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Roeder L, Breakspear M, Kerr GK, Boonstra TW. Dynamics of brain-muscle networks reveal effects of age and somatosensory function on gait. iScience 2024; 27:109162. [PMID: 38414847 PMCID: PMC10897916 DOI: 10.1016/j.isci.2024.109162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/16/2023] [Accepted: 02/05/2024] [Indexed: 02/29/2024] Open
Abstract
Walking is a complex motor activity that requires coordinated interactions between the sensory and motor systems. We used mobile EEG and EMG to investigate the brain-muscle networks involved in gait control during overground walking in young people, older people, and individuals with Parkinson's disease. Dynamic interactions between the sensorimotor cortices and eight leg muscles within a gait cycle were assessed using multivariate analysis. We identified three distinct brain-muscle networks during a gait cycle. These networks include a bilateral network, a left-lateralized network activated during the left swing phase, and a right-lateralized network active during the right swing. The trajectories of these networks are contracted in older adults, indicating a reduction in neuromuscular connectivity with age. Individuals with the impaired tactile sensitivity of the foot showed a selective enhancement of the bilateral network, possibly reflecting a compensation strategy to maintain gait stability. These findings provide a parsimonious description of interindividual differences in neuromuscular connectivity during gait.
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Affiliation(s)
- Luisa Roeder
- School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
- School of Information Systems, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia
- Chair of Human Movement Science, Department of Sport and Health Sciences, Technical University of Munich, Munich, Germany
| | - Michael Breakspear
- College of Engineering Science and Environment, College of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
| | - Graham K Kerr
- School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Tjeerd W Boonstra
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
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Hagen AC, Patrick CM, Bast IE, Fling BW. Propulsive Force Modulation Drives Split-Belt Treadmill Adaptation in People with Multiple Sclerosis. SENSORS (BASEL, SWITZERLAND) 2024; 24:1067. [PMID: 38400224 PMCID: PMC10891828 DOI: 10.3390/s24041067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 01/26/2024] [Accepted: 02/01/2024] [Indexed: 02/25/2024]
Abstract
Most people with multiple sclerosis (PwMS) experience significant gait asymmetries between their legs during walking, leading to an increased risk of falls. Split-belt treadmill training, where the speed of each limb is controlled independently, alters each leg's stepping pattern and can improve gait symmetry in PwMS. However, the biomechanical mechanisms of this adaptation in PwMS remain poorly understood. In this study, 32 PwMS underwent a 10 min split-belt treadmill adaptation paradigm with the more affected (MA) leg moving twice as fast as the less affected (LA) leg. The most noteworthy biomechanical adaptation observed was increased peak propulsion asymmetry between the limbs. A kinematic analysis revealed that peak dorsiflexion asymmetry and the onset of plantarflexion in the MA limb were the primary contributors to the observed increases in peak propulsion. In contrast, the joints in the LA limb underwent only immediate reactive adjustments without subsequent adaptation. These findings demonstrate that modulation during gait adaptation in PwMS occurs primarily via propulsive forces and joint motions that contribute to propulsive forces. Understanding these distinct biomechanical changes during adaptation enhances our grasp of the rehabilitative impact of split-belt treadmill training, providing insights for refining therapeutic interventions aimed at improving gait symmetry.
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Affiliation(s)
- Andrew C. Hagen
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523-1582, USA; (C.M.P.); (I.E.B.)
| | - Christopher M. Patrick
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523-1582, USA; (C.M.P.); (I.E.B.)
- Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO 80523-1617, USA
| | - Isaac E. Bast
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523-1582, USA; (C.M.P.); (I.E.B.)
| | - Brett W. Fling
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523-1582, USA; (C.M.P.); (I.E.B.)
- Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO 80523-1617, USA
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Alteration of ankle proprioceptive threshold during gait in the presence of acute experimental pain. PLoS One 2022; 17:e0263161. [PMID: 35078205 PMCID: PMC8789182 DOI: 10.1371/journal.pone.0263161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/12/2022] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE Human gait requires complex somatosensory processing of various inputs such as proprioception. Proprioception can be altered in the presence of pain. This has been shown mostly during controlled tasks, thereby limiting the influence of external perturbations. While controlling the environment is sometimes warranted, it limits the ecological validity of the data. Using robotic orthoses to apply perturbations during movements seems a promising tool to functionally assess proprioception, where the complex somatosensory processing required in real-life situations is at play. The main objective of this study was to compare the proprioceptive threshold of healthy participants during gait in the presence and absence of an acute experimental pain. METHODS 36 healthy participants walked on a treadmill while wearing a robotized ankle-foot orthosis (rAFO) around their right ankle. The rAFO applied torque perturbations of graded magnitudes during the swing phase of gait. Participants had to report the presence/absence of such perturbations, as a measure of proprioceptive threshold. Following initial assessment, they were randomly assigned to one of three experimental groups: Control (no stimulation), Painless (non-nociceptive stimulation) and Painful (nociceptive stimulation). Electrodes placed on the right lateral malleolus delivered an electrical stimulation during the second assessment for Painless and Painful groups. A Kruskal-Wallis was used to compare the percentage of change of the three groups between the two assessments. RESULTS A 31.80±32.94% increase in proprioceptive threshold, representing an increase of 1.3±1.2 Nm in the detection threshold, was observed for the Painful group only (p<0.005), with an effect size of 1.6. CONCLUSION Findings show that the presence of pain at the ankle can alter participants' proprioceptive threshold during gait. Clinical assessment of proprioception should therefore carefully consider the presence of pain when evaluating a patient's performance using clinical proprioceptive test and consider the negative effect of pain on proprioceptive threshold for test interpretation.
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Sato S, Choi JT. Neural Control of Human Locomotor Adaptation: Lessons about Changes with Aging. Neuroscientist 2021; 28:469-484. [PMID: 34014124 DOI: 10.1177/10738584211013723] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Walking patterns are adaptable in response to different environmental demands, which requires neural input from spinal and supraspinal structures. With an increase in age, there are changes in walking adaptation and in the neural control of locomotion, but the age-related changes in the neural control of locomotor adaptation is unclear. The purpose of this narrative review is to establish a framework where the age-related changes of neural control of human locomotor adaptation can be understood in terms of reactive feedback and predictive feedforward control driven by sensory feedback during locomotion. We parse out the effects of aging on (a) reactive adaptation to split-belt walking, (b) predictive adaptation to split-belt walking, (c) reactive visuomotor adaptation, and (d) predictive visuomotor adaptation, and hypothesize that specific neural circuits are influenced differentially with age, which influence locomotor adaptation. The differences observed in the age-related changes in walking adaptation across different locomotor adaptation paradigms will be discussed in light of the age-related changes in the neural mechanisms underlying locomotion.
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Affiliation(s)
- Sumire Sato
- Neuroscience and Behavior Program, University of Massachusetts Amherst, Amherst, MA, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Julia T Choi
- Neuroscience and Behavior Program, University of Massachusetts Amherst, Amherst, MA, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
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Dambreville C, Pairot de Fontenay B, Blanchette AK, Roy JS, Mercier C, Bouyer L. Ankle proprioception during gait in individuals with incomplete spinal cord injury. Physiol Rep 2019; 7:e14328. [PMID: 31883208 PMCID: PMC6934873 DOI: 10.14814/phy2.14328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Proprioception is known to be affected after a spinal cord injury (SCI). However, it is currently assessed during simple tasks that do not reflect activities of daily living. To better understand how proprioception affects movement, assessing it during a functional sensorimotor task such as walking is therefore of primary importance. Therefore, the objectives of this study were as follows: (a) measure the protocol reliability of a new robotic test in nondisabled controls; (b) evaluate the effect nonlesion-related factors such as sex, age, pain, and gait speed on ankle proprioception; and (c) assess ankle proprioception during walking in individuals with SCI. METHODS In the current study, ankle proprioception was assessed during gait in individuals with an incomplete spinal cord injury (iSCI; n = 15) using an electrohydraulic robotized ankle-foot orthosis (rAFO). Ankle proprioceptive threshold was quantified as the participants' ability to detect torque perturbations of varied amplitude applied during swing by the rAFO. In addition, test-retest reliability and the potential effect of nonlesion-related factors (sex, age, pain, and gait speed) were evaluated in nondisabled (ND; n = 65) participants. RESULTS During gait, individuals with iSCI had a 53% poorer proprioceptive threshold than ND controls (p < .05). Test-retest reliability was good (ICC = 0.78), and only gait speed affected proprioceptive threshold (p = .018). CONCLUSION This study is the first to show that ankle proprioception assessed during gait is impaired in individuals with an iSCI. The developed test can now be used to better characterize proprioception in population with other neurological conditions and has potential to maximize functional recovery during gait training in those populations.
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Affiliation(s)
- Charline Dambreville
- Centre for Interdisciplinary Research in Rehabilitation And Social Integration, Quebec City, QC, Canada
| | - Benoit Pairot de Fontenay
- Centre for Interdisciplinary Research in Rehabilitation And Social Integration, Quebec City, QC, Canada
| | - Andreanne K Blanchette
- Centre for Interdisciplinary Research in Rehabilitation And Social Integration, Quebec City, QC, Canada.,Department of Rehabilitation, Faculty of Medicine, Universite Laval, Quebec City, QC, Canada
| | - Jean-Sebastien Roy
- Centre for Interdisciplinary Research in Rehabilitation And Social Integration, Quebec City, QC, Canada.,Department of Rehabilitation, Faculty of Medicine, Universite Laval, Quebec City, QC, Canada
| | - Catherine Mercier
- Centre for Interdisciplinary Research in Rehabilitation And Social Integration, Quebec City, QC, Canada.,Department of Rehabilitation, Faculty of Medicine, Universite Laval, Quebec City, QC, Canada
| | - Laurent Bouyer
- Centre for Interdisciplinary Research in Rehabilitation And Social Integration, Quebec City, QC, Canada.,Department of Rehabilitation, Faculty of Medicine, Universite Laval, Quebec City, QC, Canada
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Sombric CJ, Calvert JS, Torres-Oviedo G. Large Propulsion Demands Increase Locomotor Adaptation at the Expense of Step Length Symmetry. Front Physiol 2019; 10:60. [PMID: 30800072 PMCID: PMC6376174 DOI: 10.3389/fphys.2019.00060] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/18/2019] [Indexed: 11/23/2022] Open
Abstract
There is an interest to identify factors facilitating locomotor adaptation induced by split-belt walking (i.e., legs moving at different speeds) because of its clinical potential. We hypothesized that augmenting braking forces, rather than propulsion forces, experienced at the feet would increase locomotor adaptation during and after split-belt walking. To test this, forces were modulated during split-belt walking with distinct slopes: incline (larger propulsion than braking), decline (larger braking than propulsion), and flat (similar propulsion and braking). Step length asymmetry was compared between groups because it is a clinically relevant measure robustly adapted on split-belt treadmills. Unexpectedly, the group with larger propulsion demands (i.e., the incline group) changed their gait the most during adaptation, reached their final adapted state more quickly, and had larger after-effects when the split-belt perturbation was removed. We also found that subjects who experienced larger disruptions of propulsion forces in early adaptation exhibited greater after-effects, which further highlights the catalytic role of propulsion forces on locomotor adaptation. The relevance of mechanical demands on shaping our movements was also indicated by the steady state split-belt behavior, during which each group recovered their baseline leg orientation to meet leg-specific force demands at the expense of step length symmetry. Notably, the flat group was nearly symmetric, whereas the incline and decline group overshot and undershot step length symmetry, respectively. Taken together, our results indicate that forces propelling the body facilitate gait changes during and after split-belt walking. Therefore, the particular propulsion demands to walk on a split-belt treadmill might explain the gait symmetry improvements in hemiparetic gait following split-belt training.
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Affiliation(s)
| | | | - Gelsy Torres-Oviedo
- Sensorimotor Learning Laboratory, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
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Howe EE, Toth AJ, Bent LR. Online visual cues can compensate for deficits in cutaneous feedback from the dorsal ankle joint for the trailing limb but not the leading limb during obstacle crossing. Exp Brain Res 2018; 236:2887-2898. [PMID: 30073386 DOI: 10.1007/s00221-018-5342-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 07/21/2018] [Indexed: 11/24/2022]
Abstract
Precise control of the ankle is required to safely clear the ground during walking. Skin input contributes to proprioception about the ankle joint, during both passive movements and level walking. How skin might contribute to proprioceptive control of the ankle during a more complex functional task such as obstacle avoidance is unknown. The purpose of this study was to investigate skin contribution from the dorsum of the ankle joint to safely cross an obstacle, and examine the interaction between vision and skin. It was hypothesized that the lead and trail limbs would be influenced primarily by visual information and skin cues, respectively. Eleven healthy adults crossed an obstacle with either (1) intact sensory input (control) (2) reduced skin input using a topical anesthetic (anesthesia), (3) reduced visual input of the lower half of the visual field (partial vision) or (4) simultaneous reduction of skin and vision (paired). Kinematic measures of phase-dependent changes during these conditions were examined while subjects crossed the obstacle with their anesthetised foot as either the leading or trailing limb. Interestingly, lead limb toe trajectory was significantly affected both by deficits in visual and skin input, although the joint angle strategies differed across these sensory conditions. Subjects increased lead hip flexion with partial vision but increased hip roll with skin anesthesia relative to control. In contrast, trail limb toe trajectory was affected only by visual sensory loss. Overall visual feedback and skin input from the ankle dorsum differentially affect lead and trail limb kinematics to successfully cross an obstacle. Interestingly, it appears vision is not entirely able to compensate for reduced skin input during obstacle crossing.
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Affiliation(s)
- Erika E Howe
- Department Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Adam J Toth
- Department Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Leah R Bent
- Department Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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Mildren R, Yip M, Lowrey C, Harpur C, Brown S, Bent L. Ageing reduces light touch and vibrotactile sensitivity on the anterior lower leg and foot dorsum. Exp Gerontol 2017; 99:1-6. [DOI: 10.1016/j.exger.2017.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/24/2017] [Accepted: 09/11/2017] [Indexed: 02/09/2023]
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Cruz-Montecinos C, Maas H, Pellegrin-Friedmann C, Tapia C. The importance of cutaneous feedback on neural activation during maximal voluntary contraction. Eur J Appl Physiol 2017; 117:2469-2477. [PMID: 29018954 DOI: 10.1007/s00421-017-3734-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 10/02/2017] [Indexed: 10/18/2022]
Abstract
PURPOSE The purpose of this study was to investigate the importance of cutaneous feedback on neural activation during maximal voluntary contraction (MVC) of the ankle plantar flexors. METHODS The effects of cutaneous plantar anaesthesia were assessed in 15 subjects and compared to 15 controls, using a one-day pre/post-repeated measures design. Cutaneous plantar anaesthesia was induced by lidocaine injection at the centre of forefoot, lateral midfoot, and heel. Each subject performed isometric MVCs of the ankle plantar flexors. During each isometric ramp contraction, the following variables were assessed: maximal isometric torque; surface electromyography (EMG) activity of the medial gastrocnemius (MG) and tibialis anterior (TA) muscles; and co-contraction index (CCI) between the MG and TA. RESULTS For ankle torque, two-way ANOVA showed no significant interaction between the pre/post-measurements × group (p = 0.166). However, MG activity presented significant interactions between the pre/post-measurements × group (p = 0.014). Post hoc comparisons indicated a decrease of MG activity in the experimental group, from 85.9 ± 11.9 to 62.7 ± 30.8% (p = 0.016). Additionally, the post-anaesthesia MG activity of the experimental group differed statistically with pre- and post-MG activity of the control group (p = 0.027 and p = 0.008, respectively). For TA activity and CCI, two-way ANOVA detected no significant interactions between the pre/post-measurements × group (p = 0.605 and p = 0.332, respectively). CONCLUSION Our results indicate that during MVC, cutaneous feedback modulates neural activity to MG muscle, without changing the extent of MG-TA co-contraction.
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Affiliation(s)
- Carlos Cruz-Montecinos
- Programa de Magister en Kinesiología y Biomecánica Clínica, Departamento de Kinesiología, Universidad Metropolitana de Ciencias de la Educación, Santiago, Chile.,Department of Physical Therapy, Faculty of Medicine, University of Chile, Santiago, Chile.,Laboratory of Biomechanics and Kinesiology, San José Hospital, Santiago, Chile
| | - Huub Maas
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Van der Boechorststraat 9, 1081 BT, Amsterdam, The Netherlands
| | | | - Claudio Tapia
- Facultad de Ciencias de la Rehabilitacion, Universidad Andres Bello, Fernandez Concha 700, Las Condes, Santiago, Chile. .,Department of Electrical Engineering, Universidad de Chile, Santiago, Chile.
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Geertsen SS, Willerslev-Olsen M, Lorentzen J, Nielsen JB. Development and aging of human spinal cord circuitries. J Neurophysiol 2017; 118:1133-1140. [PMID: 28566459 DOI: 10.1152/jn.00103.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/25/2017] [Accepted: 05/25/2017] [Indexed: 01/25/2023] Open
Abstract
The neural motor circuitries in the spinal cord receive information from our senses and the rest of the nervous system and translate it into purposeful movements, which allow us to interact with the rest of the world. In this review, we discuss how these circuitries are established during early development and the extent to which they are shaped according to the demands of the body that they control and the environment with which the body has to interact. We also discuss how aging processes and physiological changes in our body are reflected in adaptations of activity in the spinal cord motor circuitries. The complex, multifaceted connectivity of the spinal cord motor circuitries allows them to generate vastly different movements and to adapt their activity to meet new challenges imposed by bodily changes or a changing environment. There are thus plenty of possibilities for adaptive changes in the spinal motor circuitries both early and late in life.
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Affiliation(s)
- Svend Sparre Geertsen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark.,Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen N, Denmark; and
| | - Maria Willerslev-Olsen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark.,Elsass Institute, Charlottenlund, Denmark
| | - Jakob Lorentzen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark.,Elsass Institute, Charlottenlund, Denmark
| | - Jens Bo Nielsen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark; .,Elsass Institute, Charlottenlund, Denmark
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Honeine JL, Schieppati M, Crisafulli O, Do MC. The Neuro-Mechanical Processes That Underlie Goal-Directed Medio-Lateral APA during Gait Initiation. Front Hum Neurosci 2016; 10:445. [PMID: 27642280 PMCID: PMC5015477 DOI: 10.3389/fnhum.2016.00445] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/19/2016] [Indexed: 02/06/2023] Open
Abstract
Gait initiation (GI) involves passing from bipedal to unipedal stance. It requires a rapid movement of the center of foot pressure (CoP) towards the future swing foot and of the center of mass (CoM) in the direction of the stance foot prior to the incoming step. This anticipatory postural adjustment (APA) allows disengaging the swing leg from the ground and establishing favorable conditions for stepping. This study aimed to describe the neuro-mechanical process that underlies the goal-directed medio-lateral (ML) APA. We hypothesized that controlled knee flexion of the stance leg contributes to the initial ML displacement of the CoP and to the calibration of the first step. Fourteen subjects initiated gait starting from three different initial stance widths of 15 cm (Small), 30 cm (Medium), and 45 cm (Large). Optoelectronic, force platform and electromyogram (EMG) measurements were performed. During APA, soleus activity diminished bilaterally, while tibialis anterior (TA) activity increased, more so in the stance leg than in the swing leg, and to a larger extent with increasing initial stance width. Knee flexion of the stance leg was observed during APA and correlated with the ML CoP displacement towards the swing leg. ML CoP and CoM displacements during APA increased with increasing stance width. The activity of stance-leg TA was correlated with the degree of knee flexion. Swing-leg tensor fasciae latae (TFL) was also active during APA. Across subjects, when stance-leg tibialis activity was low, TFL activity was large and vice versa. The modulation of the ML CoP position during APA allowed the gravity-driven torque to place the CoM just lateral to the stance foot during step execution. Accordingly, the gravity-driven torque, the ML CoM velocity during step execution, and the step width at foot contact (FC) were lower in the Small and greater in the Large condition. Consequently, the position of the stepping foot at FC remained close to the sagittal plane in all three conditions. Conclusively, coordinated activation of hip abductors and ankle dorsiflexors during APA displaces the CoP towards the swing leg, and sets the contact position for the swing foot.
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Affiliation(s)
- Jean-Louis Honeine
- Department of Public Health, Experimental and Forensic Medicine, University of Pavia Pavia, Italy
| | - Marco Schieppati
- Department of Public Health, Experimental and Forensic Medicine, University of PaviaPavia, Italy; Centro Studi Attività Motorie (CSAM), Fondazione Salvatore Maugeri (IRCSS), Scientific Institute of PaviaPavia, Italy
| | - Oscar Crisafulli
- Department of Public Health, Experimental and Forensic Medicine, University of Pavia Pavia, Italy
| | - Manh-Cuong Do
- Faculty of Sport Science, Complexité, Innovations, Activités Motrices et Sportives (CIAMS), Université Paris-Saclay Orsay, France
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