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  • Core stability is an important part of a human's body as it can provide better support for the spine and support when doing everyday activities or sporting activities. but it is, to me, more important for sport as alot more movement is involved at higher levels intensity. Also when participating in gym activities, whether for sport or recreation, the core is very important in preventing injury as it supports the spine and the motion at which one does the exercises. The core has also been know to allow the body to push more weight and work at higher intensities. Strengthening the core has made a difference in my gym work for example, i was able to work at a higher rate and with higher weights just by strengthening my core.

    The core is probably the most important thing for sportsman and for the prevention of injury in any situation whether it be sitting wrong in class or at work, or simply doing everyday activities. 14234450
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    Core stability Core stability Presentation Transcript

    • Department of Public and Occupational Health EMGO+ Institute for Health and Care Research VU University Medical Center, Amsterdam, the Netherlands Evert Verhagen CORE STABILITY MYTH OR REALITY? vrijdag 23 augustus 13
    • Department of Public and Occupational Health EMGO+ Institute for Health and Care Research VU University Medical Center, Amsterdam, the Netherlands Evert Verhagen vrijdag 23 augustus 13
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    • EMGO+ INSTITUTE FOR HEALTH AND CARE RESEARCH • Interfaculty research institute of the VU University Amsterdam and VU University Medical Center Amsterdam • Activities deal with research in primary care and public health, focusing on chronic diseases and aging • Public Health is binding factor of studies ... "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals." vrijdag 23 augustus 13
    • TWO DIMENSIONS PopulationLaboratory Effectiveness Efficacy Optimal effect for society or individual vrijdag 23 augustus 13
    • TWO DIMENSIONS PopulationLaboratory 90% efficacious 10% effective 50% efficacious 50% effective 10% efficacious 90% effective vrijdag 23 augustus 13
    • CORE STABILITY FOR THE PUBLIC • Core stability relates to the bodily region bounded by the abdominal wall, the pelvis, the lower back and the diaphragm and its ability to stabilise the body during movement Source: wikipedia vrijdag 23 augustus 13
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    • PARALLELS WITH STRETCHING • Stretching has become embedded in sport folklore as the universal strategy for injury prevention Thacker et al. MSSE 2004 vrijdag 23 augustus 13
    • PARALLELS WITH STRETCHING • Ongoing debate on the beneficial and detrimental effects of stretching on ... performance injury risk therapeutic outcomes vrijdag 23 augustus 13
    • 1. Identify burden of disease 2. Define theories for causation 3. Establish efficacy 4. Establish effectiveness 5. Community effectiveness, economic implications 6. Implemen- tation 7. Program evaluation Tugwell et al. J Chronic Dis 1985 vrijdag 23 augustus 13
    • 1 biomechanical, physical and neurophysiological changes 2 epidemiological (cost)effectiveness evidence leading to clinical / practical guidelines 3 practical & public health impact through high compliance and proper use of effective measures vrijdag 23 augustus 13
    • 1 biomechanical, physical and neurophysiological changes 2 epidemiological (cost)effectiveness evidence leading to clinical / practical guidelines 3 practical & public health impact through high compliance and proper use of effective measures vrijdag 23 augustus 13
    • 1 biomechanical, physical and neurophysiological changes • Theoretical concept What is CS? • Conceptual definition How do we define CS? • Operational definition Which muscles and movements adjoin to CS? • Measurements Valid? Reliable? Responsive? • Most of these ... Ill described No consensus Contradicting results 2 epidemiological (cost)effectiveness evidence leading to clinical / practical guidelines 3 practical & public health impact through high compliance and proper use of effective measures vrijdag 23 augustus 13
    • 1 biomechanical, physical and neurophysiological changes 2 epidemiological (cost)effectiveness evidence leading to clinical / practical guidelines 3 practical & public health impact through high compliance and proper use of effective measures • Theoretical concept What is CS? • Conceptual definition How do we define CS? • Operational definition Which muscles and movements adjoin to CS? • Measurements Valid? Reliable? Responsive? • Most of these ... Ill described No consensus Contradicting results vrijdag 23 augustus 13
    • 1 biomechanical, physical and neurophysiological changes 2 epidemiological (cost)effectiveness evidence leading to clinical / practical guidelines 3 practical & public health impact through high compliance and proper use of effective measures • Theoretical concept What is CS? • Conceptual definition How do we define CS? • Operational definition Which muscles and movements adjoin to CS? • Measurements Valid? Reliable? Responsive? • Most of these ... Ill described No consensus Contradicting results vrijdag 23 augustus 13
    • • Bottom up approach • Learn from practical and clinical outcomes What works in practice? Can we measure that? What if we repeat practical approaches in controlled settings? 1 biomechanical, physical and neurophysiological changes 2 epidemiological (cost)effectiveness evidence leading to clinical / practical guidelines 3 practical & public health impact through high compliance and proper use of effective measures vrijdag 23 augustus 13
    • Optimizing Performance by Improving Core Stability and Core Strength Angela E. Hibbs,1,3 Kevin G. Thompson,1,4 Duncan French,1 Allan Wrigley2 and Iain Spears3 1 English Institute of Sport, Gateshead, UK 2 Canadian Sport Centre Pacific, Vancouver, British Columbia, Canada 3 University of Teesside, Middlesbrough, UK 4 School of Psychology and Sports Science, Northumbria University, Newcastle, UK Contents Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 995 1. Definition of Performance, Core Stability and Core Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 996 2. Functional Anatomy of the ‘Core’ as it Relates to Athletic Performance . . . . . . . . . . . . . . . . . . . . . . . 997 3. Types of Core Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 998 4. Evidence of Core Training Benefits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000 4.1 Rehabilitation Sector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1001 4.2 Athletic Sector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1002 5. Measuring the Core and its Relation to Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1004 6. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1006 Abstract Core stability and core strength have been subject to research since the early 1980s. Research has highlighted benefits of training these processes for people with back pain and for carrying out everyday activities. However, less research has been performed on the benefits of core training for elite athletes and how this training should be carried out to optimize sporting perfor- mance. Many elite athletes undertake core stability and core strength training as part of their training programme, despite contradictory findings and conclusions as to their efficacy. This is mainly due to the lack of a gold standard method for measuring core stability and strength when performing everyday tasks and sporting movements. A further confounding factor is that because of the differing demands on the core musculature during everyday activities (low load, slow movements) and sporting activities (high load, resisted, dynamic movements), research performed in the rehabilitation sec- tor cannot be applied to the sporting environment and, subsequently, data regarding core training programmes and their effectiveness on sporting performance are lacking. There are many articles in the literature that promote core training pro- grammes and exercises for performance enhancement without providing a strong scientific rationale of their effectiveness, especially in the sporting sector. In the rehabilitation sector, improvements in lower back injuries have been reported by improving core stability. Few studies have observed any performance enhancement in sporting activities despite observing REVIEW ARTICLE Sports Med 2008; 38 (12): 995-1008 0112-1642/08/0012-0995/$48.00/0 ª 2008 Adis Data Information BV. All rights reserved. CS TO IMPROVE SPORTS PERFORMANCE • There are many articles in the literature that promote core training for performance enhancement without providing a strong scientific rationale of their effectiveness • Evidence of core training benefits? Hibbs et al. 2012 vrijdag 23 augustus 13
    • CORE TRAINING AND POTENTIAL PERFORMANCE BENEFITS definitions valid and reliable measures Clinical core stability tests are not reliable ICCs did not exceed 0.40 Weir et al. CJSM 2010 Hibbs et al. 2012 vrijdag 23 augustus 13
    • WHAT DOES THE LITERATURE SAY? • Improvements in core stability and core strength following a core training program • Ambiguous results on performance enhancement in sporting activities Indirect impact on sporting performance by allowing athletes to train injury free more often? Hibbs et al. 2012 vrijdag 23 augustus 13
    • RELATIONSHIP BETWEEN CORE STABILITY, FUNCTIONAL MOVEMENT, AND PERFORMANCE TOMOKO OKADA, KELLIE C. HUXEL, AND THOMAS W. NESSER Exercise Physiology Laboratory, Athletic Training Department, Indiana State University, Terre Haute, Indiana ABSTRACT Okada, T, Huxel, KC, and Nesser, TW. Relationship between core stability, functional movement, and performance. J Strength Cond Res 25(1): 252–261, 2011—The purpose of this study was to determine the relationship between core stability, functional movement, and performance. Twenty-eight healthy individuals (age = 24.4 6 3.9 yr, height = 168.8 6 12.5 cm, mass = 70.2 6 14.9 kg) performed several tests in 3 categories: core stability (flexion [FLEX], extension [EXT], right and left lateral [LATr/LATl]), functional movement screen (FMS) (deep squat [DS], trunk-stability push-up [PU], right and left hurdle step [HSr/HSl], in-line lunge [ILLr/ILLl], shoulder mobility [SMr/SMl], active straight leg raise [ASLRr/ASLRl], and rotary stability [RSr/RSl]), and performance tests (backward medicine ball throw [BOMB], T-run [TR], and single leg squat [SLS]). Statistical significance was set at p # 0.05. There were significant correlations between SLS and FLEX (r = 0.500), LATr (r = 0.495), and LATl (r = 0.498). The TR correlated significantly with both LATr (r = 0.383) and LATl (r = 0.448). Of the FMS, BOMB was significantly correlated with HSr (r = 0.415), SMr (r = 0.388), PU (r = 0.407), and RSr (r = 0.391). The TR was significantly related with HSr (r = 0.518), ILLl (r = 0.462) and SMr (r = 0.392). The SLS only correlated significantly with SMr (r = 0.446). There were no significant correlations between core stability and FMS. Moderate to weak correlations identified suggest core stability and FMS are not strong predictors of performance. In addition, existent assess- ments do not satisfactorily confirm the importance of core stability on functional movement. Despite the emphasis fitness profes- sionals have placed on functional movement and core training for increased performance, our results suggest otherwise. Although training for core and functional movement are important to include in a fitness program, especially for injury prevention, they should not be the primary emphasis of any training program. KEY WORDS power, agility, muscle endurance INTRODUCTION C ore stability is achieved through stabilization of one’s torso, thus allowing optimal production, transfer, and control of force and motion to the terminal segment during an integrated kinetic chain activity (8,14,15,23). Research has demonstrated the importance and contributions of core stability in human movement (12) in producing efficient trunk and limb actions for the generation, transfer, and control of forces or energy during integrated kinetic chain activities (3,6,8,14,18). For example, Hodges and Richardson (12) examined the sequence of muscle activation during whole- body movements and found that some of the core stabilizers (i.e., transversus abdominis, multifidus, rectus abdominis, and oblique abdominals) were consistently activated before any limb movements. These findings support the theory that movement control and stability are developed in a core-to-extremity (proximal-distal) and a cephalo-caudal progression (head-to-toe) (8). Functional movement is the ability to produce and maintain a balance between mobility and stability along the kinetic chain while performing fundamental patterns with accuracy and efficiency (20). Muscular strength, flexibility, endurance, coordination, balance, and move- ment efficiency are components necessary to achieve functional movement, which is integral to performance and sport-related skills (8,20). Direct and quantitative measures of functional movement are limited; however, Cook (9) proposes qualitative assessment to gain insight about whether abnormal movements are present, which purportedly translate to one’s level of core stability and how it impacts performance or injury. To determine whether relationships truly exist between core stability and performance, functional movement and individual components of performance, including power, strength, and balance, must be assessed. However, relationships between these variables have not been established. One explanation for the lack of evidence may be a result of the fact that universal definitions and testing methods do not exist (1,2,20,25,26,28). We hypothesized that there would be a significant relationship between core stability and functional movement and between functional movement and performance. Also, a positive relationship would exist between core stability and functional movement. Address correspondence to Tomoko Okada, tokada01@gmail.com. 25(1)/252–261 Journal of Strength and Conditioning Research Ó 2011 National Strength and Conditioning Association 252 Journal of Strength and Conditioning Research the TM Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited. CS, PERFORMANCE & FUNCTIONAL MOVEMENT? • To examine in healthy individuals the relationship amongst ... Core stability Performance Functional Movement • 22 healthy subjects (male & female) • Amateur athletes from various sports Okada et al. JSCR 2011 vrijdag 23 augustus 13
    • RELATIONSHIP BETWEEN CORE STABILITY, FUNCTIONAL MOVEMENT, AND PERFORMANCE TOMOKO OKADA, KELLIE C. HUXEL, AND THOMAS W. NESSER Exercise Physiology Laboratory, Athletic Training Department, Indiana State University, Terre Haute, Indiana ABSTRACT Okada, T, Huxel, KC, and Nesser, TW. Relationship between core stability, functional movement, and performance. J Strength Cond Res 25(1): 252–261, 2011—The purpose of this study was to determine the relationship between core stability, functional movement, and performance. Twenty-eight healthy individuals (age = 24.4 6 3.9 yr, height = 168.8 6 12.5 cm, mass = 70.2 6 14.9 kg) performed several tests in 3 categories: core stability (flexion [FLEX], extension [EXT], right and left lateral [LATr/LATl]), functional movement screen (FMS) (deep squat [DS], trunk-stability push-up [PU], right and left hurdle step [HSr/HSl], in-line lunge [ILLr/ILLl], shoulder mobility [SMr/SMl], active straight leg raise [ASLRr/ASLRl], and rotary stability [RSr/RSl]), and performance tests (backward medicine ball throw [BOMB], T-run [TR], and single leg squat [SLS]). Statistical significance was set at p # 0.05. There were significant correlations between SLS and FLEX (r = 0.500), LATr (r = 0.495), and LATl (r = 0.498). The TR correlated significantly with both LATr (r = 0.383) and LATl (r = 0.448). Of the FMS, BOMB was significantly correlated with HSr (r = 0.415), SMr (r = 0.388), PU (r = 0.407), and RSr (r = 0.391). The TR was significantly related with HSr (r = 0.518), ILLl (r = 0.462) and SMr (r = 0.392). The SLS only correlated significantly with SMr (r = 0.446). There were no significant correlations between core stability and FMS. Moderate to weak correlations identified suggest core stability and FMS are not strong predictors of performance. In addition, existent assess- ments do not satisfactorily confirm the importance of core stability on functional movement. Despite the emphasis fitness profes- sionals have placed on functional movement and core training for increased performance, our results suggest otherwise. Although training for core and functional movement are important to include in a fitness program, especially for injury prevention, they should not be the primary emphasis of any training program. KEY WORDS power, agility, muscle endurance INTRODUCTION C ore stability is achieved through stabilization of one’s torso, thus allowing optimal production, transfer, and control of force and motion to the terminal segment during an integrated kinetic chain activity (8,14,15,23). Research has demonstrated the importance and contributions of core stability in human movement (12) in producing efficient trunk and limb actions for the generation, transfer, and control of forces or energy during integrated kinetic chain activities (3,6,8,14,18). For example, Hodges and Richardson (12) examined the sequence of muscle activation during whole- body movements and found that some of the core stabilizers (i.e., transversus abdominis, multifidus, rectus abdominis, and oblique abdominals) were consistently activated before any limb movements. These findings support the theory that movement control and stability are developed in a core-to-extremity (proximal-distal) and a cephalo-caudal progression (head-to-toe) (8). Functional movement is the ability to produce and maintain a balance between mobility and stability along the kinetic chain while performing fundamental patterns with accuracy and efficiency (20). Muscular strength, flexibility, endurance, coordination, balance, and move- ment efficiency are components necessary to achieve functional movement, which is integral to performance and sport-related skills (8,20). Direct and quantitative measures of functional movement are limited; however, Cook (9) proposes qualitative assessment to gain insight about whether abnormal movements are present, which purportedly translate to one’s level of core stability and how it impacts performance or injury. To determine whether relationships truly exist between core stability and performance, functional movement and individual components of performance, including power, strength, and balance, must be assessed. However, relationships between these variables have not been established. One explanation for the lack of evidence may be a result of the fact that universal definitions and testing methods do not exist (1,2,20,25,26,28). We hypothesized that there would be a significant relationship between core stability and functional movement and between functional movement and performance. Also, a positive relationship would exist between core stability and functional movement. Address correspondence to Tomoko Okada, tokada01@gmail.com. 25(1)/252–261 Journal of Strength and Conditioning Research Ó 2011 National Strength and Conditioning Association 252 Journal of Strength and Conditioning Research the TM Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited. CS, PERFORMANCE & FUNCTIONAL MOVEMENT? • CS assessed through trunk muscle endurance tests (McGill) • Functional Movement assessed through FMS (Cook) • Performance ... Backward Overhead Medicine Ball Throw (BOMB) T-Run Agility Test (TR) Single-Leg Squat (SLS) Okada et al. JSCR 2011 vrijdag 23 augustus 13
    • Performance Assessments TABLE 2. Summary of correlations between core stability, functional movement screen, and performance tests (n = 28).* BOMB TR SLS r r2 p r r2 p r r2 p CS FLEX 0.092 0.01 0.643 20.292 0.09 0.131 0.500† 0.00 0.007 EXT 0.052 0.00 0.794 20.188 0.04 0.337 20.063 0.00 0.748 LATr 0.152 0.02 0.441 20.383‡ 0.15 0.045 0.495† 0.25 0.007 LATl 0.167 0.03 0.397 20.448‡ 0.20 0.017 0.498† 0.25 0.007 DS 20.229 0.05 0.241 0.108 0.01 0.585 20.225 0.05 0.249 PU 0.407‡ 0.17 0.032 20.331 0.11 0.085 0.355 0.13 0.064 HSr 0.415‡ 0.17 0.028 20.518† 0.27 0.005 0.356 0.13 0.063 HSl 0.336 0.11 0.080 20.290 0.08 0.135 0.199 0.04 0.310 ILLr 0.045 0.00 0.822 20.159 0.03 0.419 0.014 0.00 0.944 FMS ILLl 0.361 0.13 0.059 20.462‡ 0.21 0.013 0.175 0.03 0.374 SMr 20.388‡ 0.15 0.042 0.392‡ 0.15 0.039 20.446‡ 0.20 0.017 SMl 20.055 0.00 0.781 20.099 0.01 0.616 20.246 0.06 0.207 ASLRr 0.093 0.01 0.639 20.009 0.00 0.964 0.027 0.00 0.893 ASLRl 0.083 0.01 0.674 20.038 0.00 0.848 0.073 0.01 0.710 RSr 0.391‡ 0.15 0.040 20.293 0.09 0.130 0.327 0.11 0.089 RSl 0.255 0.07 0.191 20.221 0.05 0.260 0.246 0.06 0.327 *CS = core stability; FMS = functional movement screen; BOMB = backward overhead medicine ball throw; TR = T-run; SLS = single leg squat; FLEX = flexion; EXT = extension; LATr = right lateral; LATl = left lateral; DS = deep squat; PU = core stability push-up; HSr = right hurdle step; HSl = left hurdle step; ILLr = right in-line lunge; ILLl = left in-line lunge; SMr = right shoulder mobility; SMl = left shoulder mobility; ASLRr = right active straight leg raise; ASLRl = left active straight leg raise; RSr = right rotary stability; RSl = left rotary stability. †p # 0.01. ‡p # 0.05. Okada et al. JSCR 2011 vrijdag 23 augustus 13
    • CORE STABILITY AS AN INJURY RISK FACTOR? • Prospective study 80 females 60 males • Core stability measures.. Hip abduction isometric strength Hip external rotation (ER) isometric strength Modified Biering-Sorensen test (posterior core) Side bridge test (lateral core) Core Stability Measures as Risk Factors for Lower Extremity Injury in Athletes DARIN T. LEETUN1 , MARY LLOYD IRELAND1 , JOHN D. WILLSON2,3 , BRYON T. BALLANTYNE2 , and IRENE MCCLAY DAVIS2,3 1 Kentucky Sports Medicine Clinic, Lexington, KY; 2 Joyner Sportsmedicine Institute, Lexington, KY; and 3 University of Delaware, Department of Physical Therapy, Newark, DE ABSTRACT LEETUN, D. T., M. L. IRELAND, J. D. WILLSON, B. T. BALLANTYNE, and I. M. DAVIS. Core Stability Measures as Risk Factors for Lower Extremity Injury in Athletes. Med. Sci. Sports Exerc., Vol. 36, No. 6, pp. 926–934, 2004. Introduction/Purpose: Decreased lumbo-pelvic (or core) stability has been suggested to contribute to the etiology of lower extremity injuries, particularly in females. This prospective study compares core stability measures between genders and between athletes who reported an injury during their season versus those who did not. Finally, we looked for one or a combination of these strength measures that could be used to identify athletes at risk for lower extremity injury. Methods: Before their season, 80 female (mean age ϭ 19.1 Ϯ 1.37 yr, mean weight 65.1 Ϯ 10.0 kg) and 60 male (mean age ϭ 19.0 Ϯ 0.90 yr, mean weight 78.8 Ϯ 13.3 kg) intercollegiate basketball and track athletes were studied. Hip abduction and external rotation strength, abdominal muscle function, and back extensor and quadratus lumborum endurance was tested for each athlete. Results: Males produced greater hip abduction (males ϭ 32.6 Ϯ 7.3%BW, females ϭ 29.2 Ϯ 6.1%BW), hip external rotation (males ϭ 21.6 Ϯ 4.3%BW, females ϭ 18.4 Ϯ 4.1%BW), and quadratus lumborum measures (males ϭ 84.3 Ϯ 32.5 s, females ϭ 58.9 Ϯ 26.0 s). Athletes who did not sustain an injury were significantly stronger in hip abduction (males ϭ 31.6 Ϯ 7.1%BW, females ϭ 28.6 Ϯ 5.5%BW) and external rotation (males ϭ 20.6 Ϯ 4.2%BW, females ϭ 17.9 Ϯ 4.4%BW). Logistic regression analysis revealed that hip external rotation strength was the only useful predictor of injury status (OR ϭ 0.86, 95% CI ϭ 0.77, 0.097). Conclusion: Core stability has an important role in injury prevention. Future study may reveal that differences in postural stability partially explain the gender bias among female athletes. Key Words: GENDER, HIP STRENGTH, TRUNK ENDURANCE, BASKETBALL, TRACK N umerous reports indicate that females who partici- pate in athletics experience particular injuries at a disproportionate rate versus males (14,26,38). Such injuries include traumatic anterior cruciate ligament (ACL) ruptures to overuse injuries such as patellofemoral pain syndrome, iliotibial band friction syndrome, and femoral, pubic, tibial, and metatarsal stress fracture (14,26,36,38). The identification of risk factors for these lower extremity injuries continues to interest researchers, health care profes- sionals, and athletes alike. Recent studies suggest that structural differences between males and females (18,24) may lead to altered movement patterns that may, in turn, contribute to this gender bias (12). In a study of gender differences in runners, female subjects demonstrated greater hip adduction, knee abduction, hip inter- nal rotation, and tibial external rotation during the stance phase of running (12). The authors felt that these kinematic differ- ences placed greater demands on female lumbo-pelvic muscu- lature, commonly referred to as the core. Increasingly, scientists are widening their focus to include assessment of joint mechanics proximal and distal to the sites where injuries tend to occur. This is largely due to the closed chain nature of athletic activities. When the distal ends of a segment are relatively fixed, motion at one seg- ment will influence that of all other segments in the chain. The influence of foot mechanics on proximal structures has been studied extensively (35,39). However, the influence of proximal stability on lower extremity structure and pathol- ogy remains largely unknown. Bouisset (7) initially pro- posed that stabilization of the pelvis and trunk is necessary for all movements of the extremities. Hodges and Richard- son (17) later identified trunk muscle activity before the activ- ity of the lower extremities, which he felt served to stiffen the spine to provide a foundation for functional movements. Considering the wide variety of movements associated with athletics, athletes must possess sufficient strength in hip and trunk muscles that provide stability in all three planes of motion. Indeed, recent research demonstrates that the contribution of different muscle groups to lumbar spine stability depends on the direction and magnitude of trunk loading (10). The abdominal muscles control external forces that may cause the spine to extend, laterally flex, or rotate (2). The abdominals have also been reported to increase the stability of the spine through co-contraction with the lumbar extensors (2). Ireland (19) further suggests that the abdomi- Address for correspondence: John D. Willson, MSPT, University of Del- aware, Department of Physical Therapy, 305 McKinly Lab, Newark, DE 19716; E-mail: jdwillson@yahoo.com. Submitted for publication November 2003. Accepted for publication January 2004. 0195-9131/04/3606-0926 MEDICINE & SCIENCE IN SPORTS & EXERCISE® Copyright © 2004 by the American College of Sports Medicine DOI: 10.1249/01.MSS.0000128145.75199.C3 926 Leetun et al. AJSM 2004 vrijdag 23 augustus 13
    • Hip abduction isometric strength testing was performed with subjects positioned in sidelying on a treatment table (Fig. 1). A pillow was placed between the subjects’ legs, using additional toweling as needed, such that the hip of the leg to be tested was abducted approximately 10° as mea- sured with respect to a line connecting the anterior superior iliac spines. A strap placed just proximal to the iliac crest and secured firmly around the underside of the table was used to stabilize the subjects’ trunk. The center of the force pad of a Nicholas hand-held dynamometer (Lafayette In- struments, Lafayette, IN) was then placed directly over a mark located 5 cm proximal to the lateral knee joint line. This dynamometer uses a load cell force detecting system to measure static force ranging from 0 to 199.9 kg with accu- racy to 0.1 kg Ϯ 2%. The dynamometer was secured be- tween the leg and a second strap that was wrapped around the leg and the underside of the table. The strap eliminated the effect of tester strength on this measure which has been reported to be a limitation of hand-held dynamometry (4). After zeroing the dynamometer, the subject was instructed to push the leg upward with maximal effort for 5 s. The force value displayed on the dynamometer was recorded and the device was re-zeroed. One practice trial and three ex- perimental trials were performed, with 15 s of rest between trials. The peak value from the three experimental trials was recorded. The athlete was then repositioned on their oppo- site side to test the hip strength of the contralateral limb using the same procedures. Hip external rotation (ER) isometric strength testing was performed with subjects positioned on a padded chair with the hips and knees flexed to 90° (Fig. 2). To limit the contri- bution of the hip adductors to force production in rotation, a strap was used to stabilize the thigh of the involved leg and a towel roll was placed between the subjects’ knees. The dyna- mometer was then placed such that the center of the force pad was directly over a mark that was 5 cm proximal to the medial malleolus. A strap around the leg and around the base of a stationary object held the dynamometer in place during con- tractions. Collection of peak hip external rotation isometric strength for each leg then proceeded in the same manner as that for hip abduction strength. Muscle capacity of the posterior core was measured using the modified Biering-Sorensen test (30) (Fig. 3). The athlete was positioned in prone with the pelvis at the edge of a treatment table. Straps were used to secure the athletes’ pelvis and legs to the table. The athlete supported their torso with their hands on a bench in front of the table until they FIGURE 2—Isometric testing of hip external rotation strength using hand-held dynamometry and strap stabilization. FIGURE 1—Isometric testing of hip abduction strength using hand- held dynamometry and strap stabilization. 928 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org Hip abduction isometric strength testing was performed with subjects positioned in sidelying on a treatment table (Fig. 1). A pillow was placed between the subjects’ legs, using additional toweling as needed, such that the hip of the leg to be tested was abducted approximately 10° as mea- sured with respect to a line connecting the anterior superior iliac spines. A strap placed just proximal to the iliac crest and secured firmly around the underside of the table was used to stabilize the subjects’ trunk. The center of the force pad of a Nicholas hand-held dynamometer (Lafayette In- struments, Lafayette, IN) was then placed directly over a mark located 5 cm proximal to the lateral knee joint line. This dynamometer uses a load cell force detecting system to measure static force ranging from 0 to 199.9 kg with accu- racy to 0.1 kg Ϯ 2%. The dynamometer was secured be- tween the leg and a second strap that was wrapped around the leg and the underside of the table. The strap eliminated the effect of tester strength on this measure which has been reported to be a limitation of hand-held dynamometry (4). After zeroing the dynamometer, the subject was instructed the modified Biering-Sorensen test (30) (Fig. 3). The athlete was positioned in prone with the pelvis at the edge of a treatment table. Straps were used to secure the athletes’ pelvis and legs to the table. The athlete supported their torso with their hands on a bench in front of the table until they FIGURE 2—Isometric testing of hip external rotation strength using hand-held dynamometry and strap stabilization. FIGURE 1—Isometric testing of hip abduction strength using hand- held dynamometry and strap stabilization. 928 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org were instructed to cross their arms and assume a horizontal position. The athlete was required to maintain the body in a horizontal position for as long as possible. The total time that the athlete was able to maintain the horizontal position until they touched down on the bench in front of them with their hands was recorded in seconds using a stopwatch. Athletes performed the side bridge test as described by McGill et al. (30) as a measure of lateral core muscle This test was performed with the patient supine on the treatment table with their hips flexed to 90° and their knees fully extended. Patients were asked to steadily lower their legs back to the table over a 10-s period while they main- tained contact with the examiner’s hand at their L4–L5 interspace. A large board was placed behind the athlete during this test with marks indicating 10° increments of hip flexion. The angle at which the athlete’s low back raised from the examiner’s hand was recorded. Lower angles of hip flexion indicate a better performance on the test. After 1 yr of testing, we questioned the sensitivity of the straight leg lowering test for this population of subjects. There was very little variability in the measurement as nearly 70% of the athletes raised from the examiner’s hand between 50° and 60° of hip flexion, making the effect size small and increasing our likelihood of Type II error. There- fore, subjects enrolled in the second year of testing per- formed the flexor endurance test as described by McGill et al. (30) This test is performed seated on a treatment table with the athlete’s back supported on a 60° wedge (measured from horizontal). The athlete’s hands were crossed over their chest and their toes were placed under a stabilization strap. The athletes were then asked to maintain the position as the supporting wedge was pulled 10 cm away from the athlete. The time the athlete was able to maintain the 60° angle was recorded using a stopwatch. The test ended FIGURE 3—Endurance testing of lumbar extensors using the modi- fied Beiring-Sorensen test. Isometric testing of hip abduction strength using hand-held dynamometry and strap stabilization Isometric testing of hip external rotation strength using hand-held dynamometry and strap stabilization Endurance testing of lumbar extensors using the modified Beiring-Sorensen test were instructed to cross their arms and assume a horizontal position. The athlete was required to maintain the body in a horizontal position for as long as possible. The total time that the athlete was able to maintain the horizontal position until they touched down on the bench in front of them with their hands was recorded in seconds using a stopwatch. Athletes performed the side bridge test as described by McGill et al. (30) as a measure of lateral core muscle capacity, particularly the quadratus lumborum (Fig. 4). The athletes were positioned in right sidelying with their top foot in front of their bottom foot and their hips in zero degrees of flexion. The athletes were asked to lift their hips off the treatment table, using only their feet and right elbow for support. The left arm was held across their chest with their hand placed on the right shoulder. The total time the athlete was able lift their bottom hip from the table was recorded using a stopwatch. McGill (30) previously documented no significant difference between right and left side bridge endurance times. Therefore, the measure for the right lateral core muscles was used for data analysis. Anterior core muscle testing was performed using the straight leg lowering test for the first year of testing (23). fore, subjects enrolled formed the flexor endur al. (30) This test is per with the athlete’s back s from horizontal). The their chest and their toe strap. The athletes were as the supporting wedge athlete. The time the at angle was recorded us when the angle of the a 60° threshold. Based o uted values, we found indicator of anterior straight leg lowering te Injuries. The head at participating in the stud tremity injuries that oc games throughout the se event that occurred du quired treatment or atten doctor, or other medical resulted in at least one f participation. Trainers w the details of each inju (practice or game enviro tact with another player involved, and the type o number of whole days l each injury. Data analysis. Core pared between genders and injury and those w variance tests (SPSS 11 level of 0.05 was used abdominal muscle perfo descriptively but were n due to the previously associated lack of powe sion was used to analy status and postural musc cess began with simultan FIGURE 4—Endurance testing of the lateral trunk using the side bridge test. Left side test position shown here. FIGURE 3—Endurance testing of lumbar extensors using the modi- fied Beiring-Sorensen test. CORE STABILITY IN ATHLETES Medicin Endurance testing of the lateral trunk using the side bridge test (left side test position) Leetun et al. AJSM 2004 vrijdag 23 augustus 13
    • the first prospective study to demonstrate a relationship between these variables. However, several retrospective and cross-sectional studies have been performed that previously indicated that such a relationship may exist for a variety of injuries (1,13,20,21). For example, Ireland et al. (20) iden- tified significant weakness among young female athletes However, in a m isometric hip s tion, are more a injury than trun These resul versus enduran TABLE 5. Comparison of core stability measures by injury status. Hip Abduction (% Body Weight) Hip External Rotation (% Body Weight) Average (SD) Average (SD) Avera Uninjured (N ϭ 99) 31.6 (7.1) 20.6 (4.2) 72.0 Injured (N ϭ 41) 28.6 (5.5) 17.9 (4.4) 64.7 P 0.02 0.001 CORE STABILITY IN ATHLETES tion and internal rotation. Indeed, recent literature verifies that females tend to display greater hip internal rotation and adduction during athletic tasks (12,22,25). Athletes who sustained an injury in this study displayed significantly less hip abduction and external rotation strength than uninjured athletes. To our knowledge, this is the first prospective study to demonstrate a relationship between these variables. However, several retrospective and cross-sectional studies have been performed that previously indicated that such a relationship may exist for a variety of injuries (1,13,20,21). For example, Ireland et al. (20) iden- tified significant weakness among young female athletes maintain force McGill et al. endurance is g erate force in endurance of th occurrence of l However, in a m isometric hip s tion, are more a injury than trun These resul versus endura TABLE 5. Comparison of core stability measures by injury status. Hip Abduction (% Body Weight) Hip External Rotation (% Body Weight) Average (SD) Average (SD) Aver Uninjured (N ϭ 99) 31.6 (7.1) 20.6 (4.2) 72. Injured (N ϭ 41) 28.6 (5.5) 17.9 (4.4) 64. P 0.02 0.001 CORE STABILITY IN ATHLETES iterature verifies rnal rotation and study displayed xternal rotation nowledge, this is e a relationship retrospective and d that previously t for a variety of et al. (20) iden- female athletes maintain force (endurance) in the lumbo-pelvic-hip complex. McGill et al. (29) suggest that the value of trunk muscle endurance is greater than the ability of these muscles to gen- erate force in the prevention of low back pain. Indeed, the endurance of the trunk extensors has been found to predict the occurrence of low back pain among 30- to 60-yr-old adults (3). However, in a more athletic population, this study suggests that isometric hip strength measures, particularly in external rota- tion, are more accurate predictors of back and lower extremity injury than trunk endurance measures. These results may reflect the significance of strength versus endurance for individuals who participate in high tus. Hip External Rotation (% Body Weight) Side Bridge (s) Back Extension (s) Average (SD) Average (SD) Average (SD) 20.6 (4.2) 72.0 (32.4) 128.3 (43.6) 17.9 (4.4) 64.7 (28.8) 121.6 (48.9) 0.001 0.22 0.43 Medicine & Science in Sports & Exerciseா 931 CORE STABILITY BY INJURY STATUS Leetun et al. AJSM 2004 vrijdag 23 augustus 13
    • LOGISTIC REGRESSION INJURY STATUS AS DEPENDENT VARIABLE s s n h . n dynamic test. Future studies on the potential of core stability programs to prevent serious knee ligament injuries also seem justified. TABLE 8. Logistic regression results (dependent variable ϭ injury during the season). Variable Coefficient t P Odds Ratio (95% CI OR) Constant 2.931 2.37 0.018 Hip abduction Ϫ0.031 Ϫ0.85 0.40 0.97 (0.90, 1.04) Hip external rotation Ϫ0.146 Ϫ2.49 0.013 0.86 (0.77, 0.97) Side bridge 0.007 0.73 0.46 1.01 (0.99, 1.02) Back extension Ϫ0.004 Ϫ0.77 0.44 1.00 (0.99, 1.01) Likelihood ratio [df] 12.72 [4] 0.013 % correct prediction 62.6% McFadden’s-R2 0.076 http://www.acsm-msse.org Leetun et al. AJSM 2004 vrijdag 23 augustus 13
    • MULTICOMPONENT INTERVENTIONS THE 11+ • comprehensive warmup program designed to reduce the risk of injuries Strength, plyometrics, balance Plank, Side plank, Nordic hamstring, Single leg balance, Squat, Jumping vrijdag 23 augustus 13
    • RESEARCH Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomised controlled trial Torbjørn Soligard, PhD student,1 Grethe Myklebust, associate professor,1 Kathrin Steffen, research fellow,1 Ingar Holme, professor,1 Holly Silvers, physical therapist,2 Mario Bizzini, physical therapist,3 Astrid Junge, associate professor,3 Jiri Dvorak, professor,3 Roald Bahr, professor,1 Thor Einar Andersen, associate professor1 ABSTRACT ObjectiveTo examinetheeffectofa comprehensive warm- up programme designed to reduce the risk of injuries in female youth football. Design Cluster randomised controlled trial with clubs as the unit of randomisation. Setting 125 football clubs from the south, east, and middle of Norway (65 clusters in the intervention group; 60 in the control group) followed for one league season (eight months). Participants 1892 female players aged 13-17 (1055 players in the intervention group; 837 players in the control group). Intervention A comprehensive warm-up programme to improve strength, awareness, and neuromuscular control during static and dynamic movements. Main outcome measure Injuries to the lower extremity (foot, ankle, lower leg, knee, thigh, groin, and hip). Results During one season, 264 players had relevant injuries: 121 players in the intervention group and 143 in the controlgroup (rate ratio 0.71, 95% confidence interval 0.49 to 1.03). In the intervention group there was a significantly lower risk of injuries overall (0.68, 0.48 to 0.98), overuse injuries (0.47, 0.26 to 0.85), and severe injuries (0.55, 0.36 to 0.83). Conclusion Though the primary outcome of reduction in lowerextremityinjurydidnotreachsignificance,theriskof severe injuries, overuse injuries, and injuries overall was reduced. This indicates that a structured warm-up programme can prevent injuries in young female football players. Trial registration ISRCTN10306290. INTRODUCTION Football (soccer) is the most popular team sport in the world. There are already more than 265 million registered players, and the number of participants is continuing to grow.1 In particular, the number of women players is increasing rapidly.1 Playing football, however, entails a substantial risk of injury, and studies on elite and non-elite female footballers have reported rates of injury similar to those in men,2-11 the most common being injuries to the knee and ankle ligament and thigh muscle strains.2-9 11 12 Women might even be at greater risk of serious injury than men; the rate of anterior cruciate ligament injuries is three to five times higher for girls than for boys.13 14 The high injury rate among football players in general and female players in particular constitutes a considerable problem for the player, the club, and— given the popularity of the sport—for society at large. Health consequences are seen not just in the short term but also in the dramatic increase in the risk of early osteoarthritis.15-17 Despite the urgent need to develop programmes to prevent knee and ankle injuries in footballers, there exist only a few small or non- randomised studies on prevention of injury in female football players.18-20 Inarecentrandomisedcontrolledtrial,weexamined the effect of a structured training programme (“The 11”)21 over one season among 2000 female players aged 13-17.22 The intervention consisted of exercises focusing on core stability, balance, dynamic stabilisa- tion, and eccentric hamstring strength. We found no difference in the injury risk between the intervention group and control group, though the study was limited by low compliance among the intervention teams. This led us to develop an exercise programme to improve both the preventive effect of the programme and the compliance of coaches and players. The revised programme (“The 11+”) included key exer- cises and additional exercises to provide variation and progression. It also included a new set of structured running exercises that made it better suited as a comprehensive warm-up programme for training and matches. We conducted a randomised controlled trial to examinetheeffectoftherevisedprogrammeonratesof lower extremity injury in young female footballers. To minimise contamination bias within clubs, we used a cluster randomised design. 1 Oslo Sports Trauma Research Centre, Norwegian School of Sport Sciences, PO Box 4014 Ullevaal Stadion, 0806 Oslo, Norway 2 Santa Monica Orthopaedic and Sports Medicine Research Foundation, 1919 Santa Monica Blvd, Suite 350, Santa Monica, CA 90404 USA 3 FIFA Medical Assessment and Research Centre, Schulthess Clinic, Lengghalde 2, CH-8008 Zurich, Switzerland Correspondence to: T Soligard torbjorn.soligard@nih.no Cite this as: BMJ 2008;337:a2469 doi:10.1136/bmj.a2469 BMJ | ONLINE FIRST | bmj.com page 1 of 91476 A Randomized Controlled Trial to Prevent Noncontact Anterior Cruciate Ligament Injury in Female Collegiate Soccer Players Julie Gilchrist,*† MD, Bert R. Mandelbaum,‡ MD, Heidi Melancon,§ MPH, George W. Ryan, || PhD, Holly J. Silvers,‡ MPT, Letha Y. Griffin,¶ MD, PhD, Diane S. Watanabe, ‡ MA, ATC, Randall W. Dick, # MS, and Jiri Dvorak,** MD From the † Division of Unintentional Injury Prevention, National Center for Injury Prevention & Control, Centers for Disease Control & Prevention, Atlanta, Georgia, ‡ Santa Monica Orthopedic & Sports Medicine Research Foundation, Santa Monica, California, the § National Recreation and Park Association, Ashburn, Virginia, the || Office of Statistics and Programming, National Center for Injury Prevention & Control, Centers for Disease Control & Prevention, Atlanta, Georgia, ¶ Peachtree Orthopedics, Atlanta, Georgia, the # National Collegiate Athletic Association, Indianapolis, Indiana, and the **Fédération Internationale de Football Association (FIFA), Medical Assessment and Research Center, Schulthess Clinic, Zurich, Switzerland. Background: Neuromuscular and proprioceptive training programs can decrease noncontact anterior cruciate ligament injuries; however, they may be difficult to implement within an entire team or the community at large. Hypothesis: A simple on-field alternative warm-up program can reduce noncontact ACL injuries. Study Design: Randomized controlled trial (clustered); Level of evidence, 1. Methods: Participating National Collegiate Athletic Association Division I women’s soccer teams were assigned randomly to intervention or control groups. Intervention teams were asked to perform the program 3 times per week during the fall 2002 sea- son. All teams reported athletes’ participation in games and practices and any knee injuries. Injury rates were calculated based on athlete exposures, expressed as rate per 1000 athlete exposures. A z statistic was used for rate ratio comparisons. Results: Sixty-one teams with 1435 athletes completed the study (852 control athletes; 583 intervention). The overall anterior cruciate ligament injury rate among intervention athletes was 1.7 times less than in control athletes (0.199 vs 0.340; P = .198; 41% decrease). Noncontact anterior cruciate ligament injury rate among intervention athletes was 3.3 times less than in control athletes (0.057 vs 0.189; P = .066; 70% decrease). No anterior cruciate ligament injuries occurred among intervention athletes during practice versus 6 among control athletes (P = .014). Game-related noncontact anterior cruciate ligament injury rates in intervention athletes were reduced by more than half (0.233 vs 0.564; P = .218). Intervention athletes with a history of anterior cruciate ligament injury were significantly less likely to suffer another anterior cruciate ligament injury compared with control ath- letes with a similar history (P = .046 for noncontact injuries). Conclusion: This program, which focuses on neuromuscular control, appears to reduce the risk of anterior cruciate ligament injuries in collegiate female soccer players, especially those with a history of anterior cruciate ligament injury. Keywords: RCT; ACL; soccer; injuries *Address correspondence to Julie Gilchrist, MD, CDC/NCIPC, Division of Unintentional Injury Prevention, 4770 Buford Hwy, MS F62, Atlanta, GA 30341 (e-mail: jrg7@cdc.gov). Presented at the interim meeting of the AOSSM, San Francisco, California, March 2004. Dr. Mandelbaum, Ms. Silvers, and Ms. Watanabe, employees of Santa Monica Orthopedic and Sports Medicine Research Foundation (SMOSMRF), were involved with the development of the PEP Program under evaluation in this study but have no financial interest in the PEP Program and did not participate in data collection or analysis. Ms. Melancon was employed by the SMOSMRF and participated in data collection and analysis. The American Journal of Sports Medicine, Vol. 36, No. 8 DOI: 10.1177/0363546508318188 © 2008 American Orthopaedic Society for Sports Medicine Soligard et al. BMJ 2008Gilchrist et al. AJSM 2008 ~50% reduction of risk for non contact LE injuries how much is due to core stability components? vrijdag 23 augustus 13
    • Performance aspects of an injury prevention program: a ten-week intervention in adolescent female football players K. Steffen, H. M. Bakka, G. Myklebust, R. Bahr Department of Sports Medicine, Oslo Sports Trauma Research Center, Norwegian School of Sport Sciences, Oslo, Norway Corresponding author: Kathrin Steffen, Department of Sports Medicine, Oslo Sports Trauma Research Center, Norwegian School of Sport Sciences, P.O. Box 4014 Ulleva˚l Stadion, 0806 Oslo, Norway. Fax: 147 23 26 23 07, E-mail: kathrin.steffen@nih.no Accepted for publication 10 May 2007 The injury rate in football is high, and effective injury prevention methods are needed. An exercise program, the ‘‘11,’’ has been designed to prevent the most common injury types in football. However, the effect of such a program on performance is not known. The aim of this randomized- controlled trial was to investigate the effect of the ‘‘11’’ on performance after a 10-week training period. Thirty-four adolescent female football players were randomly assigned to either an intervention (n 5 18) or a control group (n 5 16). The ‘‘11’’ is a 15-min program consisting of ten exercises for core stability, lower extremity strength, bal- ance and agility. Performance tests included isokinetic and isometric strength protocols for the quadriceps and ham- strings, isometric hip adduction and abduction strength, vertical jump tests, sprint running and soccer skill tests. There was no difference between the intervention and control groups in the change in performance from the pre- to post-test for any of the tests used. In conclusion, no effect was observed on a series of performance tests in a group of adolescent female football players using the ‘‘11’’ as a structured warm-up program. Background Football is probably the most popular sport world- wide, with a growing interest and an increasing number of female players in particular (Norwegian Football Association, 2005). It is a contact sport and challenges physical fitness by requiring a variety of skills at different intensities. Running is the predo- minant activity, and explosive efforts during sprints, duels, jumps and kicks are important performance factors, requiring maximal strength and anaerobic power of the neuromuscular system (Wisløff et al., 1998; Cometti et al., 2001; Reilly & Gilbourne, 2003; Hoff & Helgerud, 2004). Unfortunately, the game is associated with a high risk of injuries, which results in significant costs for the public health system (de Loes et al., 2000) and may even cause long-term disability for the injured player (Lohmander et al., 2004; von Porat et al., 2004; Myklebust & Bahr, 2005). Serious knee inju- ries, such as anterior cruciate ligament injuries, are of particular concern in female team sports (Powell & Barber-Foss, 2000; Myklebust et al., 2003; Agel et al., 2005; Olsen et al., 2005). Consequently, there is every reason to emphasize the prevention of injuries in football, and to develop and implement prevention programs for young players as early in their career as possible. Several programs have successfully incorporated one or more exercise components, including plyo- metrics, strength, neuromuscular training, running and cutting movement patterns, to prevent injuries in female (Hewett et al., 1999; Heidt et al., 2000; Myklebust et al., 2003; Mandelbaum et al., 2005; Olsen et al., 2005) and male athletes (Askling et al., 2003). However, compliance is a concern (Myklebust et al., 2003), and it may be difficult to motivate coaches and players to follow such exercise programs merely to prevent injuries, unless there is a direct effect performance benefit as well. Exercises used in prevention protocols have also been shown to have performance effects among male football players, such as increased strength (Askling et al., 2003; Mjølsnes et al., 2004). Core stability exercises may improve technical skills and total awareness of the game (Holm et al., 2004; Leetun et al., 2004; Paterno et al., 2004). Comprehensive neuromuscular training programs that combine plyo- metrics, core strengthening, balance, resistance or speed/agility training may improve several measures of performance concomitantly and at the same time improve biomechanical measures related to lower Scand J Med Sci Sports 2008: 18: 596–604 Copyright & 2007 The Authors Journal compilation & 2007 Blackwell MunksgaardPrinted in Singapore .All rights reserved DOI: 10.1111/j.1600-0838.2007.00708.x 596 PERFORMANCE ENHANCEMENT? • No significant effects were observed on different performance variables among players participating in a 10- week injury prevention program, compared with players who trained as usual more intense training stimulus needed? 34 adolescent female football players from two elite sport high schools Steffen et al. SJMSS 2008 vrijdag 23 augustus 13
    • vrijdag 23 augustus 13
    • HEALTH BENEFITS VS HEALTH RISK Type and amount of activity Novice runners Recreational Runners males Recreational Runners females Competitive runners Marathon runners 2.56 2.55-2.60 2.06 2.02-2.10 1.80 1.70-1.90 1.55 1.54-1.56 1.10 1.09-1.20 Tonoli et al. 2010 vrijdag 23 augustus 13
    • • General preventive approach lies in reducing the load or increasing loading capacity to reduce risk for RRI • However ... specific loads leading up to RRI are biomechanically different and caused by local overloading • An individual set of weak links that predispose to injury? OVERLOADING THE SYSTEM? vrijdag 23 augustus 13
    • ILL-LOADING? 914 | december 2011 | volume 41 | number 12 | journal of orthopaedic & sports physical therapy [ CASE REPORT ] P atellofemoral pain (PFP) is one of the most common overuse injuries of the lower extremity. It affects 10% to 20% of the general population18 and is associated with higher risk of injury in active females.34 The findings of a previous study suggested that a history of PFP increases the risk for subsequent development of patellofemoral osteoarthritis.35 The nature of PFP is multifactorial, and many risk factors have been associated with this condition.5,10 Locally, imbalance of the quadriceps muscula- ture25 and maltracking of the patella24 are 2 potential factors that may lead to STUDY DESIGN: Case series. BACKGROUND: Patellofemoral pain is a com- mon overuse injury in runners. Recent findings suggest that patellofemoral pain is related to high- impact loading associated with a rearfoot strike pattern. This case series describes the potential training effects of a landing pattern modification program to manage patellofemoral pain in runners. CASE DESCRIPTION: Three female runners with unilateral patellofemoral pain who initially presented with a rearfoot strike pattern underwent 8 sessions of landing pattern modification program using real-time audio feedback from a force sensor placed within the shoe. Ground reaction forces during running were assessed with an instru- mented treadmill. Patellofemoral pain symptoms were assessed using 2 validated questionnaires. Finally, running performance was measured by self-reported best time to complete a 10-km run in the previous month. The runners were assessed before, immediately after, and 3 months following training. OUTCOMES: The landing pattern of runners was successfully changed from a rearfoot to a non- rearfoot strike pattern after training. This new pat- tern was maintained 3 months after the program. The vertical impact peak and rates of loading were shown to be reduced. Likewise, the symptoms related to patellofemoral pain and associated functional limitations were improved. However, only 1 of the participants reported improved running performance after the training. DISCUSSION: This case series provided preliminary data to support further investigation of interventions leading to landing pattern modification in runners with patellofemoral pain. LEVEL OF EVIDENCE: Therapy, level 4. J Orthop Sports Phys Ther 2011;41(12):914-919, Epub 25 October 2011. doi:10.2519/jospt.2011.3771 KEY WORDS: biofeedback, gait retraining, impact peak, impact rate, landing pattern 1 Research Associate, Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hung Hom, Hong Kong, China; Postdoctoral Fellow, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Harvard University, Cambridge, MA. 2 Director, Spaulding National Running Center, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Harvard University, Cambridge, MA. The experimental protocol of this study was reviewed and approved by The Ethics Review Committee of the Hong Kong Polytechnic University. Address correspondence to Dr Roy Cheung, Spaulding National Running Center, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Harvard University, Cambridge, MA 02138. Email: RTCheung@partners.org ROY T.H. CHEUNG, PT, PhD1 • IRENE S. DAVIS, PT, PhD2 Landing Pattern Modification to Improve Patellofemoral Pain in Runners: A Case Series PFP. Through the linkage of the kine- matic chain, hip muscle weakness11,29 and excessive foot pronation20 have also been proposed to lead to the development of PFP. Therefore, different treatment ap- proaches6,11 have been evaluated in the management of PFP. Running is a popular sport worldwide. According to an epidemiological study,36 the overall annual rate of running injury ranges from 37% to 56%. The incidence rate, calculated according to running time, is between 2.5 to 12.1 injuries per 1000 hours of running, with the knee being the most vulnerable joint. Among those knee injuries, PFP is the most common condition. PFP in runners has been linked to abnormal lower extremity movement patterns4,22 and weaknesses of hip muscles.33 However, the role of abnormal kinetics in the development of PFP has not been fully examined. Verti- cal impact loading has been associated with a number of conditions, including plantar fasciitis,27 tibial stress fractures,28 and knee osteoarthritis.13,23 A recent pi- lot study suggested that runners with a history of PFP may exhibit a higher im- pact peak and loading rate than healthy runners.9 Approximately 75% of runners make initial contact with the ground using a rearfoot strike pattern (ie, they land on their heels).12 This rearfoot strike pattern results in a very distinct vertical impact peak, which may be eliminated or signifi- Original article Br J Sports Med 2011;45:691–696. doi:10.1136/bjsm.2009.069112 691 Accepted 19 January 2010 Published Online First 28 June 2010 ABSTRACT Background Patellofemoral pain syndrome (PFPS) is the most common overuse injury in runners. Recent research suggests that hip mechanics play a role in the development of this syndrome. Currently, there are no treatments that directly address the atypical mechanics associated with this injury. Objective The purpose of this study was to deter- mine whether gait retraining using real-time feedback improves hip mechanics and reduces pain in subjects with PFPS. Methods Ten runners with PFPS participated in this study. Real-time kinematic feedback of hip adduction (HADD) during stance was provided to the subjects as they ran on a treadmill. Subjects completed a total of eight training sessions. Feedback was gradually removed over the last four sessions. Variables of interest included peak HADD, hip internal rotation (HIR), contralateral pel- vic drop, as well as pain on a verbal analogue scale and the lower-extremity function index. We also assessed HADD, HIR and contralateral pelvic drop during a single leg squat. Comparisons of variables of interest were made between the initial, final and 1-month follow-up visit. Results Following the gait retraining, there was a significant reduction in HADD and contralateral pelvic drop while running. Although not statistically significant, HIR decreased by 23% following gait retraining. The 18% reduction in HADD during a single leg squat was very close to significant. There were also significant improvements in pain and function. Subjects were able to maintain their improvements in running mechanics, pain and function at a 1-month follow-up. An unexpected benefit of the retraining was an 18% and 20% reduc- tion in instantaneous and average vertical load rates, respectively. Conclusions Gait retraining in individuals with PFPS resulted in a significant improvement of hip mechan- ics that was associated with a reduction in pain and improvements in function. These results suggest that interventions for PFPS should focus on addressing the underlying mechanics associated with this injury. The reduction in vertical load rates may be protective for the knee and reduce the risk for other running-related injuries. INTRODUCTION Running is one of the most popular forms of exercise in the USA. Annually, 50–85% of runners will sustain an injury.1 2 Of these injures, patell- ofemoral pain syndrome (PFPS) is the most com- monlyreported.3 PFPSoftenbecomeschronic,with up to 91% of individuals reporting continued knee pain 4–18 years after being initially diagnosed.4 In addition, recent research suggests that having a history of PFPS increases the risk of later develop- ing patellofemoral osteoarthritis (OA).5 The aetiology of PFPS is multifactorial in nature. Most investigators agree that PFPS is related, in part, to faulty lower-extremity mechanics. In particular, there is growing scientific support for the relationship between hip mechanics and patellofemoral joint mechanics. In an early cadav- eric study, Huberti et al reported that increasing the Q-angle (which would be associated with increased hip adduction (HADD)) resulted in greater contact pressure on the lateral aspect of the patella.6 In a more recent cadaveric study, Li et al demonstrated that increasing femoral inter- nal rotation resulted in greater lateral patellar con- tact pressure.7 Over time, the repetitive exposure to these motions may damage the cartilage and lead to greater stress on the highly innervated subchondral bone.8 9 There is also emerging evidence that altered hip kinematics during dynamic activities are present in individuals with PFPS. For example, a recent study has found greater peak hip internal rotation (HIR) during running in individuals with PFPS.10 In addition, Willson et al reported that individu- als with PFPS run, jump and squat with greater HADD compared with healthy controls.11 They also found greater contralateral pelvic drop across activities.11 Finally, a recent prospective study has found that runners who developed PFPS had greater HADD compared with their healthy counterparts.12 Several investigators have examined the effect of hip abductor and external rotation strength- ening on PFPS.13 14 While they have reported improvements in hip strength and reductions in knee pain, most have lacked any follow-up beyond the completion of the treatment. However, in a study by Blønd et al, it was reported that 80% of individuals who had engaged in a strengthening programme continued to have pain 5 years later. In addition, 74% had to reduce their physical activity as a result of pain.15 This suggests that the underlying mechanics were not addressed directly. There is increasing evidence that individuals can successfully alter their gait mechanics using real-time feedback.16–18 19 As an example, White et al studied a group of individuals with a unilat- eral hip replacement and associated reduced load- ing on their involved side.16 After 8 weeks of gait retraining using real-time force feedback from an 1Division of Physical Therapy, University of Kentucky, Lexington, Kentucky, USA 2University of Delaware, Newark, Delaware, USA Correspondence to Dr Brian Noehren, Division of Physical Therapy, University of Kentucky, Wethington Bldg rm 204D, 900 S, Limestone Road, Lexington, KY 40536-0200, USA; bwn51@yahoo.com The effect of real-time gait retraining on hip kinematics, pain and function in subjects with patellofemoral pain syndrome B Noehren,1 J Scholz,2 I Davis2 06_bjsports69112.indd 69106_bjsports69112.indd 691 6/8/2011 9:28:14 PM6/8/2011 9:28:14 PM vrijdag 23 augustus 13
    • OUTCOMES • As a result of fatigue novice runners display changes in ... trunk flexion and extension hip extension ankle pronation • Trunk kinematics appear to be significantly affected during fatigued running and should not be overlooked Koblbauer et al. JSAMS 2013 vrijdag 23 augustus 13
    • translating and transferring fundamental and efficacious evidence into practical prevention strategies epidemiological (cost)effectiveness evidence leading to clinical / practical guidelines biomechanical and neurophysiological changes practical & public health impact through high compliance and proper use of effective measures translating and transferring effectiveness evidence into biomechanical experiments unravelling the underlying pathways by which measures prevent injury vrijdag 23 augustus 13
    • MYTH OR REALITY DOES IT MATTER? • Of course it matters, but the discussion seems to revolve around fundamental approaches What is CS Can we measure CS? Which measures are affected by CS? Is there a theoretical background to CS? ... vrijdag 23 augustus 13
    • Myth or legend? It doesn’t matter to have this discussion on a fundamental level if there is no clinical effectiveness to support the practical use of CS vrijdag 23 augustus 13
    • With current clinical knowledge CS appears to be a myth Weak correlations between CS and performance measures Weak predictive value of CS in regards to injury risk Weak outcomes due to methodological issues? Myth or legend? vrijdag 23 augustus 13
    • With  current  clinical  knowledge   CS  could  become  a  legend Posi8ve  outcomes  when  CS  is   employed  in  LBP  management In  novice  or  recrea8onal   athletes  there  is  room  to  CS   improvement  providing  hooks   for  preven8on Myth or legend? vrijdag 23 augustus 13
    • Department of Public and Occupational Health EMGO+ Institute for Health and Care Research VU University Medical Center, Amsterdam, the Netherlands Evert Verhagen www.slhamsterdam.com @evertverhagen e.verhagen@vumc.nl vrijdag 23 augustus 13