavno študijo. Namen je bil preveriti razlike v osmih glavnih mišicah nog med: (i) ravninskim kolesarjenjem, (ii) kolesarjenjem v 10 % naklon in (iii) kolesarjenjem v 20 % naklon z dvema različnima analizama. Želeli smo ugotoviti časovno razporejenost mišične aktivnosti, kjer smo vzeli 10 % največje zavestne kontrakcije za prag, ki določa začetek in konec aktivnega dela. Naknadno smo preverili razlike v amplitudi. Generalno je naklon učinkoval na med-mišično in znotraj-mišično koordinacijo. Metodološki pristop je dobro prikazal razlike v časovnih in amplitudnih lastnostih mišične aktivnosti in bo zato uporabljen tudi v glavni študiji.
Changes of Pedaling Technique and Muscle Coordination during an Exhaustive Exercise
Medicine & Science in Sports & Exercise, 2009
Purpose: Alterations of the mechanical patterns during an exhaustive pedaling exercise have been previously shown. We designed the present study to test the hypothesis that these alterations in the biomechanics of pedaling, which occur during exhaustive exercise, are linked to changes in the activity patterns of lower limb muscles. Methods: Ten well-trained cyclists were tested during a limited time to exhaustion, performing 80% of maximal power tolerated. Pedal force components were measured continuously using instrumented pedals and were synchronized with surface EMG signals measured in 10 lower limb muscles. Results: The results confirmed most of the alterations of the mechanical patterns previously described in the literature. The magnitude of the root mean squared of the EMG during the complete cycle (RMS cycle ) for tibialis anterior and gastrocnemius medialis decreased significantly (P G 0.05) from 85% and 75% of T lim , respectively. A higher RMS cycle was obtained for gluteus maximus (P G 0.01) and biceps femoris (P G 0.05) from 75% of T lim . The k values that resulted from the cross-correlation technique indicated that the activities of six muscles (gastrocnemius medialis, gastrocnemius lateralis, tibialis anterior, vastus lateralis, vastus medialis, and rectus femoris) were shifted forward in the cycle at the end of the exercise. Conclusions: The large increases in activity for gluteus maximus and biceps femoris, which are in accordance with the increase in force production during the propulsive phase, could be considered as instinctive coordination strategies that compensate for potential fatigue and loss of force of the knee extensors (i.e., vastus lateralis and vastus medialis) by a higher moment of the hip extensors. FIGURE 1-Experimental setup for the first (A) and the second sessions (B).