Muscle coordination in cycling: effect of surface incline and posture

Li, Li; Caldwell, Graham E.

doi:10.1152/jappl.1998.85.3.927

Cited by 107 publications

(149 citation statements)

References 23 publications

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“…Based on electromyography activity, the VL muscle provides a good representation of muscle activation during cycling (27) and thus this location was chosen for single-site NIRS measurement conducted by previous studies (e.g., 13,16,47). However, there have been no studies that provide absolute quantification of the dynamic heterogeneity of muscle deoxygenation in the different regional muscle capillary beds following the onset of exercise in humans.…”

Section: Absolute Quantification Of the Dynamic Heterogeneity Of Muscmentioning

confidence: 99%

Methodological validation of the dynamic heterogeneity of muscle deoxygenation within the quadriceps during cycle exercise

Koga

Poole

Fukuoka

et al. 2011

American Journal of Physiology-Regulatory, Integrative and Comp

100

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-The conventional continuous wave near-infrared spectroscopy (CW-NIRS) has enabled identification of regional differences in muscle deoxygenation following onset of exercise. However, assumptions of constant optical factors (e.g., path length) used to convert the relative changes in CW-NIRS signal intensity to values of relative concentration, bring the validity of such measurements into question. Furthermore, to justify comparisons among sites and subjects, it is essential to correct the amplitude of deoxygenated hemoglobin plus myoglobin [deoxy(HbϩMb)] for the adipose tissue thickness (ATT). We used two time-resolved NIRS systems to measure the distribution of the optical factors directly, thereby enabling the determination of the absolute concentrations of deoxy(HbϩMb) simultaneously at the distal and proximal sites within the vastus lateralis (VL) and the rectus femoris muscles. Eight subjects performed cycle exercise transitions from unloaded to heavy work rates (Ͼgas exchange threshold). Following exercise onset, the ATT-corrected amplitudes (Ap), time delay (TDp), and time constant (p) of the primary component kinetics in muscle deoxy(Hb ϩ Mb) were spatially heterogeneous (intersite coefficient of variation range for the subjects: 10 -50 for Ap, 16 -58 for TDp, 14 -108% for p). The absolute and relative amplitudes of the deoxy(HbϩMb) responses were highly dependent on ATT, both within subjects and between measurement sites. The present results suggest that regional heterogeneity in the magnitude and temporal profile of muscle deoxygenation is a consequence of differential matching of O 2 delivery and O2 utilization, not an artifact caused by changes in optical properties of the tissue during exercise or variability in the overlying adipose tissue. near-infrared spectroscopy; oxygen uptake kinetics; muscle oxygen delivery; muscle oxygen utilization MUSCLE OXYGENATION/DEOXYGENATION reflects the balance between O 2 delivery (Q o 2 ) and O 2 utilization (V O 2 ), i.e., Q o 2 /V O 2 ratio (or V O 2 /Q o 2 as deoxygenation). Thus, the profile of muscle deoxygenation, for example, following the onset of exercise can provide important information regarding the adequacy of the vascular response and the O 2 pressures essential for driving blood-muscle O 2 flux (1, 4 -8, 11, 13, 15-17, 25, 32, 39, 43, 47).Recently, we found that the dynamics of muscle microvascular deoxygenation [deoxy(Hb ϩ Mb)] measured by continuous wave near-infrared spectroscopy (CW-NIRS) were spatially heterogeneous within the quadriceps muscles in transient states where metabolic rate was changing rapidly (25, 43). However, the spatial heterogeneity of the muscle deoxygenation dynamics may have been related to intra-and intersubject variability in unmeasured optical factors such as path length, absorption, and scattering coefficients inherent in CW-NIRS technology (15). Thus, it remains unknown to what extent the absolute amplitude of muscle deoxygenation of the different regions reflects the temporal profile of the mean muscle oxygen pressur...

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Section: Absolute Quantification Of the Dynamic Heterogeneity Of Muscmentioning

confidence: 99%

Methodological validation of the dynamic heterogeneity of muscle deoxygenation within the quadriceps during cycle exercise

Koga

Poole

Fukuoka

et al. 2011

American Journal of Physiology-Regulatory, Integrative and Comp

100

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“…It should also be noted that the first phase of pedalling, where the lower limb is extended in the knee joint, occurs in the direction of gravity, which supports the work of the extensors of this joint. The literature also shows that cycling substantially engages the vastus lateralis muscle [7], which might cause lower activity of the VM muscle. The longest time of the presence of the action potential of the GCL muscle is likely to be caused by the foot position on the pedal.…”

Section: Discussionmentioning

confidence: 99%

“…The longest time of the presence of the action potential of the GCL muscle is likely to be caused by the foot position on the pedal. The crankset is moved with the pressure of the forefoot, with the main movement of the knee joint being plantar flexion [7] driven by the gastrocnemius muscle. Consequently, changes in the quality of the EMG signal in individual muscles during pedalling can be expected.…”

Section: Discussionmentioning

confidence: 99%

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Effect of Changes in Cycle Ergometer Settings on Bioelectrical Activity in Selected Muscles of the Lower Limbs

Staszkiewicz

Kawulak

Nosiadek

et al. 2017

Polish Journal of Sport and Tourism

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Introduction. The aim of this study was to measure the duration of biopotentials in selected muscles of the lower limbs, evaluate the time of elevated bioelectrical activity in these muscles, and identify similarities and differences in electrical phenomena that occur in the muscles for various external settings of a cycle ergometer. Material and methods. The study examined 10 healthy people (5 women and 5 men) aged from 20 to 30 years. A cycle ergometer and EMG apparatus were used in the experiment. The bioelectrical activity of six muscles of the lower limbs (rectus femoris, vastus medialis, tibialis anterior, biceps femoris, gastrocnemius caput mediale, and gastrocnemius caput laterale) was recorded for four different settings of the cycle ergometer (variable saddle height and method of foot attachment to pedals). The EMG records were presented with reference to the bicycle crankset rotation cycle. Conclusions. The study found that changing the height of the saddle of the cycle ergometer and the use of toe clips in the pedals caused changes in bioelectrical activity in the muscles. The adjustment of saddle height affected the duration of potentials more noticeably than the use of toe clips. Furthermore, only one period of elevated electrical activity in the muscles of the lower limbs was found in the pedalling cycle. The longest time of the presence of action potentials was recorded for the m. gastrocnemius caput laterale, whereas the shortest time was observed in the m. vastus medialis.

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“…Other factors that may have affected leg muscle activation and coordination during cycling were the crank inertial load alteration and gear ratio [17], postural effects on biarticular and monoarticular muscles [18], and subject training background [19]. All these factors were not deemed relevant in the current study, as the load and gear ratio were constant, posture was carefully controlled, and subjects were introduced to both exercise systems only during the experimental session.…”

Section: Relationship Of Muscle Activation To Kinematic Propertiesmentioning

confidence: 99%

Isokinetic Cycling and Elliptical Stepping: A Kinematic and Muscle Activation Analysis

Hamzaid

Smith²,

Davis³

2013

Clin Res Foot Ankle

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Background: Semi-recumbent cycling exercise has been used as a strategy to complement gait retraining in individuals with disordered walking ability. However, seated elliptical stepping might be a more potent exercise modality for this purpose. Yet, there has not been a kinematic analysis of elliptical stepping exercise, whereby the movement path is produced by a slider-crank mechanism. This study compared the kinematic and leg muscle activation patterns of two isokinetic exercise modalities -cycling and elliptical stepping.

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Muscle coordination in cycling: effect of surface incline and posture

Cited by 107 publications

References 23 publications

Methodological validation of the dynamic heterogeneity of muscle deoxygenation within the quadriceps during cycle exercise

Methodological validation of the dynamic heterogeneity of muscle deoxygenation within the quadriceps during cycle exercise

Effect of Changes in Cycle Ergometer Settings on Bioelectrical Activity in Selected Muscles of the Lower Limbs

Isokinetic Cycling and Elliptical Stepping: A Kinematic and Muscle Activation Analysis

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