Contribution of Feedback and Feedforward Strategies to Locomotor Adaptations

2006 ◽  
Vol 95 (2) ◽  
pp. 766-773 ◽  
Author(s):  
Tania Lam ◽  
Martin Anderschitz ◽  
Volker Dietz
Keyword(s):  
Feedforward Control ◽  
Human Subjects ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Null Condition ◽  
Adaptive Changes ◽  
Force Condition ◽  
Walking Pattern ◽  
Locomotor Adaptations

The aim of this study was to examine the strategies used by human subjects to adapt their walking pattern to a velocity-dependent resistance applied against hip and knee movements. Subjects first walked on a treadmill with their lower limbs strapped to an exoskeletal robotic gait orthosis with no resistance against leg motions (null condition). Afterward, a velocity-dependent resistance was applied against left hip and knee movements (force condition). Catch trials were interspersed throughout the experiment to track the development of adaptive changes in the walking pattern. After 188 steps in the force condition, subjects continued to step in the null condition for another 100 steps (washout period). Leg muscle activity and joint kinematics were recorded and analyzed. The adaptive modifications in the locomotor pattern suggest the involvement of both feedback and feedforward control strategies. Feedback-driven adaptations were reflected in increases in rectus femoris and tibialis anterior activity during swing, which occurred immediately, only in the presence of resistance, and not during the catch trials. Locomotor adaptations involving feedforward strategies were reflected in enhanced pre-swing activity in the biceps femoris and medial hamstrings muscles, which required experience and persisted in the catch trials. During washout subjects showed a gradual deadaptation of locomotor activity to control levels. In summary, adaptive changes in the walking pattern were driven by both feedback and feedforward adjustments in the walking pattern appropriate for overcoming the effects of resistance.

Muscle Activation in the Main Muscle Groups of the Lower Limbs in High-Level Dancesport Athletes

2018 ◽  
Vol 33 (4) ◽  
pp. 231-237
Author(s):  
Encarnación Liébana ◽  
Cristina Monleón ◽  
Raquel Morales ◽  
Carlos Pablos ◽  
Consuelo Moratal ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Gastrocnemius Medialis ◽  
Leg Muscles ◽  
Relative Activation ◽  
Muscle Groups ◽  
High Level

Dancers are subjected to high-intensity workouts when they practice dancesport, and according to the literature, they are prone to injury, primarily of the lower limbs. The purpose of this study was to determine whether differences exist in relative activation amplitudes for dancers involved in dancesport due to muscle, gender, and type of dance. Measurements were carried out using surface electromyography equipment during the choreography of a performance in the following leg muscles: rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius medialis. Eight couples of active dancesport athletes (aged 20.50±2.75 yrs) were analyzed. Significant gender differences were found in rumba in the tibialis anterior (p≤0.05) and gastrocnemius medialis (p≤0.05). Based on the different activations, it is possible to establish possible mechanisms of injury, as well as tools for preventing injuries and improving sports performance.

scholarly journals Functional assessment of muscle response in lower limbs of tumbling gymnasts through tensiomyography

2016 ◽  
Vol 64 (3) ◽  
pp. 505
Author(s):  
Nicolás Rojas-Barrionuevo ◽  
Mercedes Vernetta-Santana ◽  
Jesús López-Bedoya
Keyword(s):  
Delay Time ◽  
High Performance ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Response Speed ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Muscle Response ◽  
Antagonist Muscles ◽  
Before And After

Introduction: Jumping capacity, a distinctive technical skill of tumbling gymnasts, is associated to a successful performance in training and competition; hence the need for an individualized, precise and localized assessment of the most demanded muscle structures.Objective: To assess muscle response of the flexo-extension structure in the knee joint and the extension of the ankle joint in a sample of 12 high-performance male gymnasts.Materials and methods: An acrobatic training protocol including sets of forward somersault in tumbling track was conducted. The contraction time, delay time and deformation of muscle belly were evaluated, and the muscular response speed was calculated using tensiomyography before and after the training intervention in different periods of time.Results: Significant differences were found (p<0.05) according to the muscle group involved, where rectus femoris and biceps femoris presented greater enhancement and shortening of the contraction and delay time. Major differences appeared between agonist-antagonist muscles (vastus lateralis-biceps femoris) (p<0.05) due to a decrease in the contraction and delay speed in vastus medialis (p<0.001).Conclusions: Tensiomyography allows estimating the states of activation-enhancing of the musculature responsible of jumping in tumblers, as well as planning the training based on the state of muscle fatigue.

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

2017 ◽  
Vol 24 (4) ◽  
pp. 228-234
Author(s):  
Robert Staszkiewicz ◽  
Michał Kawulak ◽  
Leszek Nosiadek ◽  
Jarosław Omorczyk ◽  
Andrzej Nosiadek
Keyword(s):  
Electrical Activity ◽  
Action Potentials ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Cycle Ergometer ◽  
Lower Limbs ◽  
Bioelectrical Activity ◽  
Vastus Medialis ◽  
Similarities And Differences

AbstractIntroduction. 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.

scholarly journals Changes in Lower-Limb Biomechanics, Soft Tissue Vibrations, and Muscle Activation During Unanticipated Bipedal Landings

2019 ◽  
Vol 67 (1) ◽  
pp. 25-35
Author(s):  
Shen Zhang ◽  
Weijie Fu ◽  
Yu Liu
Keyword(s):  
Soft Tissue ◽  
Muscle Activation ◽  
Impact Force ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Drop Jump ◽  
Basketball Players ◽  
Drop Landing ◽  
Muscle Activations

AbstractWe aimed to explore the biomechanical differences between the anticipated drop jump and unanticipated drop landing. Twelve male collegiate basketball players completed an anticipated drop jump and unanticipated drop landing with double legs from a height of 30 cm. Kinematics, impact force, soft tissue vibrations, and electromyographic (EMG) amplitudes of the dominant leg were collected simultaneously. The anticipated drop jump showed more flexed lower limbs during landing and increased range of motion compared to the unanticipated drop landing. The anticipated drop jump also had lower impact force, lesser soft tissue vibration, and a greater damp coefficient at the thigh muscles compared with the unanticipated drop landing. Significant increases in the EMG amplitudes of the tibialis anterior, lateral gastrocnemius, rectus femoris, and biceps femoris were observed in the anticipated drop jump during the pre/post-activation and downward phases. The anticipated drop jump presented more optimized landing posture control with more joint flexion, lower impact force, less soft tissue vibrations, and full preparation of muscle activations compared with the unanticipated drop landing.

scholarly journals Effect of Dropping Height on the Forces of Lower Extremity Joints and Muscles during Landing: A Musculoskeletal Modeling

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Wenxin Niu ◽  
Lejun Wang ◽  
Chenghua Jiang ◽  
Ming Zhang
Keyword(s):  
Computational Simulation ◽  
Reaction Force ◽  
Gluteus Maximus ◽  
Lower Extremities ◽  
Rectus Femoris ◽  
Gluteus Medius ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Muscle Forces ◽  
Element Analysis

The objective of this study was to investigate the effect of dropping height on the forces of joints and muscles in lower extremities during landing. A total of 10 adult subjects were required to landing from three different heights (32 cm, 52 cm, and 72 cm), and the ground reaction force and kinematics of lower extremities were measured. Then, the experimental data were input into the AnyBody Modeling System, in which software the musculoskeletal system of each subject was modeled. The reverse dynamic analysis was done to calculate the joint and muscle forces for each landing trial, and the effect of dropping-landing on the results was evaluated. The computational simulation showed that, with increasing of dropping height, the vertical forces of all the hip, knee, and ankle joints, and the forces of rectus femoris, gluteus maximus, gluteus medius, vastii, biceps femoris and adductor magnus were all significantly increased. The increased dropping height also resulted in earlier activation of the iliopsoas, rectus femoris, gluteus medius, gluteus minimus, and soleus, but latter activation of the tibialis anterior. The quantitative joint and muscle forces can be used as loading conditions in finite element analysis to calculate stress and strain and energy absorption processes in various tissues of the lower limbs.

scholarly journals Electromyographic evaluation of the lower limbs of patients with Down syndrome in hippotherapy

2017 ◽  
Vol 39 (1) ◽  
pp. 17 ◽  
Author(s):  
Mariane Fernandes Ribeiro ◽  
Ana Paula Espindula ◽  
Alex Abadio Ferreira ◽  
Luciane Aparecida Pascucci Sande de Souza ◽  
Vicente De Paula Antunes Teixeira
Keyword(s):  
Down Syndrome ◽  
Muscle Activation ◽  
Motor Behavior ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Gluteus Medius ◽  
Biceps Femoris ◽  
Functional Results ◽  
Lower Limbs ◽  
Tensor Fasciae Latae

Hippotherapy is a therapeutic method that uses the horse’s movement to achieve functional results in practitioners with Down syndrome (DS), who present motor and neurophysiological changes that affect the musculoskeletal system. Evaluating the motor behavior related to the control and the improvement of muscle activation in practitioners with Down syndrome subjected to hippotherapy. 10 practitioners were divided into two groups: Down Group (DG) – practitioners with DS, and Healthy Group (HG) – practitioners with no physical impairment. The muscles gluteus medius, tensor fasciae latae, rectus femoris, vastus medialis, vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius were evaluated by electromyography using gross RMS values, which correspond to muscle activation; the evaluations were performed on the 1st and 10th hippotherapy sessions (frequency: once a week), and after 2 months interval without treatment, they were performed on the 1st and 10th hippotherapy sessions (frequency: twice a week). It was noted that activation of the studied muscles increased with the passing of sessions, regardless the weekly frequency of attendance; however, the period without treatment resulted in reduction of this effect. Practitioners with DS presented satisfactory changes in muscle activation pattern, in learning and in motor behavior during hippotherapy sessions. 

Role of the Unperturbed Limb and Arms in the Reactive Recovery Response to an Unexpected Slip During Locomotion

2003 ◽  
Vol 89 (4) ◽  
pp. 1727-1737 ◽  
Author(s):  
Daniel S. Marigold ◽  
Allison J. Bethune ◽  
Aftab E. Patla
Keyword(s):  
Imaging System ◽  
Center Of Mass ◽  
Rectus Femoris ◽  
Gluteus Medius ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Lower Limbs ◽  
Upper Body ◽  
Recovery Response

Understanding reactive recovery responses to slipping is fundamental in falls research and prevention. The primary purpose of this study was to investigate the role of the unperturbed limb and arms in the reactive recovery response to an unexpected slip. Ten healthy, young adults participated in this experiment in which an unexpected slip was induced by a set of steel free-wheeling rollers. Surface electromyography (EMG) data were collected from the unperturbed limb (i.e., the swing limb) rectus femoris, biceps femoris, tibialis anterior, and the medial head of gastrocnemius, and bilateral gluteus medius, erector spinae, and deltoids. Kinematic data were also collected by an optical imaging system to monitor limb trajectories. The first slip response was significantly different from the subsequent recovery responses to the unexpected slips, with an identifiable reactive recovery response and no proactive changes in EMG patterns. The muscles of the unperturbed limb, upper body, and arms were recruited at the same latency as those previously found for the perturbed limb. The arm elevation strategies assisted in shifting the center of mass forward after it was posteriorly displaced with the slip, while the unperturbed limb musculature demonstrated an extensor strategy supporting the observed lowering of the limb to briefly touch the ground to widen the base of support and to increase stability. Evidently a dynamic multilimb coordinated strategy is employed by the CNS to control and coordinate the upper and lower limbs in reactive recovery responses to unexpected slips during locomotion.

scholarly journals Kinesiological Analysis of Stationary Running Performed in Aquatic and Dry Land Environments

2015 ◽  
Vol 49 (1) ◽  
pp. 5-14 ◽  
Author(s):  
Cristine Lima Alberton ◽  
Stephanie Santana Pinto ◽  
Natália Amélia da Silva Azenha ◽  
Eduardo Lusa Cadore ◽  
Marcus Peikriszwili Tartaruga ◽  
...  
Keyword(s):  
Aquatic Environment ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Distinct Pattern ◽  
Lower Limbs ◽  
Maximal Velocity ◽  
Dry Land ◽  
Emg Signal ◽  
Neuromuscular Responses

Abstract The purpose of the present study was to analyze the electromyographic (EMG) signals of the rectus femoris (RF), vastus lateralis (VL), semitendinosus (ST) and short head of the biceps femoris (BF) during the performance of stationary running at different intensities in aquatic and dry land environments. The sample consisted of 12 female volunteers who performed the stationary running exercise in aquatic and dry land environments at a submaximal cadence (80 beats·min-1 controlled by a metronome) and at maximal velocity, with EMG signal measurements from the RF, VL, ST and BF muscles. The results showed a distinct pattern between environments for each muscle examined. For the submaximal cadence of 80 beats·min-1, there was a reduced magnitude of the EMG signal in the aquatic environment, except for the ST muscle, the pattern of which was similar in both environments. In contrast to the submaximal cadence, the pattern of the EMG signal from all of the muscles showed similar magnitudes for both environments and phases of movement at maximal velocity, except for the VL muscle. Therefore, the EMG signals from the RF, VL, ST and BF muscles of women during stationary running had different patterns of activation over the range of motion between aquatic and dry land environments for different intensities. Moreover, the neuromuscular responses of the lower limbs were optimized by an increase in intensity from submaximal cadence to maximal velocity.

scholarly journals Anticipatory Electromyographic Activity and Onset Time in Selected Muscles of Lower Limb Between the Active and Inactive Old Women

2019 ◽  
Vol 11 (2) ◽  
pp. 89-96
Author(s):  
Najme Noghani Ardestani ◽  
◽  
Rahman Sheikhhoseini ◽  
Farideh Babakhani ◽  
◽  
...  
Keyword(s):  
Lower Limb ◽  
Onset Time ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Activity Level ◽  
Lower Limbs ◽  
Electromyographic Activity ◽  
Biceps Femoris Muscle ◽  
Rectus Femoris Muscle ◽  
Femoris Muscle

Introduction: This study aimed to investigate the onset time and the electromyographic activity level of the selected lower limb muscles in the active and inactive old women. Materials and Methods: In this case-control study, 28 old women with a Mean±SD age of 61.07±0.88 years were selected in the inactive (15 people) and active (13 people) groups. The electrical activity of the selected muscles of the lower limbs was collected by the EMG device in a stair down movement. Results: The onset time of tibialis anterior, vastus lateralis, and biceps femoris muscles are faster in the active group (p <0.05). Besides, the activity level of the rectus femoris muscle in the interval of 100 ms before the initial contact and the ratio of the vastus medialis muscle to the biceps femoris muscle was significantly lower (p <0.05) in the active group. Conclusion: It seems that the muscles of the lower limbs in the group of women with regular physical activity are activated faster than the inactive group and the decrease in the activity of the rectus femoris muscle and the ratio of the vastus medialis to the biceps femoris muscle in the active women may be accompanied by fatigue and reduced intra-articular forces. Therefore, it is recommended that old women participate in regular and active exercise programs to improve their onset times of muscle activity.

scholarly journals Bilateral Asymmetries Assessment in Elite and Sub-Elite Male Futsal Players

2020 ◽  
Vol 17 (9) ◽  
pp. 3169 ◽  
Author(s):  
Jorge López-Fernández ◽  
Jorge García-Unanue ◽  
Javier Sánchez-Sánchez ◽  
Enrique Colino ◽  
Enrique Hernando ◽  
...  
Keyword(s):  
Fat Mass ◽  
Rectus Femoris ◽  
Bioelectrical Impedance ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Mass Percentage ◽  
Balance Test ◽  
Bilateral Asymmetry ◽  
Morphological Asymmetry ◽  
The Third

This study aimed to investigate morphological, functional, and neuromuscular asymmetries on futsal players’ lower limbs at different competitive levels. Sixteen male elite futsal players from the Spanish National Futsal League and thirteen male sub-elite futsal players from the third division participated in this study. Morphological asymmetry was assessed through bioelectrical impedance (fat-mass (g and %) and lean-mass (g)). Functional asymmetry was assessed by means of a 20-s static unipedal balance test. Finally, neuromuscular asymmetry was assessed using tensiomiography tests on both the rectus femoris (RF) and biceps femoris (BF) of each participant. The three tests conducted did not reveal significant bilateral asymmetries in elite players. On the other hand, sub-elite players showed significant bilateral asymmetry in fat-mass percentage between dominant and non-dominant limbs (+6%; CI95%: 1 to 11; ES: 0.88; p = 0.019). They also showed higher bilateral asymmetry in the delay time of the RF (+13%; CI95%: 7 to 21; ES: 1.3; p < 0.05). However, the static unipedal balance test (p > 0.05) did not evidence asymmetries regardless of the level of the participants. Elite futsal players do not develop bilateral asymmetries in lower limbs in the studied parameters. On the contrary, sub-elite players are likely to develop morphological and neuromuscular asymmetries between their dominant leg and non-dominant leg.

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