Optimization of the anterior cruciate ligament injury prevention paradigm: Novel feedback techniques to enhance motor learning and reduce injury risk

Journal of Orthopaedic and Sports Physical Therapy

Volumn 45, Issue 3, 2015, Pages 170-182

  Benjaminse, Anne ^a,b   Gokeler, Alli ^a   Dowling, Ariel V ^c   Faigenbaum, Avery ^d   Ford, Kevin R ^e,f   Hewett, Timothy E ^f,g   Onate, James A ^g   Otten, Bert ^a   Myer, Gregory D ^f,g,h,i  

^a UNIVERSITY MEDICAL CENTER GRONINGEN   (Netherlands)

^b HANZE UNIVERSITY OF APPLIED SCIENCES   (Netherlands)

^c STANFORD UNIVERSITY   (United States)

^d The College of New Jersey   (United States)

^e HIGH POINT UNIVERSITY   (United States)

^f CINCINNATI CHILDREN'S HOSPITAL MEDICAL CENTER   (United States)

^g OHIO STATE UNIVERSITY   (United States)

^h UNIVERSITY OF CINCINNATI COLLEGE OF MEDICINE   (United States)

ⁱ Harvard Medical School   (United States)

Author keywords

ACL; Focus of attention; Knee

Indexed keywords

ANTERIOR CRUCIATE LIGAMENT; ATHLETIC INJURIES; AUDIOVISUAL AID; BIOMECHANICS; BODY EQUILIBRIUM; FEEDBACK SYSTEM; FEMALE; HUMAN; INJURIES; KNEE INJURIES; LEARNING; MALE; MOTOR PERFORMANCE; MOVEMENT (PHYSIOLOGY); PHYSICAL EDUCATION; PHYSIOLOGY; PLYOMETRICS; PROCEDURES; RISK FACTOR;

ANTERIOR CRUCIATE LIGAMENT; ATHLETIC INJURIES; AUDIOVISUAL AIDS; BIOMECHANICAL PHENOMENA; FEEDBACK; FEMALE; HUMANS; KNEE INJURIES; LEARNING; MALE; MOTOR SKILLS; MOVEMENT; PHYSICAL EDUCATION AND TRAINING; PLYOMETRIC EXERCISE; POSTURAL BALANCE; RISK FACTORS;

EID: 84925448727     PISSN: 01906011     EISSN: None     Source Type: Journal    
DOI: 10.2519/jospt.2015.4986     Document Type: Article

References (104)

1. Adams JA. A closed-loop theory of motor learning. J Mot Behav. 1971;3:111-149.
2. Alentorn-Geli E, Mendiguchia J, Samuelsson K, et al. Prevention of non-contact anterior cruciate ligament injuries in sports. Part II: systematic review of the effectiveness of prevention programmes in male athletes. Knee Surg Sports Traumatol Arthrosc. 2014;22:16-25. http://dx.doi.org/10.1007/s00167-013-2739-x
3. Andrieux M, Danna J, Thon B. Self-control of task difficulty during training enhances motor learning of a complex coincidence-anticipation task. Res Q Exerc Sport. 2012;83:27-35. http://dx.doi.org/10.1080/02701367.2012.10599822
4. Badami R, VaezMousavi M, Wulf G, Namazizadeh M. Feedback after good versus poor trials affects intrinsic motivation. Res Q Exerc Sport. 2011;82:360-364. http://dx.doi.org/10.1080/02701367.2011.10599765
5. Badets A, Blandin Y. The role of knowledge of results frequency in learning through observation. J Mot Behav. 2004;36:62-70. http://dx.doi.org/10.3200/JMBR.36.1.62-70
6. Baltaci G, Harput G, Haksever B, Ulusoy B, Ozer H. Comparison between Nintendo Wii Fit and conventional rehabilitation on functional performance outcomes after hamstring anterior cruciate ligament reconstruction: prospective, randomized, controlled, doubleblind clinical trial. Knee Surg Sports Traumatol Arthrosc. 2013;21:880-887. http://dx.doi.org/10.1007/s00167-012-2034-2
7. Barrios JA, Crossley KM, Davis IS. Gait retraining to reduce the knee adduction moment through real-time visual feedback of dynamic knee alignment. J Biomech. 2010;43:2208-2213. http://dx.doi.org/10.1016/j.jbiomech.2010.03.040
8. Beek PJ. Toward a theory of implicit learning in the perceptual-motor domain. Int J Sport Psychol. 2000;31:547-554.
9. Beilock SL, Carr TH, MacMahon C, Starkes JL. When paying attention becomes counterproductive: impact of divided versus skill-focused attention on novice and experienced performance of sensorimotor skills. J Exp Psychol Appl. 2002;8:6-16.
10. Benjaminse A, Otten E. ACL injury prevention, more effective with a different way of motor learning? Knee Surg Sports Traumatol Arthrosc. 2011;19:622-627. http://dx.doi.org/10.1007/s00167-010-1313-z
11. Benjaminse A, Welling W, Otten B, Gokeler A. Novel methods of instruction in ACL injury prevention programs, a systematic review. Phys Ther Sport . In press. http://dx.doi.org/10.1016/j.ptsp.2014.06.003
12. Betker AL, Szturm T, Moussavi ZK, Nett C. Video game-based exercises for balance rehabilitation: a single-subject design. Arch Phys Med Rehabil. 2006;87:1141-1149. http://dx.doi.org/10.1016/j.apmr.2006.04.010
13. Boutin A, Badets A, Salesse RN, Fries U, Panzer S, Blandin Y. Practice makes transfer of motor skills imperfect. Psychol Res. 2012;76:611-625. http://dx.doi.org/10.1007/s00426-011-0355-2
14. Brass M, Heyes C. Imitation: is cognitive neuroscience solving the correspondence problem? Trends Cogn Sci. 2005;9:489-495. http://dx.doi.org/10.1016/j.tics.2005.08.007
15. Buccino G, Binkofski F, Riggio L. The mirror neuron system and action recognition. Brain Lang. 2004;89:370-376. http://dx.doi.org/10.1016/S0093-934X(03)00356-0
16. Chen DD, Hendrick JL, Lidor R. Enhancing self-controlled learning environments: the use of self-regulated feedback information. J Hum Mov Stud. 2002;43:69-86.
17. Chimera NJ, Swanik KA, Swanik CB, Straub SJ. Effects of plyometric training on muscle-activation strategies and performance in female athletes. J Athl Train. 2004;39:24-31.
18. Chiviacowsky S, Wulf G. Self-controlled feedback: does it enhance learning because performers get feedback when they need it? Res Q Exerc Sport. 2002;73:408-415. http://dx.doi.org/10.1080/02701367.2002.10609040
19. Chiviacowsky S, Wulf G. Self-controlled feedback is effective if it is based on the learner's performance. Res Q Exerc Sport. 2005;76:42-48. http://dx.doi.org/10.1080/02701367.2005.10599260
20. Chiviacowsky S, Wulf G, Lewthwaite R. Self-controlled learning: the importance of protecting perceptions of competence. Front Psychol. 2012;3:458. http://dx.doi.org/10.3389/fpsyg.2012.00458
21. Crowell HP, Davis IS. Gait retraining to reduce lower extremity loading in runners. Clin Biomech (Bristol, Avon). 2011;26:78-83. http://dx.doi.org/10.1016/j.clinbiomech.2010.09.003
22. Dempsey AR, Elliott BC, Munro BJ, Steele JR, Lloyd DG. Whole body kinematics and knee moments that occur during an overhead catch and landing task in sport. Clin Biomech (Bristol, Avon). 2012;27:466-474. http://dx.doi.org/10.1016/j.clinbiomech.2011.12.001
23. Dowling AV, Favre J, Andriacchi TP. Inertial sensor-based feedback can reduce key risk metrics for anterior cruciate ligament injury during jump landings. Am J Sports Med. 2012;40:1075-1083. http://dx.doi.org/10.1177/0363546512437529
24. Dowling AV, Favre J, Andriacchi TP. A wearable system to assess risk for anterior cruciate ligament injury during jump landing: measurements of temporal events, jump height, and sagittal plane kinematics. J Biomech Eng. 2011;133:071008. http://dx.doi.org/10.1115/1.4004413
25. Etnoyer J, Cortes N, Ringleb SI, Van Lunen BL, Onate JA. Instruction and jump-landing kinematics in college-aged female athletes over time. J Athl Train. 2013;48:161-171. http://dx.doi.org/10.4085/1062-6050-48.2.09
26. Feijen L, Hodges NJ, Beek PJ. Acquiring a novel coordination skill without practicing the correct motor commands. J Mot Behav. 2010;42:295-306. http://dx.doi.org/10.1080/00222895.2010.504760
27. Ferrari A, Cutti AG, Garofalo P, et al. First in vivo assessment of "Outwalk": a novel protocol for clinical gait analysis based on inertial and magnetic sensors. Med Biol Eng Comput. 2010;48:1-15. http://dx.doi.org/10.1007/s11517-009-0544-y
28. Fitts PM, Posner MI. Human Performance. Belmont, CA: Brooks/Cole; 1967.
29. Gokeler A, Benjaminse A, Welling W, Alferink M, Eppinga P, Otten B. The effects of attentional focus on jump performance and knee joint kinematics in patients after ACL reconstruction. Phys Ther Sport. In press. http://dx.doi.org/10.1016/j.ptsp.2014.06.002
30. Granados C, Wulf G. Enhancing motor learning through dyad practice: contributions of observation and dialogue. Res Q Exerc Sport. 2007;78:197-203. http://dx.doi.org/10.1080/02701367.2007.10599417
31. Hardy L, Mullen R, Jones G. Knowledge and conscious control of motor actions under stress. Br J Psychol. 1996;87 pt 4:621-636.
32. Hardy L, Mullen R, Martin N. Effect of task-relevant cues and state anxiety on motor performance. Percept Mot Skills. 2001;92:943-946. http://dx.doi.org/10.2466/pms.2001.92.3.943
33. Hebert EP, Landin D. Effects of a learning model and augmented feedback on tennis skill acquisition. Res Q Exerc Sport. 1994;65:250-257. http://dx.doi.org/10.1080/02701367.1994.10607626
34. Heidt RS, Jr., Sweeterman LM, Carlonas RL, Traub JA, Tekulve FX. Avoidance of soccer injuries with preseason conditioning. Am J Sports Med. 2000;28:659-662.
35. Hewett TE, Myer GD, Ford KR, et al. Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes: a prospective study. Am J Sports Med. 2005;33:492-501. http://dx.doi.org/10.1177/0363546504269591
36. Holm I, Fosdahl MA, Friis A, Risberg MA, Myklebust G, Steen H. Effect of neuromuscular training on proprioception, balance, muscle strength, and lower limb function in female team handball players. Clin J Sport Med. 2004;14:88-94.
37. Hossner EJ, Ehrlenspiel F. Time-referenced effects of an internal vs. external focus of attention on muscular activity and compensatory variability. Front Psychol. 2010;1:230. http://dx.doi.org/10.3389/fpsyg.2010.00230
38. Iacoboni M. Neural mechanisms of imitation. Curr Opin Neurobiol. 2005;15:632-637. http://dx.doi.org/10.1016/j.conb.2005.10.010
39. Janelle CM, Barba DA, Frehlich SG, Tennant LK, Cauraugh JH. Maximizing performance feedback effectiveness through videotape replay and a self-controlled learning environment. Res Q Exerc Sport. 1997;68:269-279. http://dx.doi.org/10.1080/02701367.1997.10608008
40. Joy EA, Taylor JR, Novak MA, Chen M, Fink BP, Porucznik CA. Factors influencing the implementation of anterior cruciate ligament injury prevention strategies by girls soccer coaches. J Strength Cond Res. 2013;27:2263-2269. http://dx.doi.org/10.1519/JSC.0b013e31827ef12e
41. Krosshaug T, Nakamae A, Boden BP, et al. Mechanisms of anterior cruciate ligament injury in basketball: video analysis of 39 cases. Am J Sports Med. 2007;35:359-367. http://dx.doi.org/10.1177/0363546506293899
42. Kyllo LB, Landers DM. Sport psychology goal setting in sport and exercise: a research synthesis to resolve the controversy. J Sport Exerc Psychol. 1995;17:117-137.
43. Laufer Y, Rotem-Lehrer N, Ronen Z, Khayutin G, Rozenberg I. Effect of attention focus on acquisition and retention of postural control following ankle sprain. Arch Phys Med Rehabil. 2007;88:105-108. http://dx.doi.org/10.1016/j.apmr.2006.10.028
44. Lephart SM, Abt JP, Ferris CM, et al. Neuromuscular and biomechanical characteristic changes in high school athletes: a plyometric versus basic resistance program. Br J Sports Med. 2005;39:932-938. http://dx.doi.org/10.1136/bjsm.2005.019083
45. Makaruk H, Porter JM, Czaplicki A, Sadowski J, Sacewicz T. The role of attentional focus in plyometric training. J Sports Med Phys Fitness. 2012;52:319-327.
46. Mandelbaum BR, Silvers HJ, Watanabe DS, et al. Effectiveness of a neuromuscular and proprioceptive training program in preventing anterior cruciate ligament injuries in female athletes: 2-year follow-up. Am J Sports Med. 2005;33:1003-1010. http://dx.doi.org/10.1177/0363546504272261
47. Marchant DC, Clough PJ, Crawshaw M. The effects of attentional focusing strategies on novice dart throwing performance and their task experiences. Int J Sport Exerc Psychol. 2007;5:291-303. http://dx.doi.org/10.1080/1612197X.2007.9671837
48. Masters RS, Poolton JM, Maxwell JP. Stable implicit motor processes despite aerobic locomotor fatigue. Conscious Cogn. 2008;17:335-338. http://dx.doi.org/10.1016/j.concog.2007.03.009
49. Masters RS, Poolton JM, Maxwell JP, Raab M. Implicit motor learning and complex decision making in time-constrained environments. J Mot Behav. 2008;40:71-79. http://dx.doi.org/10.3200/JMBR.40.1.71-80
50. Maxwell JP, Masters RS, Eves FF. From novice to no know-how: a longitudinal study of implicit motor learning. J Sports Sci. 2000;18:111-120. http://dx.doi.org/10.1080/026404100365180
51. McCullagh P, Meyer KN. Learning versus correct models: influence of model type on the learning of a free-weight squat lift. Res Q Exerc Sport. 1997;68:56-61. http://dx.doi.org/10.1080/02701367.1997.10608866
52. McCullagh P, Weiss MR, Ross D. Modeling considerations in motor skill acquisition and performance: an integrated approach. Exerc Sport Sci Rev. 1989;17:475-513.
53. McGlashan AJ, Finch CF. The extent to which behavioural and social sciences theories and models are used in sport injury prevention research. Sports Med. 2010;40:841-858. http://dx.doi.org/10.2165/11534960-000000000-00000
54. McGough R, Paterson K, Bradshaw EJ, Bryant AL, Clark RA. Improving lower limb weight distribution asymmetry during the squat using Nintendo Wii Balance Boards and real-time feedback. J Strength Cond Res. 2012;26:47-52. http://dx.doi.org/10.1519/JSC.0b013e318220b515
55. McNair PJ, Prapavessis H, Callender K. Decreasing landing forces: effect of instruction. Br J Sports Med. 2000;34:293-296.
56. McNevin NH, Wulf G, Carlson C. Effects of attentional focus, self-control, and dyad training on motor learning: implications for physical rehabilitation. Phys Ther. 2000;80:373-385.
57. Molenberghs P, Cunnington R, Mattingley JB. Is the mirror neuron system involved in imitation? A short review and meta-analysis. Neurosci Biobehav Rev. 2009;33:975-980. http://dx.doi.org/10.1016/j.neubiorev.2009.03.010
58. Myer GD, Brent JL, Ford KR, Hewett TE. A pilot study to determine the effect of trunk and hip focused neuromuscular training on hip and knee isokinetic strength. Br J Sports Med. 2008;42:614-619. http://dx.doi.org/10.1136/bjsm.2007.046086
59. Myer GD, Ford KR, Brent JL, Hewett TE. The effects of plyometric vs. dynamic stabilization and balance training on power, balance, and landing force in female athletes. J Strength Cond Res. 2006;20:345-353.
60. Myer GD, Ford KR, McLean SG, Hewett TE. The effects of plyometric versus dynamic stabilization and balance training on lower extremity biomechanics. Am J Sports Med. 2006;34:445-455. http://dx.doi.org/10.1177/0363546505281241
61. Myer GD, Ford KR, Palumbo JP, Hewett TE. Neuromuscular training improves performance and lower-extremity biomechanics in female athletes. J Strength Cond Res. 2005;19:51-60.
62. Myklebust G, Engebretsen L, Braekken IH, Skjølberg A, Olsen OE, Bahr R. Prevention of anterior cruciate ligament injuries in female team handball players: a prospective intervention study over three seasons. Clin J Sport Med. 2003;13:71-78.
63. Myklebust G, Skjølberg A, Bahr R. ACL injury incidence in female handball 10 years after the Norwegian ACL prevention study: important lessons learned. Br J Sports Med. 2013;47:476-479. http://dx.doi.org/10.1136/bjsports-2012-091862
64. Noehren B, Scholz J, Davis I. The effect of real-time gait retraining on hip kinematics, pain and function in subjects with patellofemoral pain syndrome. Br J Sports Med. 2011;45:691-696. http://dx.doi.org/10.1136/bjsm.2009.069112
65. Olsen OE, Myklebust G, Engebretsen L, Bahr R. Injury mechanisms for anterior cruciate ligament injuries in team handball: a systematic video analysis. Am J Sports Med. 2004;32:1002-1012.
66. Onate JA, Guskiewicz KM, Marshall SW, Giuliani C, Yu B, Garrett WE. Instruction of jump-landing technique using videotape feedback: altering lower extremity motion patterns. Am J Sports Med. 2005;33:831-842. http://dx.doi.org/10.1177/0363546504271499
67. Onate JA, Guskiewicz KM, Sullivan RJ. Augmented feedback reduces jump landing forces. J Orthop Sports Phys Ther. 2001;31:511-517. http://dx.doi.org/10.2519/jospt.2001.31.9.511
68. Ong NT, Bowcock A, Hodges NJ. Manipulations to the timing and type of instructions to examine motor skill performance under pressure. Front Psychol. 2010;1:196. http://dx.doi.org/10.3389/fpsyg.2010.00196
69. Park JH, Shea CH, Wright DL. Reduced-frequency concurrent and terminal feedback: a test of the guidance hypothesis. J Mot Behav. 2000;32:287-296. http://dx.doi.org/10.1080/00222890009601379
70. Parsons JL, Alexander MJ. Modifying spike jump landing biomechanics in female adolescent volleyball athletes using video and verbal feedback. J Strength Cond Res. 2012;26:1076-1084. http://dx.doi.org/10.1519/JSC.0b013e31822e5876
71. Picerno P, Cereatti A, Cappozzo A. Joint kinematics estimate using wearable inertial and magnetic sensing modules. Gait Posture. 2008;28:588-595. http://dx.doi.org/10.1016/j.gaitpost.2008.04.003
72. Pollard CD, Sigward SM, Ota S, Langford K, Powers CM. The influence of in-season injury prevention training on lower-extremity kinematics during landing in female soccer players. Clin J Sport Med. 2006;16:223-227.
73. Poolton JM, Masters RS, Maxwell JP. Passing thoughts on the evolutionary stability of implicit motor behaviour: performance retention under physiological fatigue. Conscious Cogn. 2007;16:456-468. http://dx.doi.org/10.1016/j.concog.2006.06.008
74. Prapavessis H, McNair PJ. Effects of instruction in jumping technique and experience jumping on ground reaction forces. J Orthop Sports Phys Ther. 1999;29:352-356. http://dx.doi.org/10.2519/jospt.1999.29.6.352
75. Ram N, Riggs SM, Skaling S, Landers DM, McCullagh P. A comparison of modelling and imagery in the acquisition and retention of motor skills. J Sports Sci. 2007;25:587-597. http://dx.doi.org/10.1080/02640410600947132
76. Riskowski JL. Gait and neuromuscular adaptations after using a feedback-based gait monitoring knee brace. Gait Posture. 2010;32:242-247. http://dx.doi.org/10.1016/j.gaitpost.2010.05.002
77. Rizzolatti G. The mirror neuron system and its function in humans. Anat Embryol (Berl). 2005;210:419-421. http://dx.doi.org/10.1007/s00429-005-0039-z
78. Rizzolatti G, Craighero L. The mirror-neuron system. Annu Rev Neurosci. 2004;27:169-192. http://dx.doi.org/10.1146/annurev.neuro.27.070203.144230
79. Rizzolatti G, Fogassi L, Gallese V. Neurophysiological mechanisms underlying the understanding and imitation of action. Nat Rev Neurosci. 2001;2:661-670. http://dx.doi.org/10.1038/35090060
80. Schmidt R, Wrisberg C. Motor Learning and Performance: A Problem-Based Learning Approach. 3rd ed. Champaign, IL: Human Kinetics; 2004.
81. Schöllhorn WI, Beckmann H, Michelbrink M, Sechelmann M, Trockel M, Davids K. Does noise provide a basis for the unification of motor learning theories? Int J Sport Psychol. 2006;37:186-206.
82. Shea CH, Wright DL, Wulf G, Whitacre C. Physical and observational practice afford unique learning opportunities. J Mot Behav. 2000;32:27-36. http://dx.doi.org/10.1080/00222890009601357
83. Shea CH, Wulf G. Schema theory: a critical appraisal and reevaluation. J Mot Behav. 2005;37:85-101. http://dx.doi.org/10.3200/JMBR.37.2.85-102
84. Shea CH, Wulf G, Whitacre C. Enhancing training efficiency and effectiveness through the use of dyad training. J Mot Behav. 1999;31:119-125. http://dx.doi.org/10.1080/00222899909600983
85. Shultz SJ, Schmitz RJ, Benjaminse A, Chaudhari AM, Collins M, Padua DA. ACL Research Retreat VI: an update on ACL injury risk and prevention. J Athl Train. 2012;47:591-603.
86. Simon SR, Meunier M, Piettre L, Berardi AM, Segebarth CM, Boussaoud D. Spatial attention and memory versus motor preparation: premotor cortex involvement as revealed by fMRI. J Neurophysiol. 2002;88:2047-2057.
87. Sims J, Cosby N, Saliba EN, Hertel J, Saliba SA. Exergaming and static postural control in individuals with a history of lower limb injury. J Athl Train. 2013;48:314-325. http://dx.doi.org/10.4085/1062-6050-48.2.04
88. Steffen K, Myklebust G, Olsen OE, Holme I, Bahr R. Preventing injuries in female youth football - a cluster-randomized controlled trial. Scand J Med Sci Sports. 2008;18:605-614. http://dx.doi.org/10.1111/j.1600-0838.2007.00703.x
89. Sugimoto D, Myer GD, McKeon JM, Hewett TE. Evaluation of the effectiveness of neuromuscular training to reduce anterior cruciate ligament injury in female athletes: a critical review of relative risk reduction and numbers-needed-to-treat analyses. Br J Sports Med. 2012;46:979-988. http://dx.doi.org/10.1136/bjsports-2011-090895
90. Vernadakis N, Derri V, Tsitskari E, Antoniou P. The effect of Xbox Kinect intervention on balance ability for previously injured young competitive male athletes: a preliminary study. Phys Ther Sport. 2014;15:148-155. http://dx.doi.org/10.1016/j.ptsp.2013.08.004
91. Weinberg RS. Goal setting and performance in sport and exercise settings: a synthesis and critique. Med Sci Sports Exerc. 1994;26:469-477.
92. Wu WF, Porter JM, Brown LE. Effect of attentional focus strategies on peak force and performance in the standing long jump. J Strength Cond Res. 2012;26:1226-1231. http://dx.doi.org/10.1519/JSC.0b013e318231ab61
93. Wulf G. Attentional focus and motor learning: a review of 15 years. Int Rev Sport Exerc Psychol. 2013;6:77-104. http://dx.doi.org/10.1080/1750984X.2012.723728
94. Wulf G, Chiviacowsky S, Schiller E, Avila LT. Frequent external-focus feedback enhances motor learning. Front Psychol. 2010;1:190. http://dx.doi.org/10.3389/fpsyg.2010.00190
95. Wulf G, Dufek JS. Increased jump height with an external focus due to enhanced lower extremity joint kinetics. J Mot Behav. 2009;41:401-409. http://dx.doi.org/10.1080/00222890903228421
96. Wulf G, Dufek JS, Lozano L, Pettigrew C. Increased jump height and reduced EMG activity with an external focus. Hum Mov Sci. 2010;29:440-448. http://dx.doi.org/10.1016/j.humov.2009.11.008
97. Wulf G, Höß M, Prinz W. Instructions for motor learning: differential effects of internal versus external focus of attention. J Mot Behav. 1998;30:169-179. http://dx.doi.org/10.1080/00222899809601334
98. Wulf G, Lewthwaite R. Conceptions of ability affect motor learning. J Mot Behav. 2009;41:461-467. http://dx.doi.org/10.3200/35-08-083
99. Wulf G, Mercer J, McNevin N, Guadagnoli MA. Reciprocal influences of attentional focus on postural and suprapostural task performance. J Mot Behav. 2004;36:189-199. http://dx.doi.org/10.3200/JMBR.36.2.189-199
100. Wulf G, Prinz W. Directing attention to movement effects enhances learning: a review. Psychon Bull Rev. 2001;8:648-660.
101. Wulf G, Shea C, Lewthwaite R. Motor skill learning and performance: a review of influential factors. Med Educ. 2010;44:75-84. http://dx.doi.org/10.1111/j.1365-2923.2009.03421.x
102. Wulf G, Weigelt C. Instructions about physical principles in learning a complex motor skill: to tell or not to tell. Res Q Exerc Sport. 1997;68:362-367. http://dx.doi.org/10.1080/02701367.1997.10608018
103. Wulf G, Zachry T, Granados C, Dufek JS. Increases in jump-and-reach height through an external focus of attention. Int J Sports Sci Coach. 2007;2:275-284. http://dx.doi.org/10.1260/174795407782233182
104. Zachry T, Wulf G, Mercer J, Bezodis N. Increased movement accuracy and reduced EMG activity as the result of adopting an external focus of attention. Brain Res Bull. 2005;67:304-309. http://dx.doi.org/10.1016/j.brainresbull.2005.06.035