Fatigue is often suggested as a risk factor for noncontact ACL injuries. Nyland et al. 77 investigated the effects of fatigue on ground reaction forces, lower extremity kinematics, and muscle activation during running, rapid stop tasks, and cross-cutting. After fatigue, running and rapid stop performance showed trends of late quadriceps and hamstring muscle onset of activation, and early occurrence of maximal knee flexion. They suggested that the late quadriceps and hamstring muscle activation and early maximum knee flexion enhanced shock absorption at landing and knee stabilization in the presence of fatigue. The same group of investigators studied the effects of quadriceps and hamstring fatigue on the knee and ankle kinematics and kinetics during cross-cutting task. 78 Quadriceps fatigue results in increased ankle dorsiflexion moment, decreased peak posterior breaking force, decreased peak extension moments, and delayed peak knee flexion angle. Hamstring fatigue resulted in decreased peak impact knee flexion moment, increased internal tibia rotation, and decreased peak ankle dorsiflexion.
Injuries to the ACL are common in sports, with devastating effects on the quality of life for patients. Most ACL injuries are noncontact in nature. Most noncontact ACL injuries occur in sports that require frequent cutting, pivoting, sudden stops, or landing from a jump. In comparable sports, female athletes have higher risk for noncontact ACL injuries than their male counterparts. Noncontact ACL injuries may be preventable, if modifiable risk factors can be identified. Several factors have been proposed and categorized as intrinsic and extrinsic factors, or as environmental, anatomic, hormonal, and biomechanical and motor control factors. Extensive studies of these proposed risk factors have been undertaken. No studies, however, have critically established the association between any proposed risk factors and noncontact ACL injuries. Accumulated evidence suggests that alternated lower extremity neuromuscular motor controls may contribute significantly to the risk for noncontact ACL injuries. Future studies should critically establish the association between these risk factors for noncontact ACL injuries, and focus on modifiable factors. Environmental factors should be studied with the consideration of performances. The effects of female sex hormones on mechanical properties of the ACL and knee joint should be conducted, considering knee motion patterns in athletic tasks. Anatomic and hormonal factors need to be studied dynamically, while considering biomechanical and motor control factors.
1. Miyasaka KC, Daniel DM, Stone ML, et al. The incidence of knee ligament injuries in the general population. Am J Knee Surgery 1991; 4:3–8.
2. Paulos LE. Why Failures Occur Symposium: Revision ACL Surgery. Presented at the American Orthopedic Society for Sports Medicine Eighteenth Annual Meeting, San Diego, July 1992.
3. Griffin LY, Agel J, Albohm MJ, et al. Noncontact anterior cruciate ligament
injuries: risk factors and prevention strategies. J Am Acad of Orthop Surg 2000; 8 (3):141–150.
4. Huston LJ, Greenfield ML, Wojtys EM. Anterior cruciate ligament
injuries in the female athlete: potential risk factors. Clin Ortho Related Res 2000; 372:50–63.
5. Gottlob CA, Baker CL, Pellissier JM, et al. Cost effectiveness of anterior cruciate ligament
reconstruction in young adults. Clin Orthop Research 1999; 367:272–282.
6. Jacobsen K. Stress radiographical measurement of the anteroposterior, medial, and lateral stability of the knee joint. Acta Ortho Scand 1976; 47:335–334.
7. Fetto JF, Marshall JL. The natural history and diagnosis of anterior cruciate ligament
insufficiency. Clin Ortho 1980; 147:29–38.
8. Giove TP, Miller SJ, Kent BE, Sanford TL, Garrick JG. Nonoperative treatment of the torn ACL. J Bone Joint Surg 1983; 65A:184–192.
9. Noyes FR, Mooar PA, Matthews DS, et al. The symptomatic ACL-deficient knee. J Bone Joint Surg 1983; 65A:154–174.
10. Satku K, Kumar VP, Ngoi SS. ACL injuries: to counsel or to operate? J Bone Joint Surg 1986; 68B:458–461.
11. Kannus P, Jarvinen M. Conservatively treated tears of the ACL: long term results. J Bone Joint Surg 1987; 69A:1007–1012.
12. Irvine LB, Glasgow MM. The natural history of the meniscus in anterior cruciate insufficiency. J Bone Joint Surg 1992; 74A:403–405.
13. Smith BA, Livesay GA, Woo SLY. Biology and biomechanics
of the anterior cruciate ligament
. Clin Sports Med 1993; 12:637–666.
14. Jackson, RW. The torn ACL: natural history of untreated lesions and rationale for selective treatment. In: Feagin JA, ed. The Crucial Ligaments. New York: Churchill Livingstone; 1988:341–348.
15. Woo SLY, Lewis JL, Suh JK, Engebretsen L. Acute injury
to ligament and meniscus as inducers of osteoarthritis. In: Kuettner KE, Goldberg VM, eds. Osteoarthritic Disorders. Rosemont, IL: American Academy of Orthopedic Surgeons; 1994:185–196.
16. McNair P, Marshall R, Matheson J. Important features associated with acute anterior cruciate ligament injury
. NZ Med J 1993; 103:537–539.
17. Boden BP, Dean GS, Feagin JA, Garrett Jr. WE Mechanism of anterior cruciate ligament injury
. Orthopedics. 2000; 23 (6):573–578.
18. Haycock CE, Gillette JV. Susceptibility of women athletes to injury
. Myths vs. reality. JAMA 1976; 236:163–165.
19. Zelisko JA, Noble, HB, Porter M. A comparison of men's and women's professional basketball injuries. Am J Sports Med 1982; 10:297–299.
20. Cox J, Heinz WL. Women midshipmen in sports. Am J Sports Med 1984; 12:241–243.
21. Beck JL, Widermuth BP. The female athlete's knee. Clin Sports Med 1985; 4:345–466.
22. DeHaven K, Lintner D. Athletic injuries: comparison by age, sport, and gender. Am J Sports Med 1986; 14:218–224.
23. Ferretti A, Papandrea P, Conteduca F, et al. Knee ligament injuries in volleyball players. Am J Sports Med 1992; 20:203–207.
24. Malone TR, Hardaker WT, Garrett WE, et al. Relationship of gender to anterior cruciate ligament
injuries in intercollegiate basketball players. J South Orthop Assoc 1993; 2:36–39.
25. Pearl AJ. The Athletic Female
. Champaign, IL: Human Kinetic Publishers; 1993:302–303.
26. Irelan ML. Special concerns of the female athlete. Sports injuries: mechanism, prevention, and treatment. 2nd ed. Philadelphia, PA: Williams & Wilkins; 1994:153–187.
27. Lindenfeld TN, Schmitt DJ, Hendy MP, et al. Incidence of injury
in indoor soccer. Am J Sports Med 1994; 22:354–371.
28. Woodford-Rogers B, Cyphert L, Deneger CR. Risk factors for anterior cruciate ligament injury
in high school and college athletes. J Athl Train 1994; 29:343–346.
29. Arendt EA, Dick R. Knee injury
patterns among men and women in collegiate basketball and soccer. Am J Sports Med 1995; 23:694–701.
30. Chandy TA, Grana WA. Secondary school athletic injury
in boys and girls: a three-year comparison. Physician Sportsmed 1985; 13:106–111.
31. Emerson RJ. Basketball injuries and anterior cruciate ligament
. Clin Sports Med 1993; 12:317–328.
32. Torg JS, Quedenfeld TC, Landau, S. The shoe-surface interface and its relationship to football knee injuries. J Sports Med 1974; 2:261–269.
33. Cahill, BR, Griffith, EH. Effect of preseason conditioning on the incidence and severity of high school football knee injuries. Am J Sports Med 1978; 6:180–184.
34. Kowal DM. Nature and causes of injuries in women resulting from an endurance training program. Am J Sports Med 1980; 8:265–269.
35. Feagin Jr, JA Lambert KL. Mechanism of injury
and pathology of anterior cruciate ligament
injuries. Orthop Clin North Am 1985; 16:41–45.
36. Gray J, Taunton JE, McKenzie DC, et al. A survey of injuries to the anterior cruciate ligament
of the knee in female basketball players. Int J Sports Med 1985; 6:314–316.
37. Myklebust G, Maehlum S, Engebretsen L, et al. Registration of cruciate ligament injuries in Norwegian top level team handball: a prospective study covering two seasons. Scand J Med Sci Sports 1997; 7:289–292.
38. Scranton Jr, PE Whitesel JP, Powell JW, et al. A review of selected noncontact anterior cruciate ligament
injuries in the National Football League. Foot Ankle Int 1997; 18:772–776.
39. Lambson RB, Barnhill BS, Higgins RW. Football cleat design and its effect on anterior cruciate ligament
injuries: a three-year prospective study. Am J Sports Med 1996; 24:155–159.
40. Houseworth SW, Mauro VJ, Mellon BA, et al. The intercondylar notch in acute tears of the anterior cruciate ligament
: a computer graphics study. Am J Sports Med 1987; 15:221–224.
41. Howe JG, Wertheimer C, Johnson RJ, et al. Arthroscopic strain gauge measurement of the normal anterior cruciate ligament
. Arthroscopy 1990; 6:198–204.
42. Good L, Odensten M, Gillquist J. Intercondylar notch measurements with special reference to anterior cruciate ligament
surgery. Clin Orthop 1991; 263:185–189.
43. Beckett ME, Massie DL, Bowers, KD, et al. Incidence of hyperpronation in the ACL injured knee: a clinical perspective. J Athl Train 1992; 27:58–62.
44. Schichendantz MS, Weiker GG. The predictive value of radiographs in the evaluation of unilateral and bilateral anterior cruciate ligament
injuries. Am J Sports Med 1993; 21:110–113.
45. Herzog RJ, Silliman JF, Hutton K, et al. Measurements of intercondylar notch by plain film radiograph and magnetic resonance imaging. Am J Sports Med 1994; 22:204–210.
46. LaPrade RF, Burnett QM. Femoral intercondylar notch stenosis and correlation to anterior cruciate ligament
injuries: a prospective study. Am J Sports Med 1994; 22:198–203.
47. Lund-Hanssen H, Gannon J, Engebretsen L, et al. Intercondylar notch width and the risk for anterior cruciate ligament
rupture: a case control study in 46 female handball players. Acta Orthop Scand 1994; 65:529–532.
48. Shelbourne, KD, Davis, TJ, Klootwyk, T. The relationship between intercondylar notch width of the femur and the incidence of anterior cruciate ligament
tears. Am J Sports Med 1986; 26:402–408.
49. Muneta T, Takakuda K, Yamamoto H. Intercondylar notch width and its relation to the configuration and cross-sectional area of the anterior cruciate ligament
. Am J Sports Med 1985; 25:69–72.
50. Loudon JK, Jenkins W, Loudon KL. The relationship between static posture and ACL injury
in female athletes
. J Orthop Sports Phys Ther 1996; 24:91–97.
51. Nunley RM, Wright D, Renner JB, Yu B, Garrett WE. Gender comparison of patellar tendon tibial shaft angle with weightbearing. Am J Sports Med
2000. In review.
52. Liu SH, Al-Shaikh R, Panossian V, et al. Primary immunolocalization of estrogen and progesterone target cells in the human anterior cruciate ligament
. J Orthop Res 1996; 14:526–533.
53. Liu SH, Al-Shaikh R, Panossian V, et al. Estrogen affects the cellular metabolism of the anterior cruciate ligament
: a potential explanation for female athletic injury
. Am J Sports Med 1997; 25:704–709.
54. Yu WD, Liu SH, Hatch JD, et al. Effect of estrogen on cellular metabolism of the human anterior cruciate ligament
. Clin Orthop Related Res 1999; 336:229–238.
55. Slauterbeck J, Clevenger C, Lundberg W, et al. Estrogen level alters the failure load of the rabbit anterior cruciate ligament
. J Orthop Res 1999; 17:405–408.
56. Moller-Nielsen J, Hammar M. Women's soccer injuries in relation to the menstrual cycle and oral contraceptive use. Med Sci Sports Exerc 1989; 21:126–129.
57. Wojtys EW, Huston LJ, Lindenfeld TN, et al. Association between the menstrual cycle and anterior cruciate ligament
injuries in female athletes
. Am J Sports Med 1998; 26 (5):614–619.
58. McShane JM, Balsbaugh T, Simpson Z, et al. Association between the menstrual cycle and anterior cruciate ligament
injuries in female athletes
[letter to the editor]. Am J Sports Med 2000; 28 (1):131.
59. Wojtys EW. Association between the menstrual cycle and anterior cruciate ligament
injuries in female athletes
[author's response]. Am J Sports Med 2000; 28 (1):131.
60. Myklebust G, Maehlum S, Holm I, et al. A prospective cohort study of anterior cruciate ligament
injuries in elite Norwegian team handball. Scand J Med Sci Sports 1998; 8:149–153.
61. Traina SM, Bromberg, DF. ACL injury
patterns in women. Orthopedics 1997; 20 (6):545–549.
62. Feagin JA. The syndrome of the torn anterior cruciate ligament
. Orthop Clin North Am 1979; 10:81–90.
63. Delee JC, Curtis R. Anterior cruciate ligament
insufficiency in children. Clin Orthop 1983; 172:112–118.
64. Weisman G, Pope MH, Johnson RJ. Cyclic loading in knee ligament injuries. Am J Sports Med 1980; 8:24–30.
65. McLean SG, Neal RJ, Myers PT, et al. Knee joint kinematics during the sidestep cutting maneuver: potential for injury
in women. Med Sci Sports Exerc 1999; 31 (7):959–968.
66. Malinzak R, Cobby S, Kirkendall D, et al. A comparison of knee motion and electromyography patterns between men and women in selected athletic maneuvers. Clin Biomech 2001; 16 (5):438–445.
67. Buff HU, Jones LC Hungerford DS. Experimental determination of forces transmitted through the patellofemoral joint. J Biomech 1988; 21:17–23.
68. Smidt JG. Biomechanical analysis of knee flexion and extension. J Biomech 1973; 6:79–92.
69. van Eijden TMGJ, DeBoer W Weijs WA. The orientation of the distal part of the quadriceps femoris muscle as a function of the knee flexion-extension angle. J Biomech 1985; 18:803–809.
70. Chappell JD, Yu B, Kirkendall DT, et al. A comparison of knee kinetics between male and female recreational athletes in stop–jump tasks. Am J Sports Med
. In press.
71. Lerat JL, Moyen BL, Cladiere F, et al. Knee instability after injury
to the anterior cruciate ligament
: quantification of the Lachman test. JBJS 2000; B-82 (1):42–47.
72. Ma CB, Janaushek MA, Vogrin TM, et al. Significance of changes in reference position for measurement of tibial translation and diagnosis of cruciate ligament deficiency. J Orthop Research 2000; 18 (2):176–182.
73. Noyes FR, Grood ES, Suntay WJ. Three-dimensional motion analysis of clinical stress tests for anterior knee subluxations. Acta Orthop Scan 1989; 60 (3):308–318.
74. Renstrom P, Arms SW, Stanwyck TS, et al. Strain within the anterior cruciate ligament
during hamstring and quadriceps activity. Am J Sports Med 1986; 14:83–87.
75. Bendjaballah MZ, Shirazi-Adl A, Zukor DJ. Finite element analysis of human knee joint in varus-valgus. Clin Biomech 1997; 12:139–148.
76. Chappell JD, Yu B, Kirkendall DT, et al. Knee kinetics and kinematics in different landing tasks: implication to anterior cruciate ligament
injuries. J Bone Joint Surgery
. In review.
77. Nyland JA, Shapiro R, Stine RL, et al. Relationship of fatigued run and rapid stop to ground reaction forces, lower extremity kinematics, and muscle activation. J Orthop Sports Phys Therapy 1994; 20 (3):132–137.
78. Nyland JA, Shapiro R, Caborn DNM, et al. The effect of quadriceps femoris, hamstring, and placebo eccentric fatigue on knee and ankle dynamics during crossover cutting. J Orthop Sports Phys Therapy 1997; 25 (3):171–184.
79. Rozzi SL, Lephart SM, Fu FH. Effects of muscular fatigue on knee joint laxity and neuromuscular characteristics of male and female athletes
. Journal of Athletic Training 1989; 24 (2):106–114.
80. Wojtys EM, Wylie BB, Huston LJ. The effects of muscle fatigue on neuromuscular function and anterior tibial translation in healthy knees. Am J Sports Med 1996; 24 (5):615–621.
81. Sinner HB. Effect of fatigue on joint position sense of the knee. J Orthop Research 1986; 4:112–118.
82. Chappell JD, Yu B, Kirkendall DT, et al. The effects of lower extremity muscle fatigue on knee kinetics and kinematics in stop–jump tasks. Scand J Med Sci Sports
2001. In review.
Nicola Maffulli, M.D., Guest Editor