scholarly journals Temporal and spatial asymmetries during stationary cycling cause different feedforward and feedback modifications in the muscular control of the lower limbs

2019 ◽  
Vol 121 (1) ◽  
pp. 163-176 ◽  
Author(s):  
Magdalena Zych ◽  
Ian Rankin ◽  
Donal Holland ◽  
Giacomo Severini
Keyword(s):  
Lower Limb ◽  
Neuromuscular Control ◽  
Task Demands ◽  
The Other ◽  
Lower Limbs ◽  
Muscle Synergy ◽  
Accelerometer Data ◽  
Temporal Asymmetry ◽  
Spatial Asymmetries ◽  
The Right

Motor adaptations are useful for studying the way in which the lower limbs are controlled by the brain. However, motor adaptation paradigms for the lower limbs are typically based on locomotion tasks, where the necessity of maintaining postural stability is the main driver of adaptation and could possibly mask other underlying processes. In this study we investigated whether small temporal or spatial asymmetries can trigger motor adaptations during stationary cycling, where stability is not directly compromised. Fourteen healthy individuals participated in two experiments: in one of the experiments, the angle between the crank arms of the pedals was altered by 10° to induce a temporal asymmetry; in the other experiment, the length of the right pedal was shortened by 2.4 cm to induce a spatial asymmetry. We recorded the acceleration of the crank arms and the electromographic signals of 16 muscles (8 per leg). The analysis of the accelerometer data was used to investigate the presence of motor adaptations. Muscle synergy analysis was performed on each side to quantify changes in neuromuscular control. We found that motor adaptations are present in response to temporal asymmetries and are obtained by progressively shifting the activation patterns of two synergies on the right leg. Spatial asymmetries, on the other hand, appear to trigger a feedback-driven response that does not present an aftereffect. This response is characterized by a steplike decrease in activity in the right gastrocnemius when the asymmetry is present and likely reflects the altered task demands. NEW & NOTEWORTHY The processes driving lower limb motor adaptations are not fully clear, and previous research appears to indicate that adaptations are mainly driven by stability. We show that lower limb adaptations can be obtained also in the absence of an explicit balance threat. We also show that adaptations are present when kinematic error cannot be compensated for, suggesting the presence of intrinsic error measures regulating the timing of activation of the two legs.

scholarly journals Temporal and spatial asymmetries during stationary cycling cause different feedforward and feedback modifications in the muscular control of the lower limbs

2018 ◽  
Author(s):  
Magdalena Zych ◽  
Ian Rankin ◽  
Donal Holland ◽  
Giacomo Severini
Keyword(s):  
Lower Limb ◽  
Motor Adaptation ◽  
Neuromuscular Control ◽  
Task Demands ◽  
Lower Limbs ◽  
Muscle Synergy ◽  
Accelerometer Data ◽  
Temporal Asymmetry ◽  
Spatial Asymmetries ◽  
The Right

AbstractMotor adaptations are useful for studying the way in which the lower limbs are controlled by the brain. However, motor adaptation paradigms for the lower limbs are typically based on locomotion tasks, where the necessity of maintaining postural stability is the main driver of adaptation and could possibly mask other underlying processes. In this study we investigated whether small temporal or spatial asymmetries can trigger motor adaptations during stationary cycling, where stability is not directly compromised. Fourteen healthy individuals participated in two experiments: in one of the experiments the angle between the crank arms of the pedals was altered by 10° to induce a temporal asymmetry; in the other the length of the right pedal was shortened by 2.4 cm to induce a spatial asymmetry. We recorded the acceleration of the crank arms and the EMG signals of 16 muscles (8 per leg). The analysis of the accelerometer data was used to investigate the presence of motor adaptations. Muscle synergy analysis was performed on each side to quantify changes in neuromuscular control. We found that feedforward motor adaptations are present in response to temporal asymmetries and are obtained by progressively shifting the activation patterns of two synergies on the right leg. Spatial asymmetries appear to trigger a feedback-driven response that does not present an aftereffect and is not consistent with a motor adaptation. This response is characterized by a step-like decrease in activity in the right gastrocnemius when the asymmetry is present and likely reflects the altered task demands.New and NoteworthyThe processes driving lower limb motor adaptations are not fully clear, and previous research appears to indicate that adaptations are mainly driven by stability. Here we show that lower limb adaptations can be obtained also in the absence of an explicit balance threat. We also show that adaptations are present also when kinematic error cannot be compensated for, suggesting the presence of intrinsic error measures regulating the timing of activation of the two legs.

scholarly journals An Evaluation of Symmetry in the Lower Limb Joints During the Able-Bodied Gait of Women and Men

2012 ◽  
Vol 35 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Wanda Forczek ◽  
Robert Staszkiewicz
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Temporal Structure ◽  
Asymmetry Index ◽  
Lower Limbs ◽  
Inclusion Criteria ◽  
3D Motion Analysis ◽  
Spatio Temporal ◽  
Analysis System ◽  
The Right

For many years, mainly to simplify data analysis, scientists assumed that during a gait, the lower limbs moved symmetrically. However, even a cursory survey of the more recent literature reveals that the human walk is symmetrical only in some aspects. That is why the presence of asymmetry should be considered in all studies of locomotion. The gait data were collected using the 3D motion analysis system Vicon. The inclusion criteria allowed the researchers to analyze a very homogenous group, which consisted of 54 subjects (27 women and 27 men). Every selected participant moved at a similar velocity: approximately 1,55 m/s. The analysis included kinematic parameters defining spatio-temporal structure of locomotion, as well as angular changes of the main joints of the lower extremities (ankle, knee and hip) in the sagittal plane. The values of those variables were calculated separately for the left and for the right leg in women and men. This approach allowed us to determine the size of the differences, and was the basis for assessing gait asymmetry using a relative asymmetry index, which was constructed by the authors. Analysis of the results demonstrates no differences in the temporal and phasic variables of movements of the right and left lower limb. However, different profiles of angular changes in the sagittal plane were observed, measured bilaterally for the ankle joint.

scholarly journals Asymmetry and changes in the neuromuscular profile of short-track athletes as a result of strength training

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261265
Author(s):  
Paweł Pakosz ◽  
Anna Lukanova-Jakubowska ◽  
Edyta Łuszczki ◽  
Mariusz Gnoiński ◽  
Oscar García-García
Keyword(s):  
Strength Training ◽  
Lower Limb ◽  
Female Athletes ◽  
Lower Limbs ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Before And After ◽  
Monthly Period ◽  
Track Athletes ◽  
The Right

Background The purpose of this study was to identify the biomedical signals of short-track athletes by evaluating the effects of monthly strength training on changes in their neuromuscular profile, strength, and power parameters of the lower limb muscles. Muscle asymmetry, which can cause a risk of injury, was also evaluated. Methods and results This study involved female athletes, age 18.8 ± 2.7 years, with a height of 162 ± 2.4 cm, and weight of 55.9 ± 3.9 kg. Before and after the monthly preparatory period prior to the season, strength measurements were assessed through the Swift SpeedMat platform, and reactivity of the lower limb muscles was assessed with tensiomyography (TMG). The athletes were also tested before and after the recovery training period. In the test after strength training, all average countermovement jump (CMJ) results improved. Flight time showed an increase with a moderate to large effect, using both legs (5.21%). Among the TMG parameters, time contraction (Tc) changed globally with a decrease (-5.20%). Changes in the results of the test after recovery training were most often not significant. Conclusion A monthly period of strength training changes the neuromuscular profile of short-track female athletes, with no significant differences between the right and left lower limbs.

scholarly journals Brain Activity during Lower-Limb Movement with Manual Facilitation: An fMRI Study

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Patrícia Maria Duarte de Almeida ◽  
Ana Isabel Correia Matos de Ferreira Vieira ◽  
Nádia Isabel Silva Canário ◽  
Miguel Castelo-Branco ◽  
Alexandre Lemos de Castro Caldas
Keyword(s):  
Motor Control ◽  
Lower Limb ◽  
Healthy Subjects ◽  
Brain Activity ◽  
Verbal Stimulus ◽  
Limb Movement ◽  
Lower Limbs ◽  
Normal Brain ◽  
Lower Limb Movement ◽  
The Right

Brain activity knowledge of healthy subjects is an important reference in the context of motor control and reeducation. While the normal brain behavior for upper-limb motor control has been widely explored, the same is not true for lower-limb control. Also the effects that different stimuli can evoke on movement and respective brain activity are important in the context of motor potentialization and reeducation. For a better understanding of these processes, a functional magnetic resonance imaging (fMRI) was used to collect data of 10 healthy subjects performing lower-limb multijoint functional movement under three stimuli: verbal stimulus, manual facilitation, and verbal + manual facilitation. Results showed that, with verbal stimulus, both lower limbs elicit bilateral cortical brain activation; with manual facilitation, only the left lower limb (LLL) elicits bilateral activation while the right lower limb (RLL) elicits contralateral activation; verbal + manual facilitation elicits bilateral activation for the LLL and contralateral activation for the RLL. Manual facilitation also elicits subcortical activation in white matter, the thalamus, pons, and cerebellum. Deactivations were also found for lower-limb movement. Manual facilitation is stimulus capable of generating brain activity in healthy subjects. Stimuli need to be specific for bilateral activation and regarding which brain areas we aim to activate.

scholarly journals Study of Nutrient Foramina in Human Typical Long Bones of Lower Limb

2019 ◽  
Vol 08 (02) ◽  
pp. 077-081 ◽  
Author(s):  
Ajay Parmar ◽  
Pankaj Maheria ◽  
Kanan Shah
Keyword(s):  
Blood Supply ◽  
Lower Limb ◽  
Fracture Repair ◽  
Lower Limbs ◽  
Long Bones ◽  
Posterior Aspect ◽  
Nutrient Foramen ◽  
Nutrient Artery ◽  
Nutrient Foramina ◽  
The Right

Abstract Background and Aim Nutrient foramina form important landmarks on human bones as they form portal of entry for nutrient artery. Nutrient artery is an important source of blood supply for a growing bone. Different parameters of nutrient foramina are important in various procedures such as vascularized bone grafting, tumor resections, fracture repair, and other surgical procedures in orthopedics. The objective of the present study was to report the number, position, direction, size, and foraminal index of nutrient foramen in the femur, tibia, and fibula. Materials and Methods The present study analyzed the location, direction, size, and the number of nutrient foramina in the diaphysis of 180 long bones of the lower limbs of adults: 60 femurs, 60 tibiae, and 60 fibulae. Result The location of the nutrient foramina is predominant on the posterior aspect of the lower limb long bones. Single nutrient foramen found in the tibia (100%), femur (48.3%), and fibula (60%) may represent as a single source of blood supply. The majority of the femur (50%) and few fibulae (5%) had a double nutrient foramen. The mean foraminal index for the lower limb bones was 40.5% for the left and 38.2% for the right side of the femur, 31.69% for the left and 32.3% for the right side of the tibia, and 32.7% for the left and 31.7% for the right side of the fibula. Conclusion The present study provides information on the number, size, position, and direction of nutrient foramina of the femur, tibia, and fibula bones.

A Prospective Study of Postoperative Lymphedema After Surgery for Cervical Cancer

2010 ◽  
Vol 20 (5) ◽  
pp. 900-904 ◽  
Author(s):  
Michael J. Halaska ◽  
Marta Novackova ◽  
Ivana Mala ◽  
Marek Pluta ◽  
Roman Chmel ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Lower Limb ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Conservative Surgery ◽  
Cancer Surgery ◽  
Lower Limbs ◽  
Control Group ◽  
The Right ◽  
A Prospective Study

Objective:Lymphedema is a severe postoperative complication in oncological surgery. Multifrequency bioelectrical impedance analysis (MFBIA) is a new method for early lymphedema detection. The objective was to establish the methodology of MFBIA for lower-limb lymphedema and to detect a lymphedema in patients undergoing cervical cancer surgery.Methods:From a population of 60 patients undergoing cervical cancer surgery, 39 underwent radical hysterectomy Wertheim III (RAD group), and 21 underwent conservative surgery (laparoscopic lymphadenectomy plus simple trachelectomy/simple hysterectomy - CONS group). A control group of 29 patients (CONTR group) was used to determine the SD of impedance at zero frequency (R0). Patients were examined before surgery and at 3 and 6 months after surgery by MFBIA and by measuring the circumference of the lower limbs.Results:No differences were found between the CONS and RAD groups on age, height, weight, and histopathologic type of tumor. However, the number of dissected lymph nodes differed significantly between the groups (17.3 in the CONS group vs 25.8 in the RAD group,P= 0.0012). The SD ofR0in the CONTR group was 36.0 and 39.0 for the right and the left leg, respectively. No difference in prevalence of lymphedema based on circumference method was found (35.9% in the RAD and 47.6% in the CONS groups, not statistically significant).Conclusions:No difference in the prevalence of lymphedema was found between the CONS and RAD groups. A methodology for MFBIA for the detection of lower-limb lymphedema was described.

scholarly journals Amble Gait EEG Points at Complementary Cortical Networks Underlying Stereotypic Multi-Limb Co-ordination

2021 ◽  
Vol 15 ◽  
Author(s):  
Joyce B. Weersink ◽  
Natasha M. Maurits ◽  
Bauke M. de Jong
Keyword(s):  
Lower Limb ◽  
Primary Motor Cortex ◽  
Right Hemisphere ◽  
Gait Pattern ◽  
Lower Limbs ◽  
Human Gait ◽  
Hemisphere Dominance ◽  
The Right ◽  
Spectral Perturbation ◽  
Healthy Participants

BackgroundWalking is characterized by stable antiphase relations between upper and lower limb movements. Such bilateral rhythmic movement patterns are neuronally generated at levels of the spinal cord and brain stem, that are strongly interconnected with cortical circuitries, including the Supplementary Motor Area (SMA).ObjectiveTo explore cerebral activity associated with multi-limb phase relations in human gait by manipulating mutual attunement of the upper and lower limb antiphase patterns.MethodsCortical activity and gait were assessed by ambulant EEG, accelerometers and videorecordings in 35 healthy participants walking normally and 19 healthy participants walking in amble gait, where upper limbs moved in-phase with the lower limbs. Power changes across the EEG frequency spectrum were assessed by Event Related Spectral Perturbation analysis and gait analysis was performed.ResultsAmble gait was associated with enhanced Event Related Desynchronization (ERD) prior to and during especially the left swing phase and reduced Event Related Synchronization (ERS) at final swing phases. ERD enhancement was most pronounced over the putative right premotor, right primary motor and right parietal cortex, indicating involvement of higher-order organization and somatosensory guidance in the production of this more complex gait pattern, with an apparent right hemisphere dominance. The diminished within-step ERD/ERS pattern in amble gait, also over the SMA, suggests that this gait pattern is more stride driven instead of step driven.ConclusionIncreased four-limb phase complexity recruits distributed networks upstream of the primary motor cortex, primarily lateralized in the right hemisphere. Similar parietal-premotor involvement has been described to compensate impaired SMA function in Parkinson’s disease bimanual antiphase movement, indicating a role as cortical support regions.

scholarly journals Effect of lower limb dominance on walking adaptations in young adults when stepping into a hole

2020 ◽  
Vol 13 (5) ◽  
pp. 133-143
Author(s):  
Luciana Oliveira Dos Santos ◽  
Andréia Abud da Silva Costa ◽  
Renato Moraes
Keyword(s):  
Young Adults ◽  
Lower Limb ◽  
The Other ◽  
Lower Limbs ◽  
Normal Walking ◽  
Other Hand ◽  
The Individual ◽  
Limb Dominance

Background. Depending on the dimensions of a hole, the characteristics of the walking surface, and the position of the hole relative to normal walking, individuals may need to step into the hole with the dominant or non-dominant limb. Aim. We investigated the effect of the lower limb dominance in walking adaptations in the presence of a hole on the ground. Methods: Twenty young adults walked and stepped into a hole positioned in the middle of the pathway using the dominant and non-dominant lower limbs. Results. For the trailing limb, the impulses were not affected by the lower limb dominance, but for the leading limb, the non-dominant leg increased the braking and propulsive impulses compared to the dominant leg. On the other hand, toe-off velocity increased when the non-dominant leg was used as trailing and leading limbs. Stride speed increased when the non-dominant leg was the trailing limb. Interpretation. Our results were consistent with asymmetrical behavior between dominant and non-dominant legs. Although the differences between the dominant and non-dominant legs have not affected the success in the task, they can put the individual at higher risk of stumbling and consequently a fall when stepping with the non-dominant leg into the hole.

Determination of lower limbs loading during balance beam exercise

2020 ◽  
Author(s):  
Petr Hedbávný ◽  
Miriam Kalichová ◽  
Michal Rabenseifner ◽  
Adam Borek
Keyword(s):  
Lower Limb ◽  
Reaction Force ◽  
The Other ◽  
Lower Limbs ◽  
Balance Beam ◽  
Video Recordings ◽  
Maximum Reaction ◽  
Load Asymmetry ◽  
Load Volume ◽  
Reaction Forces

In women’s artistic gymnastics, the balance beam belongs among the disciplines with the heaviest lower limbs load. The aim of our research was to disclose a lower limbs weekly load volume regarding load asymmetry, and to determine the take-off and landing reaction forces between landing ground and foot in selected gymnastic elements. In 9 female artistic gymnasts of junior and senior category one training week was video-recorded and analysed. The reaction forces were measured using 5 Bertec force plates in one female Czech nation-al team member. Based on the training video recordings 12 jump and acrobatic elements were analysed. Among the total of 422 recorded take-offs and landings 41% were performed from both legs, (BL), 44.5% from one lower limb (HL) and 14.5% from the other lower limb (LL). The maximum reaction force of the landing ground during take-offs was 2.4 BW in av-erage, 3.1 BW in landings. In asymmetrical elements, one leg was loaded three times more (538.3 BW) than the other (174.1 BW) in one training day in total. We recommend to record the load asymmetry in the course of the gymnastic trainings in order to choose and person-alise the appropriate regeneration process and compensational exercise.

scholarly journals 055 An unusual presentation of SOD1-ALS: a case report

2019 ◽  
Vol 90 (e7) ◽  
pp. A18.1-A18
Author(s):  
Allycia MacDonald ◽  
Jason Dyke ◽  
Simon Khangure ◽  
Andrew Kelly
Keyword(s):  
Lower Limb ◽  
Nerve Root ◽  
Neuronal Degeneration ◽  
Case Reports ◽  
Cauda Equina ◽  
Lower Limbs ◽  
High Dose ◽  
Initial Examination ◽  
Limb Weakness ◽  
The Right

IntroductionApproximately 10% of amyotrophic lateral sclerosis (ALS) cases are inherited, of which 20% are due to mutations in the superoxide dismutase-1 gene (SOD1). MRI abnormalities are not uncommon in ALS, and there have been previous case reports of peripheral nerve enhancement in patients with SOD1 mutations, typically attributed to rapid neuronal degeneration.CaseA 31-year-old previously well Malaysian woman presented with a 3 month history of progressive lower limb weakness, initially involving the right lower limb but progressing to involve the left, requiring the use of a walking aid. Initial examination demonstrated asymmetric upper and lower motor neuron signs in bilateral upper and lower limbs. EMG findings were of a severe pure motor axonal process. CSF examination revealed elevated protein without significant elevation of white cells. MRI brain and spine demonstrated smooth cauda-equina ventral nerve root thickening and enhancement. Treatment with intravenous immunoglobulin and high dose corticosteroid was commenced for a presumed inflammatory process, with no clinical improvement. A cauda-equina nerve root biopsy was performed, demonstrating features consistent with an immune-mediated demyelinating neuropathy. The patient continued to deteriorate, developing flaccid upper limb weakness and facial involvement. Plasma exchange, azathioprine, cyclophosphamide, and rituximab were sequentially administered over the following two months without altering the rate of disease progression. Genetic testing returned a positive SOD1 heterozygous gene mutation, confirming the diagnosis of ALS.ConclusionsWe present a case of SOD1-ALS with atypical features on imaging and histopathology suggesting an underlying demyelinating process, expanding the known clinical spectrum of this mutation.

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