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Winter L, Taylor P, Bellenger C, Grimshaw P, Crowther RG. The application of the Lyapunov Exponent to analyse human performance: A systematic review. J Sports Sci 2023; 41:1994-2013. [PMID: 38326239 DOI: 10.1080/02640414.2024.2308441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 01/15/2024] [Indexed: 02/09/2024]
Abstract
Variability is a normal component of human movement, allowing one to adapt to environmental perturbations. It can be analysed from linear or non-linear perspectives. The Lyapunov Exponent (LyE) is a commonly used non-linear technique, which quantifies local dynamic stability. It has been applied primarily to walking gait and appears to be limited application in other movements. Therefore, this systematic review aims to summarise research methodologies applying the LyE to movements, excluding walking gait. Four databases were searched using keywords related to movement variability, dynamic stability, LyE and divergence exponent. Articles written in English, using the LyE to analyse movements, excluding walking gait were included for analysis. 31 papers were included for data extraction. Quality appraisal was conducted and information related to the movement, data capture method, data type, apparatus, sampling rate, body segment/joint, number of strides/steps, state space reconstruction, algorithm, filtering, surrogation and time normalisation were extracted. LyE values were reported in supplementary materials (Appendix 2). Running was the most prevalent non-walking gait movement assessed. Methodologies to calculate the LyE differed in various aspects resulting in different LyE values being generated. Additionally, test-retest reliability, was only conducted in one study, which should be addressed in future.
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Affiliation(s)
- Lachlan Winter
- UniSA Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
- Alliance for Research in Exercise, Nutrition & Activity (ARENA), University of South Australia, Adelaide, South Australia, Australia
| | - Paul Taylor
- School of Behavioural and Health Sciences, Australian Catholic University, North Sydney, New South Wales, Australia
| | - Clint Bellenger
- UniSA Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
- Alliance for Research in Exercise, Nutrition & Activity (ARENA), University of South Australia, Adelaide, South Australia, Australia
| | - Paul Grimshaw
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
- Faculty of Sciences, Engineering and Technology, Computer and Mathematical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Robert G Crowther
- UniSA Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
- Alliance for Research in Exercise, Nutrition & Activity (ARENA), University of South Australia, Adelaide, South Australia, Australia
- School of Behavioural and Health Sciences, Australian Catholic University, Melbourne, Victoria, Australia
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2
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Ekizos A, Santuz A. "Biofeedback-based return to sport": individualization through objective assessments. Front Physiol 2023; 14:1185556. [PMID: 37378078 PMCID: PMC10291093 DOI: 10.3389/fphys.2023.1185556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023] Open
Abstract
Elite athletes are regularly exposed to high and repetitive mechanical stresses and impacts, resulting in high injury rates. The consequences of injury can range from time lost from training and competition to chronic physical and psychological burden, with no guarantee that the athlete will return to preinjury levels of sport activity and performance. Prominent predictors include load management and previous injury, highlighting the importance of the postinjury period for effective return to sport (RTS). Currently, there is conflicting information on how to choose and assess the best reentry strategy. Treating RTS as a continuum, with controlled progression of training load and complexity, seems to provide benefits in this process. Furthermore, objectivity has been identified as a critical factor in improving the effectiveness of RTS. We propose that assessments derived from biomechanical measurements in functional settings can provide the objectivity needed for regular biofeedback cycles. These cycles should aim to identify weaknesses, customize the load, and inform on the status of RTS progress. This approach emphasizes individualization as the primary determinant of RTS and provides a solid foundation for achieving it.
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Affiliation(s)
| | - Alessandro Santuz
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
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3
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Udin G, Fernandez Menendez A, Hoyois J, Chevalier M, Malatesta D. Time course of muscle activation, energetics and mechanics of running in minimalist and traditional cushioned shoes during level running. Sci Rep 2023; 13:5007. [PMID: 36973387 PMCID: PMC10043033 DOI: 10.1038/s41598-023-31984-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 03/21/2023] [Indexed: 03/29/2023] Open
Abstract
The study aimed to compare the ankle muscles activation, biomechanics and energetics of running in male runners during submaximal level run using minimalist (MinRS) and traditional cushioned (TrdRS) running shoes. During 45-min running in MinRS and TrdRS, the ankle muscles pre- and co-activation, biomechanics, and energetics of running of 16 male endurance runners (25.5 ± 3.5 yr) were assessed using surface electromyography (tibialis anterior and gastrocnemius lateralis), instrumented treadmill and indirect calorimetry, respectively. The net energy cost of running (Cr) was similar for both conditions (P = 0.25) with a significant increase over time (P < 0.0001). Step frequency (P < 0.001), and total mechanical work (P = 0.001) were significantly higher in MinRS than in TrdRS with no evolution over time (P = 0.28 and P = 0.85, respectively). The ankle muscles pre- and co-activation during the contact phase did not differ between the two shoe conditions (P ≥ 0.33) or over time (P ≥ 0.15). In conclusion, during 45-min running, Cr and muscle pre- and co-activation were not significantly different between MinRS and TrdRS with significantly higher step frequency and total mechanical work noted in the former than in the latter. Moreover, Cr significantly increased during the 45-min trial in both shoe conditions along with no significant change over time in muscle activation and biomechanical variables.
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Affiliation(s)
- Gilles Udin
- Institute of Sport Sciences of University of Lausanne (ISSUL), University of Lausanne, Bâtiment Synathlon, 1015, Lausanne, Switzerland
| | - Aitor Fernandez Menendez
- Institute of Sport Sciences of University of Lausanne (ISSUL), University of Lausanne, Bâtiment Synathlon, 1015, Lausanne, Switzerland
| | - Jonas Hoyois
- Institute of Sport Sciences of University of Lausanne (ISSUL), University of Lausanne, Bâtiment Synathlon, 1015, Lausanne, Switzerland
| | - Mathias Chevalier
- Institute of Sport Sciences of University of Lausanne (ISSUL), University of Lausanne, Bâtiment Synathlon, 1015, Lausanne, Switzerland
| | - Davide Malatesta
- Institute of Sport Sciences of University of Lausanne (ISSUL), University of Lausanne, Bâtiment Synathlon, 1015, Lausanne, Switzerland.
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4
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Fohrmann D, Hamacher D, Sanchez-Alvarado A, Potthast W, Mai P, Willwacher S, Hollander K. Reliability of Running Stability during Treadmill and Overground Running. SENSORS (BASEL, SWITZERLAND) 2022; 23:347. [PMID: 36616946 PMCID: PMC9823852 DOI: 10.3390/s23010347] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Running stability is the ability to withstand naturally occurring minor perturbations during running. It is susceptible to external and internal running conditions such as footwear or fatigue. However, both its reliable measurability and the extent to which laboratory measurements reflect outdoor running remain unclear. This study aimed to evaluate the intra- and inter-day reliability of the running stability as well as the comparability of different laboratory and outdoor conditions. Competitive runners completed runs on a motorized treadmill in a research laboratory and overground both indoors and outdoors. Running stability was determined as the maximum short-term divergence exponent from the raw gyroscope signals of wearable sensors mounted to four different body locations (sternum, sacrum, tibia, and foot). Sacrum sensor measurements demonstrated the highest reliabilities (good to excellent; ICC = 0.85 to 0.91), while those of the tibia measurements showed the lowest (moderate to good; ICC = 0.55 to 0.89). Treadmill measurements depicted systematically lower values than both overground conditions for all sensor locations (relative bias = -9.8% to -2.9%). The two overground conditions, however, showed high agreement (relative bias = -0.3% to 0.5%; relative limits of agreement = 9.2% to 15.4%). Our results imply moderate to excellent reliability for both overground and treadmill running, which is the foundation of further research on running stability.
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Affiliation(s)
- Dominik Fohrmann
- Institute of Interdisciplinary Exercise Science and Sports Medicine, Faculty of Medicine, MSH Medical School Hamburg, 20457 Hamburg, Germany
- Institute of Biomechanics and Orthopedics, German Sport University Cologne, 50933 Cologne, Germany
| | - Daniel Hamacher
- Institute of Sports Science, Friedrich Schiller University Jena, 07749 Jena, Germany
| | - Alberto Sanchez-Alvarado
- Department of Sports and Exercise Medicine, Institute of Human Movement Science, University of Hamburg, 20148 Hamburg, Germany
| | - Wolfgang Potthast
- Institute of Biomechanics and Orthopedics, German Sport University Cologne, 50933 Cologne, Germany
| | - Patrick Mai
- Institute of Biomechanics and Orthopedics, German Sport University Cologne, 50933 Cologne, Germany
- Department of Mechanical and Process Engineering, Offenburg University of Applied Sciences, 77652 Offenburg, Germany
| | - Steffen Willwacher
- Department of Mechanical and Process Engineering, Offenburg University of Applied Sciences, 77652 Offenburg, Germany
| | - Karsten Hollander
- Institute of Interdisciplinary Exercise Science and Sports Medicine, Faculty of Medicine, MSH Medical School Hamburg, 20457 Hamburg, Germany
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5
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Su W, Zhang S, Ye D, Sun X, Zhang X, Fu W. Effects of Barefoot and Shod on the In Vivo Kinematics of Medial Longitudinal Arch During Running Based on a High-Speed Dual Fluoroscopic Imaging System. Front Bioeng Biotechnol 2022; 10:917675. [PMID: 35837546 PMCID: PMC9274304 DOI: 10.3389/fbioe.2022.917675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/20/2022] [Indexed: 11/16/2022] Open
Abstract
Shoes affect the biomechanical properties of the medial longitudinal arch (MLA) and further influence the foot’s overall function. Most previous studies on the MLA were based on traditional skin-marker motion capture, and the observation of real foot motion inside the shoes is difficult. Thus, the effect of shoe parameters on the natural MLA movement during running remains in question. Therefore, this study aimed to investigate the differences in the MLA’s kinematics between shod and barefoot running by using a high-speed dual fluoroscopic imaging system (DFIS). Fifteen healthy habitual rearfoot runners were recruited. All participants ran at a speed of 3 m/s ± 5% along with an elevated runway in barefoot and shod conditions. High-speed DFIS was used to acquire the radiographic images of MLA movements in the whole stance phase, and the kinematics of the MLA were calculated. Paired sample t-tests were used to compare the kinematic characteristics of the MLA during the stance phase between shod and barefoot conditions. Compared with barefoot, shoe-wearing showed significant changes (p < 0.05) as follows: 1) the first metatarsal moved with less lateral direction at 80%, less anterior translation at 20%, and less superiority at 10–70% of the stance phase; 2) the first metatarsal moved with less inversion amounting to 20–60%, less dorsiflexion at 0–10% of the stance phase; 3) the inversion/eversion range of motion (ROM) of the first metatarsal relative to calcaneus was reduced; 4) the MLA angles at 0–70% of the stance phase were reduced; 5) the maximum MLA angle and MLA angle ROM were reduced in the shod condition. Based on high-speed DFIS, the above results indicated that shoe-wearing limited the movement of MLA, especially reducing the MLA angles, suggesting that shoes restricted the compression and recoil of the MLA, which further affected the spring-like function of the MLA.
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Affiliation(s)
- Wanyan Su
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Shen Zhang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- School of Physical Education and Training, Shanghai University of Sport, Shanghai, China
- *Correspondence: Shen Zhang, ; Weijie Fu,
| | - Dongqiang Ye
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Xiaole Sun
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Xini Zhang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Weijie Fu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai, China
- Shanghai Frontiers Science Research Base of Exercise and Metabolic Health, Shanghai University of Sport, Shanghai, China
- *Correspondence: Shen Zhang, ; Weijie Fu,
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6
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Influence of the Shod Condition on Running Power Output: An Analysis in Recreationally Active Endurance Runners. SENSORS 2022; 22:s22134828. [PMID: 35808324 PMCID: PMC9268959 DOI: 10.3390/s22134828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 12/01/2022]
Abstract
Several studies have already analysed power output in running or the relation between VO2max and power production as factors related to running economy; however, there are no studies assessing the difference in power output between shod and barefoot running. This study aims to identify the effect of footwear on the power output endurance runner. Forty-one endurance runners (16 female) were evaluated at shod and barefoot running over a one-session running protocol at their preferred comfortable velocity (11.71 ± 1.07 km·h−1). The mean power output (MPO) and normalized MPO (MPOnorm), form power, vertical oscillation, leg stiffness, running effectiveness and spatiotemporal parameters were obtained using the Stryd™ foot pod system. Additionally, footstrike patterns were measured using high-speed video at 240 Hz. No differences were noted in MPO (p = 0.582) and MPOnorm (p = 0.568), whereas significant differences were found in form power, in both absolute (p = 0.001) and relative values (p < 0.001), running effectiveness (p = 0.006), stiffness (p = 0.002) and vertical oscillation (p < 0.001). By running barefoot, lower values for contact time (p < 0.001) and step length (p = 0.003) were obtained with greater step frequency (p < 0.001), compared to shod running. The prevalence of footstrike pattern significantly differs between conditions, with 19.5% of runners showing a rearfoot strike, whereas no runners showed a rearfoot strike during barefoot running. Running barefoot showed greater running effectiveness in comparison with shod running, and was consistent with lower values in form power and lower vertical oscillation. From a practical perspective, the long-term effect of barefoot running drills might lead to increased running efficiency and leg stiffness in endurance runners, affecting running economy.
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7
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Hollander K, Petersen E, Zech A, Hamacher D. Effects of barefoot vs. shod walking during indoor and outdoor conditions in younger and older adults. Gait Posture 2022; 95:284-291. [PMID: 34020852 DOI: 10.1016/j.gaitpost.2021.04.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 04/08/2021] [Accepted: 04/14/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND Gait stability and variability measures in barefoot and shod locomotion are frequently investigated in younger but rarely in older adults. Moreover, most studies examine gait measures in laboratory settings instead of real-life settings. RESEARCH QUESTIONS How are gait stability and variability parameters affected by footwear compared to barefoot walking in younger and older adults as well as under indoor vs. outdoor conditions? METHODS Healthy younger (<35 years) and older adults (>65 years) participated in the randomised within-subject study design. Participants conducted consecutive 25 m walking trials barefoot and with standardised footwear inside and outside. Inertial measurement units were mounted on the participant's foot and used to calculate local dynamic stability (LDS), velocity and minimal toe clearance (MTC), stride length and stride time, including variabilities for these parameters. Linear mixed models were calculated. RESULTS Data of 32 younger (17 female, 15 male, age: 30 ± 4 years) and 42 older participants (24 female, 18 male, age: 71 ± 4 years) were analysed. MTC variability was higher in shod conditions compared to barefoot (p = 0.048) and in outdoor conditions (p < 0.001). LDS was different between age groups (p < 0.001). Gait velocity and MTC were higher in shod and outdoor conditions (both p < 0.001). Stride length and time were higher in shod conditions (both p < 0.001) and different between outdoor vs. indoor (longer stride length and shorter stride time outdoor, both (p < 0.001) as well as age groups (shorter stride length (p < 0.021) and stride time in older adults (p < 0.001). SIGNIFICANCE Results suggest that gait stability and variability in older and younger adults are acutely affected by footwear vs. barefoot and indoor vs. outdoor walking conditions, indicating a high adaptiveness of these parameters to different experimental conditions. Consequently, future studies should be careful with generalising results obtained under certain conditions. Findings stress the clinical potential of barefoot walking.
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Affiliation(s)
| | - Evi Petersen
- Department of Sports, Physical Education and Outdoor Life, University of South-Eastern Norway, Norway.
| | - Astrid Zech
- Department of Sport Science, Friedrich Schiller University Jena, Germany
| | - Daniel Hamacher
- Department of Sport Science, Friedrich Schiller University Jena, Germany
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8
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Padulo J, Ayalon M, Barbieri FA, Di Capua R, Doria C, Ardigò LP, Dello Iacono A. Effects of Gradient and Speed on Uphill Running Gait Variability. Sports Health 2022; 15:67-73. [PMID: 35343321 PMCID: PMC9808836 DOI: 10.1177/19417381211067721] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The aim of this study was to investigate the effects of gradient and speed on running variability (RV) and local dynamic stability (LDS) during uphill running. HYPOTHESES (1) Both gradient and speed increase metabolic effort, in terms of heart rate (HR) and perceived exertion (CR10), in line with the contemporary literature, and (2) gradient increases RV and impairs LDS. STUDY DESIGN "Crossover" observational design. LEVEL OF EVIDENCE Level 3. METHODS A total of 25 runners completed 10-minute running trials in 3 different conditions and in a randomized order: gradient at 0% (0CON), 2% (2CON), and 2% at isoefficiency speed (2IES). 0CON and 2CON speeds were calculated as the "best 10-km race performance" minus 1 km·h-1, whereas 2IES speed was adjusted to induce the same metabolic expenditure as 0CON. HR and perceived exertion as well as running kinematic variables were collected across all trials and conditions. Running variability was calculated as the standard deviation of the mean stride-to-stride intervals over 100 strides, while LDS was expressed by the Lyapunov exponent (LyE) determined on running cycle time over different running conditions. RESULTS Increases in HR and CR10 were observed between 0CON and 2CON (P < 0.001) and between 2IES and 2CON (P < 0.01). Higher RV was found in 2CON compared with 0CON and 2IES (both P < 0.001). Finally, the largest LyE was observed in 2IES compared with 0CON and 2CON (P = 0.02 and P = 0.01, respectively). CONCLUSION Whereas RV seems to be dependent more on metabolic effort, LDS is affected by gradient to a greater extent. CLINICAL RELEVANCE Running variability could be used to monitor external training load in marathon runners.
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Affiliation(s)
- Johnny Padulo
- Department of Biomedical Sciences for Health,
Università degli Studi di Milano, Milan, Italy
| | - Moshe Ayalon
- The Academic College at Wingate, Netanya,
Israel
| | - Fabio A. Barbieri
- Human Movement Research Laboratory
(MOVI-LAB), Department of Physical Education, São Paulo State University (UNESP), Bauru,
Brazil
| | - Roberto Di Capua
- Department of Physics “E. Pancini,”
University of Naples “Federico II,” Naples, Italy,CNR-SPIN Institute, Naples, Italy
| | - Christian Doria
- Department of Biomedical Sciences for Health,
Università degli Studi di Milano, Milan, Italy
| | - Luca P. Ardigò
- School of Exercise and Sport Science,
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona,
Verona, Italy,Luca P. Ardigò, PhD, School of
Exercise and Sport Science, Department of Neurosciences, Biomedicine and Movement
Sciences, University of Verona, Via Felice Casorati, 43, Verona, 37131, Italy (
)
| | - Antonio Dello Iacono
- School of Health and Life Sciences,
University of the West of Scotland, Glasgow, UK
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9
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Aghaie Ataabadi P, Sarvestan J, Alaei F, Yazdanbakhsh F, Abbasi A. Linear and non-linear analysis of lower limb joints angle variability during running at different speeds. ACTA GYMNICA 2021. [DOI: 10.5507/ag.2021.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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10
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Ekizos A, Santuz A, Arampatzis A. Runners Employ Different Strategies to Cope With Increased Speeds Based on Their Initial Strike Patterns. Front Physiol 2021; 12:686259. [PMID: 34795597 PMCID: PMC8593104 DOI: 10.3389/fphys.2021.686259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 10/07/2021] [Indexed: 11/17/2022] Open
Abstract
In this paper we examined how runners with different initial foot strike pattern (FSP) develop their pattern over increasing speeds. The foot strike index (FSI) of 47 runners [66% initially rearfoot strikers (RFS)] was measured in six speeds (2.5–5.0 ms−1), with the hypotheses that the FSI would increase (i.e., move toward the fore of the foot) in RFS strikers, but remain similar in mid- or forefoot strikers (MFS) runners. The majority of runners (77%) maintained their original FSP by increasing speed. However, we detected a significant (16.8%) decrease in the FSI in the MFS group as a function of running speed, showing changes in the running strategy, despite the absence of a shift from one FSP to another. Further, while both groups showed a decrease in contact times, we found a group by speed interaction (p < 0.001) and specifically that this decrease was lower in the MFS group with increasing running speeds. This could have implications in the metabolic energy consumption for MFS-runners, typically measured at low speeds for the assessment of running economy.
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Affiliation(s)
- Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany.,Olympic Training Center, Berlin, Germany
| | - Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
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11
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Yu B, Kramer PA. Walking Speed Alters Barefoot Gait Coordination and Variability. J Mot Behav 2021; 54:410-421. [PMID: 34641775 DOI: 10.1080/00222895.2021.1990005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Using the dynamic system approach, we examined the pattern and variability of inter-joint coordination in barefoot and shod walking in 20 women at three speeds: SLOW, FAST, and comfortable walking speed (CWS). We found that barefoot and shod walking used different coordination strategies to cope with increasing walking speed. As walking speed increased, ankle-knee coordination patterns between shod and barefoot became less different (p < 0.00001), and ankle-hip coordination patterns became more different (p < 0.001). Compared to shod, barefoot walking had significantly lower coordination variability in mid stance of knee-hip at CWS and FAST and late swing of ankle-hip at SLOW and CWS with medium effect (effect size 0.61-0.74). Future research should investigate the connection between the decreased coordination variability and joint tissue stress to understand the impact of barefoot walking on the lower extremity joints.
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Affiliation(s)
- Binnan Yu
- Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, USA
| | - Patricia Ann Kramer
- Department of Anthropology, University of Washington, Seattle, Washington, USA
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12
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Standing on unstable surface challenges postural control of tracking tasks and modulates neuromuscular adjustments specific to task complexity. Sci Rep 2021; 11:6122. [PMID: 33731729 PMCID: PMC7969732 DOI: 10.1038/s41598-021-84899-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 02/22/2021] [Indexed: 01/31/2023] Open
Abstract
Understanding the modulations of motor control in the presence of perturbations in task conditions of varying complexity is a key element towards the design of effective perturbation-based balance exercise programs. In this study we investigated the effect of mechanical perturbations, induced by an unstable surface, on muscle activation and visuo-postural coupling, when actively tracking target motion cues of different complexity. Four postural tasks following a visual oscillating target of varying target complexity (periodic-sinusoidal vs. chaotic-Lorenz) and surface (stable-floor vs. unstable-foam) were performed. The electromyographic activity of the main plantarflexor and dorsiflexor muscles was captured. The coupling between sway and target was assessed through spectral analysis and the system's local dynamic stability through the short-term maximum Lyapunov exponent. We found that external perturbations increased local instability and deteriorated visuo-motor coupling. Visuo-motor deterioration was greater for the chaotic target, implying that the effect of the induced perturbations depends on target complexity. There was a modulation of the neuromotor system towards amplification of muscle activity and coactivation to compensate surface-related perturbations and to ensure robust motor control. Our findings provide evidence that, in the presence of perturbations, target complexity induces specific modulations in the neuromotor system while controlling balance and posture.
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13
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Hollander K, Hamacher D, Zech A. Running barefoot leads to lower running stability compared to shod running - results from a randomized controlled study. Sci Rep 2021; 11:4376. [PMID: 33623054 PMCID: PMC7902604 DOI: 10.1038/s41598-021-83056-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 01/28/2021] [Indexed: 12/24/2022] Open
Abstract
Local dynamic running stability is the ability of a dynamic system to compensate for small perturbations during running. While the immediate effects of footwear on running biomechanics are frequently investigated, no research has studied the long-term effects of barefoot vs. shod running on local dynamic running stability. In this randomized single-blinded controlled trial, young adults novice to barefoot running were randomly allocated to a barefoot or a cushioned footwear running group. Over an 8-week-period, both groups performed a weekly 15-min treadmill running intervention in the allocated condition at 70% of their VO2 max velocity. During each session, an inertial measurement unit on the tibia recorded kinematic data (angular velocity) which was used to determine the short-time largest Lyapunov exponents as a measure of local dynamic running stability. One hundred running gait cycles at the beginning, middle, and end of each running session were analysed using one mixed linear multilevel random intercept model. Of the 41 included participants (48.8% females), 37 completed the study (drop-out = 9.7%). Participants in the barefoot running group exhibited lower running stability than in the shod running group (p = 0.037) with no changes during the intervention period (p = 0.997). Within a single session, running stability decreased over the course of the 15-min run (p = 0.012) without differences between both groups (p = 0.060). Changing from shod to barefoot running reduces running stability not only in the acute phase but also in the longer term. While running stability is a relatively new concept, it enables further insight into the biomechanical influence of footwear.
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Affiliation(s)
- Karsten Hollander
- Faculty of Medicine, MSH Medical School Hamburg, Am Kaiserkai 1, 20457, Hamburg, Germany.
| | - Daniel Hamacher
- Department of Sport Science, Friedrich Schiller University Jena, Jena, Germany
| | - Astrid Zech
- Department of Sport Science, Friedrich Schiller University Jena, Jena, Germany
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Jahn VDS, Correia CK, Dell’Antonio E, Mochizuki L, Ruschel C. BIOMECHANICS OF SHOD AND BAREFOOT RUNNING: A LITERATURE REVIEW. REV BRAS MED ESPORTE 2020. [DOI: 10.1590/1517-869220202606219320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT This study aims to analyze and summarize the biomechanical (kinematics, kinetics and neuromuscular) differences between shod and barefoot running, through a literature review. Searches were conducted for complete articles published between 2013 and November 2018 in the Web of Science, PubMed, Scopus and SPORTdiscus databases. The search terms used were Biomechanics, Kinetics, Kinematics, Electromyography, “Surface Electromyography”; and Unshod, Barefoot, Barefeet and Running. The search resulted in 687 articles; after excluding duplicates and selecting by title, abstract and full text, 40 articles were included in the review. The results show that there are important differences in the biomechanics of running when shod or barefoot. In general, studies indicate that in barefoot running: a) individuals present forefoot or midfoot foot strike patterns, while in shod running the typical pattern is the rearfoot strike; (b) greater cadence and shorter stride length are observed; and (c) there is greater knee flexion, lower peak vertical ground reaction force and greater activation of the medial gastrocnemius. In addition, barefoot runners contact the ground with greater plantar flexion, possibly as a strategy to reduce impact when stepping without footwear. These differences, as well as runners’ individual characteristics, should be considered in the prescription of the barefoot running, in order to minimize injuries resulting from the practice. Level of Evidence II; Review.
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Mahaki M, Mimar R, Sadeghi H, Khaleghi Tazji M, Vieira MF. The effects of general fatigue induced by incremental exercise test and active recovery modes on energy cost, gait variability and stability in male soccer players. J Biomech 2020; 106:109823. [PMID: 32517989 DOI: 10.1016/j.jbiomech.2020.109823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 04/21/2020] [Accepted: 05/05/2020] [Indexed: 11/21/2022]
Abstract
The aerobic endurance is considered an important physiological capacity of soccer players which is examined by Incremental Exercise Test (IET). However, it is not clear how general fatigue induced by IET influences physiological and biomechanical gait features in soccer players and how players recover optimally at post-IET. Here, the effect of general fatigue induced by IET on energy cost, gait variability and stability in soccer players was investigated. To identify an optimal recovery mode, the effect of walking at Preferred Walking Speed (PWS), running at Individual Ventilation Threshold (IVT) (two active recovery modes), and Rest (a passive recovery mode) on aforementioned features were studied. Nine male players walked 4-min at PWS on a treadmill prior IET (PreT), which was followed by four 4-min walking trials (PosT-0, 1, 2, and 3) with three 4-min recovery intervals (PWS, IVT, or Rest) between them, in three sessions (one for each recovery mode) in a random order. Energy cost, gait variability and stability were examined at PreT (baseline), and at PosT-0, 1, 2, and 3 (intervals of respectively 0-4, 8-12, 16-20, 24-28 min at post-IET). Gait variability was assessed by the standard deviation of trunk angle and gait stability was assessed by the local dynamic stability of trunk angular velocity. Gait stability was not affected by IET, despite increases in gait variability and energy cost. Different from IVT, PWS and Rest recovery modes reduced energy cost at post-IET. Gait variability and energy cost recovered at PosT-1 and PosT-2, suggesting that 8-12 and 16-20 min recovery intervals, respectively, were required for returning to their baselines. No preference for active over passive recovery was found in terms of gait variability and energy cost.
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Affiliation(s)
- Mohammadreza Mahaki
- Faculty of Physical Education and Sport Sciences, Kharazmi University of Tehran, Tehran, Iran; Faculty of Behavioural and Movement Sciences, VU University of Amsterdam, Amsterdam, The Netherlands.
| | - Raghad Mimar
- Faculty of Physical Education and Sport Sciences, Kharazmi University of Tehran, Tehran, Iran
| | - Heydar Sadeghi
- Faculty of Physical Education and Sport Sciences, Kharazmi University of Tehran, Tehran, Iran; Kinesiology Research Center, Kharazmi University of Tehran, Tehran, Iran
| | - Mehdi Khaleghi Tazji
- Faculty of Physical Education and Sport Sciences, Kharazmi University of Tehran, Tehran, Iran
| | - Marcus Fraga Vieira
- Bioengineering and Biomechanics Laboratory, Federal University of Goiás, Goiânia, Brazil
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Janshen L, Santuz A, Ekizos A, Arampatzis A. Fuzziness of muscle synergies in patients with multiple sclerosis indicates increased robustness of motor control during walking. Sci Rep 2020; 10:7249. [PMID: 32350313 PMCID: PMC7190675 DOI: 10.1038/s41598-020-63788-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 04/02/2020] [Indexed: 12/22/2022] Open
Abstract
Deficits during gait poses a significant threat to the quality of life in patients with Multiple Sclerosis (MS). Using the muscle synergy concept, we investigated the modular organization of the neuromuscular control during walking in MS patients compared to healthy participants (HP). We hypothesized a widening and increased fuzziness of motor primitives (e.g. increased overlap intervals) in MS patients compared to HP allowing the motor system to increase robustness during walking. We analysed temporal gait parameters, local dynamic stability and muscle synergies from myoelectric signals of 13 ipsilateral leg muscles using non-negative matrix factorization. Compared to HP, MS patients showed a significant decrease in the local dynamic stability of walking during both, preferred and fixed (0.7 m/s) speed. MS patients demonstrated changes in time-dependent activation patterns (motor primitives) and alterations of the relative muscle contribution to the specific synergies (motor modules). We specifically found a widening in three out of four motor primitives during preferred speed and in two out of four during fixed speed in MS patients compared to HP. The widening increased the fuzziness of motor control in MS patients, which allows the motor system to increase its robustness when coping with pathology-related motor deficits during walking.
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Affiliation(s)
- Lars Janshen
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany.
| | - Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany
| | - Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany
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Sánchez-Ramírez C, Alegre LM. Plantar support adaptations in healthy subjects after eight weeks of barefoot running training. PeerJ 2020; 8:e8862. [PMID: 32266122 PMCID: PMC7120041 DOI: 10.7717/peerj.8862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 03/05/2020] [Indexed: 11/24/2022] Open
Abstract
Background Although the studies of barefoot running have intensified, it is still missing longitudinal work analyzing the effects of barefoot running on the phases of plantar support. The objective of this research was to analyze the modifications undergone by the Total Foot Contact (TFC) phase and its Flat Foot Phase (FFP) in subjects beginning the practice of barefoot running, in its acute and chronic effects. Methods A total of 28 subjects were divided into the Barefoot Group (BFGr) (n = 16) and the Shod Group (SHGr) (n = 12), evaluated before (Baseline) and after running for 20 min at 3.05 m·s−1 (Post 20 min Running), and at the end of a running training protocol with an 8-week long progressive volume (Post-8-week Training). The dynamic plantar support was measured with a baropodoscope. The duration of TFC (ms), the moment at which the FFP occurred, the maximum surface of TFC (MSTFC) (cm2), the FFP surface (SFFP) (cm2), the peak pressure of TFC (PP°TFC) (kg·cm−2), and the peak pressure of FFP (PP°FFP) (kg·cm−2) were recorded. The 3 × 2 ANOVA analysis was made to determine the effects and interactions that the condition produced (Shod/Barefoot), and the time factor (Baseline/Post 20 min Running/Post-8-week Training). Results The condition factor caused more significant effects than the time factor in all the variables. Duration of TFC in BFGr showed significant differences between the Baseline and Post-8-week Training (p = 0.000) and between Post-20-min Running and Post-8-week Training (p = 0.000), with an increasing trend. In the moment at which the FFP occurred a significant increase (p = 0.029) increase was found in Post-20 min Running (48.5%) compared to the Baseline (42.9%). In MSTFC, BFGr showed in Post-8-week Training values significantly higher than the Baseline (p = 0.000) and than Post-20-min Running (p = 0.000). SHGr presented a significant difference between the Baseline and Post-8-week Training (p = 0.040). SFFP in BFGr modified its values with an increasing trend (p = 0.000). PP°TFC in BFGr showed a significant decrease (p = 0.003) in Post-8-week Training (1.9 kg·cm−2) compared to the Baseline (2.4 kg·cm−2). In PP°FFP significant decreases were recorded in BFGr and between Post-8-week Training and Baseline (p = 0.000), and Post-8-week Training and Post 20 min Running (p = 0.035). Conclusions The adaptation took place after the 8-week training. The adaptations to running barefoot were characterized by causing an increase of the foot’s plantar support in TFC and in FFP, as well as a decrease of the plantar pressure peak in both phases. Also, there is an increased duration of the TFC and FFP, which may be related to an acquired strategy to attenuate the impacts of the ground’s reaction forces.
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Affiliation(s)
- Celso Sánchez-Ramírez
- Escuela de Ciencias de la Actividad Física/Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Santiago, Región Metropolitana, Chile
| | - Luis M Alegre
- Grupo de Investigación GENUD, CIBER de Fragilidad y Envejecimiento Saludable, Universidad de Castilla La Mancha, Toledo, Toledo, Spain
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Santuz A, Brüll L, Ekizos A, Schroll A, Eckardt N, Kibele A, Schwenk M, Arampatzis A. Neuromotor Dynamics of Human Locomotion in Challenging Settings. iScience 2019; 23:100796. [PMID: 31962235 PMCID: PMC6971393 DOI: 10.1016/j.isci.2019.100796] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 09/15/2019] [Accepted: 12/19/2019] [Indexed: 12/20/2022] Open
Abstract
Is the control of movement less stable when we walk or run in challenging settings? Intuitively, one might answer that it is, given that challenging locomotion externally (e.g., rough terrain) or internally (e.g., age-related impairments) makes our movements more unstable. Here, we investigated how young and old humans synergistically activate muscles during locomotion when different perturbation levels are introduced. Of these control signals, called muscle synergies, we analyzed the local stability and the complexity (or irregularity) over time. Surprisingly, we found that perturbations force the central nervous system to produce muscle activation patterns that are less unstable and less complex. These outcomes show that robust locomotion control in challenging settings is achieved by producing less complex control signals that are more stable over time, whereas easier tasks allow for more unstable and irregular control. We examined the dynamics of motor control of locomotion in challenging settings We extracted muscle synergies (motor modules and primitives) from electromyography The dynamics of the time-dependent motor primitives were modified by perturbations Primitives were wider, less unstable, and complex in the presence of perturbations
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Affiliation(s)
- Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - Leon Brüll
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Network Aging Research, Heidelberg University, 69117 Heidelberg, Germany
| | - Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Arno Schroll
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Nils Eckardt
- Department of Training and Movement Science, Institute for Sport and Sports Science, University of Kassel, 34125 Kassel, Germany; Department of Sport and Movement Science, Institute of Sport Science, Carl von Ossietzky University of Oldenburg, 26129 Oldenburg, Germany
| | - Armin Kibele
- Department of Training and Movement Science, Institute for Sport and Sports Science, University of Kassel, 34125 Kassel, Germany
| | - Michael Schwenk
- Network Aging Research, Heidelberg University, 69117 Heidelberg, Germany; Institute of Sports and Sports Sciences, Heidelberg University, 69117 Heidelberg, Germany
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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Patikas DA, Papavasileiou A, Ekizos A, Hatzitaki V, Arampatzis A. Swaying slower reduces the destabilizing effects of a compliant surface on voluntary sway dynamics. PLoS One 2019; 14:e0226263. [PMID: 31826026 PMCID: PMC6905565 DOI: 10.1371/journal.pone.0226263] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 11/24/2019] [Indexed: 11/18/2022] Open
Abstract
The ability to control weight shifting (voluntary sway) is a crucial factor for stability during standing. Postural tracking of an oscillating visual target when standing on a compliant surface (e.g. foam) is a challenging weight shifting task that may alter the stability of the system and the muscle activation patterns needed to compensate for the perturbed state. The purpose of this study was to examine the effects of surface stability and sway frequency on the muscle activation of the lower limb, during visually guided voluntary postural sway. Seventeen volunteers performed a 2-min voluntary sway task in the anterior-posterior direction following with their projected center of pressure (CoPAP) a periodically oscillating visual target on a screen. The target oscillated at a frequency of 0.25 Hz or 0.125 Hz, while the participants swayed on solid ground (stable surface) or on a foam pad (unstable surface), resulting in four experimental conditions. The electromyogram (EMG) of 13 lower limb muscles was measured and the target–CoPAP coupling was evaluated with coherence analysis, whereas the difference in the stability of the system between the conditions was estimated by the maximum Lyapunov exponent (MLE). The results showed that slower oscillations outperformed the faster in terms of coherence and revealed greater stability. On the other hand, unstable ground resulted in an undershooting of the CoPAP to the target and greater MLE. Regarding the EMG data, a decreased triceps surae muscle activation at the low sway frequency compared to the higher was observed, whereas swaying on foam induced higher activation on the tibialis anterior as well. It is concluded that swaying voluntarily on an unstable surface results in reduced CoPAP and joint kinematics stability, that is accomplished by increasing the activation of the distal leg muscles, in order to compensate for this perturbation. The reduction of the sway frequency limits the effect of the unstable surface, on the head and upper body, improves the temporal component of coherence between CoP and target, whereas EMG activity is decreased. These findings might have implications in rehabilitation programs.
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Affiliation(s)
- Dimitrios A. Patikas
- School of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece
- * E-mail:
| | - Anastasia Papavasileiou
- School of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Vassilia Hatzitaki
- School of Physical Education and Sport Science, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
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20
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Center of Pressure Feedback Modulates the Entrainment of Voluntary Sway to the Motion of a Visual Target. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9193952] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Visually guided weight shifting is widely employed in balance rehabilitation, but the underlying visuo-motor integration process leading to balance improvement is still unclear. In this study, we investigated the role of center of pressure (CoP) feedback on the entrainment of active voluntary sway to a moving visual target and on sway’s dynamic stability as a function of target predictability. Fifteen young and healthy adult volunteers (height 175 ± 7 cm, body mass 69 ± 12 kg, age 32 ± 5 years) tracked a vertically moving visual target by shifting their body weight antero-posteriorly under two target motion and feedback conditions, namely, predictable and less predictable target motion, with or without visual CoP feedback. Results revealed lower coherence, less gain, and longer phase lag when tracking the less predictable compared to the predictable target motion. Feedback did not affect CoP-target coherence, but feedback removal resulted in greater target overshooting and a shorter phase lag when tracking the less predictable target. These adaptations did not affect the dynamic stability of voluntary sway. It was concluded that CoP feedback improves spatial perception at the cost of time delays, particularly when tracking a less predictable moving target.
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21
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Munoz-Martel V, Santuz A, Ekizos A, Arampatzis A. Neuromuscular organisation and robustness of postural control in the presence of perturbations. Sci Rep 2019; 9:12273. [PMID: 31439926 PMCID: PMC6706387 DOI: 10.1038/s41598-019-47613-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 07/16/2019] [Indexed: 01/11/2023] Open
Abstract
Perturbation-based exercise interventions challenge balance and improve reactive motor control. Our purpose was to investigate the modular organisation during a standing balance task in both stable and unstable conditions to provide new insights into the neuromuscular control mechanisms needed to cope with perturbations. Fifteen participants performed 54 cycles of a specific task (i.e. pass from a double- to a single-leg standing) on stable ground and an unstable oscillating platform (Posturomed). Muscle synergies were extracted from the electromyographic activity of thirteen lower limb muscles. The maximum Lyapunov exponents of different body segments were calculated using kinematic data. We found two synergies functionally associated with the single- and double-leg stance in both stable and unstable conditions. Nonetheless, in the unstable condition participants needed an extra muscle synergy also functionally related to the single stance. Although a simple organisation of the neuromuscular system was sufficient to maintain the postural control in both conditions, the increased challenge in the oscillating platform was solved by adding one extra synergy. The addition of a new synergy with complementary function highlighted an increased motor output's robustness (i.e. ability to cope with errors) in the presence of perturbations.
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Affiliation(s)
- Victor Munoz-Martel
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany.
| | - Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany.
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22
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Santuz A, Akay T, Mayer WP, Wells TL, Schroll A, Arampatzis A. Modular organization of murine locomotor pattern in the presence and absence of sensory feedback from muscle spindles. J Physiol 2019; 597:3147-3165. [DOI: 10.1113/jp277515] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/15/2019] [Indexed: 11/08/2022] Open
Affiliation(s)
- Alessandro Santuz
- Department of Training and Movement SciencesHumboldt‐Universität zu Berlin 10115 Berlin Germany
- Berlin School of Movement ScienceHumboldt‐Universität zu Berlin 10115 Berlin Germany
- Atlantic Mobility Action ProjectBrain Repair CentreDepartment of Medical NeuroscienceDalhousie University Halifax Nova Scotia B3H 4R2 Canada
| | - Turgay Akay
- Atlantic Mobility Action ProjectBrain Repair CentreDepartment of Medical NeuroscienceDalhousie University Halifax Nova Scotia B3H 4R2 Canada
| | - William P. Mayer
- Atlantic Mobility Action ProjectBrain Repair CentreDepartment of Medical NeuroscienceDalhousie University Halifax Nova Scotia B3H 4R2 Canada
- Department of MorphologyFederal University of Espirito Santo Vitoria CEP 29040–090 Brazil
| | - Tyler L. Wells
- Atlantic Mobility Action ProjectBrain Repair CentreDepartment of Medical NeuroscienceDalhousie University Halifax Nova Scotia B3H 4R2 Canada
| | - Arno Schroll
- Department of Training and Movement SciencesHumboldt‐Universität zu Berlin 10115 Berlin Germany
- Berlin School of Movement ScienceHumboldt‐Universität zu Berlin 10115 Berlin Germany
| | - Adamantios Arampatzis
- Department of Training and Movement SciencesHumboldt‐Universität zu Berlin 10115 Berlin Germany
- Berlin School of Movement ScienceHumboldt‐Universität zu Berlin 10115 Berlin Germany
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23
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Frank NS, Prentice SD, Callaghan JP. Local dynamic stability of the lower extremity in novice and trained runners while running intraditional and minimal footwear. Gait Posture 2019; 68:50-54. [PMID: 30458428 DOI: 10.1016/j.gaitpost.2018.10.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 10/23/2018] [Accepted: 10/31/2018] [Indexed: 02/02/2023]
Abstract
BACKGROUND Understanding how footwear cushioning influences movement stability may be helpful in reducing injuries related to repetitive loading. RESEARCH QUESTION The purpose of this study was to identify the relationship between running experience and midsole cushioning on local dynamic stability of the ankle, knee and hip. METHODS Twenty-four trained and novice runners were recruited to run on a treadmill for five minutes at the same relative intensity. Midsole thickness (thick/thin) and stiffness (soft / hard) were manipulated yielding four unique conditions. Lyapunov exponents were estimated using the Wolf algorithm from sagittal ankle, knee and hip kinematics. RESULTS Trained runners had increased movement stability in all shoe conditions compared to their novice counterparts. Midsole thickness and stiffness, overall, did not affect movement stability within each of the running groups. Novice runners displayed decreased movement stability at the hip while running in the thick/soft running shoes. It was found that running experience has a greater influence on movement stability in the lower limbs compared to the midsole characteristics that were manipulated in this experiment. The hip was most stable followed by the knee and the ankle highlighting decreased stability in distal joints. CONCLUSIONS It appears that midsole design within current design ranges do not have the ability to influence movement stability.
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Affiliation(s)
- Nicholas S Frank
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
| | - Stephen D Prentice
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Jack P Callaghan
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
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24
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Hoenig T, Hamacher D, Braumann KM, Zech A, Hollander K. Analysis of running stability during 5000 m running . Eur J Sport Sci 2018; 19:413-421. [PMID: 30257130 DOI: 10.1080/17461391.2018.1519040] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
In the analysis of human walking, the assessment of local dynamic stability (LDS) has been widely used to determine gait stability. To extend the concepts of LDS to the analysis of running biomechanics, this study aimed to compare LDS during exhaustive running between competitive and recreational runners. Fifteen recreational and fifteen competitive runners performed an exhaustive 5000 m run. Inertial measurement units at foot, pelvis, and thorax were used to determine local dynamic running stability as quantified by the largest Lyapunov exponent. In addition, we measured running velocity, lactate levels, perceived exertion, and foot strike patterns. LDS at the start, mid, and end of a 5000 m run was compared between the two groups by a two-way repeated-measures analysis of variance (ANOVA). Local dynamic stability increased during the run (thorax, pelvis) in both recreational and competitive runners (PThorax = 0.006; PPelvis = 0.001). During the whole run, competitive runners showed a significantly higher LDS (P = 0.029) compared to recreational runners at the foot kinematics. In conclusion, exhaustive running can lead to improvements in LDS, indicating a higher local dynamic stability of the running technique with increasing exhaustion. Furthermore, LDS of the foot differs between the two groups at all measurement points. The results of this study show the value of determining LDS in athletes as it can give a better understanding into the biomechanics of running.
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Affiliation(s)
- Tim Hoenig
- a Department of Sports and Exercise Medicine, Institute of Human Movement Science , University of Hamburg , Hamburg , Germany
| | - Daniel Hamacher
- b Institute of Sport Science , Friedrich Schiller University Jena , Jena , Germany
| | - Klaus-Michael Braumann
- a Department of Sports and Exercise Medicine, Institute of Human Movement Science , University of Hamburg , Hamburg , Germany
| | - Astrid Zech
- b Institute of Sport Science , Friedrich Schiller University Jena , Jena , Germany
| | - Karsten Hollander
- a Department of Sports and Exercise Medicine, Institute of Human Movement Science , University of Hamburg , Hamburg , Germany.,c Department of Sports and Rehabilitation Medicine , BG Trauma Hospital of Hamburg , Hamburg , Germany
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25
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Ekizos A, Santuz A, Schroll A, Arampatzis A. The Maximum Lyapunov Exponent During Walking and Running: Reliability Assessment of Different Marker-Sets. Front Physiol 2018; 9:1101. [PMID: 30197597 PMCID: PMC6117405 DOI: 10.3389/fphys.2018.01101] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 07/23/2018] [Indexed: 12/31/2022] Open
Abstract
The maximum Lyapunov exponent (MLE) has often been suggested as the prominent measure for evaluation of dynamic stability of locomotion in pathological and healthy population. Although the popularity of the MLE has increased in the last years, there is scarce information on the reliability of the method, especially during running. The purpose of the current study was, thus, to examine the reliability of the MLE during both walking and running. Sixteen participants walked and ran on a treadmill completing two measurement blocks (i.e., two trials per day for three consecutive days per block) separated by 2 months on average. Six different marker-sets on the trunk were analyzed. Intraday, interday and between blocks reliability was assessed using the intraclass correlation coefficient (ICC) and the root mean square difference (RMSD). The MLE was on average significantly higher (p < 0.001) in running (1.836 ± 0.080) compared to walking (1.386 ± 0.207). All marker-sets showed excellent ICCs (>0.90) during walking and mostly good ICCs (>0.75) during running. The RMSD ranged from 0.023 to 0.047 for walking and from 0.018 to 0.050 for running. The reliability was better when comparing MLE values between blocks (ICCs: 0.965–0.991 and 0.768–0.961; RMSD: 0.023–0.034 and 0.018–0.027 for walking and running respectively), and worse when considering trials of the same day (ICCs: 0.946–0.980 and 0.739–0.844; RMSD: 0.042–0.047 and 0.045–0.050 for walking and running respectively). Further, different marker-sets affect the reliability of the MLE in both walking and running. Our findings provide evidence that the assessment of dynamic stability using the MLE is reliable in both walking and running. More trials spread over more than 1 day should be considered in study designs with increased demands of accuracy independent of the locomotion condition.
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Affiliation(s)
- Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Arno Schroll
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
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Snow NJ, Blair JFL, MacDonald GZ, Byrne JM, Basset FA. Barefoot running does not affect simple reaction time: an exploratory study. PeerJ 2018; 6:e4605. [PMID: 29666760 PMCID: PMC5896505 DOI: 10.7717/peerj.4605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 03/21/2018] [Indexed: 11/20/2022] Open
Abstract
Background Converging evidence comparing barefoot (BF) and shod (SH) running highlights differences in foot-strike patterns and somatosensory feedback, among others. Anecdotal evidence from SH runners attempting BF running suggests a greater attentional demand may be experienced during BF running. However, little work to date has examined whether there is an attentional cost of BF versus SH running. Objective This exploratory study aimed to examine whether an acute bout of BF running would impact simple reaction time (SRT) compared to SH running, in a sample of runners naïve to BF running. Methods Eight male distance runners completed SRT testing during 10 min of BF or SH treadmill running at 70% maximal aerobic speed (17.9 ± 1.4 km h−1). To test SRT, participants were required to press a hand-held button in response to the flash of a light bulb placed in the center of their visual field. SRT was tested at 1-minute intervals during running. BF and SH conditions were completed in a pseudo-randomized and counterbalanced crossover fashion. SRT was defined as the time elapsed between the light bulb flash and the button press. SRT errors were also recorded and were defined as the number of trials in which a button press was not recorded in response to the light bulb flash. Results Overall, SRT later in the exercise bouts showed a statistically significant increase compared to earlier (p < 0.05). Statistically significant increases in SRT were present at 7 min versus 5 min (0.29 ± 0.02 s vs. 0.27 ± 0.02 s, p < 0.05) and at 9 min versus 2 min (0.29 ± 0.03 s vs. 0.27 ± 0.03 s, p < 0.05). However, BF running did not influence this increase in SRT (p > 0.05) or the number of SRT errors (17.6 ± 6.6 trials vs. 17.0 ± 13.0 trials, p > 0.05). Discussion In a sample of distance runners naïve to BF running, there was no statistically significant difference in SRT or SRT errors during acute bouts of BF and SH running. We interpret these results to mean that BF running does not have a greater attentional cost compared to SH running during a SRT task throughout treadmill running. Literature suggests that stride-to-stride gait modulation during running may occur predominately via mechanisms that preclude conscious perception, thus potentially attenuating effects of increased somatosensory feedback experienced during BF running. Future research should explore the present experimental paradigm in a larger sample using over-ground running trials, as well as employing different tests of attention.
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Affiliation(s)
- Nicholas J Snow
- Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Jason F L Blair
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Graham Z MacDonald
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Jeannette M Byrne
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Fabien A Basset
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
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Challenging human locomotion: stability and modular organisation in unsteady conditions. Sci Rep 2018; 8:2740. [PMID: 29426876 PMCID: PMC5807318 DOI: 10.1038/s41598-018-21018-4] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/29/2018] [Indexed: 01/10/2023] Open
Abstract
The need to move over uneven terrain is a daily challenge. In order to face unexpected perturbations due to changes in the morphology of the terrain, the central nervous system must flexibly modify its control strategies. We analysed the local dynamic stability and the modular organisation of muscle activation (muscle synergies) during walking and running on an even- and an uneven-surface treadmill. We hypothesized a reduced stability during uneven-surface locomotion and a reorganisation of the modular control. We found a decreased stability when switching from even- to uneven-surface locomotion (p < 0.001 in walking, p = 0.001 in running). Moreover, we observed a substantial modification of the time-dependent muscle activation patterns (motor primitives) despite a general conservation of the time-independent coefficients (motor modules). The motor primitives were considerably wider in the uneven-surface condition. Specifically, the widening was significant in both the early (+40.5%, p < 0.001) and late swing (+7.7%, p = 0.040) phase in walking and in the weight acceptance (+13.6%, p = 0.006) and propulsion (+6.0%, p = 0.041) phase in running. This widening highlighted an increased motor output’s robustness (i.e. ability to cope with errors) when dealing with the unexpected perturbations. Our results confirmed the hypothesis that humans adjust their motor control strategies’ timing to deal with unsteady locomotion.
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Ekizos A, Santuz A, Arampatzis A. Short- and long-term effects of altered point of ground reaction force application on human running energetics. J Exp Biol 2018; 221:jeb.176719. [DOI: 10.1242/jeb.176719] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 06/06/2018] [Indexed: 12/27/2022]
Abstract
The current study investigates an acute and a gradual transition of the point of force application (PFA) from the rearfoot towards the fore of the foot during running, on the rate of metabolic energy consumption. The participants were randomly assigned in two experimental and one control groups: a short-term intervention group (STI, N=17; two training sessions), a long-term intervention group (LTI, N=10; 14-week gradual transition) and a control group (CG, N=11). Data were collected at two running velocities (2.5 and 3.0 m/s). The cost coefficient (i.e. energy required for a unit of vertical ground reaction force, J/N) decreased (p<0.001) after both interventions due to a more anterior PFA during running (STI:12%, LTI:11%), but led to a higher (p<0.001) rate of force generation (STI:17%, LTI:15.2%). Dynamic stability of running showed a significant (p<0.001) decrease in the STI (2.1%), but no differences (p=0.673) in the LTI. The rate of metabolic energy consumption increased in the STI (p=0.038), but remained unchanged in the LTI (p=0.660). The control group had no changes. These results demonstrate that the cost coefficient was successfully decreased following an alteration in the running technique towards a more anterior PFA. However, the energy consumption remained unchanged because of a simultaneous increase in rate of force generation due to a decreased contact time per step. The increased instability found during the short-term intervention and its neutralization after the long-term intervention indicates a role of motor control errors in the economy of running after acute alterations in habitual running execution.
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Affiliation(s)
- Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
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Santuz A, Ekizos A, Janshen L, Baltzopoulos V, Arampatzis A. The Influence of Footwear on the Modular Organization of Running. Front Physiol 2017; 8:958. [PMID: 29213246 PMCID: PMC5702634 DOI: 10.3389/fphys.2017.00958] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/10/2017] [Indexed: 01/06/2023] Open
Abstract
For most of our history, we predominantly ran barefoot or in minimalist shoes. The advent of modern footwear, however, might have introduced alterations in the motor control of running. The present study investigated shod and barefoot running under the perspective of the modular organization of muscle activation, in order to help addressing the neurophysiological factors underlying human locomotion. On a treadmill, 20 young and healthy inexperienced barefoot runners ran shod and barefoot at preferred speed (2.8 ± 0.4 m/s). Fundamental synergies, containing the time-dependent activation coefficients (motor primitives) and the time-invariant muscle weightings (motor modules), were extracted from 24 ipsilateral electromyographic activities using non-negative matrix factorization. In shod running, the average foot strike pattern was a rearfoot strike, while in barefoot running it was a mid-forefoot strike. In both conditions, five fundamental synergies were enough to describe as many gait cycle phases: weight acceptance, propulsion, arm swing, early swing and late swing. We found the motor primitives to be generally shifted earlier in time during the stance-related phases and later in the swing-related ones in barefoot running. The motor primitive describing the propulsion phase was significantly of shorter duration (peculiarity confirmed by the analysis of the spinal motor output). The arm swing primitive, instead, was significantly wider in the barefoot condition. The motor modules demonstrated analogous organization with some significant differences in the propulsion, arm swing and late swing synergies. Other than to the trivial absence of shoes, the differences might be deputed to the lower ankle gear ratio (and the consequent increased system instability) and to the higher recoil capabilities of the longitudinal foot arch during barefoot compared to shod running.
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Affiliation(s)
- Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Lars Janshen
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Vasilios Baltzopoulos
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
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