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Sjöberg M, Berg HE, Norrbrand L, Andersen MS, Gutierrez-Farewik EM, Sundblad P, Eiken O. Influence of gravity on biomechanics in flywheel squat and leg press. Sports Biomech 2020; 22:767-783. [PMID: 32500840 DOI: 10.1080/14763141.2020.1761993] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Resistance exercise on Earth commonly involves both body weight and external load. When developing exercise routines and devices for use in space, the absence of body weight is not always adequately considered. This study compared musculoskeletal load distribution during two flywheel resistance knee-extension exercises, performed in the direction of (vertical squat; S) or perpendicular to (horizontal leg press; LP) the gravity vector. Eleven participants performed these two exercises at a given submaximal load. Motion analysis and musculoskeletal modelling were used to compute joint loads and to simulate a weightless situation. The flywheel load was more than twice as high in LP as in S (p < 0.001). Joint moments and forces were greater during LP than during S in the ankle, hip and lower back (p < 0.01) but were similar in the knee. In the simulated weightless situation, hip and lower-back loadings in S were higher than corresponding values at Earth gravity (p ≤ 0.01), whereas LP joint loads did not increase. The results suggest that LP is a better terrestrial analogue than S for knee-extension exercise in weightlessness and that the magnitude and direction of gravity during resistance exercise should be considered when designing and evaluating countermeasure exercise routines and devices for space.
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Affiliation(s)
- Maria Sjöberg
- Division of Environmental Physiology, Swedish Aerospace Physiology Centre, School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), KTH Royal Institute of Technology, Solna, Sweden
| | - Hans E. Berg
- Department of Orthopaedic Surgery, Division for Orthopedics and Biotechnology, CLINTEC, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Lena Norrbrand
- Division of Environmental Physiology, Swedish Aerospace Physiology Centre, School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), KTH Royal Institute of Technology, Solna, Sweden
| | - Michael S. Andersen
- Department of Materials and Production, Aalborg University, Aalborg, Denmark
| | | | - Patrik Sundblad
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Ola Eiken
- Division of Environmental Physiology, Swedish Aerospace Physiology Centre, School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), KTH Royal Institute of Technology, Solna, Sweden
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De Roeck J, Van Houcke J, Almeida D, Galibarov P, De Roeck L, Audenaert EA. Statistical Modeling of Lower Limb Kinetics During Deep Squat and Forward Lunge. Front Bioeng Biotechnol 2020; 8:233. [PMID: 32300586 PMCID: PMC7142215 DOI: 10.3389/fbioe.2020.00233] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 03/06/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Modern statistics and higher computational power have opened novel possibilities to complex data analysis. While gait has been the utmost described motion in quantitative human motion analysis, descriptions of more challenging movements like the squat or lunge are currently lacking in the literature. The hip and knee joints are exposed to high forces and cause high morbidity and costs. Pre-surgical kinetic data acquisition on a patient-specific anatomy is also scarce in the literature. Studying the normal inter-patient kinetic variability may lead to other comparable studies to initiate more personalized therapies within the orthopedics. Methods Trials are performed by 50 healthy young males who were not overweight and approximately of the same age and activity level. Spatial marker trajectories and ground reaction force registrations are imported into the Anybody Modeling System based on subject-specific geometry and the state-of-the-art TLEM 2.0 dataset. Hip and knee joint reaction forces were obtained by a simulation with an inverse dynamics approach. With these forces, a statistical model that accounts for inter-subject variability was created. For this, we applied a principal component analysis in order to enable variance decomposition. This way, noise can be rejected and we still contemplate all waveform data, instead of using deduced spatiotemporal parameters like peak flexion or stride length as done in many gait analyses. In addition, this current paper is, to the authors’ knowledge, the first to investigate the generalization of a kinetic model data toward the population. Results Average knee reaction forces range up to 7.16 times body weight for the forwarded leg during lunge. Conversely, during squat, the load is evenly distributed. For both motions, a reliable and compact statistical model was created. In the lunge model, the first 12 modes accounts for 95.26% of inter-individual population variance. For the maximal-depth squat, this was 95.69% for the first 14 modes. Model accuracies will increase when including more principal components. Conclusion Our model design was proved to be compact, accurate, and reliable. For models aimed at populations covering descriptive studies, the sample size must be at least 50.
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Affiliation(s)
- Joris De Roeck
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium
| | - J Van Houcke
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium
| | - D Almeida
- Centre for Rapid and Sustainable Product Development, Polytechnic Institute of Leiria, Leiria, Portugal
| | | | - L De Roeck
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium
| | - Emmanuel A Audenaert
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium.,Department of Orthopaedic Surgery and Traumatology, Ghent University Hospital, Ghent, Belgium.,Department of Trauma and Orthopaedics, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom.,Department of Electromechanics, Op3Mech Research Group, University of Antwerp, Antwerp, Belgium
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53
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Sayers MGL, Bachem C, Schütz P, Taylor WR, List R, Lorenzetti S, Nasab SHH. The effect of elevating the heels on spinal kinematics and kinetics during the back squat in trained and novice weight trainers. J Sports Sci 2020; 38:1000-1008. [PMID: 32183616 DOI: 10.1080/02640414.2020.1738675] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This research assessed the influence of various heel elevation conditions on spinal kinematic and kinetic data during loaded (25% and 50% of body weight) high-bar back squats. Ten novice (mass 67.6 ± 12.4 kg, height 1.73 ± 0.10 m) and ten regular weight trainers (mass 66.0 ± 10.7 kg, height 1.71 ± 0.09 m) completed eight repetitions at each load wearing conventional training shoes standing on the flat level floor (LF) and on an inclined board (EH). The regular weight training group performed an additional eight repetitions wearing weightlifting shoes (WS). Statistical parametric mapping (SPM1D) and repeated measures analysis of variance were used to assess differences in spinal curvature and kinetics across the shoe/floor conditions and loads. SPM1D analyses indicated that during the LF condition the novice weight trainers had greater moments around L4/L5 than the regular weight trainers during the last 20% of the lift (P < 0.05), with this difference becoming non-significant during the EH condition. This study indicates that from a perspective of spinal safety, it appears advantageous for novice weight trainers to perform back squats with their heels slightly elevated, while regular weight trainers appear to realize only limited benefits performing back squats with either EH or WS.
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Affiliation(s)
- Mark G L Sayers
- School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore DC, Australia
| | | | - Pascal Schütz
- ETH, Institute for Biomechanics, Zürich, Switzerland
| | | | - Renate List
- ETH, Institute for Biomechanics, Zürich, Switzerland.,Human Performance Lab, Schulthess Clinic, Zürich, Switzerland
| | - Silvio Lorenzetti
- ETH, Institute for Biomechanics, Zürich, Switzerland.,Swiss Federal Institute of Sport, Magglingen, Switzerland
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Trindade T, de Medeiros J, Dantas P, de Oliveira Neto L, Schwade D, de Brito Vieira W, Oliveira-Dantas FF. A comparison of muscle electromyographic activity during different angles of the back and front squat. ISOKINET EXERC SCI 2020. [DOI: 10.3233/ies-193142] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Thiago Barbosa Trindade
- Department of Physical Education, Catholic University of Brasilia, Brasilia, Brazil
- Department of Physical Education, University Center of Rio Grande do Norte, Natal, Brazil
| | | | | | | | - Daniel Schwade
- Department of Physical Education, Federal University of Rio Grande do Norte, Natal, Brazil
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55
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Effects of Multimodal Intervention Program Among Elite Weightlifters with Knee Pain. Asian J Sports Med 2020. [DOI: 10.5812/asjsm.95220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Rodríguez-Rosell D, Yáñez-García JM, Mora-Custodio R, Pareja-Blanco F, Ravelo-García AG, Ribas-Serna J, González-Badillo JJ. Velocity-based resistance training: impact of velocity loss in the set on neuromuscular performance and hormonal response. Appl Physiol Nutr Metab 2020; 45:817-828. [PMID: 32017598 DOI: 10.1139/apnm-2019-0829] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study aimed to compare the effects of 2 resistance training (RT) programs with different velocity losses (VLs) allowed in each set: 10% (VL10%) versus 30% (VL30%) on neuromuscular performance and hormonal response. Twenty-five young healthy males were randomly assigned into 2 groups: VL10% (n = 12) or VL30% (n = 13). Subjects followed a velocity-based RT program for 8 weeks (2 sessions per week) using only the full-squat (SQ) exercise at 70%-85% 1-repetition maximum (1RM). Repetition velocity was recorded in all training sessions. A 20-m running sprint, countermovement jump (CMJ), 1RM, muscle endurance, and electromyogram (EMG) during SQ exercise and resting hormonal concentrations were assessed before and after the RT program. Both groups showed similar improvements in muscle strength and endurance variables (VL10%: 7.0%-74.8%; VL30%: 4.2%-73.2%). The VL10% resulted in greater percentage increments in CMJ (9.2% vs. 5.4%) and sprint performance (-1.5% vs. 0.4%) than VL30%, despite VL10% performing less than half of the repetitions than VL30% during RT. In addition, only VL10% showed slight increments in EMG variables, whereas no significant changes in resting hormonal concentrations were observed. Therefore, our results suggest that velocity losses in the set as low as 10% are enough to achieve significant improvements in neuromuscular performance, which means greater efficiency during RT. Novelty The VL10% group showed similar or even greater percentage of changes in physical performance compared with VL30%. No significant changes in resting hormonal concentrations were observed for any training group. Curvilinear relationships between percentage VL in the set and changes in strength and CMJ performance were observed.
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Affiliation(s)
- David Rodríguez-Rosell
- Physical Performance & Sports Research Center, Universidad Pablo de Olavide, Seville 41013, Spain.,Department of Sport and Informatics, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Juan Manuel Yáñez-García
- Physical Performance & Sports Research Center, Universidad Pablo de Olavide, Seville 41013, Spain.,Department of Sport and Informatics, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Ricardo Mora-Custodio
- Physical Performance & Sports Research Center, Universidad Pablo de Olavide, Seville 41013, Spain.,Department of Sport and Informatics, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Fernando Pareja-Blanco
- Physical Performance & Sports Research Center, Universidad Pablo de Olavide, Seville 41013, Spain.,Department of Sport and Informatics, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Antonio G Ravelo-García
- Institute for Technological Development and Innovation in Communications, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria 35017, Spain
| | - Juan Ribas-Serna
- Department of Medical Physiology and Biophysics, University of Seville, Seville 41009, Spain
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Takei S, Hirayama K, Okada J. Is the Optimal Load for Maximal Power Output During Hang Power Cleans Submaximal? Int J Sports Physiol Perform 2020; 15:18-24. [PMID: 30958042 DOI: 10.1123/ijspp.2018-0894] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 02/10/2019] [Accepted: 03/03/2019] [Indexed: 10/27/2023]
Abstract
PURPOSE The optimal load for maximal power output during hang power cleans (HPCs) from a mechanical perspective is the 1-repetition-maximum (1RM) load; however, previous research has reported otherwise. The present study thus aimed to investigate the underlying factors that determine optimal load during HPCs. METHODS Eight competitive Olympic weight lifters performed HPCs at 40%, 60%, 70%, 80%, 90%, 95%, and 100% of their 1RM while the ground-reaction force and bar/body kinematics were simultaneously recorded. The success criterion during HPC was set above parallel squat at the receiving position. RESULTS Both peak power and relative peak power were maximized at 80% 1RM (3975.7 [439.1] W, 50.4 [6.6] W/kg, respectively). Peak force, force at peak power, and relative values tended to increase with heavier loads (P < .001), while peak system velocity and system velocity at peak power decreased significantly above 80% 1RM (P = .005 and .011, respectively). There were also significant decreases in peak bar velocity (P < .001) and bar displacement (P < .001) toward heavier loads. There was a strong positive correlation between peak bar velocity and bar displacement in 7 of 8 subjects (r > .90, P < .01). The knee joint angle at the receiving position fell below the quarter-squat position above 70% 1RM. CONCLUSIONS Submaximal loads were indeed optimal for maximal power output for HPC when the success criterion was set above the parallel-squat position. However, when the success criterion was defined as the quarter-squat position, the optimal load became the 1RM load.
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Ribeiro AS, Afonso C. Selection-Related Aspects of Resistance Exercises for Elderly. JOURNAL OF HEALTH SCIENCES 2019. [DOI: 10.17921/2447-8938.2019v21n3p208-215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
AbstractResistance exercise has been widely recommended for elderly population, since this type of exercise induces important health benefits, especially to improve functional capacity and preserve muscle mass, thus reflecting on the quality of life of older individuals. Among the several components of the resistance exercises the selection of movements to be performed is one of the most important and must be carefully analyzed. Although there may be a wide range of options, the most important recommendations do not specifically indicate the movements that should be included and muscle groups that should be prioritized when prescribing resistance exercise for the elderly. Therefore, considering that there is a lack of information for the Physical Education professional about the topic, this study was developed to support the choices of the movements that will compose the resistance exercise program for the elderly. The study was carried out by compiling and analyzing assumptions and scientific evidences related to resistance exercises and needs of elderly individuals. In conclusion, the choice of movements should be based on the principles of kinesiology, the needs of the elderly, muscle action and exercise safety in order to obtain beneficial results for general health and attenuate possible risks.Keywords: Exercise. Aging. Physical Exertion.ResumoO exercício resistido vem sendo amplamente recomendado para população idosa, uma vez que esse tipo de exercício físico induz a importantes benefícios para saúde; sobretudo, no aprimoramento da capacidade funcional e na preservação da massa muscular, refletindo, desse modo, na qualidade de vida do indivíduo idoso. Dentre os diversos componentes dos exercícios resistidos, a seleção dos movimentos a serem executados é um dos mais importantes e deve ser cuidadosamente analisado. Embora possa existir vasta gama de opções, as principais recomendações não indicam especificamente os movimentos que devem ser incluídos e os grupos musculares que devem ser priorizados nos programas de exercícios resistidos. Portanto, considerando haver uma lacuna de informações sobre o tema, o estudo foi realizado com intuito de subsidiar a seleção dos movimentos que deverão compor os programas de exercícios resistidos para idosos. O estudo foi realizado mediante compilação e análise de pressupostos e evidências científicas referentes aos exercícios resistidos e as necessidades dos idosos. Concluiu-se que a seleção dos movimentos deve ser baseada nos princípios da cinesiologia, nas necessidades dos idosos, na ação muscular e na segurança de execução para se alcançar resultados benéficos para saúde em geral e atenuar possíveis riscos.Palavras-chave: Exercício. Envelhecimento. Esforço Físico.
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de Sá EC, Ricarte Medeiros A, Santana Ferreira A, García Ramos A, Janicijevic D, Boullosa D. Validity of the iLOAD® app for resistance training monitoring. PeerJ 2019; 7:e7372. [PMID: 31410306 PMCID: PMC6689219 DOI: 10.7717/peerj.7372] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/28/2019] [Indexed: 11/20/2022] Open
Abstract
Background This study aimed (I) to assess the inter-rater agreement for measuring the mean velocity (MV) of the barbell with the iLOAD® app, and (II) to compare the magnitude of the MV and total work of a training session between the iLOAD® app and a linear encoder (reference method). Method Sixteen young healthy individuals (four women and 12 men) were tested in two sessions separated by 48 h. The 10 repetition maximum (RM) load was determined in the first testing session in the half squat exercise. The second testing session consisted of 3 sets of 10 repetitions during the half squat exercise performed against the 10RM load. Both the iLOAD® app and a linear encoder were used to calculate the MV and total work of each training set. MV was recorded with the iLOAD® app by two independent researchers to evaluate the inter-rater agreement. Results Trivial differences and nearly perfect correlations were observed between raters for the MV values collected under individual sets (effect size [ES] ≤ 0.02, r ≥ 0.987), as well as for the whole training session (ES = 0.01, r = 0.997). Trivial-small differences and nearly perfect correlations were observed between the iLOAD® app and the linear encoder (Chronojump, Barcelona, Spain) for MV (EV ≤ 0.25, r ≥ 0.903) and total work (ES ≤ 0.05, r ≥ 0.973). Bland-Altman plots did not reveal heteroscedasticity of the errors between the iLOAD® app and the linear encoder for MV (r2 = 0.010) and total work (r2 < 0.001). Conclusions iLOAD® is a valid smartphone app which can provide real-time feedback of the MV and total work completed in a set of multiple repetitions in the half squat exercise.
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Affiliation(s)
- Evandro Claudino de Sá
- iLOAD Solutions, Brasilia, Brazil.,Catholic University of Brasilia, Águas Claras, Brazil
| | | | | | - Amador García Ramos
- Department of Sports Sciences and Physical Conditioning, Faculty of Education, Universidad Católica de la Santísima Concepción, Concepción, Chile.,Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Danica Janicijevic
- Faculty of sport and physical education, The Research Centre, University of Belgrade, Belgrade, Serbia
| | - Daniel Boullosa
- iLOAD Solutions, Brasilia, Brazil.,College of Healthcare Sciences, James Cook University, Townsville, Australia.,Faculty of Healthcare Sciences, University of Brasilia, Brasilia, Brazil
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60
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Rates and treatments of CrossFit-related injuries at a single hospital system. CURRENT ORTHOPAEDIC PRACTICE 2019. [DOI: 10.1097/bco.0000000000000766] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Albesa-Albiol L, Serra-Payá N, Garnacho-Castaño MA, Guirao Cano L, Pleguezuelos Cobo E, Maté-Muñoz JL, Garnacho-Castaño MV. Ventilatory efficiency during constant-load test at lactate threshold intensity: Endurance versus resistance exercises. PLoS One 2019; 14:e0216824. [PMID: 31112561 PMCID: PMC6528988 DOI: 10.1371/journal.pone.0216824] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/29/2019] [Indexed: 12/22/2022] Open
Abstract
There is a lack of evidence about the ventilatory efficiency in resistance exercises despite the key role played in endurance exercises. This study aimed to compare the cardiorespiratory, metabolic responses and ventilatory efficiency between half-squat (HS) and cycle ergometer exercises during a constant-load test at the lactate threshold (LT) intensity. Eighteen healthy male participants were randomly assigned in a crossover design to carry out HS or cycle ergometer tests. For the three HS tests, a one repetition maximum (1RM) test was performed first to determine the load (kg) corresponding to the 1RM percentages. In the second test, the incremental HS exercise was carried out to establish the load (kg) at the LT intensity. Finally, a constant-load HS test was performed at the LT intensity. The first cycle ergometer test was incremental loading to determine the intensity in watts corresponding to the LT, followed by a constant-load test at the LT intensity. A recovery time of 48 hours between each test was established. During both constant-load test, cardiorespiratory and metabolic responses were monitored. A significant exercise mode x time interaction effect was only detected in oxygen uptake (VO2), heart rate, and blood lactate (p < 0.001). No differences were found between the two types of exercise in ventilatory efficiency (p >0.05). Ventilation (VE) and carbon dioxide were highly correlated (p <0.001) in the cycle ergometer (r = 0.892) and HS (r = 0.915) exercises. In the VO2 efficiency slope (OUES), similarly significant and high correlations (p <0.001) were found between VO2 and log10 VE in the cycle ergometer (r = 0.875) and in the HS (r = 0.853) exercise. Although the cardioventilatory responses were greater in the cycle ergometer test as compared to HS exercise, ventilatory efficiency was very similar between the two exercise modalities in a predominantly aerobic metabolism.
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Affiliation(s)
- Lluis Albesa-Albiol
- GRI-AFIRS, School of Health Sciences, TecnoCampus-Pompeu Fabra University, Mataró, Barcelona, Spain
| | - Noemí Serra-Payá
- GRI-AFIRS, School of Health Sciences, TecnoCampus-Pompeu Fabra University, Mataró, Barcelona, Spain
| | | | - Lluis Guirao Cano
- GRI-AFIRS, School of Health Sciences, TecnoCampus-Pompeu Fabra University, Mataró, Barcelona, Spain
- Department of Rehabilitation, Hospital Asepeyo, Sant Cugat, Barcelona, Spain
| | - Eulogio Pleguezuelos Cobo
- GRI-AFIRS, School of Health Sciences, TecnoCampus-Pompeu Fabra University, Mataró, Barcelona, Spain
- Department of Physical and Rehabilitation Medicine, Hospital de Mataró, Mataró, Barcelona, Spain
| | - José Luis Maté-Muñoz
- Department of Physical Activity and Sports Science, Alfonso X El Sabio University, Villanueva de la Cañada, Madrid, Spain
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Pallarés JG, Cava AM, Courel-Ibáñez J, González-Badillo JJ, Morán-Navarro R. Full squat produces greater neuromuscular and functional adaptations and lower pain than partial squats after prolonged resistance training. Eur J Sport Sci 2019; 20:115-124. [PMID: 31092132 DOI: 10.1080/17461391.2019.1612952] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The choice of the optimal squatting depth for resistance training (RT) has been a matter of debate for decades and is still controversial. In this study, fifty-three resistance-trained men were randomly assigned to one of four training groups: full squat (F-SQ), parallel squat (P-SQ), half squat (H-SQ), and Control (training cessation). Experimental groups completed a 10-week velocity-based RT programme using the same relative load (linear periodization from 60% to 80% 1RM), only differing in the depth of the squat trained. The individual range of motion and spinal curvatures for each squat variation were determined in the familiarization and subsequently replicated in every lift during the training and testing sessions. Neuromuscular adaptations were evaluated by one-repetition maximum strength (1RM) and mean propulsive velocity (MPV) at each squatting depth. Functional performance was assessed by countermovement jump, 20-m sprint and Wingate tests. Physical functional disability included pain and stiffness records. F-SQ was the only group that increased 1RM and MPV in the three squat variations (ES = 0.77-2.36), and achieved the highest functional performance (ES = 0.35-0.85). P-SQ group obtained the second best results (ES = 0.15-0.56). H-SQ produced no increments in neuromuscular and functional performance (ES = -0.11-0.28) and was the only group reporting significant increases in pain, stiffness and physical functional disability (ES = 1.21-0.87). Controls declined on all tests (ES = 0.02-1.32). We recommend using F-SQ or P-SQ exercises to improve strength and functional performance in well-trained athletes. In turn, the use of H-SQ is inadvisable due to the limited performance improvements and the increments in pain and discomfort after continued training.
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Affiliation(s)
- Jesús G Pallarés
- Faculty of Sport Sciences, Human Performance and Sports Science Laboratory, University of Murcia, Murcia, Spain
| | - Alejandro M Cava
- Faculty of Sport Sciences, Human Performance and Sports Science Laboratory, University of Murcia, Murcia, Spain
| | - Javier Courel-Ibáñez
- Faculty of Sport Sciences, Human Performance and Sports Science Laboratory, University of Murcia, Murcia, Spain
| | | | - Ricardo Morán-Navarro
- Faculty of Sport Sciences, Human Performance and Sports Science Laboratory, University of Murcia, Murcia, Spain
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Reichel T, Mitnacht M, Fenwick A, Meffert R, Hoos O, Fehske K. Incidence and characteristics of acute and overuse injuries in elite powerlifters. COGENT MEDICINE 2019. [DOI: 10.1080/2331205x.2019.1588192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Affiliation(s)
- Thomas Reichel
- Department of Orthopaedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital Wuerzburg, Oberduerrbacher Str. 6, 97080 Wuerzburg, Germany
| | - Martin Mitnacht
- Department of Orthopaedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital Wuerzburg, Oberduerrbacher Str. 6, 97080 Wuerzburg, Germany
| | - Annabel Fenwick
- Department of Orthopaedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital Wuerzburg, Oberduerrbacher Str. 6, 97080 Wuerzburg, Germany
| | - Rainer Meffert
- Department of Orthopaedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital Wuerzburg, Oberduerrbacher Str. 6, 97080 Wuerzburg, Germany
| | - Olaf Hoos
- Center for Sports and Physical Education, University of Wuerzburg, Wuerzburg, Germany
| | - Kai Fehske
- Department of Orthopaedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital Wuerzburg, Oberduerrbacher Str. 6, 97080 Wuerzburg, Germany
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Layer JS, Grenz C, Hinshaw TJ, Smith DT, Barrett SF, Dai B. Kinetic Analysis of Isometric Back Squats and Isometric Belt Squats. J Strength Cond Res 2019; 32:3301-3309. [PMID: 30273281 DOI: 10.1519/jsc.0000000000002854] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Layer, JS, Grenz, C, Hinshaw, TJ, Smith, DT, Barrett, SF, and Dai, B. Kinetic analysis of isometric back squats and isometric belt squats. J Strength Cond Res 32(12): 3301-3309, 2018-Belt squats seem to provide an alternative to back squats. However, it is not clear how musculoskeletal loading differs between the two. This study compared lower extremity and low-back kinetics during isometric back squats and isometric belt squats. Sixteen men (age: 22.6 ± 3.4 years; height: 1.74 ± 0.11 m; mass: 82.0 ± 5.6 kg) and 10 women (age: 21.5 ± 2.5 years; height: 1.64 ± 0.10 m; mass: 68.9 ± 7.1 kg) performed isometric back squats and belt squats at 4 squat depths. Joint resultant moments were calculated from kinematic and ground reaction force data. Linear interpolation was used to estimate peak vertical forces and joint moments at a 45° thigh segment angle. Subjects increased peak forces, ankle moments, and knee moments but decreased low-back moments from back to belt squats (p ≤ 0.023). Hip moments did not significantly change between 2 squats. Subjects demonstrating smaller ankle and knee moments during back squats showed greater increases in these moments from back to belt squats (p ≤ 0.012, R ≤ 0.24). Subjects whose back squats were characterized by greater low-back moments displayed greater decreases in low-back moments from back to belt squats (p < 0.001, R = 0.98). Compared with isometric back squats, isometric belt squats may provide a similar or greater external loading for the musculoskeletal system of the lower extremities while reducing external spinal loading. Belt squats may be considered by individuals with upper-body or spinal injuries and those displaying excessive external back moments.
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Affiliation(s)
- Jacob S Layer
- Division of Kinesiology and Health, University of Wyoming, Laramie, Wyoming
| | - Christylynne Grenz
- Division of Kinesiology and Health, University of Wyoming, Laramie, Wyoming
| | - Taylour J Hinshaw
- Division of Kinesiology and Health, University of Wyoming, Laramie, Wyoming
| | - Derek T Smith
- Division of Kinesiology and Health, University of Wyoming, Laramie, Wyoming
| | - Steven F Barrett
- Department of Electrical and Computer Engineering, University of Wyoming, Laramie, Wyoming
| | - Boyi Dai
- Division of Kinesiology and Health, University of Wyoming, Laramie, Wyoming
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65
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Hondzinski JM, Ikuma L, de Queiroz M, Wang C. Effects of exoskeleton use on movement kinematics during performance of common work tasks: A case study. Work 2019; 61:575-588. [DOI: 10.3233/wor-162827] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Jan M. Hondzinski
- School of Kinesiology, Louisiana State University, Baton Rouge, LA, USA
| | - Laura Ikuma
- Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA, USA
| | - Marcio de Queiroz
- Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA, USA
| | - Chao Wang
- Bert S. Turner Department of Construction Management, Louisiana State University, Baton Rouge, LA, USA
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66
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Bousquet BA, Olson T. Starting at the Ground Up: Range of Motion Requirements and Assessment Procedures for Weightlifting Movements. Strength Cond J 2018. [DOI: 10.1519/ssc.0000000000000399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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67
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Martínez-Cava A, Morán-Navarro R, Sánchez-Medina L, González-Badillo JJ, Pallarés JG. Velocity- and power-load relationships in the half, parallel and full back squat. J Sports Sci 2018; 37:1088-1096. [PMID: 30426840 DOI: 10.1080/02640414.2018.1544187] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study aimed to compare the load-velocity and load-power relationships of three common variations of the squat exercise. 52 strength-trained males performed a progressive loading test up to the one-repetition maximum (1RM) in the full (F-SQ), parallel (P-SQ) and half (H-SQ) squat, conducted in random order on separate days. Bar velocity and vertical force were measured by means of a linear velocity transducer time-synchronized with a force platform. The relative load that maximized power output (Pmax) was analyzed using three outcome measures: mean concentric (MP), mean propulsive (MPP) and peak power (PP), while also including or excluding body mass in force calculations. 1RM was significantly different between exercises. Load-velocity and load-power relationships were significantly different between the F-SQ, P-SQ and H-SQ variations. Close relationships (R2 = 0.92-0.96) between load (%1RM) and bar velocity were found and they were specific for each squat variation, with faster velocities the greater the squat depth. Unlike the F-SQ and P-SQ, no sticking region was observed for the H-SQ when lifting high loads. The Pmax corresponded to a broad load range and was greatly influenced by how force output is calculated (including or excluding body mass) as well as the exact outcome variable used (MP, MPP, PP).
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Affiliation(s)
- Alejandro Martínez-Cava
- a Human Performance and Sports Science Laboratory. Faculty of Sport Sciences , University of Murcia , Murcia , Spain
| | - Ricardo Morán-Navarro
- a Human Performance and Sports Science Laboratory. Faculty of Sport Sciences , University of Murcia , Murcia , Spain
| | - Luis Sánchez-Medina
- b Centre for Studies, Research & Sports Medicine , Government of Navarre , Pamplona , Spain
| | | | - Jesús G Pallarés
- a Human Performance and Sports Science Laboratory. Faculty of Sport Sciences , University of Murcia , Murcia , Spain
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68
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Hecker KA, Carlson LA, Lawrence MA. Effects of the Safety Squat Bar on Trunk and Lower-Body Mechanics During a Back Squat. J Strength Cond Res 2018; 33 Suppl 1:S45-S51. [PMID: 30363042 DOI: 10.1519/jsc.0000000000002912] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hecker, KA, Carlson, LA, and Lawrence, MA. Effects of the safety squat bar on trunk and lower-body mechanics during a back squat. J Strength Cond Res 33(7S): S45-S51, 2019-The purpose of this study was to determine whether the safety squat bar (SSB) alters the mechanics and muscle activity of a back squat compared with a standard barbell (ST). Motion and muscle activation of the trunk and lower extremity were measured while 12 competitive powerlifters (8 males, 4 females, age 31.5 ± 6.3 years, body mass 88.1 ± 20.7 kg, competitive lifting experience 3.3 ± 2.8 years) squatted 3 sets of 5 repetitions at 75% of their 3 repetition maximum (3RM). Mean muscle activity and peak joint flexion angles were measured for the trunk and one lower extremity. A repeated-measures analysis of variance (p = 0.05) revealed an 11.3% decrease in 3RM when using the SSB. When using the SSB, there was a decrease in trunk and hip flexion (7.3 and 5.7° respectively) and a 50.3% increase in lower trapezius activation. However, using the SSB decreased activation of the rectus abdominis (46.3%), medial hamstring (17.1%), lateral hamstring (15.1%), vastus lateralis (9.3%), and medial gastrocnemius (18.8%). Squatting with the SSB resulted in a more upright trunk angle, which places less stress on the lower back, a commonly injured area when squatting. Decreases in lower-extremity muscle activation are likely due to the decreased load used, suggesting that the SSB may not be as effective as a standard bar to increase lower-extremity strength. However, the increase in the lower trapezius with the lighter load suggests that midback musculature may be challenged more by the SSB than a standard barbell.
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Affiliation(s)
- Kara A Hecker
- Department of Exercise and Sport Performance, University of New England, Biddeford, Maine
| | - Lara A Carlson
- Department of Physical Therapy, University of New England, Portland, Maine.,Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine
| | - Michael A Lawrence
- Department of Physical Therapy, University of New England, Portland, Maine
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69
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Bengtsson V, Berglund L, Aasa U. Narrative review of injuries in powerlifting with special reference to their association to the squat, bench press and deadlift. BMJ Open Sport Exerc Med 2018; 4:e000382. [PMID: 30057777 PMCID: PMC6059276 DOI: 10.1136/bmjsem-2018-000382] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/25/2018] [Indexed: 11/17/2022] Open
Abstract
Pain and injuries are considered a common problem among elite athletes and recreational lifters performing the squat, bench press and deadlift. Since all three lifts engage multiple joints and expose the lifters’ bodies to high physical demands often several times a week, it has been suggested that their injuries might be related to the excessively heavy loads, the large range of motion during the exercises, insufficient resting times between training sessions and/or faulty lifting technique. However, no previous article has summarised what is known about specific injuries and the injury aetiology associated with the three lifts. Thus, the aim of this narrative review was to summarise what is known about the relationships between the powerlifting exercises and the specific injuries or movement impairments that are common among lifters and recreationally active individuals.
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Affiliation(s)
- Victor Bengtsson
- Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden
| | - Lars Berglund
- Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden.,Umeå School of Sport Sciences, Umeå University, Umeå, Sweden
| | - Ulrika Aasa
- Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden.,Umeå School of Sport Sciences, Umeå University, Umeå, Sweden.,Medfit, Primary Care Rehabilitation and Fitness Centre, Stockholm, Sweden
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70
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Clark DR, Lambert MI, Hunter AM. Contemporary perspectives of core stability training for dynamic athletic performance: a survey of athletes, coaches, sports science and sports medicine practitioners. SPORTS MEDICINE - OPEN 2018; 4:32. [PMID: 30014195 PMCID: PMC6047949 DOI: 10.1186/s40798-018-0150-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/05/2018] [Indexed: 11/10/2022]
Abstract
BACKGROUND Core stability training has grown in popularity over 25 years, initially for back pain prevention or therapy. Subsequently, it developed as a mode of exercise training for health, fitness and sport. The scientific basis for traditional core stability exercise has recently been questioned and challenged, especially in relation to dynamic athletic performance. Reviews have called for clarity on what constitutes anatomy and function of the core, especially in healthy and uninjured people. Clinical research suggests that traditional core stability training is inappropriate for development of fitness for heath and sports performance. However, commonly used methods of measuring core stability in research do not reflect functional nature of core stability in uninjured, healthy and athletic populations. Recent reviews have proposed a more dynamic, whole body approach to training core stabilization, and research has begun to measure and report efficacy of these modes training. The purpose of this study was to assess extent to which these developments have informed people currently working and participating in sport. METHODS An online survey questionnaire was developed around common themes on core stability training as defined in the current scientific literature and circulated to a sample population of people working and participating in sport. Survey results were assessed against key elements of the current scientific debate. RESULTS Perceptions on anatomy and function of the core were gathered from a representative cohort of athletes, coaches, sports science and sports medicine practitioners (n = 241), along with their views on effectiveness of various current and traditional exercise training modes. Most popular method of testing and measuring core function was subjective assessment through observation (43%), while a quarter (22%) believed there was no effective method of measurement. Perceptions of people in sport reflect the scientific debate, and practitioners have adopted a more functional approach to core stability training. There was strong support for loaded, compound exercises performed upright, compared to moderate support for traditional core stability exercises. Half of the participants (50%) in the survey, however, still support a traditional isolation core stability training. CONCLUSION Perceptions in applied practice on core stability training for dynamic athletic performance are aligned to a large extent to the scientific literature.
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Affiliation(s)
- David R. Clark
- School of Sport and Exercise Sciences, Faculty of Science, Liverpool John Moore’s University, 102, 2 Moorfields, Liverpool, L2 2BS UK
| | - Michael I. Lambert
- Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Angus M. Hunter
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, UK
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71
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Strömbäck E, Aasa U, Gilenstam K, Berglund L. Prevalence and Consequences of Injuries in Powerlifting: A Cross-sectional Study. Orthop J Sports Med 2018; 6:2325967118771016. [PMID: 29785405 PMCID: PMC5954586 DOI: 10.1177/2325967118771016] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Powerlifting consists of the squat, bench press, and dead lift, and extreme loads are lifted during training and competitions. Previous studies, which have defined an injury as an event that causes an interruption in training or competitions, have reported a relatively low frequency of powerlifting injuries (1.0-4.4 injuries/1000 hours of training). No previous study has investigated the prevalence of injuries, defined as a condition of pain or impairment of bodily function that affects powerlifters’ training, in a balanced sample of men and women, and no studies have established possible risk factors for an injury. Purpose: To investigate the prevalence, localization, and characterization of injuries among Swedish subelite classic powerlifters, with an emphasis on differences between men and women, and to investigate whether training and lifestyle factors are associated with an injury. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 53 female and 51 male Swedish subelite powerlifters answered an online questionnaire including questions about background characteristics, training habits, and lifestyle factors. The main part of the questionnaire included questions about injuries and their consequences. An injury was defined as a condition of pain or impairment of bodily function that affects powerlifters’ training. Results: Seventy percent (73/104) of participants were currently injured, and 87% (83/95) had experienced an injury within the past 12 months. The lumbopelvic region, shoulder, and hip were the most commonly injured areas for both sexes. Women experienced a significantly greater frequency of injuries in the neck and thoracic region than men. Injuries seemed to occur during training, although only 16% (11/70) of those currently injured had to completely refrain from training. Training frequency, greater personal best in the dead lift, injury onset during bench-press and dead-lift training, use of straps, alcohol consumption, and dietary issues were associated with current injuries. Conclusion: Injuries are very common in subelite powerlifters. Men and women report similar injury frequencies but different anatomic locations. These injuries do not prevent powerlifters from training and competing, but they may change the content of training sessions. Why powerlifters develop injuries is still unclear; however, it is likely that the management of training loads and optimization of the lifting technique during the squat, bench press, and dead lift are of importance.
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Affiliation(s)
- Edit Strömbäck
- Unit of Sports Medicine, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden
| | - Ulrika Aasa
- Unit of Physiotherapy, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden
| | - Kajsa Gilenstam
- Unit of Sports Medicine, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden
| | - Lars Berglund
- Unit of Physiotherapy, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden
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72
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Otero-Esquina C, de Hoyo Lora M, Gonzalo-Skok Ó, Domínguez-Cobo S, Sánchez H. Is strength-training frequency a key factor to develop performance adaptations in young elite soccer players? Eur J Sport Sci 2017; 17:1241-1251. [DOI: 10.1080/17461391.2017.1378372] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | - Moisés de Hoyo Lora
- Fitness Section, Sevilla Football Club, Seville, Spain
- Department of Physical Education and Sport, University of Seville, Seville, Spain
| | | | | | - Hugo Sánchez
- Fitness Section, Sevilla Football Club, Seville, Spain
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73
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Kinematic and Electromyographic Activity Changes during Back Squat with Submaximal and Maximal Loading. Appl Bionics Biomech 2017; 2017:9084725. [PMID: 28546738 PMCID: PMC5435978 DOI: 10.1155/2017/9084725] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 02/12/2017] [Accepted: 03/06/2017] [Indexed: 12/20/2022] Open
Abstract
The aim of this study was to investigate the possible kinematic and muscular activity changes with maximal loading during squat maneuver. Fourteen healthy male individuals, who were experienced at performing squats, participated in this study. Each subject performed squats with 80%, 90%, and 100% of the previously established 1 repetition maximum (1RM). Electromyographic (EMG) activities were measured for the vastus lateralis, vastus medialis, rectus femoris, semitendinosus, biceps femoris, gluteus maximus, and erector spinae by using an 8-channel dual-mode portable EMG and physiological signal data acquisition system (Myomonitor IV, Delsys Inc., Boston, MA, USA). Kinematical data were analyzed by using saSuite 2D kinematical analysis program. Data were analyzed with repeated measures analysis of variance (p < 0.05). Overall muscle activities increased with increasing loads, but significant increases were seen only for vastus medialis and gluteus maximus during 90% and 100% of 1RM compared to 80% while there was no significant difference between 90% and 100% for any muscle. The movement pattern in the hip joint changed with an increase in forward lean during maximal loading. Results may suggest that maximal loading during squat may not be necessary for focusing on knee extensor improvement and may increase the lumbar injury risk.
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74
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Sánchez-Medina L, Pallarés JG, Pérez CE, Morán-Navarro R, González-Badillo JJ. Estimation of Relative Load From Bar Velocity in the Full Back Squat Exercise. Sports Med Int Open 2017; 1:E80-E88. [PMID: 30539090 PMCID: PMC6226068 DOI: 10.1055/s-0043-102933] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/19/2017] [Accepted: 01/25/2017] [Indexed: 11/08/2022] Open
Abstract
The use of bar velocity to estimate relative load in the back squat exercise was examined. 80 strength-trained men performed a progressive loading test to determine their one-repetition maximum (1RM) and load-velocity relationship. Mean (MV), mean propulsive (MPV) and peak (PV) velocity measures of the concentric phase were analyzed. Both MV and MPV showed a very close relationship to %1RM (R
2
=0.96), whereas a weaker association (R
2
=0.79) and larger SEE (0.14 vs. 0.06 m·s
−1
) were found for PV. Prediction equations to estimate load from velocity were obtained. When dividing the sample into 3 groups of different relative strength (1RM/body mass), no differences were found between groups for the MPV attained against each %1RM. MV attained with the 1RM was 0.32±0.03 m·s
−1
. The propulsive phase accounted for ~82% of concentric duration at 40% 1RM, and progressively increased until reaching 100% at 1RM. Provided that repetitions are performed at maximal intended velocity, a good estimation of load (%1RM) can be obtained from mean velocity as soon as the first repetition is completed. This finding provides an alternative to the often demanding, time-consuming and interfering 1RM or nRM tests and allows implementing a velocity-based resistance training approach.
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Affiliation(s)
- Luis Sánchez-Medina
- Instituto Navarro de Deporte y Juventud (INDJ), Studies, Research and Sports Medicine Centre, Pamplona, Spain
| | - Jesús G Pallarés
- University of Murcia, Human Performance and Sports Science Laboratory, Murcia, Spain
| | - Carlos E Pérez
- University of Murcia, Sports Medicine Centre, Murcia, Spain
| | - Ricardo Morán-Navarro
- University of Murcia, Human Performance and Sports Science Laboratory, Murcia, Spain
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75
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Todoroff M. Dynamic Deep Squat: Lower-Body Kinematics and Considerations Regarding Squat Technique, Load Position, and Heel Height. Strength Cond J 2017. [DOI: 10.1519/ssc.0000000000000278] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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76
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Southwell DJ, Petersen SA, Beach TA, Graham RB. The effects of squatting footwear on three-dimensional lower limb and spine kinetics. J Electromyogr Kinesiol 2016; 31:111-118. [DOI: 10.1016/j.jelekin.2016.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 10/06/2016] [Accepted: 10/10/2016] [Indexed: 10/20/2022] Open
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77
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Aasa U, Svartholm I, Andersson F, Berglund L. Injuries among weightlifters and powerlifters: a systematic review. Br J Sports Med 2016; 51:211-219. [PMID: 27707741 DOI: 10.1136/bjsports-2016-096037] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2016] [Indexed: 11/04/2022]
Abstract
BACKGROUND Olympic weightlifting and powerlifting are two sports that expose the body to great forces. Injury characteristics have not been systematically reviewed for these two growing sports. OBJECTIVE The purpose of this study was to systematically review the literature regarding various definitions of injuries used, injury localisation, the prevalence and incidence of injuries and the associated risk factors for injuries in weightlifting and powerlifting. DESIGN Systematic review. DATA SOURCES Five databases, PubMed, MEDLINE, SPORTDiscus, Scopus and Web of Science, were searched between 9 March and 6 April 2015. ELIGIBILITY CRITERIA FOR SELECTING STUDIES Studies assessing injury incidence and prevalence in Olympic weightlifting and powerlifting were included. The Quality assessment tool for observational cohort and cross-sectional studies was used to assess methodological quality. RESULTS 9 studies were included in the review. Injury was defined fairly consistently across studies. Most studies were of low methodological quality. The spine, shoulder and the knee were the most common injury localisations in both sports. The injury incidence in weightlifting was 2.4-3.3 injuries/1000 hours of training and 1.0-4.4 injuries/1000 hours of training in powerlifting. Only one retrospective study had analysed possible risk factors. SUMMARY/CONCLUSIONS The risk of injury in both sports were similar to other non-contact sports also requiring strength/power, but low compared to contact sports. The severity of injuries differed in the included studies. Since little has been studied regarding possible risk factors to injuries, further research is therefore warranted to explain why athletes get injured and how to prevent injuries. TRIAL REGISTRATION NUMBER PROSPERO CRD42015014805.
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Affiliation(s)
- Ulrika Aasa
- Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden.,Umeå School of Sport Sciences, Umeå University, Umeå, Sweden
| | - Ivar Svartholm
- Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden
| | - Fredrik Andersson
- Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden
| | - Lars Berglund
- Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden.,Umeå School of Sport Sciences, Umeå University, Umeå, Sweden
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78
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Fregly BJ, Fregly CD, Kim BT. Computational Prediction of Muscle Moments During ARED Squat Exercise on the International Space Station. J Biomech Eng 2016; 137:121005. [PMID: 26473475 DOI: 10.1115/1.4031795] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Indexed: 11/08/2022]
Abstract
Prevention of muscle atrophy caused by reduced mechanical loading in microgravity conditions remains a challenge for long-duration spaceflight. To combat leg muscle atrophy, astronauts on the International Space Station (ISS) often perform squat exercise using the Advanced Resistive Exercise Device (ARED). While the ARED is effective at building muscle strength and volume on Earth, NASA researchers do not know how closely ARED squat exercise on the ISS replicates Earth-level squat muscle moments, or how small variations in exercise form affect muscle loading. This study used dynamic simulations of ARED squat exercise on the ISS to address these two questions. A multibody dynamic model of the complete astronaut-ARED system was constructed in OpenSim. With the ARED base locked to ground and gravity set to 9.81 m/s², we validated the model by reproducing muscle moments, ground reaction forces, and foot center of pressure (CoP) positions for ARED squat exercise on Earth. With the ARED base free to move relative to the ISS and gravity set to zero, we then used the validated model to simulate ARED squat exercise on the ISS for a reference squat motion and eight altered squat motions involving changes in anterior-posterior (AP) foot or CoP position on the ARED footplate. The reference squat motion closely reproduced Earth-level muscle moments for all joints except the ankle. For the altered squat motions, changing the foot position was more effective at altering muscle moments than was changing the CoP position. All CoP adjustments introduced an undesirable shear foot reaction force that could cause the feet to slip on the ARED footplate, while some foot and CoP adjustments introduced an undesirable sagittal plane foot reaction moment that would cause the astronaut to rotate off the ARED footplate without the use of some type of foot fixation. Our results provide potentially useful information for achieving desired increases or decreases in specific muscle moments during ARED squat exercise performed on the ISS.
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79
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Wirth K, Hartmann H, Mickel C, Szilvas E, Keiner M, Sander A. Core Stability in Athletes: A Critical Analysis of Current Guidelines. Sports Med 2016; 47:401-414. [DOI: 10.1007/s40279-016-0597-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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80
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Campos MH, Giraldi NM, Gentil P, de Lira CAB, Vieira CA, de Paula MC. The geometric curvature of the spine during the sirshasana, the yoga's headstand. J Sports Sci 2016; 35:1134-1141. [PMID: 27458692 DOI: 10.1080/02640414.2016.1211310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This study analysed the behaviour of the geometric curvature of the spine during sirshasana. The position of dorsal retroreflective markers was computed via stereophotogrammetric analysis in six males and five females (29.4 ± 8.8 years, 63.0 ± 11.4 kg, 1.66 ± 0.08 m [average ± standard deviation]). The spinal points were projected onto the sagittal and frontal planes of the trunk, a polynomial was fitted to the data and the two-dimensional geometric curvature was quantified. The inferior lumbar lordosis decreased compared to the orthostatic position and gait, which may favour the posterior protrusion of the lumbar spinal nucleus pulposus in people with posterior herniation. The lateral deviation at the middle of the thoracic spine increases during sirshasana, which may reflect increased difficulties for postural control and spinal loads. It could be useful for promoting positive spinal structural and functional chronic adaptations for healthy participants, if the yoga programme is carefully planned and the spinal alignment is carefully monitored during a headstand. However, it may aggravate some spinal diseases, especially scoliosis.
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Affiliation(s)
- Mário Hebling Campos
- a Laboratório de Avaliação do Movimento Humano, Faculdade de Educação Física e Dança , Universidade Federal de Goiás , Goiânia , Brazil
| | - Nayane Martins Giraldi
- a Laboratório de Avaliação do Movimento Humano, Faculdade de Educação Física e Dança , Universidade Federal de Goiás , Goiânia , Brazil
| | - Paulo Gentil
- b Faculdade de Educação Física e Dança , Universidade Federal de Goiás , Goiânia , Brazil
| | - Claudio Andre Barbosa de Lira
- c Setor de Fisiologia Humana e do Exercício, Faculdade de Educação Física e Dança , Universidade Federal de Goiás , Goiânia , Brazil
| | - Carlos A Vieira
- b Faculdade de Educação Física e Dança , Universidade Federal de Goiás , Goiânia , Brazil
| | - Marcelo Costa de Paula
- a Laboratório de Avaliação do Movimento Humano, Faculdade de Educação Física e Dança , Universidade Federal de Goiás , Goiânia , Brazil.,d Ciência e Tecnologia de Goiás , Instituto Federal de Educação , Goiânia , Brazil
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81
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Legg HS, Glaister M, Cleather DJ, Goodwin JE. The effect of weightlifting shoes on the kinetics and kinematics of the back squat. J Sports Sci 2016; 35:508-515. [PMID: 27096286 DOI: 10.1080/02640414.2016.1175652] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Weightlifting shoes (WS) are often used by athletes to facilitate their squat technique; however, the nature of these benefits is not well understood. In this study, the effects of footwear and load on the mechanics of squatting were assessed for 32 participants (age: 25.4 ± 4.4 years; mass 72.87 ± 11.35 kg) grouped by sex and experience. Participants completed loaded and unloaded back squats wearing both WS and athletic shoes (AS). Data were collected utilising a 3D motion capture system synchronised with a force platform and used to calculate kinematic and kinetic descriptors of squatting. For both load conditions, WS gave significantly (P < 0.05) reduced ankle flexion and increased knee flexion than AS, as well as a more upright trunk and greater knee moment for the unloaded condition. In addition, the experienced group experienced a significantly greater increase in knee and hip flexion with WS than the novices when unloaded. These results are consistent with the idea that WS permit a more knee flexed, upright posture during squatting, and provide preliminary evidence that experienced squatters are more able to exploit this effect. Decisions about footwear should recognise the effect of footwear on movement and reflect an athlete's movement capabilities and training objectives.
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Affiliation(s)
- Hayley S Legg
- a School of Sport, Health and Applied Science , St Mary's University , Twickenham , London , UK
| | - Mark Glaister
- a School of Sport, Health and Applied Science , St Mary's University , Twickenham , London , UK
| | - Daniel J Cleather
- a School of Sport, Health and Applied Science , St Mary's University , Twickenham , London , UK
| | - Jon E Goodwin
- a School of Sport, Health and Applied Science , St Mary's University , Twickenham , London , UK
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82
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Jaberzadeh S, Yeo D, Zoghi M. The Effect of Altering Knee Position and Squat Depth on VMO : VL EMG Ratio During Squat Exercises. PHYSIOTHERAPY RESEARCH INTERNATIONAL 2015; 21:164-73. [DOI: 10.1002/pri.1631] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 01/25/2015] [Accepted: 04/13/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Shapour Jaberzadeh
- Department of Physiotherapy, Faculty of Medicine, Nursing and Health Sciences; Monash University; Melbourne Australia
| | - Daniel Yeo
- Physica Devonport Physiotherapy; Devonport Australia
| | - Maryam Zoghi
- Department of Medicine (Royal Melbourne Hospital); The University of Melbourne; Melbourne Australia
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