scholarly journals The Effect of Crank Resistance on Arm Configuration and Muscle Activation Variances in Arm Cycling Movements

2021 ◽  
Vol 76 (1) ◽  
pp. 175-189
Author(s):  
Mariann Mravcsik ◽  
Lilla Botzheim ◽  
Norbert Zentai ◽  
Davide Piovesan ◽  
Jozsef Laczko
Keyword(s):  
Muscle Activation ◽  
Hand Movement ◽  
Joint Stiffness ◽  
Joint Space ◽  
Cycle Ergometer ◽  
Circular Path ◽  
Arm Cranking ◽  
Joint Configuration ◽  
Motor Noise ◽  
Arm Cycling

Abstract Arm cycling on an ergometer is common in sports training and rehabilitation protocols. The hand movement is constrained along a circular path, and the user is working against a resistance, maintaining a cadence. Even if the desired hand trajectory is given, there is the flexibility to choose patterns of joint coordination and muscle activation, given the kinematic redundancy of the upper limb. With changing external load, motor noise and changing joint stiffness may affect the pose of the arm even though the endpoint trajectory is unchanged. The objective of this study was to examine how the crank resistance influences the variances of joint configuration and muscle activation. Fifteen healthy participants performed arm cranking on an arm-cycle ergometer both unimanually and bimanually with a cadence of 60 rpm against three crank resistances. Joint configuration was represented in a 3-dimensional joint space defined by inter-segmental joint angles, while muscle activation in a 4-dimensional "muscle activation space" defined by EMGs of 4 arm muscles. Joint configuration variance in the course of arm cranking was not affected by crank resistance, whereas muscle activation variance was proportional to the square of muscle activation. The shape of the variance time profiles for both joint configuration and muscle activation was not affected by crank resistance. Contrary to the prevailing assumption that an increased motor noise would affect the variance of auxiliary movements, the influence of noise doesn’t appear at the joint configuration level even when the system is redundant. Our results suggest the separation of kinematic- and force-control, via mechanisms that are compensating for dynamic nonlinearities. Arm cranking may be suitable when the aim is to perform training under different load conditions, preserving stable and secure control of joint movements and muscle activations.

scholarly journals Motor Variances in Arm Cranking as a Function of the Resistance

2020 ◽  
Author(s):  
Mariann Mravcsik ◽  
Lilla Botzheim ◽  
Norbert Zentai ◽  
Davide Piovesan ◽  
Jozsef Laczko
Keyword(s):  
Neural Control ◽  
Muscle Activation ◽  
Hand Movement ◽  
Joint Stiffness ◽  
Cycle Ergometer ◽  
Circular Path ◽  
Arm Cranking ◽  
Joint Coordination ◽  
Motor Noise ◽  
Arm Cycling

Abstract Background: Arm cycling on an ergometer is common in sports training and rehabilitation protocols, but has not been widely studied from an aspect of neural control. The hand movement is constrained along a circular path, and the user is working against a resistance, maintaining a cadence. Even if the desired hand trajectory is given, there is the flexibility to choose patterns of joint coordination and muscle activation, given the kinematic redundancy of the upper limb. With changing external load, motor noise and changing joint stiffness may affect the pose of the arm even though the endpoint trajectory is unchanged, unless a control mechanism maintains the same arm configuration in corresponding time points of the cycles. However, the effect of crank resistance on the variances of arm configuration and muscle activation has not been investigated, yet. Methods: Fifteen healthy participants performed arm cranking on an arm-cycle ergometer both unimanually and bimanually with a cadence of 60 rpm against three crank resistances. We investigated arm configuration variances and muscle activation variances. Arm configuration was given by inter-segmental joint angles, while muscle activation by surface EMGs of arm muscles. Applying multifactorial ANOVA we evaluated the effects of resistance conditions. Results: Arm configuration variance in the course of arm cranking was not affected by crank resistance, while muscle activation variance was proportional to the square of electromyographic muscle activity. Furthermore, the shape of the variance time profiles for both arm configuration and muscle activation was not affected by crank resistance independently on cranking being performed unimanually or bimanually. Conclusions: Contrary to the prevailing assumption that an increased motor noise would affect the variance of auxiliary movements, the influence of noise doesn’t appear at the arm configuration level even when the system is redundant. Our results suggest that neural control stabilizes arm configurations against altered external force in arm cranking. This may reflect the separation of kinematic- and force-control, via mechanisms that are compensating for dynamic non-linearities. Arm cranking may be suitable when the aim is to perform training under different load conditions, preserving stable and secure control of joint movements and muscle activations.

Development of an Apparatus for Bilateral Rhythmical Training of Arm Movement Via Linear and Elliptical Trajectories of Various Directions

2014 ◽  
Vol 8 (3) ◽  
Author(s):  
Zlatko Matjačić ◽  
Matjaž Zadravec ◽  
Jakob Oblak
Keyword(s):  
Muscle Activation ◽  
Arm Movement ◽  
Emg Activity ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Arm Cycling ◽  
Arm Reaching ◽  
Direction Of Movement ◽  
Muscle Groups ◽  
Neurologically Intact

Clinical rehabilitation of individuals with various neurological disorders requires a significant number of movement repetitions in order to improve coordination and restoration of appropriate muscle activation patterns. Arm reaching movement is frequently practiced via motorized arm cycling ergometers where the trajectory of movement is circular thus providing means for practicing a single and rather nonfunctional set of muscle activation patterns, which is a significant limitation. We have developed a novel mechanism that in the combination with an existing arm ergometer device enables nine different movement modalities/trajectories ranging from purely circular trajectory to four elliptical and four linear trajectories where the direction of movement may be varied. The main objective of this study was to test a hypothesis stating that different movement modalities facilitate differences in muscle activation patterns as a result of varying shape and direction of movement. Muscle activation patterns in all movement modalities were assessed in a group of neurologically intact individuals in the form of recording the electromyographic (EMG) activity of four selected muscle groups of the shoulder and the elbow. Statistical analysis of the root mean square (RMS) values of resulting EMG signals have shown that muscle activation patterns corresponding to each of the nine movement modalities significantly differ in order to accommodate to variation of the trajectories shape and direction. Further, we assessed muscle activation patterns following the same protocol in a selected clinical case of hemiparesis. These results have shown the ability of the selected case subject to produce different muscle activation patterns as a response to different movement modalities which show some resemblance to those assessed in the group of neurologically intact individuals. The results of the study indicate that the developed device may significantly extend the scope of strength and coordination training in stroke rehabilitation which is in current clinical rehabilitation practice done through arm cycling.

Effect of gravity and kinematic constraints on muscle synergies in arm cycling.

2021 ◽  
Author(s):  
Lilla Botzheim ◽  
Jozsef Laczko ◽  
Diego Torricelli ◽  
Mariann Mravcsik ◽  
José L. Pons ◽  
...  
Keyword(s):  
Motor Control ◽  
Muscle Activation ◽  
Biceps Brachii ◽  
Body Position ◽  
Medical Rehabilitation ◽  
Muscle Synergies ◽  
Muscle Coordination ◽  
Arm Cycling ◽  
Custom Made ◽  
Crank Length

Arm cycling is a bi-manual motor task used in medical rehabilitation and in sports training. Understanding how muscle coordination changes across different biomechanical constraints in arm cycling is a step towards improved rehabilitation approaches. This exploratory study aims to get new insights on motor control during arm cycling. To achieve our main goal, we used the muscle synergies analysis to test three hypotheses: 1) body position with respect to gravity (sitting and supine) has an effect on muscle synergies; 2) the movement size (crank length) has an effect on the synergistic behavior; 3) the bimanual cranking mode (asynchronous and synchronous) requires different synergistic control. Thirteen able-bodied volunteers performed arm cranking on a custom-made device with unconnected cranks, which allowed testing three different conditions: body position (sitting versus supine), crank length (10cm versus 15cm) and cranking mode (synchronous versus asynchronous). For each of the eight possible combinations, subjects cycled for 30 seconds while electromyography of 8 muscles (4 from each arm) were recorded: biceps brachii, triceps brachii, anterior deltoid and posterior deltoid. Muscle synergies in this 8-dimensional muscle space were extracted by non-negative matrix factorization. Four synergies accounted for over 90% of muscle activation variances in all conditions. Results showed that synergies were affected by body position and cranking mode but practically unaffected by movement size. These results suggest that the central nervous system may employ different motor control strategies in response to external constraints such as cranking mode and body position during arm cycling.

scholarly journals Acetaminophen ingestion improves muscle activation and performance during a 3-min all-out cycling test

2019 ◽  
Vol 44 (4) ◽  
pp. 434-442 ◽  
Author(s):  
Paul T. Morgan ◽  
Anni Vanhatalo ◽  
Joanna L. Bowtell ◽  
Andrew M. Jones ◽  
Stephen J. Bailey
Keyword(s):  
Muscle Activation ◽  
Femoral Nerve ◽  
Time Trial ◽  
Cycle Ergometer ◽  
Membrane Excitability ◽  
Mean Power ◽  
Cycling Exercise ◽  
M Wave ◽  
Cycling Test ◽  
Work Done

Acute acetaminophen (ACT) ingestion has been shown to enhance cycling time-trial performance. The purpose of this study was to assess whether ACT ingestion enhances muscle activation and critical power (CP) during maximal cycling exercise. Sixteen active male participants completed two 3-min all-out tests against a fixed resistance on an electronically braked cycle ergometer 60 min after ingestion of 1 g of ACT or placebo (maltodextrin, PL). CP was estimated as the mean power output over the final 30 s of the test and W′ (the curvature constant of the power–duration relationship) was estimated as the work done above CP. The femoral nerve was stimulated every 30 s to measure membrane excitability (M-wave) and surface electromyography (EMGRMS) was recorded continuously to infer muscle activation. Compared with PL, ACT ingestion increased CP (ACT: 297 ± 32 W vs. PL: 288 ± 31 W, P < 0.001) and total work done (ACT: 66.4 ± 6.5 kJ vs. PL: 65.4 ± 6.4 kJ, P = 0.03) without impacting W′ (ACT: 13.1 ± 2.9 kJ vs. PL: 13.6 ± 2.4 kJ, P = 0.19) or the M-wave amplitude (P = 0.66) during the 3-min all-out cycling test. Normalised EMGRMS amplitude declined throughout the 3-min protocol in both PL and ACT conditions; however, the decline in EMGRMS amplitude was attenuated in the ACT condition, such that the EMGRMS amplitude was greater in ACT compared with PL over the last 60 s of the test (P = 0.04). These findings indicate that acute ACT ingestion might increase performance and CP during maximal cycling exercise by enhancing muscle activation.

Neuromuscular Reflexes Contribute to Knee Stiffness During Valgus Loading

2005 ◽  
Vol 93 (5) ◽  
pp. 2698-2709 ◽  
Author(s):  
Y. Y. Dhaher ◽  
A. D. Tsoumanis ◽  
T. T. Houle ◽  
W. Z. Rymer
Keyword(s):  
Knee Joint ◽  
Muscle Activation ◽  
Joint Stiffness ◽  
Muscle Contractions ◽  
Emg Activity ◽  
Lateral Direction ◽  
Reflex Responses ◽  
Torque Response ◽  
Joint Dynamics ◽  
Periarticular Tissue

We have previously shown that abduction angular perturbations applied to the knee consistently elicit reflex responses in knee joint musculature. Although a stabilizing role for such reflexes is widely proposed, there are as of yet no studies quantifying the contribution of these reflex responses to joint stiffness. In this study, we estimate the mechanical contributions of muscle contractions elicited by mechanical excitation of periarticular tissue receptors to medial-lateral knee joint stiffness. We hypothesize that these reflex muscle contractions will significantly increase knee joint stiffness in the adduction/abduction direction and enhance the overall stability of the knee. To assess medial-lateral joint stiffness, we applied an abducting positional deflection to the fully extended knee using a servomotor and recorded the torque response using a six degree-of-freedom load-cell. EMG activity was also recorded in both relaxed and preactivated quadriceps and hamstrings muscles with surface electrodes. A simple, linear, second-order, delayed model was used to describe the knee joint dynamics in the medial/lateral direction. Our data indicate that excitation of reflexes from periarticular tissue afferents results in a significant increase of the joint’s adduction-abduction stiffness. Similar to muscle stretch reflex action, which is modulated with background activation, these reflexes also show dependence on muscle activation. The potential significance of this reflex stiffness during functional tasks was also discussed. We conclude that reflex activation of knee muscles is sufficient to enhance joint stabilization in the adduction/abduction direction, where knee medial-lateral loading arises frequently during many activities.

scholarly journals A method for detecting the temporal sequence of muscle activation during cycling using MRI

2011 ◽  
Vol 110 (3) ◽  
pp. 826-833 ◽  
Author(s):  
Christopher P. Elder ◽  
Ryan N. Cook ◽  
Kenneth L. Wilkens ◽  
Marti A. Chance ◽  
Otto A. Sanchez ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Transverse Relaxation Time ◽  
Biceps Femoris ◽  
Cycle Ergometer ◽  
Muscle Recruitment ◽  
Spatial And Temporal Patterns ◽  
Variable Loading ◽  
Limited Applicability ◽  
The Difference ◽  
Long Head

Surface electromyography (EMG) can assess muscle recruitment patterns during cycling, but has limited applicability to studies of deep muscle recruitment and electrically stimulated contractions. We determined whether muscle recruitment timing could be inferred from MRI-measured transverse relaxation time constant (T2) changes and a cycle ergometer modified to vary power as a function of pedal angle. Six subjects performed 6 min of single-leg cycling under two conditions (E0°-230° and E90°-230°), which increased the power from 0°-230° and 90–230° of the pedal cycle, respectively. The difference condition produced a virtual power output from 0–180° (V0°-180°). Recruitment was assessed by integrating EMG over the pedal cycle (IEMG) and as the (post-pre) exercise T2 change (ΔT2). For E0°-230°, the mean IEMG for vastus medialis and lateralis (VM/VL; 49.3 ± 3.9 mV·s; mean ± SE) was greater ( P < 0.05) than that for E90°-230° (17.9 ± 1.9 mV·s); the corresponding ΔT2 values were 8.7 ± 1.0 and 1.4 ± 0.5 ms ( P < 0.05). For E0°-230° and E90°-230°, the IEMG values for biceps femoris/long head (BFL) were 37.7 ± 5.4 and 27.1 ± 5.6 mV·s ( P > 0.05); the corresponding ΔT2 values were 0.9 ± 0.9 and 1.5 ± 0.9 ms ( P > 0.05). MRI data indicated activation of the semitendinosus and BF/short head for E0°-230° and E90°-230°. For V0°-180°, ΔT2 was 7.2 ± 0.9 ms for VM/VL and −0.6 ± 0.6 ms for BFL; IEMG was 31.5 ± 3.7 mV·s for VM/VL and 10.6 ± 7.0 mV·s for BFL. MRI and EMG data indicate VM/VL activity from 0 to 180° and selected hamstring activity from 90 to 230°. Combining ΔT2 measurements with variable loading allows the spatial and temporal patterns of recruitment during cycling to be inferred from MRI data.

scholarly journals Patterns of muscle activity for digital coarticulation

2013 ◽  
Vol 110 (1) ◽  
pp. 230-242 ◽  
Author(s):  
Sara A. Winges ◽  
Shinichi Furuya ◽  
Nathaniel J. Faber ◽  
Martha Flanders
Keyword(s):  
Time Course ◽  
Muscle Activation ◽  
Motor Pattern ◽  
Hand Movement ◽  
Time Frame ◽  
Pattern Generation ◽  
Emg Activity ◽  
Key Press ◽  
Basic Features ◽  
Piano Playing

Although piano playing is a highly skilled task, basic features of motor pattern generation may be shared across tasks involving fine movements, such as handling coins, fingering food, or using a touch screen. The scripted and sequential nature of piano playing offered the opportunity to quantify the neuromuscular basis of coarticulation, i.e., the manner in which the muscle activation for one sequential element is altered to facilitate production of the preceding and subsequent elements. Ten pianists were asked to play selected pieces with the right hand at a uniform tempo. Key-press times were recorded along with the electromyographic (EMG) activity from seven channels: thumb flexor and abductor muscles, a flexor for each finger, and the four-finger extensor muscle. For the thumb and index finger, principal components of EMG waveforms revealed highly consistent variations in the shape of the flexor bursts, depending on the type of sequence in which a particular central key press was embedded. For all digits, the duration of the central EMG burst scaled, along with slight variations across subjects in the duration of the interkeystroke intervals. Even within a narrow time frame (about 100 ms) centered on the central EMG burst, the exact balance of EMG amplitudes across multiple muscles depended on the nature of the preceding and subsequent key presses. This fails to support the idea of fixed burst patterns executed in sequential phases and instead provides evidence for neuromuscular coarticulation throughout the time course of a hand movement sequence.

scholarly journals How Well Do Commonly Used Co-contraction Indices Approximate Lower Limb Joint Stiffness Trends During Gait for Individuals Post-stroke?

2021 ◽  
Vol 8 ◽  
Author(s):  
Geng Li ◽  
Mohammad S. Shourijeh ◽  
Di Ao ◽  
Carolynn Patten ◽  
Benjamin J. Fregly
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Sagittal Plane ◽  
Joint Stiffness ◽  
Energetic Cost ◽  
Electromechanical Delay ◽  
Antagonist Muscle ◽  
Post Stroke ◽  
Methodological Choices ◽  
Model Based

Muscle co-contraction generates joint stiffness to improve stability and accuracy during limb movement but at the expense of higher energetic cost. However, quantification of joint stiffness is difficult using either experimental or computational means. In contrast, quantification of muscle co-contraction using an EMG-based Co-Contraction Index (CCI) is easier and may offer an alternative for estimating joint stiffness. This study investigated the feasibility of using two common CCIs to approximate lower limb joint stiffness trends during gait. Calibrated EMG-driven lower extremity musculoskeletal models constructed for two individuals post-stroke were used to generate the quantities required for CCI calculations and model-based estimation of joint stiffness. CCIs were calculated for various combinations of antagonist muscle pairs based on two common CCI formulations: Rudolph et al. (2000) (CCI1) and Falconer and Winter (1985) (CCI2). CCI1 measures antagonist muscle activation relative to not only total activation of agonist plus antagonist muscles but also agonist muscle activation, while CCI2 measures antagonist muscle activation relative to only total muscle activation. We computed the correlation between these two CCIs and model-based estimates of sagittal plane joint stiffness for the hip, knee, and ankle of both legs. Although we observed moderate to strong correlations between some CCI formulations and corresponding joint stiffness, these associations were highly dependent on the methodological choices made for CCI computation. Specifically, we found that: (1) CCI1 was generally more correlated with joint stiffness than was CCI2, (2) CCI calculation using EMG signals with calibrated electromechanical delay generally yielded the best correlations with joint stiffness, and (3) choice of antagonist muscle pairs significantly influenced CCI correlation with joint stiffness. By providing guidance on how methodological choices influence CCI correlation with joint stiffness trends, this study may facilitate a simpler alternate approach for studying joint stiffness during human movement.

Assessing Joint Stability from Eigenvalues Obtained from Multi-Channel EMG

2014 ◽  
pp. 203-218
Author(s):  
Dianne M. Ikeda ◽  
Stuart M. McGill
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Muscle Activation ◽  
Joint Stiffness ◽  
Clinical Intervention ◽  
Joint Stability ◽  
Treatment Interventions ◽  
Quantitative Stability ◽  
Assessment And Treatment

Electromyographic (EMG) signals have many uses. This chapter addresses the role of EMG signals to assess joint stability. Low back pain assessment and treatment interventions often involve the concepts of stability and/or joint stiffness. Using muscle activation and lumbar spine posture to calculate segmental stiffness and potential energy of the spine, eigenvalues can be linked to quantitative stability. It is reasoned that if a relationship exists between eigenvalues and individual muscles, then this approach can guide customized clinical intervention for people with defined spine instability.

scholarly journals Kinematics and control of frog hindlimb movements

1991 ◽  
Vol 65 (3) ◽  
pp. 547-562 ◽  
Author(s):  
D. J. Ostry ◽  
A. G. Feldman ◽  
J. R. Flanagan
Keyword(s):  
Nervous System ◽  
High Speed ◽  
Imaging System ◽  
Maximum Velocity ◽  
Joint Space ◽  
Motion Path ◽  
Three Dimension ◽  
Joint Angles ◽  
Joint Configuration ◽  
Straight Line

1. The determinants of the motion path of the hindlimb were explored in both intact and spinal frogs. In the spinal preparations the kinematic properties of withdrawal and crossed-extension reflexes were studied. In the intact frog the kinematics of withdrawal and swimming movements were examined. Frog hindlimb paths were described in joint angle (intrinsic) coordinates rather than limb endpoint (extrinsic) coordinates. 2. To study withdrawal and crossed-extension reflexes, the initial angles at the hip, knee, and ankle were varied. Withdrawal and crossed extension were recorded in three dimension (3-D) with the use of an infra-red spatial imaging system. Swimming movements against currents of different speeds were obtained with high-speed film. 3. Three strategies were considered related to the form of the hypothesized equilibrium paths specified by the nervous system: all trajectories lie on a single line in angular coordinates; all trajectories are directed toward a common final position; and all trajectories have the same direction independent of initial joint configuration. 4. Joint space paths in withdrawal were found to be straight and parallel independent of the initial joint configuration. The hip and knee were found to start simultaneously and in 75% of the conditions tested to reach maximum velocity simultaneously. Hip-knee maximum velocity ratios were similar in magnitude over differences in initial joint angles. This is consistent with the observation of parallel paths and supports the view that the nervous system specifies a single direction for equilibrium trajectories. 5. Straight line paths with slopes similar to those observed in withdrawal in the spinal preparation were found in swimming movements in the intact frog. Straight line paths in joint space are consistent with the idea that swimming and withdrawal are organized and controlled in a joint-level coordinate system. The similarities observed between spinal and intact preparations suggest that a common set of constructive elements underlies these behaviors. 6. Path curvature was introduced when joint limits were approached toward the end of the movement. Depending on the initial joint angles, the joint movements ended at different times. When initial joint angles were unequal, joints moving from smaller initial angles reached their functional limits earlier and stopped first. 7. In withdrawal and crossed extension in the spinal frog, velocity profiles at a given joint were similar over the initial portion of the curve for movements of different amplitude. This is consistent with the idea that withdrawal and crossed-extension movements of different amplitude are produced by a constant rate of shift of the equilibrium position.

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