Abstract
Background
Professional dancers sustain a high number of injuries. Epidemiological studies have
suggested that performing on inclined “raked” stages increases the likelihood of injury.
However, no studies have examined if biomechanical differences exist between inclined
and flat surfaces during functional tasks, such as landing from a jump. Such differences
may provide a biomechanical rationale for differences in injury risk for raked stages.
Methods
Eight professional dancers performed drop jumps from a 40 cm platform on flat and inclined surfaces while forces, lower extremity kinematics,
and electromyographic activity were collected in a controlled laboratory environment.
Findings
Dancers landed on the laterally inclined surface with significantly higher knee valgus
(4°), peak knee flexion (9°), and medial–lateral ground reaction force (GRF) (13.4%
body weight) compared to the flat condition. The posterior GRF was higher in the anterior
inclined condition compared to the flat condition. In the anterior inclined condition,
subjects landed with 1.4° higher knee valgus, 4° more plantarflexion at initial contact,
and 3° less dorsiflexion at the end of landing.
Interpretation
Biomechanical variables that have been suggested to contribute to injury in previous
studies are increased in the inclined floor conditions. These findings provide a preliminary
biomechanical rationale for differences in injury rates found in observational studies
of raked stages.
Keywords
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References
- Finite element analysis of human knee joint in varus-valgus.Clin. Biomech. 1997; 12: 139-148
- Injuries in a modern dance company: effect of comprehensive management on injury incidence and time loss.Am. J. Sports Med. 2003; 31: 365-373
- Proprioceptive training and prevention of anterior cruciate ligament injuries in soccer.J. Orthop. Sports Phys. Ther. 2001; 31: 655-660
- Effect of fatigue on knee kinetics and kinematics in stop-jump tasks.Am. J. Sports Med. 2005; 33: 1022-1029
- Effect of heel height on forefoot loading.Foot Ankle. 1993; 14: 148-152
- Gender differences in lower extremity kinematics, kinetics, and energy absorption during landing.Clin. Biomech. 2003; 18: 662-669
- Aggressive quadriceps loading can induce noncontact anterior cruciate ligament injury.Am. J. Sports Med. 2004; 32: 477-483
- The evaluation and prediction of impact forces during landings.Med. Sci. Sports Exerc. 1990; 22: 370-377
- A survey of injuries among broadway performers: types of injuries, treatments, and perceptions of performers.Med. Probl. Perform. Ar. 1996; 11: 15-19
- Survey of injuries among West End performers.Occup. Environ. Med. 1998; 55: 585-593
- Jump landing strategies in male and female college athletes and the implications of such strategies for anterior cruciate ligament injury.Am. J. Sports Med. 2003; 31: 233-240
- Valgus knee motion during landing in high school female and male basketball players.Med. Sci. Sports Exerc. 2003; 35: 1745-1750
- Effect of positive heel inclination on posture.J. Orthop. Sports Phys. Ther. 1995; 21: 94-99
- Ballet injuries. An analysis of epidemiology and financial outcome.Am. J. Sports Med. 1993; 21: 586-590
- Knee kinematics: the effects of running on cambers.Med. Sci. Sports Exerc. 1989; 21: 463-466
- Development of recommendations for SEMG sensors and sensor placement procedures.J. Electromyogr. Kines. 2000; 10: 361-374
- Plyometric training in female athletes: decreased impact forces and increased hamstring torques.Am. J. Sports Med. 1996; 24: 765-773
- The effect of neuromuscular training on the incidence of knee injury in female athletes.Am. J. Sports Med. 1999; 27: 699-705
- Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes.Am. J. Sports Med. 2005; 33: 492-501
- Anterior cruciate ligament injuries in female athletes: Part 2, a meta-analysis of neuromuscular interventions aimed at injury prevention.Am. J. Sports Med. 2006; 34: 490-498
- The effects of knee motion and external loading on the length of the anterior cruciate ligament (ACL): a kinematic study.J. Biomech. Eng. 1991; 113: 208-214
- Anterior cruciate ligament injury in female athletes: epidemiology.J. Athl. Train. 1999; 34: 150-154
- The forces in the anterior cruciate ligament and knee kinematics during a simulated pivot shift test: a human cadaveric study using robotic technology.Arthroscopy. 2000; 16: 633-639
- Gait analysis of slope walking: a study on step length, stride width, time factors and deviation in the center of pressure.Acta Med. Okayama. 1991; 45: 179-184
- Gender differences in frontal and sagittal plane biomechanics during drop landings.Med. Sci. Sports Exerc. 2005; 37: 1003-1012
- The dancer as a performing athlete: physiological considerations.Sports Med. 2004; 34: 651-661
- Thigh peak torques and lower body injuries in dancers.J. Dance Med. Sci. 1997; 1: 12-15
- Mechanisms of anterior cruciate ligament injury in basketball: video analysis of 39 cases.Am. J. Sports Med. 2007; 35: 359-367
- Psychological and physiological measurements of performance-related stress and injury rate in professional ballet dancers.Med. Probl. Perform. Ar. 1994; 9: 10-14
- Changes in landing biomechanics during a fatiguing landing activity.J. Electromyogr. Kines. 2003; 13: 491-498
- A comparison of knee joint patterns between men and women in selected athletic activities.Clin. Biomech. 2001; 16: 438-445
- Combined knee loading states that generate high anterior cruciate ligament forces.J. Orthop. Res. 1995; 13: 930-935
- Gait dynamics on an inclined walkway.J. Biomech. 2006; 39: 2491-2502
- Sagittal plane biomechanics cannot injure the ACL during sidestep cutting.Clin. Biomech. 2004; 19: 828-838
- Effect of gender and defensive opponent on the biomechanics of sidestep cutting.Med. Sci. Sports Exerc. 2004; 36: 1008-1016
- Analysis of parameters affecting impact force attenuation during landing in human vertical free fall.Eng. Med. 1982; 11: 141-147
Motion and Analysis, 2003. EvaRT 4.0, Motion Analysis, Santa Rosa, CA.
- Prevention of anterior cruciate ligament injuries in female team handball players: a prospective intervention study over three seasons.Clin. J. Sport Med. 2002; 13: 71-78
- Plantar foot pressures during treadmill walking with high-heel and low-heel shoes.Foot Ankle Int. 1996; 17: 662-666
- Injury mechanisms for anterior cruciate ligament injuries in team handball.Am. J. Sports Med. 2004; 32: 1002-1012
- Kinematics of high-heeled gait.Arch. Phys. Med. Rehabil. 1990; 71: 304-308
- Kinematics of high-heeled gait with consideration for age and experience of wearers.Arch. Phys. Med. Rehabil. 1990; 71: 905-909
- Dependence of cruciate-ligament loading on muscle forces and external load.J. Biomech. 1997; 30: 1015-1024
- The effect of gender and fatigue on the biomechanics of bilateral landings from a jump: peak values.J. Sports Sci. Med. 2007; 6: 77-84
- The effect of eccentric exercise on position sense and joint reaction angle of the lower limbs.Muscle Nerve. 2007; 35: 496-503
- Model prediction of anterior cruciate ligament force during drop-landings.Med. Sci. Sports Exerc. 2004; 36: 1949-1958
- Foundations of Clinical Research: Applications to Practice.Prentice-Hall, Upper Saddle River2000
Richards, J., 2002. Orthotrak 5.0, Motion Analysis, Santa Rosa, CA.
- Vertical jump coordination: fatigue effects.Med. Sci. Sports Exerc. 2002; 34: 105-116
- Sex differences in valgus knee angle during a single-leg drop jump.J. Athl. Train. 2006; 41: 166-171
- The effects of a sloped ground surface on trunk kinematics and L4-S1 moment during lifting.Ergonomics. 2004; 47: 646-659
- The “cost” of injuries in a professional ballet company: a five year study.Med. Probl. Perform. Ar. 1999; : 14
- The influence of surface slope on human gait characteristics: a study of urban pedestrian walking on an inclined surface.Ergonomics. 1996; 39: 677-692
- Electromyographic kinesiology of lower extremity muscles during slope walking.Arch. Phys. Med. Rehabil. 1985; 66: 610-613
- Reproducibility and accuracy of angle measurements obtained under static conditions with the motion analysis video system.Phys. Ther. 1992; 72: 300-305
- Measurement of lumbar spine kinematics in incline treadmill walking.Gait Posture. 1999; 9: 18-23
- Plantar stresses induced by inclined surfaces while standing.Med. Probl. Perform. Ar. 1999; : 180-186
- Foot-ground forces on sloping ground when lifting.Ergonomics. 1987; 30: 1671-1687
Article info
Publication history
Published online: September 10, 2007
Accepted:
July 18,
2007
Received:
March 15,
2007
Identification
Copyright
© 2007 Elsevier Ltd. Published by Elsevier Inc. All rights reserved.
