1
|
Differential Effects of Perturbation Magnitude on Reactive Balance Control in Young Sedentary Adults. Motor Control 2021; 25:437-450. [PMID: 33883296 DOI: 10.1123/mc.2020-0097] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 02/07/2021] [Accepted: 03/01/2021] [Indexed: 11/18/2022]
Abstract
This study investigates postural responses to unexpected perturbations induced by a load release of different weights. Groups of 26 men (age 22.6 ± 2.4 years, height 178.0 ± 9.1 cm, and body mass 86.9 ± 11.5 kg) and 21 women (age 21.9 ± 2.7 years, height 168.8 ± 6.8 cm, and body mass 65.3 ± 8.7 kg) underwent load-triggered postural perturbations by 1 and 2 kg while standing on a force plate with either eyes open or eyes closed. Postural perturbations induced by a heavier load, representing about 2% and 3% of body weight in men and women, respectively, led to significantly higher peak anterior and peak posterior center of pressure displacements when compared with a lighter load (29.6% and 45.4%, respectively) both with eyes open (36.9%) and closed (42.1%). Their values were significantly lower in men than women only when a higher load was used (∼25%). However, there were no significant differences in time to peak anterior and posterior center of pressure displacements. These findings indicate that heavier load-induced postural perturbations are greater in women than men regardless of visual conditions. This underlines the importance of loading dose in the magnitude of postural responses to externally induced perturbations.
Collapse
|
2
|
Burtscher M, Federolf PA, Nachbauer W, Kopp M. Potential Health Benefits From Downhill Skiing. Front Physiol 2019; 9:1924. [PMID: 30692936 PMCID: PMC6340074 DOI: 10.3389/fphys.2018.01924] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 12/20/2018] [Indexed: 01/05/2023] Open
Abstract
Objectives: Downhill skiing represents one of the most popular winter sports worldwide. Whereas a plethora of studies dealt with the risk of injury and death associated with downhill skiing, data on its favorable health effects are scarce. A more comprehensive overview on such effects might emerge from a multidisciplinary perspective. Methods: A literature search has been performed to identify original articles on downhill/alpine skiing interventions or questionnaire-based evaluation of skiing effects and the assessment of health effects (cardiorespiratory, neurophysiological, musculoskeletal, psycho-social). Results and Discussion: A total of 21 original articles dealing with potentially favorable health effects resulting from downhill skiing were included in this review. Results indicate that downhill skiing, especially when performed on a regular basis, may contribute to healthy aging by its association with a healthier life style including higher levels of physical activity. Several other mechanisms suggest further favorable health effects of downhill skiing in response to specific challenges and adaptations in the musculo-skeletal and postural control systems, to exposures to cold temperatures and intermittent hypoxia, and/or emotional and social benefits from outdoor recreation. However, reliable data corroborating these mechanisms is scarce.
Collapse
Affiliation(s)
- Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Peter A Federolf
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Werner Nachbauer
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Martin Kopp
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
3
|
Ritzmann R, Lee K, Krause A, Gollhofer A, Freyler K. Stimulus Prediction and Postural Reaction: Phase-Specific Modulation of Soleus H-Reflexes Is Related to Changes in Joint Kinematics and Segmental Strategy in Perturbed Upright Stance. Front Integr Neurosci 2018; 12:62. [PMID: 30618657 PMCID: PMC6305901 DOI: 10.3389/fnint.2018.00062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 11/23/2018] [Indexed: 12/03/2022] Open
Abstract
Anticipation determines the timing and efficiency of human motor performance. This study aimed to evaluate the effect of stimulus anticipation on proactive (prior to the event) and reactive (after the event) postural adjustments in response to perturbations. Postural set was manipulated by providing either (i) predictable, (ii) unpredictable, or (iii) cheated perturbations which require balance corrections to maintain postural stability. In 29 subjects, a protocol of anterior and posterior perturbations was applied for the conditions (i–iii). Center of pressure (COP) displacement, ankle, knee, and hip joint kinematics and electromyographic activity (EMG) of the soleus (SOL) and tibialis anterior (TA) muscles were recorded prior (PRE) and after posterior perturbations. SOL H-reflexes at the peak of the short-, medium- ,and long-latency responses (SLR, MLR, LLR) were assessed. For conditions (i to iii) EMG activity and COP differed prior to perturbation onset (p < 0.05). After perturbation, results demonstrated a progressively increased H-reflex amplitude in the MLR and LLR (p < 0.05), delayed muscle activities (p < 0.05), and shifted activation patterns, with muscles of the proximal segment being more involved in the compensatory postural response (p < 0.05). COP displacements and ankle, knee, and hip joint deflections progressively increased (p < 0.05). Neuromechanical coupling showed positive correlations for the anticipation-induced changes in EMG activity and H-reflex amplitude with that of COP displacement (p < 0.05). In conclusion, proactive and reactive postural responses indicated setting dependent modulations of segmental and phasic muscle activation. A shift to proximal muscle groups and facilitated late reflex responses compensating for cheated or unpredicted perturbations was found to recover a safe body equilibrium. In consideration of the phase-specific adaptation and its interrelationship to the kinematics, it suggested that changes in stimulus prediction challenged the central nervous system to appropriately counteract the higher postural challenges. The outcomes of this experiment are of functional relevance for experimental and training settings involving perturbation stimuli. These findings provide fundamental information of the mechanisms underlying postural adjustments in response to external perturbations.
Collapse
Affiliation(s)
- Ramona Ritzmann
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Kyungsoo Lee
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Anne Krause
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany.,Institute of Training and Computer Science, German Sport University Cologne, Cologne, Germany
| | - Albert Gollhofer
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Kathrin Freyler
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| |
Collapse
|
4
|
Kim M, Kim Y, Kim H, Yoon B. Specific muscle synergies in national elite female ice hockey players in response to unexpected external perturbation. J Sports Sci 2017; 36:319-325. [PMID: 28415899 DOI: 10.1080/02640414.2017.1306090] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This study aimed to investigate specific muscle synergies in elite ice hockey players indicating highly developed postural control strategies used to restore balance against unexpected external perturbations. Seven elite athletes (EA) on the women's national ice hockey team and 7 non-athletes (NA) participated in this study. Based on trajectories of centre of mass (COM), analysis periods were divided into an initial phase (a balance disturbance after perturbation onset) and a reversal phase (a balance recovery response), respectively. Muscle synergies were extracted at each phase by using non-negative matrix factorization. k-means cluster analysis was performed to arrange similar muscle synergies in all participants. EA showed significantly shorter recovery period of COM and smaller body sway than NA. In the initial phase, we identified 2 EA-specific synergies related to ankle plantar flexors or neck extensors. In the case of an NA-specific synergy, co-activation of the ankle plantar flexors and dorsiflexors was found. In the reversal phase, no specific muscle synergies were identified. As the results, EA-specific muscle synergies showed low co-activation strategy of agonists and antagonists in ankle and neck extensors. Our results could provide critical information for rehabilitation strategies in athletes requiring high postural stability.
Collapse
Affiliation(s)
- Minhee Kim
- a Department of Physical Therapy , College of Health Science, Korea University , Seoul , South Korea
| | - Yushin Kim
- a Department of Physical Therapy , College of Health Science, Korea University , Seoul , South Korea
| | - Hyeyoung Kim
- b Sports Medicine & Science Department , Taereung National Training Center , Seoul , South Korea
| | - BumChul Yoon
- a Department of Physical Therapy , College of Health Science, Korea University , Seoul , South Korea
| |
Collapse
|
5
|
Lee HT, Roh HL, Kim YS. Kinematic characteristics of the lower extremity during a simulated skiing exercise in healthy participants. J Phys Ther Sci 2016; 28:626-31. [PMID: 27065554 PMCID: PMC4793022 DOI: 10.1589/jpts.28.626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/19/2015] [Indexed: 12/03/2022] Open
Abstract
[Purpose] Currently, various simulators are produced and used for athlete’s exercise,
rehabilitation, and training. In this study, we analyzed the kinematic factors of
sectional and total movements in healthy participants by providing group-dependent
information during simulated exercise. [Subjects and Methods] Participants in this study
included 26 male adults (non-experts and experts); experts held a certificate issued by
the Korea Ski Instructors Association. The elapsed times in each phase, the difference in
the lower extremity angles, and muscle activity were computed through analysis of
kinematic factors. [Results] We observed that motions in the experts took shorter time to
perform than that in non-experts, and showed larger variation of lower limb joint angle in
most events during simulated skiing. There were also significant group-dependent
differences in the peak and mean EMG values during simulated skiing. [Conclusion] A
non-expert’s posture leads to enhanced muscle activity to keep the lower body in balance.
We suggest the following training guideline: initially, non-experts should maintain
appropriate range of motion with lower-intensity exercise to improve muscle endurance. It
can be useful in providing preliminary data for future training and rehabilitation
studies, as well as improvements in muscle strength and balance.
Collapse
Affiliation(s)
- Hyo Taek Lee
- Human-centered Interaction Laboratory, Department of Computer Science and Engineering, Korea University of Technology and Education, Republic of Korea
| | - Hyo Lyun Roh
- Department of Physical Therapy, Kangwon National University, Republic of Korea
| | - Yoon Sang Kim
- Human-centered Interaction Laboratory, Department of Computer Science and Engineering, Korea University of Technology and Education, Republic of Korea
| |
Collapse
|
6
|
Lee HT, Roh HL, Kim YS. Cardiorespiratory endurance evaluation using heart rate analysis during ski simulator exercise and the Harvard step test in elementary school students. J Phys Ther Sci 2016; 28:641-5. [PMID: 27065556 PMCID: PMC4793025 DOI: 10.1589/jpts.28.641] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 11/19/2015] [Indexed: 11/24/2022] Open
Abstract
[Purpose] Efficient management using exercise programs with various benefits should be provided by educational institutions for children in their growth phase. We analyzed the heart rates of children during ski simulator exercise and the Harvard step test to evaluate the cardiopulmonary endurance by calculating their post-exercise recovery rate. [Subjects and Methods] The subjects (n = 77) were categorized into a normal weight and an overweight/obesity group by body mass index. They performed each exercise for 3 minutes. The cardiorespiratory endurance was calculated using the Physical Efficiency Index formula. [Results] The ski simulator and Harvard step test showed that there was a significant difference in the heart rates of the 2 body mass index-based groups at each minute. The normal weight and the ski-simulator group had higher Physical Efficiency Index levels. [Conclusion] This study showed that a simulator exercise can produce a cumulative load even when performed at low intensity, and can be effectively utilized as exercise equipment since it resulted in higher Physical Efficiency Index levels than the Harvard step test. If schools can increase sport durability by stimulating students' interests, the ski simulator exercise can be used in programs designed to improve and strengthen students' physical fitness.
Collapse
Affiliation(s)
- Hyo Taek Lee
- Human-centered Interaction Laboratory, Department of Computer Science and Engineering, Korea University of Technology and Education, Republic of Korea
| | - Hyo Lyun Roh
- Department of Physical Therapy, Kangwon National University, Republic of Korea
| | - Yoon Sang Kim
- Human-centered Interaction Laboratory, Department of Computer Science and Engineering, Korea University of Technology and Education, Republic of Korea
| |
Collapse
|
7
|
Moon J, Koo D, Kim K, Shin I, Kim H, Kim J. Effect of ski simulator training on kinematic and muscle activation of the lower extremities. J Phys Ther Sci 2015; 27:2629-32. [PMID: 26357449 PMCID: PMC4563330 DOI: 10.1589/jpts.27.2629] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 05/18/2015] [Indexed: 11/24/2022] Open
Abstract
[Purpose] This study aimed to verify the effectiveness of an augmented reality-based ski simulator through analyzing the changes in movement patterns as well as the engagement of major muscles of the lower body. [Subjects] Seven subjects participated in the study. All were national team-level athletes studying at "K" Sports University in Korea who exhibited comparable performance levels and had no record of injuries in the preceding 6 months (Age 23.4 ± 3.8 years; Height 172.6 ± 12.1 cm; Weight 72.3 ± 16.2 kg; Experience 12.3 ± 4.8 years). [Methods] A reality-based ski simulator developed by a Korean manufacturer was used for the study. Three digital video cameras and a wireless electromyography system were used to perform 3-dimensional motion analysis and measure muscle activation level. [Results] Left hip angulation was found to increase as the frequency of the turns increased. Electromyography data revealed that the activation level of the quadriceps group's extension muscles and the biceps femoris group's flexing muscles had a crossing pattern. [Conclusion] Sustained training using an augmented reality-based ski simulator resulted in movements that extended the lower body joints, which is thought to contribute to increasing muscle fatigue.
Collapse
Affiliation(s)
- Jeheon Moon
- Department of Physical Education, Seoul National University, Republic of Korea
| | - Dohoon Koo
- Department of Physical Education, Seoul National University, Republic of Korea
| | - Kitae Kim
- Department of Physical Education, Seoul National University, Republic of Korea
| | - Insik Shin
- Department of Physical Education, Seoul National University, Republic of Korea
| | - Hyeyoung Kim
- Division of Liberal Arts and Science, Korea National Sport University, Republic of Korea
| | - Jinhae Kim
- Department of Physical Education, Korea National Sport University, Republic of Korea
| |
Collapse
|