1
|
Luciano F, Ruggiero L, Minetti AE, Pavei G. The work to swing limbs in humans versus chimpanzees and its relation to the metabolic cost of walking. Sci Rep 2024; 14:8970. [PMID: 38637567 PMCID: PMC11026468 DOI: 10.1038/s41598-024-59171-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/08/2024] [Indexed: 04/20/2024] Open
Abstract
Compared to their closest ape relatives, humans walk bipedally with lower metabolic cost (C) and less mechanical work to move their body center of mass (external mechanical work, WEXT). However, differences in WEXT are not large enough to explain the observed lower C: humans may also do less work to move limbs relative to their body center of mass (internal kinetic mechanical work, WINT,k). From published data, we estimated differences in WINT,k, total mechanical work (WTOT), and efficiency between humans and chimpanzees walking bipedally. Estimated WINT,k is ~ 60% lower in humans due to changes in limb mass distribution, lower stride frequency and duty factor. When summing WINT,k to WEXT, between-species differences in efficiency are smaller than those in C; variations in WTOT correlate with between-species, but not within-species, differences in C. These results partially support the hypothesis that the low cost of human walking is due to the concerted low WINT,k and WEXT.
Collapse
Affiliation(s)
- Francesco Luciano
- Department of Pathophysiology and Transplantation, University of Milan, 20133, Milan, Italy
| | - Luca Ruggiero
- Human Performance Research Centre, Department of Sports Science, University of Konstanz, Konstanz, Germany.
| | - Alberto E Minetti
- Department of Pathophysiology and Transplantation, University of Milan, 20133, Milan, Italy
| | - Gaspare Pavei
- Department of Pathophysiology and Transplantation, University of Milan, 20133, Milan, Italy
| |
Collapse
|
2
|
Sannasi R, Dakshinamurthy A, Dommerholt J, Desai V, Kumar A, Sugavanam T. Diaphragm and core stabilization exercises in low back pain: A narrative review. J Bodyw Mov Ther 2023; 36:221-227. [PMID: 37949564 DOI: 10.1016/j.jbmt.2023.07.008] [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: 11/12/2021] [Revised: 05/03/2023] [Accepted: 07/04/2023] [Indexed: 11/12/2023]
Abstract
INTRODUCTION Core stabilization is a vital concept in clinical rehabilitation (including low back pain rehabilitation) and competitive athletic training. The core comprises of a complex network of hip, trunk and neck muscles including the diaphragm. AIMS The paper aims to discuss the role of the diaphragm in core stability, summarize current evidence and put forth ideal core training strategies involving the diaphragm. METHOD Narrative review RESULTS: The diaphragm has a dual role of respiration and postural control. Evidence suggests that current core stability exercises for low back pain are superior than minimal or no treatment, however, no more beneficial than general exercises and/or manual therapy. There appears to be a higher focus on the transversus abdominis and multifidi muscles and minimal attention to the diaphragm. We propose that any form of core stabilization exercises for low back pain rehabilitation should consider the diaphragm. Core stabilization program could commence with facilitation of normal breathing patterns and progressive systematic restoration of the postural control role of the diaphragm muscle. CONCLUSION The role of the diaphragm is often overlooked in both research and practice. Attention to the diaphragm may improve the effectiveness of core stability exercise in low back pain rehabilitation.
Collapse
Affiliation(s)
- Rajasekar Sannasi
- Institute of Physiotherapy, Srinivas University, Mangalore, Karnataka, India.
| | - Anandhi Dakshinamurthy
- SRM College of Physiotherapy, Faculty of Medical and Health Sciences, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur, 603203, Kanchipuram, Chennai, Tamil Nadu, India.
| | - Jan Dommerholt
- Myopain Seminars, Bethesda, MD 20814, USA; Department of Physical Therapy and Rehabilitation Science, School of Medicine, University of Maryland, Baltimore, MD 21201, USA.
| | - Vidhi Desai
- Institute of Physiotherapy, Srinivas University, Mangalore, Karnataka, India.
| | - Ajay Kumar
- Institute of Physiotherapy, Srinivas University, Mangalore, Karnataka, India.
| | - Thavapriya Sugavanam
- Health Services Research Unit, Oxford Population Health, University of Oxford, Oxford, United Kingdom.
| |
Collapse
|
3
|
Modeling lactate threshold in young squad athletes: influence of sex, maximal oxygen uptake, and cost of running. Eur J Appl Physiol 2023; 123:573-583. [PMID: 36411398 PMCID: PMC9941268 DOI: 10.1007/s00421-022-05084-1] [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: 07/05/2022] [Accepted: 10/20/2022] [Indexed: 11/23/2022]
Abstract
PURPOSE This study aimed to investigate: 1. The influence of sex and age on the accuracy of the classical model of endurance performance, including maximal oxygen uptake ([Formula: see text]), its fraction (LT2%), and cost of running (CR), for calculating running speed at lactate threshold 2 (vLT2) in young athletes. 2. The impact of different CR determination methods on the accuracy of the model. 3. The contributions of [Formula: see text], LT2%, and CR to vLT2 in different sexes. METHODS 45 male and 55 female young squad athletes from different sports (age: 15.4 ± 1.3 years; [Formula: see text]: 51.4 ± 6.8 [Formula: see text]) performed an incremental treadmill test to determine [Formula: see text], LT2%, CR, and vLT2. CR was assessed at a fixed running speed (2.8 [Formula: see text]), at lactate threshold 1 (LT1), and at 80% of [Formula: see text], respectively. RESULTS Experimentally determined and modeled vLT2 were highly consistent independent of sex and age (ICC [Formula: see text] 0.959). The accuracy of vLT2 modeling was improved by reducing random variation using individualized CR at 80% [Formula: see text] (± 4%) compared to CR at LT1 (± 7%) and at a fixed speed (± 8%). 97% of the total variance of vLT2 was explained by [Formula: see text], LT2%, and CR. While [Formula: see text] and CR showed the highest unique (96.5% and 31.9% of total [Formula: see text], respectively) and common (- 31.6%) contributions to the regression model, LT2% made the smallest contribution (7.5%). CONCLUSION Our findings indicate: 1. High accuracy of the classical model of endurance performance in calculating vLT2 in young athletes independent of age and sex. 2. The importance of work rate selection in determining CR to accurately predict vLT2. 3. The largest contribution of [Formula: see text] and CR to vLT2, the latter being more important in female athletes than in males, and the least contribution of LT2%.
Collapse
|
4
|
Ruggiero L, Carpi M, Minetti AE. Rocker-profile design shoes improve pendular energy recovery in walking with no effects on total mechanical work. J Biomech 2022; 144:111345. [DOI: 10.1016/j.jbiomech.2022.111345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 09/19/2022] [Accepted: 10/05/2022] [Indexed: 10/31/2022]
|
5
|
Acute Effects of Handheld Loading on Standing Broad Jump in Youth Athletes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18095046. [PMID: 34068833 PMCID: PMC8126242 DOI: 10.3390/ijerph18095046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 12/02/2022]
Abstract
The study aimed to investigate the acute effects of handheld loading on standing broad jump (SBJ) performance and biomechanics. Fifteen youth male athletes (mean age: 14.7 ± 0.9 years; body mass: 59.3 ± 8.0 kg; height: 1.73 ± 0.07 m) volunteered to participate in the study. Participants were assigned to perform SBJ with and without 4 kg dumbbells in a random order. Kinematic and kinetic data were collected using 10 infrared high-speed motion-capture cameras at a 250 Hz sampling rate and two force platforms at a 1000 Hz sampling rate. A paired t-test was applied to all variables to determine the significance between loading and unloading SBJs. Horizontal distance (p < 0.001), take-off distance (p = 0.001), landing distance (p < 0.001), horizontal velocity of center of mass (CoM; p < 0.001), push time (p < 0.001), vertical impulse (p = 0.003), and peak horizontal and vertical ground reaction force (GRF; p < 0.001, p = 0.017) were significantly greater in loading SBJ than in unloading SBJ. The take-off vertical velocity of CoM (p = 0.001), take-off angle (p < 0.001), peak knee and hip velocity (p < 0.001, p = 0.007), peak ankle and hip moment (p = 0.006, p = 0.011), and peak hip power (p = 0.014) were significantly greater in unloading SBJ than in loading SBJ. Conclusions: Acute enhancement in SBJ performance was observed with handheld loading. The present findings contribute to the understanding of biomechanical differences in SBJ performance with handheld loading and are highly applicable to strength and conditioning training for athletes.
Collapse
|
6
|
Minetti AE, Moorhead AP, Pavei G. Frictional internal work of damped limbs oscillation in human locomotion. Proc Biol Sci 2020; 287:20201410. [PMID: 33043862 PMCID: PMC7423663 DOI: 10.1098/rspb.2020.1410] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Joint friction has never previously been considered in the computation of mechanical and metabolic energy balance of human and animal (loco)motion, which heretofore included just muscle work to move the body centre of mass (external work) and body segments with respect to it. This happened mainly because, having been previously measured ex vivo, friction was considered to be almost negligible. Present evidences of in vivo damping of limb oscillations, motion captured and processed by a suited mathematical model, show that: (a) the time course is exponential, suggesting a viscous friction operated by the all biological tissues involved; (b) during the swing phase, upper limbs report a friction close to one-sixth of the lower limbs; (c) when lower limbs are loaded, in an upside-down body posture allowing to investigate the hip joint subjected to compressive forces as during the stance phase, friction is much higher and load dependent; and (d) the friction of the four limbs during locomotion leads to an additional internal work that is a remarkable fraction of the mechanical external work. These unprecedented results redefine the partitioning of the energy balance of locomotion, the internal work components, muscle and transmission efficiency, and potentially readjust the mechanical paradigm of the different gaits.
Collapse
Affiliation(s)
- Alberto E Minetti
- Physiology Division, Department of Pathophysiology and Transplants, University of Milan, Via Mangiagalli 32, 20133 Milan, Italy
| | - Alex P Moorhead
- Physiology Division, Department of Pathophysiology and Transplants, University of Milan, Via Mangiagalli 32, 20133 Milan, Italy
| | - Gaspare Pavei
- Physiology Division, Department of Pathophysiology and Transplants, University of Milan, Via Mangiagalli 32, 20133 Milan, Italy
| |
Collapse
|
7
|
Etenzi E, Borzuola R, Grabowski AM. Passive-elastic knee-ankle exoskeleton reduces the metabolic cost of walking. J Neuroeng Rehabil 2020; 17:104. [PMID: 32718344 PMCID: PMC7385868 DOI: 10.1186/s12984-020-00719-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 07/06/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Previous studies have shown that passive-elastic exoskeletons with springs in parallel with the ankle can reduce the metabolic cost of walking. We developed and tested the use of an unpowered passive-elastic exoskeleton for walking that stores elastic energy in a spring from knee extension at the end of the leg swing phase, and then releases this energy to assist ankle plantarflexion at the end of the stance phase prior to toe-off. The exoskeleton uses a system of ratchets and pawls to store and return elastic energy through compression and release of metal springs that act in parallel with the knee and ankle, respectively. We hypothesized that, due to the assistance provided by the exoskeleton, net metabolic power would be reduced compared to walking without using an exoskeleton. METHODS We compared the net metabolic power required to walk when the exoskeleton only acts at the knee to resist extension at the end of the leg swing phase, to that required to walk when the stored elastic energy from knee extension is released to assist ankle plantarflexion at the end of the stance phase prior to toe-off. Eight (4 M, 4F) subjects walked at 1.25 m/s on a force-measuring treadmill with and without using the exoskeleton while we measured their metabolic rates, ground reaction forces, and center of pressure. RESULTS We found that when subjects used the exoskeleton with energy stored from knee extension and released for ankle plantarflexion, average net metabolic power was 11% lower than when subjects walked while wearing the exoskeleton with the springs disengaged (p = 0.007), but was 23% higher compared to walking without the exoskeleton (p < 0.0001). CONCLUSION The use of a novel passive-elastic exoskeleton that stores and returns energy in parallel with the knee and ankle, respectively, has the potential to improve the metabolic cost of walking. Future studies are needed to optimize the design and elucidate the underlying biomechanical and physiological effects of using an exoskeleton that acts in parallel with the knee and ankle. Moreover, addressing and improving the exoskeletal design by reducing and closely aligning the mass of the exoskeleton could further improve the metabolic cost of walking.
Collapse
Affiliation(s)
- Ettore Etenzi
- Beckett Thermal Solutions S.r.l, Formigine (MO), Italy
| | - Riccardo Borzuola
- Department of Movement, Human and Health Sciences, University of Rome “Foro Italico”, Rome, Italy
| | - Alena M. Grabowski
- Department of Integrative Physiology, University of Colorado, Boulder, Boulder, CO USA
- Department of Veterans Affairs Eastern Colorado Healthcare System, Aurora, CO USA
| |
Collapse
|
8
|
Gea-García GM, Espeso-García A, Marcos-Pardo PJ, Menayo-Antúnez R. Fin type and flutter technique: a study to optimise the oxygen consumption in divers. ERGONOMICS 2020; 63:756-768. [PMID: 32200696 DOI: 10.1080/00140139.2020.1745899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 03/14/2020] [Indexed: 06/10/2023]
Abstract
The purpose of this research was to assess the variability of the oxygen consumption (VO2) depending on fin type and the flutter technique used for the different divers' profile. Twenty-three SCUBA divers took part in four 2.5 hour sessions to evaluate a total of six fin models and two flutter techniques. The flutter routines lasted 30 minutes per fin and per technique. Measurements of VO2 significantly decreased on Jet (20.42 ml*min-1*kg-1) and XShot fin (20.87 ml*min-1*kg-1) compared to Twin Jet fin (22.81 ml, p < 0.05). In addition, the VO2 was in all cases higher in certified divers than in professional divers (23.87 and 19.00 ml*min-1*kg-1, p = 0.00). These differences were significant between divers' profile and flutter technique (p < 0.05). Similarly, measurements of VO2 were higher in frog kick technique than crawl kick technique (22.97 ml*min-1*kg-1 and 19.96 ml*min-1*kg-1, p = 0.00). These differences were significant between fin type and flutter technique in all fins (p = 0.03). Practitioner summary: This study investigated the impact of fin type, flutter technique and divers' profile on VO2 during diving. Results of this research suggest that combination a diving different factors significantly impacts the divers' VO2, thus providing new perspective for election of fin type and flutter technique according to the divers' profile.
Collapse
Affiliation(s)
- Gemma M Gea-García
- Department of Sport Science, Faculty of Sport Sciences, San Antonio Catholic University, Murcia, Spain
| | - Alejandro Espeso-García
- Department of Sport Science, Faculty of Sport Sciences, San Antonio Catholic University, Murcia, Spain
| | - Pablo J Marcos-Pardo
- Department of Sport Science, Faculty of Sport Sciences, San Antonio Catholic University, Murcia, Spain
| | - Ruperto Menayo-Antúnez
- Department of Education, Faculty of Teacher Training College, University of Extremadura, Cáceres, Spain
| |
Collapse
|
9
|
Fischer G, Figueiredo P, Ardigò LP. Bioenergetics and Biomechanics of Handcycling at Submaximal Speeds in Athletes with a Spinal Cord Injury. Sports (Basel) 2020; 8:sports8020016. [PMID: 32013128 PMCID: PMC7077182 DOI: 10.3390/sports8020016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/24/2020] [Accepted: 01/27/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND A study aimed at comparing bioenergetics and biomechanical parameters between athletes with tetraplegia and paraplegia riding race handbikes at submaximal speeds in ecological conditions. METHODS Five athletes with tetraplegia (C6-T1, 43 ± 6 yrs, 63 ± 14 kg) and 12 athletes with paraplegia (T4-S5, 44 ± 7 yrs, 72 ± 12 kg) rode their handbikes at submaximal speeds under metabolic measurements. A deceleration method (coasting down) was applied to calculate the rolling resistance and frontal picture of each participant was taken to calculate air resistance. The net overall Mechanical Efficiency (Eff) was calculated by dividing external mechanical work to the corresponding Metabolic Power. RESULTS Athletes with tetraplegia reached a lower aerobic speed (4.7 ± 0.6 m s-1 vs. 7.1 ± 0.9 m s-1, P = 0.001) and Mechanical Power (54 ± 15 W vs. 111 ± 25 W, P = 0.001) compared with athletes with paraplegia. The metabolic cost was around 1 J kg-1 m-1 for both groups. The Eff values (17 ± 2% vs. 19 ± 3%, P = 0.262) suggested that the handbike is an efficient assisted locomotion device. CONCLUSION Handbikers with tetraplegia showed lower aerobic performances but a similar metabolic cost compared with handbikers with paraplegia at submaximal speeds in ecological conditions.
Collapse
Affiliation(s)
- Gabriela Fischer
- School of Exercise and Sport Science, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona 37131, Italy;
- Laboratory of Biomechanics, Department of Physical Education, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil
- Correspondence: ; Tel.: +55-48-3721-8558
| | - Pedro Figueiredo
- Portugal Football School, Portuguese Football Federation, Oeiras 1495-433, Portugal;
- Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University Institute of Maia, ISMAI, Maia 4475-690, Portugal
| | - Luca Paolo Ardigò
- School of Exercise and Sport Science, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona 37131, Italy;
| |
Collapse
|
10
|
Zamparo P, Cortesi M, Gatta G. The energy cost of swimming and its determinants. Eur J Appl Physiol 2019; 120:41-66. [PMID: 31807901 DOI: 10.1007/s00421-019-04270-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/19/2019] [Indexed: 11/30/2022]
Abstract
The energy expended to transport the body over a given distance (C, the energy cost) increases with speed both on land and in water. At any given speed, C is lower on land (e.g., running or cycling) than in water (e.g., swimming or kayaking) and this difference can be easily understood when one considers that energy should be expended (among the others) to overcome resistive forces since these, at any given speed, are far larger in water (hydrodynamic resistance, drag) than on land (aerodynamic resistance). Another reason for the differences in C between water and land locomotion is the lower capability to exert useful forces in water than on land (e.g., a lower propelling efficiency in the former case). These two parameters (drag and efficiency) not only can explain the differences in C between land and water locomotion but can also explain the differences in C within a given form of locomotion (swimming at the surface, which is the topic of this review): e.g., differences between strokes or between swimmers of different age, sex, and technical level. In this review, the determinants of C (drag and efficiency, as well as energy expenditure in its aerobic and anaerobic components) will, thus, be described and discussed. In aquatic locomotion it is difficult to obtain quantitative measures of drag and efficiency and only a comprehensive (biophysical) approach could allow to understand which estimates are "reasonable" and which are not. Examples of these calculations are also reported and discussed.
Collapse
Affiliation(s)
- Paola Zamparo
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Via Felice Casorati 43, 37131, Verona, Italy.
| | - Matteo Cortesi
- Department of Life Quality Studies, University of Bologna, Bologna, Italy
| | - Giorgio Gatta
- Department of Life Quality Studies, University of Bologna, Bologna, Italy
| |
Collapse
|
11
|
Peyré-Tartaruga LA, Coertjens M. Locomotion as a Powerful Model to Study Integrative Physiology: Efficiency, Economy, and Power Relationship. Front Physiol 2018; 9:1789. [PMID: 30618802 PMCID: PMC6297284 DOI: 10.3389/fphys.2018.01789] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 11/28/2018] [Indexed: 12/02/2022] Open
Abstract
Locomotion is the most common form of movement in nature. Its study allows analysis of interactions between muscle functions (motor) and lever system arrangements (transmission), thereby facilitating performance analysis of various body organs and systems. Thus, it is a powerful model to study various aspects of integrative physiology. The results of this model can be applied in understanding body functions and design principles as performance outputs of interest for medical and biological sciences. The overall efficiency (effoverall) during locomotion is an example of an integrative parameter, which results from the ratio between mechanical output and metabolic input. Although the concepts of cost (i.e., metabolic expenditure relative to distance) and power (i.e., metabolic expenditure relative to time) are included in its calculation, the effoverall establishes peculiar relations with these variables. For a better approach to these aspects, in this study, we presented the physical-mathematical formulation of efficiency, as well as its conceptual definitions and applications. Furthermore, the concepts of efficiency, cost, and power are discussed from the biological and medical perspectives. Terrestrial locomotion is a powerful model to study integrative physiology in humans, because by analyzing the mechanical and metabolic determinants, we may verify the efficiency and economy relationship through locomotion type, and its characteristics and restrictions. Thus, it is possible to elaborate further on various improved intervention strategies, such as physical training, competition strategies, and ergogenic supplementation.
Collapse
Affiliation(s)
- Leonardo Alexandre Peyré-Tartaruga
- Exercise Research Laboratory, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Postgraduate Program in Pneumological Sciences, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Marcelo Coertjens
- Exercise Research Laboratory, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Postgraduate Program in Pneumological Sciences, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,School of Physical Therapy, Federal University of Piauì, Parnaìba, Brazil
| |
Collapse
|
12
|
Göpfert C, Lindinger SJ, Ohtonen O, Rapp W, Müller E, Linnamo V. Arm swing during skating at different skiing speeds affects skiing mechanics and performance. TRANSLATIONAL SPORTS MEDICINE 2018. [DOI: 10.1002/tsm2.40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Caroline Göpfert
- Department of Sport Science and Kinesiology; University of Salzburg; Salzburg Austria
- Sports Technology Unit; Department of Biology of Physical Activity; Neuromuscular Research Centre; University of Jyväskylä; Vuokatti Finland
| | - Stefan J. Lindinger
- Department of Sport Science and Kinesiology; University of Salzburg; Salzburg Austria
| | - Olli Ohtonen
- Sports Technology Unit; Department of Biology of Physical Activity; Neuromuscular Research Centre; University of Jyväskylä; Vuokatti Finland
| | - Walter Rapp
- Olympic Training Centre Freiburg-Schwarzwald; Freiburg Germany
| | - Erich Müller
- Department of Sport Science and Kinesiology; University of Salzburg; Salzburg Austria
| | - Vesa Linnamo
- Sports Technology Unit; Department of Biology of Physical Activity; Neuromuscular Research Centre; University of Jyväskylä; Vuokatti Finland
| |
Collapse
|
13
|
Danielsen J, Sandbakk Ø, Holmberg HC, Ettema G. Mechanical Energy and Propulsion in Ergometer Double Poling by Cross-country Skiers. Med Sci Sports Exerc 2016; 47:2586-94. [PMID: 26110695 DOI: 10.1249/mss.0000000000000723] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aims to investigate fluctuations in total mechanical energy of the body (Ebody) in relation to external ergometer work (Werg) during the poling and recovery phases of simulated double-poling cross-country skiing. METHODS Nine male cross-country skiers (mean ± SD age, 24 ± 5 yr; mean ± SD body mass, 81.7 ± 6.5 kg) performed 4-min submaximal tests at low-intensity, moderate-intensity, and high-intensity levels and a 3-min all-out test on a ski ergometer. Motion capture analysis and load cell recordings were used to measure body kinematics and dynamics. From these, Werg, Ebody (sum of the translational, rotational, and gravitational potential energies of all segments), and their time differentials (power P) were calculated. Ptot--the rate of energy absorption or generation by muscles-tendons--was defined as the sum of Pbody and Perg. RESULTS Ebody showed large fluctuations over the movement cycle, decreasing during poling and increasing during the recovery phase. The fluctuation in Pbody was almost perfectly out of phase with Perg. Some muscle-tendon energy absorption was observed at the onset of poling. For the rest of poling and throughout the recovery phase, muscles-tendons generated energy to do Werg and to increase Ebody. Approximately 50% of cycle Ptot occurred during recovery for all intensity levels. CONCLUSIONS In double poling, the extensive contribution of the lower extremities and trunk to whole-body muscle-tendon work during recovery facilitates a "direct" transfer of Ebody to Werg during the poling phase. This observation reveals that double poling involves a unique movement pattern different from most other forms of legged terrestrial locomotion, which are characterized primarily by inverted pendulum or spring-mass types of movement.
Collapse
Affiliation(s)
- Jørgen Danielsen
- 1Center for Elite Sports Research, Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, NORWAY; and 2Swedish Winter Sports Research Center, Department of Health Science, Mid Sweden University, Östersund, SWEDEN
| | | | | | | |
Collapse
|
14
|
Telli R, Seminati E, Pavei G, Minetti AE. Recumbent vs. upright bicycles: 3D trajectory of body centre of mass, limb mechanical work, and operative range of propulsive muscles. J Sports Sci 2016; 35:491-499. [PMID: 27103353 DOI: 10.1080/02640414.2016.1175650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Recumbent bicycles (RB) are high performance, human-powered vehicles. In comparison to normal/upright bicycles (NB) the RB may allow individuals to reach higher speeds due to aerodynamic advantages. The purpose of this investigation was to compare the non-aerodynamic factors that may potentially influence the performance of the two bicycles. 3D body centre of mass (BCoM) trajectory, its symmetries, and the components of the total mechanical work necessary to sustain cycling were assessed through 3D kinematics and computer simulations. Data collected at 50, 70, 90 110 rpm during stationary cycling were used to drive musculoskeletal modelling simulation and estimate muscle-tendon length. Results demonstrated that BCoM trajectory, confined in a 15-mm side cube, changed its orientation, maintaining a similar pattern across all cadences in both bicycles. RB displayed a reduced additional mechanical external power (16.1 ± 9.7 W on RB vs. 20.3 ± 8.8 W on NB), a greater symmetry on the progression axis, and no differences in the internal mechanical power compared to NB. Simulated muscle activity revealed small significant differences for only selected muscles. On the RB, quadriceps and gluteus demonstrated greater shortening, while biceps femoris, iliacus, and psoas exhibited greater stretch; however, aerodynamics still remains the principal benefit.
Collapse
Affiliation(s)
- Riccardo Telli
- a Department of Pathophysiology and Transplantation, Division of Physiology , Università degli Studi di Milano , Milano , Italy
| | - Elena Seminati
- a Department of Pathophysiology and Transplantation, Division of Physiology , Università degli Studi di Milano , Milano , Italy.,b Department for Health , University of Bath , North East Somerset , UK
| | - Gaspare Pavei
- a Department of Pathophysiology and Transplantation, Division of Physiology , Università degli Studi di Milano , Milano , Italy
| | - Alberto Enrico Minetti
- a Department of Pathophysiology and Transplantation, Division of Physiology , Università degli Studi di Milano , Milano , Italy
| |
Collapse
|
15
|
Barbosa TM, Morais JE, Marques MC, Costa MJ, Marinho DA. The power output and sprinting performance of young swimmers. J Strength Cond Res 2016; 29:440-50. [PMID: 25029007 DOI: 10.1519/jsc.0000000000000626] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The aim of this article was to compare swimming power output between boys and girls and to model the relationship between swimming power output and sprinting performance in young swimmers. One hundred young swimmers (49 boys and 51 girls, aged between 11 and 13 years) underwent a test battery including anthropometrics (body mass, height, arm span [AS], and trunk transverse surface area), kinematic and efficiency (velocity, stroke frequency, stroke length, speed fluctuation, normalized speed fluctuation, stroke index, and Froude efficiency), hydrodynamics (active drag and active drag coefficient), and power output (power to overcome drag, power to transfer kinetic energy to water, and external power) assessments and sprinting performance (official 100 freestyle race). All variables but the trunk transverse surface area, stroke length normalize to AS, speed fluctuation, active drag coefficient, and Froude efficiency were significantly higher in boys than in girls with moderate-strong effects. Comparing both sexes but controlling the effect of the sprinting performance, most variables presented a no-significant variation. There was a significant and strong relationship between power output and sprinting performance: y = 24.179x (R = 0.426; standard error of estimation = 0.485; p < 0.001). As a conclusion, boys presented better performances than girls because of their higher power output. There is a cubed relationship between power output and sprinting performance in young swimmers.
Collapse
Affiliation(s)
- Tiago M Barbosa
- 1National Institute of Education, Nanyang Technological University, Singapore, Singapore; 2Research Centre in Sports, Health and Human Development, Vila Real, Portugal; 3Department of Sport Sciences, Polytechnic Institute of Bragança, Bragança, Portugal; 4Department of Sport Sciences, University of Beira Interior, Covilhã, Portugal; and 5Department of Sport Sciences, Polytechnic Institute of Guarda, Guarda, Portugal
| | | | | | | | | |
Collapse
|
16
|
Pendergast DR, Moon RE, Krasney JJ, Held HE, Zamparo P. Human Physiology in an Aquatic Environment. Compr Physiol 2015; 5:1705-50. [PMID: 26426465 DOI: 10.1002/cphy.c140018] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Water covers over 70% of the earth, has varying depths and temperatures and contains much of the earth's resources. Head-out water immersion (HOWI) or submersion at various depths (diving) in water of thermoneutral (TN) temperature elicits profound cardiorespiratory, endocrine, and renal responses. The translocation of blood into the thorax and elevation of plasma volume by autotransfusion of fluid from cells to the vascular compartment lead to increased cardiac stroke volume and output and there is a hyperperfusion of some tissues. Pulmonary artery and capillary hydrostatic pressures increase causing a decline in vital capacity with the potential for pulmonary edema. Atrial stretch and increased arterial pressure cause reflex autonomic responses which result in endocrine changes that return plasma volume and arterial pressure to preimmersion levels. Plasma volume is regulated via a reflex diuresis and natriuresis. Hydrostatic pressure also leads to elastic loading of the chest, increasing work of breathing, energy cost, and thus blood flow to respiratory muscles. Decreases in water temperature in HOWI do not affect the cardiac output compared to TN; however, they influence heart rate and the distribution of muscle and fat blood flow. The reduced muscle blood flow results in a reduced maximal oxygen consumption. The properties of water determine the mechanical load and the physiological responses during exercise in water (e.g. swimming and water based activities). Increased hydrostatic pressure caused by submersion does not affect stroke volume; however, progressive bradycardia decreases cardiac output. During submersion, compressed gas must be breathed which introduces the potential for oxygen toxicity, narcosis due to nitrogen, and tissue and vascular gas bubbles during decompression and after may cause pain in joints and the nervous system.
Collapse
Affiliation(s)
- David R Pendergast
- Center for Research and Education in Special Environments, University at Buffalo, Buffalo, New York, USA
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York, USA
| | - Richard E Moon
- Center for Hyperbaric Medicine and Environmental Physiology, Duke University, Durham, North Carolina, USA
| | - John J Krasney
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York, USA
| | - Heather E Held
- Biomedical Hyperbarics Research Laboratory, Molecular Pharmacology and Physiology, College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Paola Zamparo
- Department of Neurological and Movement Sciences, University of Verona, Verona, Italy
| |
Collapse
|
17
|
Pellegrini B, Zoppirolli C, Bortolan L, Zamparo P, Schena F. Gait models and mechanical energy in three cross-country skiing techniques. ACTA ACUST UNITED AC 2015; 217:3910-8. [PMID: 25355851 DOI: 10.1242/jeb.106740] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fluctuations in mechanical energy of the body center of mass (COM) have been widely analyzed when investigating different gaits in human and animal locomotion. We applied this approach to estimate the mechanical work in cross-country skiing and to identify the fundamental mechanisms of this particular form of locomotion. We acquired movements of body segments, skis, poles and plantar pressures for eight skiers while they roller skied on a treadmill at 14 km h(-1) and a 2 deg slope using three different techniques (diagonal stride, DS; double poling, DP; double poling with kick, DK). The work associated with kinetic energy (KE) changes of COM was not different between techniques; the work against gravity associated with potential energy (PE) changes was higher for DP than for DK and was lowest for DS. Mechanical work against the external environment was 0.87 J m(-1) kg(-1) for DS, 0.70 J m(-1) kg(-1) for DP and 0.79 J m(-1) kg(-1) for DK. The work done to overcome frictional forces, which is negligible in walking and running, was 17.8%, 32.3% and 24.8% of external mechanical work for DS, DP and DK, respectively. The pendulum-like recovery (R%) between PE and KE was ~45%, ~26% and ~9% for DP, DK and DS, respectively, but energy losses by friction are not accounted for in this computation. The pattern of fluctuations of PE and KE indicates that DS can be described as a 'grounded running', where aerial phases are substituted by ski gliding phases, DP can be described as a pendular gait, whereas DK is a combination of both.
Collapse
Affiliation(s)
- Barbara Pellegrini
- CeRiSM, Center of Research in Mountain Sport and Health, University of Verona, 38068 Rovereto, Italy Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
| | - Chiara Zoppirolli
- CeRiSM, Center of Research in Mountain Sport and Health, University of Verona, 38068 Rovereto, Italy Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
| | - Lorenzo Bortolan
- CeRiSM, Center of Research in Mountain Sport and Health, University of Verona, 38068 Rovereto, Italy Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
| | - Paola Zamparo
- Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
| | - Federico Schena
- CeRiSM, Center of Research in Mountain Sport and Health, University of Verona, 38068 Rovereto, Italy Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
| |
Collapse
|
18
|
Cronin JB, Brughelli M, Gamble P, Brown SR, Mckenzie C. Acute kinematic and kinetic augmentation in horizontal jump performance using haltere type handheld loading. J Strength Cond Res 2015; 28:1559-64. [PMID: 24196795 DOI: 10.1519/jsc.0000000000000312] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purposes of this study were to investigate the effects of haltere/handheld loading on the kinematics and kinetics of horizontal jumping and to determine if an optimum relative load (% body mass [BM]) exists to maximize jump distance. A repeated measures analysis of variance with post hoc contrasts was used to determine the effects of haltere loading (no external loading, 6, 8, 12, and 16 kg) on the horizontal jump performance of 16 sportsmen as quantified by an in-ground force plate. The haltere loads of 6 and 8 kg elicited significant (p < 0.05) increases in jump distance (effect size [ES] = 0.22-0.37). The incremental loads also resulted in significant increases in jump duration (ES = 1.22-1.83), peak vertical ground reaction force (GRF) (ES = 0.20-0.37), and vertical (ES = 0.69-1.22) and horizontal (ES = 0.70-0.88) impulse. There was a significant reduction in jump distance with the 16 kg load (ES = 0.45). Significant decreases in mean horizontal GRF were likewise observed with the 12 and 16 kg loads. The optimum relative load for enhancing jump distance was 9.2 ± 3.4% of BM, which resulted in a predicted augmented horizontal jump of 13.6 ± 7.7 cm (ES = 0.56). The findings clearly indicate that haltere/handheld loading augments vertical and horizontal force and impulses. This could have a number of interesting training implications if the strength profiling of athletes identify horizontal and/or vertical deficits in force production. Further longitudinal investigation is warranted to establish what chronic adaptations result with repeated application of this type of training.
Collapse
Affiliation(s)
- John B Cronin
- 1Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand; and 2School of Exercise, Biomedical and Health Science, Edith Cowan University, Perth, Australia
| | | | | | | | | |
Collapse
|
19
|
Kehler A, Hajkova E, Holmberg HC, Kram R. Forces and mechanical energy fluctuations during diagonal stride roller skiing; running on wheels? J Exp Biol 2014; 217:3779-85. [DOI: 10.1242/jeb.107714] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Mechanical energy is conserved during terrestrial locomotion in two ways; the inverted pendulum mechanism for walking and the spring-mass mechanism for running. Here, we investigated if diagonal stride cross-country roller skiing (DIA) utilizes similar mechanisms. Based on previous studies, we hypothesized that running and DIA would share similar patterns of kinetic energy (KE), gravitational potential energy (GPE) and elastic energy fluctuations as if roller skiing is “running on wheels”. Experienced skiers (N=9) walked, ran and roller skied with DIA at 1.25m/s and 3 m/s on a level dual-belt treadmill that recorded perpendicular and parallel forces. We calculated the KE and GPE of the COM from the force recordings. As expected, the KE and GPE fluctuated with an out-of-phase pattern during walking and an in-phase pattern during running. Unlike walking, during DIA, the KE and GPE fluctuations were in-phase as they are in running. However, during the glide phase, KE was dissipated as frictional heat and could not be stored elastically in the tendons like in running. Elastic energy storage and return epitomize running and thus we reject our hypothesis. Diagonal stride cross-country skiing is a biomechanically unique movement that only superficially resembles walking or running.
Collapse
|
20
|
Pellegrini B, Zoppirolli C, Bortolan L, Holmberg HC, Zamparo P, Schena F. Biomechanical and energetic determinants of technique selection in classical cross-country skiing. Hum Mov Sci 2013; 32:1415-29. [PMID: 24071549 DOI: 10.1016/j.humov.2013.07.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 07/08/2013] [Accepted: 07/09/2013] [Indexed: 11/25/2022]
Abstract
Classical cross-country skiing can be performed using three main techniques: diagonal stride (DS), double poling (DP), and double poling with kick (DK). Similar to other forms of human and animal gait, it is currently unclear whether technique selection occurs to minimize metabolic cost or to keep some mechanical factors below a given threshold. The aim of this study was to find the determinants of technique selection. Ten male athletes roller skied on a treadmill at different slopes (from 0° to 7° at 10km/h) and speeds (from 6 to 18km/h at 2°). The technique preferred by skiers was gathered for every proposed condition. Biomechanical parameters and metabolic cost were then measured for each condition and technique. Skiers preferred DP for skiing on the flat and they transitioned to DK and then to DS with increasing slope steepness, when increasing speed all skiers preferred DP. Data suggested that selections mainly occur to remain below a threshold of poling force. Second, critically low values of leg thrust time may limit the use of leg-based techniques at high speeds. A small role has been identified for the metabolic cost of locomotion, which determined the selection of DP for flat skiing.
Collapse
Affiliation(s)
- Barbara Pellegrini
- CeRiSM, Center of Research in Mountain Sport and Health, University of Verona, Rovereto, Italy; Department of Neurological, Neuropsychological, Morphological and Movement Sciences, University of Verona, Verona, Italy.
| | | | | | | | | | | |
Collapse
|
21
|
Layec G, Trinity JD, Hart CR, Hopker J, Passfield L, Coen PM, Conley KE, Hunter GR, Fisher G, Ferguson RA, Sasaki K, Malatesta D, Maffiuletti NA, Borrani F, Minetti AE, Rice CL, Dalton BH, McNeil CJ, Power GA, Manini TM. Comments on point:counterpoint: skeletal muscle mechanical efficiency does/does not increase with age. J Appl Physiol (1985) 2013; 114:1114-8. [PMID: 23588541 PMCID: PMC6208486 DOI: 10.1152/japplphysiol.00185.2013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
22
|
|
23
|
Zamparo P, Swaine IL. Mechanical and propelling efficiency in swimming derived from exercise using a laboratory-based whole-body swimming ergometer. J Appl Physiol (1985) 2012; 113:584-94. [DOI: 10.1152/japplphysiol.00324.2012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Determining the efficiency of a swimming stroke is difficult because different “efficiencies” can be computed based on the partitioning of mechanical power output (Ẇ) into its useful and nonuseful components, as well as because of the difficulties in measuring the forces that a swimmer can exert in water. In this paper, overall efficiency (ηO = ẆTOT/Ė, where ẆTOT is total mechanical power output, and Ė is overall metabolic power input) was calculated in 10 swimmers by means of a laboratory-based whole-body swimming ergometer, whereas propelling efficiency (ηP = ẆD/ẆTOT, where ẆD is the power to overcome drag) was estimated based on these values and on values of drag efficiency (ηD = ẆD/Ė): ηP = ηD/ηO. The values of ηD reported in the literature range from 0.03 to 0.09 (based on data for passive and active drag, respectively). ηO was 0.28 ± 0.01, and ηP was estimated to range from ∼0.10 (ηD = 0.03) to 0.35 (ηD = 0.09). Even if there are obvious limitations to exact simulation of the whole swimming stroke within the laboratory, these calculations suggest that the data reported in the literature for ηO are probably underestimated, because not all components of ẆTOT can be measured accurately in this environment. Similarly, our estimations of ηP suggest that the data reported in the literature are probably overestimated.
Collapse
Affiliation(s)
- Paola Zamparo
- Department of Neurological, Neuropsychological, Morphological and Movement Sciences, Faculty of Exercise and Sport Sciences, University of Verona, Italy; and
| | - Ian L. Swaine
- Department of Sport Science, Canterbury Christ Church University, Canterbury, United Kingdom
| |
Collapse
|
24
|
Humans running in place on water at simulated reduced gravity. PLoS One 2012; 7:e37300. [PMID: 22815681 PMCID: PMC3399875 DOI: 10.1371/journal.pone.0037300] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 04/19/2012] [Indexed: 12/03/2022] Open
Abstract
Background On Earth only a few legged species, such as water strider insects, some aquatic birds and lizards, can run on water. For most other species, including humans, this is precluded by body size and proportions, lack of appropriate appendages, and limited muscle power. However, if gravity is reduced to less than Earth’s gravity, running on water should require less muscle power. Here we use a hydrodynamic model to predict the gravity levels at which humans should be able to run on water. We test these predictions in the laboratory using a reduced gravity simulator. Methodology/Principal Findings We adapted a model equation, previously used by Glasheen and McMahon to explain the dynamics of Basilisk lizard, to predict the body mass, stride frequency and gravity necessary for a person to run on water. Progressive body-weight unloading of a person running in place on a wading pool confirmed the theoretical predictions that a person could run on water, at lunar (or lower) gravity levels using relatively small rigid fins. Three-dimensional motion capture of reflective markers on major joint centers showed that humans, similarly to the Basilisk Lizard and to the Western Grebe, keep the head-trunk segment at a nearly constant height, despite the high stride frequency and the intensive locomotor effort. Trunk stabilization at a nearly constant height differentiates running on water from other, more usual human gaits. Conclusions/Significance The results showed that a hydrodynamic model of lizards running on water can also be applied to humans, despite the enormous difference in body size and morphology.
Collapse
|
25
|
Minetti AE, Cazzola D, Seminati E, Giacometti M, Roi GS. Skyscraper running: physiological and biomechanical profile of a novel sport activity. Scand J Med Sci Sports 2011; 21:293-301. [PMID: 20030780 DOI: 10.1111/j.1600-0838.2009.01043.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Skyscraper running is here analyzed in terms of mechanical and metabolic requirements, both at the general and at the individual level. Skyscraper runners' metabolic profile has been inferred from the total mechanical power estimated in 36 world records (48-421 m tall buildings), ranked by gender and age range. Individual athlete's performance (n=13) has been experimentally investigated during the Pirelli Vertical Sprint, with data loggers for altitude and heart rate (HR). At a general level, a non-linear regression of Wilkie's model relating maximal mechanical power to event duration revealed the gender and age differences in terms of maximum aerobic power and anaerobic energy resources particularly needed at the beginning of the race. The total mechanical power was found to be partitioned among: the fraction devolved to raise the body center of mass , the need to accelerate the limbs with respect to the body , and running in turns between flights of stairs . At the individual level, experiments revealed that these athletes show a metabolic profile similar to middle-distance runners. Furthermore, best skyscraper runners maintain a constant vertical speed and HR throughout the race, while others suddenly decelerate, negatively affecting the race performance.
Collapse
Affiliation(s)
- A E Minetti
- Department of Human Physiology, Faculty of Medicine, University of Milan, Milan, Italy.
| | | | | | | | | |
Collapse
|
26
|
How do elite cross-country skiers adapt to different double poling frequencies at low to high speeds? Eur J Appl Physiol 2010; 111:1103-19. [DOI: 10.1007/s00421-010-1736-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2010] [Indexed: 10/18/2022]
|
27
|
|
28
|
The myth of core stability. J Bodyw Mov Ther 2010; 14:84-98. [PMID: 20006294 DOI: 10.1016/j.jbmt.2009.08.001] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2008] [Revised: 05/03/2009] [Accepted: 08/04/2009] [Indexed: 01/13/2023]
Abstract
The principle of core stability has gained wide acceptance in training for the prevention of injury and as a treatment modality for rehabilitation of various musculoskeletal conditions in particular of the lower back. There has been surprisingly little criticism of this approach up to date. This article re-examines the original findings and the principles of core stability/spinal stabilisation approaches and how well they fare within the wider knowledge of motor control, prevention of injury and rehabilitation of neuromuscular and musculoskeletal systems following injury.
Collapse
|
29
|
Minetti AE, Machtsiras G, Masters JC. The optimum finger spacing in human swimming. J Biomech 2009; 42:2188-90. [PMID: 19651409 DOI: 10.1016/j.jbiomech.2009.06.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 05/13/2009] [Accepted: 06/09/2009] [Indexed: 11/16/2022]
Abstract
Competitive swimmers spread fingers during the propulsive stroke. Due to the inherent inefficiency of human swimming, the question is: does this strategy enhance performance or is it just a more comfortable hand posture? Here we show, through computational fluid dynamics (CFD) of a 3D model of the hand, that an optimal finger spacing (12 degrees , roughly corresponding to the resting hand posture) increases the drag coefficient (+8.8%), which is 'functionally equivalent' to a greater hand palm area, thus a lower stroke frequency can produce the same thrust, with benefits to muscle, hydraulic and propulsive efficiencies. CFD, through flow visualization, provides an explanation for the increased drag associated with the optimum finger spacing.
Collapse
Affiliation(s)
- Alberto E Minetti
- Department of Human Physiology, Faculty of Medicine, University of Milano, 20133 Milano, Italy.
| | | | | |
Collapse
|
30
|
STÖGGL THOMASL, MÜLLER ERICH. Kinematic Determinants and Physiological Response of Cross-Country Skiing at Maximal Speed. Med Sci Sports Exerc 2009; 41:1476-87. [DOI: 10.1249/mss.0b013e31819b0516] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
31
|
LINDINGER STEFANJOSEF, STÖGGL THOMAS, MÜLLER ERICH, HOLMBERG HANSCHRISTER. Control of Speed during the Double Poling Technique Performed by Elite Cross-Country Skiers. Med Sci Sports Exerc 2009; 41:210-20. [DOI: 10.1249/mss.0b013e318184f436] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
32
|
Michaud-Paquette Y, Pearsall DJ, Turcotte RA. Predictors of scoring accuracy: ice hockey wrist shot mechanics. SPORTS ENGINEERING 2008. [DOI: 10.1007/s12283-008-0009-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
33
|
Formenti F, Minetti AE. Human locomotion on ice: the evolution of ice-skating energetics through history. J Exp Biol 2007; 210:1825-33. [PMID: 17488946 DOI: 10.1242/jeb.002162] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
More than 3000 years ago, peoples living in the cold North European regions started developing tools such as ice skates that allowed them to travel on frozen lakes. We show here which technical and technological changes determined the main steps in the evolution of ice-skating performance over its long history. An in-depth historical research helped identify the skates displaying significantly different features from previous models and that could consequently determine a better performance in terms of speed and energy demand. Five pairs of ice skates were tested, from the bone-skates, dated about 1800 BC, to modern ones.
This paper provides evidence for the fact that the metabolic cost of locomotion on ice decreased dramatically through history, the metabolic cost of modern ice-skating being only 25% of that associated with the use of bone-skates. Moreover, for the same metabolic power, nowadays skaters can achieve speeds four times higher than their ancestors could. In the range of speeds considered, the cost of travelling on ice was speed independent for each skate model, as for running. This latter finding, combined with the accepted relationship between time of exhaustion and the sustainable fraction of metabolic power, gives the opportunity to estimate the maximum skating speed according to the distance travelled.
Ice skates were probably the first human powered locomotion tools to take the maximum advantage from the biomechanical properties of the muscular system: even when travelling at relatively high speeds, the skating movement pattern required muscles to shorten slowly so that they could also develop a considerable amount of force.
Collapse
Affiliation(s)
- Federico Formenti
- Institute for Biophysical and Clinical Research into Human Movement, Manchester Metropolitan University Cheshire, Hassall Road, Alsager, Stoke-on-Trent, ST7 2HL, UK.
| | | |
Collapse
|
34
|
Massaad F, Lejeune TM, Detrembleur C. The up and down bobbing of human walking: a compromise between muscle work and efficiency. J Physiol 2007; 582:789-99. [PMID: 17463048 PMCID: PMC2075334 DOI: 10.1113/jphysiol.2007.127969] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Human walking has a peculiar straight-legged style. Consequently, the body's centre of mass (CM) moves up and down with each step, which is noticeable in their up and down head bobbing while walking. This vertical CM movement enables humans to save energy via a pendulum-like mechanism but is probably a relatively recent locomotor innovation insofar as earliest bipeds may have walked flexed and flat. We investigated the mechanics, energetics, muscle efficiency and optimization of human walking by decreasing and increasing the vertical CM displacement (flat and bouncy walking) in comparison to normal walking at six speeds (1-6 km h(-1)). In both flat and bouncy walking, the pendular mechanism was reduced and the energy cost was increased. However, this increase was unexpectedly much sharper in flat walking where muscles provided normal mechanical work but with a decrease in muscle efficiency. In bouncy walking, muscles provided extra mechanical work in an efficient way. Our results showed that not only do humans bob up and down in normal walking to save energy via a pendulum-like mechanism but also to make their muscles work efficiently. Actually, walking flat makes the muscles work in unfavourable conditions that waste energy. Furthermore, we are still close to a flat CM displacement relative to our current ability to change this displacement, which suggests that reducing vertical CM displacement is indeed important but only to certain limits. Evolution may ultimately have chosen the best compromise between flat locomotion that requires little work to move and bouncy locomotion that improves muscle efficiency to minimize energy consumption.
Collapse
Affiliation(s)
- Firas Massaad
- Rehabilitation and Physical Medicine Unit, Université catholique de Louvain, Tour Pasteur 5375, Avenue Mounier 53, 1200 Brussels, Belgium.
| | | | | |
Collapse
|
35
|
Zamparo P, Pendergast DR, Termin A, Minetti AE. Economy and efficiency of swimming at the surface with fins of different size and stiffness. Eur J Appl Physiol 2005; 96:459-70. [PMID: 16341874 DOI: 10.1007/s00421-005-0075-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2005] [Indexed: 10/25/2022]
Abstract
The aim of this study was to investigate how fins with varying physical characteristics affect the energy cost and the efficiency of aquatic locomotion. Experiments were performed on ten college swimmers who were asked to swim the dolphin kick while using a monofin (MF) and to swim the front crawl kick with a small-flexible fin (SF), a large-stiff fin (LS) and without fins (BF, barefoot). The energy expended to cover one unit distance (C) was highest for BF (C=10.6+/-1.8 kJ m(-1) kg(-1) at 0.8 m s(-1)) and decreased by about 50% with LS, 55% with SF and 60% with MF, allowing for an increase in speed (for a given metabolic power) of about 0.4 m s(-1) for MF and of about 0.2 m s(-1) for SF and LS (compared with BF). At any given speed, the fins for which C was lower were those with the lowest kick frequency (KF): KF=1.6+/-0.22 Hz at 0.8 m s(-1) (for BF) and decreased by about 40% for SF, 50% for LS and 60% for MF. The decrease in KF from BF to SF-LS and MF was essentially due to the increasing surface area of the fin which, in turn, was associated with a higher Froude efficiency (eta(F)). eta(F) was calculated by computing the speed of the bending waves moving along the body in a caudal direction (as proposed for the undulating movements of slender fish): it increased from 0.62+/-0.01 in BF to 0.66+/-0.03 in SF and 0.67+/-0.04 in LS reaching the highest values (0.76+/-0.05) with MF. No single fin characteristic can predict a swimmer's performance, rather the better fin (i.e. MF) is the one that is able to reduce most KF at any given speed and hence to produce the greatest distance per kick (d=v/KF). The latter indeed increased from 0.50+/-0.01 m in BF to about 0.90+/-0.05 m in SF and LS and reached values of 1.22+/-0.01 m in MF.
Collapse
Affiliation(s)
- Paola Zamparo
- Dipartimento di Scienze e Tecnologie Biomediche, Università degli Studi di Udine, Piazzale Kolbe 4, 33100 Udine, Italy.
| | | | | | | |
Collapse
|
36
|
Abstract
We have developed the suspended-load backpack, which converts mechanical energy from the vertical movement of carried loads (weighing 20 to 38 kilograms) to electricity during normal walking [generating up to 7.4 watts, or a 300-fold increase over previous shoe devices (20 milliwatts)]. Unexpectedly, little extra metabolic energy (as compared to that expended carrying a rigid backpack) is required during electricity generation. This is probably due to a compensatory change in gait or loading regime, which reduces the metabolic power required for walking. This electricity generation can help give field scientists, explorers, and disaster-relief workers freedom from the heavy weight of replacement batteries and thereby extend their ability to operate in remote areas.
Collapse
Affiliation(s)
- Lawrence C Rome
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | | | | | | |
Collapse
|
37
|
Formenti F, Ardigò LP, Minetti AE. Human locomotion on snow: determinants of economy and speed of skiing across the ages. Proc Biol Sci 2005; 272:1561-9. [PMID: 16048771 PMCID: PMC1559840 DOI: 10.1098/rspb.2005.3121] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Accepted: 04/04/2005] [Indexed: 11/12/2022] Open
Abstract
We explore here the evolution of skiing locomotion in the last few thousand years by investigating how humans adapted to move effectively in lands where a cover of snow, for several months every year, prevented them from travelling as on dry ground. Following historical research, we identified the sets of skis corresponding to the 'milestones' of skiing evolution in terms of ingenuity and technology, built replicas of them and measured the metabolic energy associated to their use in a climate-controlled ski tunnel. Six sets of skis were tested, covering a span from 542 AD to date. Our results show that: (i) the history of skiing is associated with a progressive decrease in the metabolic cost of transport, (ii) it is possible today to travel at twice the speed of ancient times using the same amount of metabolic power and (iii) the cost of transport is speed-independent for each ski model, as during running. By combining this finding with the relationship between time of exhaustion and the sustainable fraction of metabolic power, a prediction of the maximum skiing speed according to the distance travelled is provided for all past epochs, including two legendary historical journeys (1206 and 1520 AD) on snow. Our research shows that the performances in races originating from them (Birkebeiner and Vasaloppet) and those of other modern competitions (skating versus classical techniques) are well predicted by the evolution of skiing economy. Mechanical determinants of the measured progression in economy are also discussed in the paper.
Collapse
Affiliation(s)
| | | | - Alberto E Minetti
- Institute for Biophysical and Clinical Research into Human Movement, Manchester Metropolitan UniversityCheshire, Hassall Road, Alsager, Stoke-on-Trent, ST7 2HL, UK
| |
Collapse
|