Evaluation and Treatment Strategies for Care of the ... · and surgical findings in cervical spine injuries. J Spinal Disord. 1989;2(4):213-222. 38. Rauschning W, Jonsson Jr. H. Injuries
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
1. Motor Vehicle Accidents and Fatalities, The 2012 Statistical Ab-stract (2012). US Census Bureau. www.census.gov › The 2012 Sta-tistical Abstract › Transportation. Accessed November 14, 2013.
2. CDC. Vital Signs: Nonfatal, motor vehicle-occupant injuries (2009) and seat belt use (2008) among adults—United States. MMWR 2011;59. www.cdc.gov/motorvehiclesafety/seatbelts/facts.html. Accessed November 14, 2013.
3. Naumann RB, Dellinger AM, Zaloshnja E, Lawrence BA, Miller TR. Incidence and total lifetime costs of motor vehicle-related fatal and nonfatal injury by road user type, United States, 2005. Traffic Inj Prev. 2010;11:353-360.
4. Teasell RW. Toward an evidence -based approach to whiplash injuries. Pain Res Manag. 2010;15(5):285-286.
5. Jull GA, Sterling M, Curatolo M, Carroll L, Hodges P. Toward lessening the rate of transition of acute whiplash to a chronic dis-order. Spine. 2011;36(25S):S173–S174.
6. Walker MJ, Ayotte NW, Rochino DA. Cervical and thoracic pain: evidence for effectiveness of physical therapy. In: Walker MJ, Ayo-tte NW, Rochino DA. Independent Study Course 21.1.1 Origins of Cervical Pain. La Crosse, WI. 2011, Orthopaedic Section, APTA, Inc.
7. Siegmund GP, Winkelstein BA, Ivancic PC, Svensson MY, Vasava-da A. The anatomy and biomechanics of acute and chronic whip-lash injury. Traffic Inj Prev. 2009;10(2):101-112.
8. Siegmund GP. What occupant kinematics and neuro-muscular responses tell us about whiplash injury. Spine. 2011;36(25S):S175-S179.
9. Spitzer WO, Skovron ML, Salmi LR, et al. Scientific monograph of the Quebec Task Force on whiplash-associated disorders: rede-fining “whiplash” and its management. Spine. 1995;20(8S):1S-2S.
10. Jansen GB, Edlund C, Grane P, et al. Whiplash injuries: diag-nosis and early management. The Swedish Society of Medicine and the Whiplash Commission Medical Task Force. Eur Spine J. 2008;S3:S355-S417.
11. Cobo EP, Mesquida ME, Fanegas EP, et al. What factors have influence on persistence of neck pain after a whiplash? Spine. 2010;35(9):E338-E343.
12. Conlin A, Bhogal S, Sequeira K, Teasell R. Treatment of whip-lash-associated disorders-part I: non-invasive interventions. Pain Res Manage. 2005;10(21):21-32.
13. Conlin A, Bhogal S, Sequeria K, Teasell R. Treatment of whip-lash-associated disorders--part II: medical and surgical interven-tions. Pain Res Manag. 2005;10(21):33-40.
14. Nijs J, Paul van Wilgen C, Van Oosterwijck JA, van Ittersum M, Meeus M. How to explain central sensitization to patients with ‘unexplained’ chronic musculoskeletal pain: practice guidelines. Man Ther. 2011;16(5):413-418.
15. Curatolo M, Bogduk N, Ivancic PC, McLean SA, Siegmund GP, Winkelstein BA. The role of tissue damage in whiplash-associated disorders: discussion paper 1. Spine. 2011;36(25S):S309–S315.
16. Ivancic PC. Does knowledge of seat design and whiplash in-jury mechanisms translate to understanding outcomes? Spine. 2011;36(25S):S187–S193.
17. Stemper BD, Pintar FA, Rao RD. The influence of morphology on cervical injury characteristics. Spine. 2011;36(25S):180-186.
18. Stammen J, Herriott R, Kang Y, et al. Sequential biomechanics
of the human upper thoracic spine and pectoral girdle. Ann Adv
Automot Med. 2012;56:151-162.
19. Panjabi MM, Cholewicki J, Nibu K, et al. Mechanism of whiplash
injury. Clin Biomech. 1998;13:239-249.
20. Duane TM, Young A, Mayglothling J, et al. CT for all or selective
approach? Who really needs a cervical spine CT after blunt trau-
ma. J Trauma Acute Care Surg. 2013;74(4):1098-1101.
21. Yoganandan N, Pintar FA, Stemper BD, et al. Biomechanics of side
impact: injury criteria, aging occupants, and airbag technology. J
Biomech. 2007;40(2):227-243.
22. Bogduk N, Yoganandan N. Review paper: biomechanics of the
cervical spine Part 3: minor injuries. Clin Biomech. 2001;16:267-
275.
23. Cusick JF, Yoganandan N. Review: biomechanics of the cervical
spine 4: major injuries. Clin Biomech. 2002;17:1-20.
24. Jull GA, Soderland A, Stemper B, et al. Toward optimal early man-
agement after whiplash injury to lessen the rate of transition to
chronicity: discussion paper 5. Spine. 2011;36(25S):S335–S342.
25. Cook C. Physical examination tests for the cervical spine. In:
Cook C, Hegedus E, eds. Orthopedic Physical Examination Tests:
An Evidence-Based Approach. 2nd ed. Boston, MA: Pearson;
2013:113-141.
26. Wang MC, Pintar F, Yoganandan N, Maiman DJ. The continued
burden of spine fractures after motor vehicle crashes. J Neurosurg
Spine. 2009;10(2):86-92.
27. Park S. Clinical analysis for the correlation of intra-abdominal
organ injury in the patients with rib fracture. Korean J Thorac Car-
diovasc Surg. 2012;45(4):246-250.
28. Gupta A, Jamshidi M, Rubin JR. Traumatic first rib fracture: is
angiography necessary? A review of 730 cases. Cardiovasc Surg.
37. Rauschning W, McAfee PC, Jónsson H II. Pathoanatomical and surgical findings in cervical spine injuries. J Spinal Disord. 1989;2(4):213-222.
38. Rauschning W, Jonsson Jr. H. Injuries of the cervical spine in automobile accidents: pathoanatomic and clinical aspects. In: Gunzburg R, Szpalski M, eds. Whiplash Injuries: Current Con-cepts in Prevention, Diagnosis, and Treatment of the Cervical Whiplash Syndrome. Philadelphia, PA: Lippincott-Raven Publish-ers; 1998:33-52.
39. Ito S, Ivancic PC, Pearson AM, et al. Cervical intervertebral disk in-jury during simulated frontal impact. Eur Spine J. 2005;14(4):356-365.
40. Bogduk N. On cervical zygapophysial joint pain after whiplash. Spine. 2011;36(25S):S194-S199.
41. Mattucci SF, Moulton JA, Chandrashekar N, Cronin DS. Strain rate dependent properties of human craniovertebral ligaments. J Mech Behav Biomed Mater. 2013;23:71-79.
42. Vetti N, Kråkenes J, Eide GE, Rørvik J, Gilhus NE, Espeland A. Are MRI high-signal changes of alar and transverse ligaments in acute whiplash injury related to outcome? BMC Musculoskelet Disord. 2010:11-260.
43. Vetti N, Kråkenes J, Erdal KA, et al. Follow-up MR imaging of the alar and transverse ligaments after whiplash injury: a prospective controlled study. AJNR Am J Neuroradiol. 2011;32(10):1836-1841.
44. Osmotherly PG, Rivett DA, Rowe LJ. The anterior shear and dis-traction tests for craniocervical instability. An evaluation using magnetic resonance imaging. Man Ther. 2012;17(5):416-421.
45. Osmotherly PG, Rawson OA, Rowe LJ. The relationship between dens height and alar ligament orientation: a radiologic study. J Manipulative Physiol Ther. 2011;34(3):181-187.
46. Osmotherly PG, Rivett DA, Rowe LJ. Toward understanding nor-mal craniocervical rotation occurring during the rotation stress test for the alar ligaments. Phys Ther. 2013;93(7):986-992.
47. Yeung E. ‘Whiplash injuries’ of the cervical spine: the relationship between the mechanism of injury and neural tissue involvement. Physiotherapy. 1996;82(5):286-290.
48. Sterling M, McLean SA, Sullivan MJ, Elliott JM, Buitenhuis J, Kamper SJ. Potential processes involved in the initiation and maintenance of whiplash-associated disorders: discussion paper 3. Spine. 2011;36(25S):S322-S329.
49. Evans RW. Neurology and Trauma. Cary, NC: Oxford University Press; 2006.
50. Winkelstein BA. How can animal models inform on the transition to chronic symptoms in whiplash? Spine. 2011;36(25S):S218-S225.
51. Nee RJ, Vicenzino B, Jull GA, Cleland JA, Coppieters MW. Base-line characteristics of patients with nerve-related neck and arm pain predict the likely response to neural tissue management. J Orthop Sports Phys Ther. 2013;43(6):379-391.
52. Freeman MD, Rosa S, Harshfield D, et al. A case-control study of cerebellar tonsillar ectopia (Chiari) and head/neck trauma (whip-lash). Brain Inj. 2010;24(7-8):988-994.
53. Martin D. The acute traumatic central cord syndrome. In: Gun-zburg R, Szpalski M, eds. Whiplash Injuries: Current Concepts in Prevention, Diagnosis, and Treatment of the Cervical Whip-lash Syndrome. Philadelphia, PA: Lippincott-Raven Publishers; 1998:129-134.
54. Orrell RW, Marsden CD. The neck-tongue syndrome. J Neurol
Neurosurg Psychiatry. 1994;57:348-352.
55. de Herring A. The whiplash syndrome: Neurolinguistic and atten-tion deficits. In: Gunzburg R, Szpalski M, eds. Whiplash Injuries: Current Concepts in Prevention, Diagnosis, and Treatment of the Cervical Whiplash Syndrome. Philadelphia, PA: Lippincott-Raven Publishers; 1998:143-149.
56. Gordon CR, Levite R, Joffe V, Gadoth N. Is posttraumatic benign paroxysmal positional vertigo different from the idiopathic form? Arch Neurol. 2004;61(10):1590-1593.
57. Curatolo M. Diagnosis of altered central pain processing. Spine. 2011;36(25S):S200-S204.
58. Sterling M, Hodkinson E, Pettiford C, Souvlis T, Curatolo M. Psy-chologic factors are related to some sensory pain thresholds but not nociceptive flexion reflex threshold in chronic whiplash. Clin J Pain. 2008;24(2):124-130.
59. Dong L, Winkelstein BA. Simulated whiplash modulates expres-sion of the glutamatergic system in the spinal cord suggesting spinal plasticity is associated with painful dynamic cervical facet loading. J Neurotrauma. 2010;27(1):163-174.
60. Gellhorn AC. Cervical facet-mediated pain. Phys Med Rehabil Clin N Am. 2011;22(3):447-458.
61. Elliott JM, O’Leary S, Sterling M, Hendrikz J, Pedler A, Jull G. Mag-netic resonance imaging findings of fatty infiltrate in the cervical flexors in chronic whiplash. Spine. 2010;35(9):948-954.
62. Elliott JM. Are there implications for morphological changes in neck muscles after whiplash injury? Spine. 2011;36(25S):S205-S210.
63. Eriksson PO, Häggman-Henrikson B, Zafar H. Jaw-neck dys-function in whiplash-associated disorders. Arch Oral Biol. 2007;52(4):404-408.
64. von Piekartz H, Hall T. Orofacial manual therapy improves cervi-cal movement impairment associated with headache and features of temporomandibular dysfunction: a randomized controlled tri-al. Man Ther. 2013;18(4):345-350.
65. Jull GA. Deep cervical neck flexor dysfunction in whiplash. J Musculoskel Pain. 2000;8:143-154.
66. Schomacher J, Falla D. Function and structure of the deep cer-vical extensor muscles in patients with neck pain. Man Ther. 2013;18(5):360-366.
67. Cagnie B, Dolphens M, Peeters I, Achten E, Cambier D, Dan-neels L. Use of muscle functional magnetic resonance imaging to compare cervical flexor activity between patients with whip-lash-associated disorders and people who are healthy. Phys Ther. 2010;90(8):1157-1164.
68. Woodhouse A, Vasseljen O. Altered motor control patterns in whiplash and chronic neck pain. BMC Musculoskelet Disord. 2008;9:90.
69. Oddsdottir GL, Kristjansson E. Two different courses of impaired cervical kinaesthesia following a whiplash injury. A one-year pro-spective study. Man Ther. 2012;17(1):60-65.
70. Treleaven J, Clamaron-Cheers C, Jull G. Does the region of pain influence the presence of sensorimotor disturbances in neck pain disorders? Man Ther. 2011;16(6):636-640.
71. Rushton A, Rivett D, Carlesso L, Flynn T, Hing W, Kerry R. Interna-tional Framework for Examination of the Cervical Region for Po-tential of Cervical Arterial Dysfunction Prior to Orthopaedic Man-ual Therapy Intervention. Auckland, NZ: :International Federation of Orthopaedic Manipulative Physical Therapists; 2012. www.if-ompt.com/ReportsDocuments.html. Accessed October 20, 2013.
72. Kerry R, Taylor AJ, Mitchell J, McCarthy C. Cervical artery dys-function and manual therapy: a critical literature review to inform
professional practice. Man Ther. 2008;13(4):278-288.
73. Allen SC. Pathoanatomic and etiological aspects of cervical spine instability. Orthop Phys Ther Clin N Am. 2001;10(3):409-415.
74. Hoke AP. NAIOMT 516: Cervical Spine I. Material presented at North American Institute of Manual Therapy course, October 26-27, 2013; Portland, Oregon.
75. Harmon KG, Drezner JA, Gammons M, et al. American Medi-cal Society for Sports Medicine position statement: concussion in sport. Br J Sports Med. 2013;47(1):15-26.
76. Centers for Disease Control and Prevention. Heads up: facts for phy-sicians about mild traumatic brain injury (MTBI). Atlanta, GA: Cen-ters for Disease Control and Prevention, US Department of Health and Human Services; 2007. http://www.cdc.gov/concussion/headsup/pdf/Facts_for_Physicians_booklet.pdf. Accessed Nov- ember 2, 2013.
77. Kashluba S, Casey JE, Paniak C. Evaluating the utility of ICD-10 diagnostic criteria for postconcussion syndrome following mild traumatic brain injury. J Int Neuropsychol Soc. 2006;12(1):111-118.
78. Graziano DL, Nitsch W, Huijbregts PA. Positive cervical artery testing in a patient with chronic whiplash syndrome: clinical de-cision-making in the presence of diagnostic uncertainty. J Man Manip Ther. 2007;15(3):E45-E63.
79. Lystad RP, Bell G, Bonnevie-Svendsen M, Carter CV. Manual ther-apy with and without vestibular rehabilitation for cervicogenic dizziness: a systematic review. Chiropr Man Ther. 2011;19(1):21.
80. Sung RD, Wang JC. Correlation between a positive Hoffmann’s reflex and cervical pathology in asymptomatic individuals. Spine. 2001;26(1):67-70.
81. Dobbs A. Manual therapy assessment of cervical instability. Or-thop Phys Ther Clin N Am. 2001;10(3):431-445.
82. Pettman E. Stress tests of the craniovertebral joints. In: Boyling JD, Palastanga N, Grieve G, eds. Grieve’s Modern Manual Therapy. 2nd ed. New York, NY: Churchill-Livingstone; 1994:529-537.
83. Beighton P, Grahame R, Bird H. Hypermobility of Joints. 4th ed. New York, NY: Springer; 2012.
84. Bishop MD, Mintken P, Bialosky JE, Cleland JA. Patient expecta-tions of benefit from interventions for neck pain and resulting in-fluence on outcomes. J Orthop Sports Phys Ther. 2013;43(7):457-465.
85. Hill JC, Lewis M, Sim J, Hay EM, Dziedzic K. Predictors of poor outcome in patients with neck pain treated by physical therapy. Clin J Pain. 2007;23(8):683-690.
86. Nieto R, Miró J, Huguet A. Disability in subacute whip-lash patients: usefulness of the neck disability index. Spine. 2008;33(18):E630-E635.
87. Sterling M, Kenardy J, Jull G, Vincenzino B. The development of psychological changes following whiplash injury. Pain. 2003;106(3):481-489.
88. Sterling M. Does knowledge of predictors of recovery and nonrecovery assist outcomes after whiplash injury? Spine. 2011;36(25S):S257-S262.
89. Takasaki H, Johnston V, Treleaven JM, Jull GA. The Neck Pain Driving Index (NPDI) for chronic whiplash-associated disor-ders: development, reliability, and validity assessment. Spine J. 2012;12(10):912-920.
90. Kenardy J, Dunne R. Traumatic injury and traumatic stress. Spine. 2011;36(25S):S233-S237.
91. McLean SA, Clauw DJ, Abelson JL, Liberzon I. The development of persistent pain and psychological morbidity after motor vehicle collision: integrating the potential role of stress response systems
into a biopsychosocial model. Psychosom Med. 2005;67(5):783-
790.
92. Buitenhuis J, de Jong PJ. Fear avoidance and illness beliefs in post-traumatic neck pain. Spine. 2011;36(25S):S238-S243.
93. Sullivan M, Adams H, Martel MO, Scott W, Wideman T. Catastro-phizing and perceived injustice: risk factors for the transition to chronicity after whiplash injury. Spine. 2011;36(25S):S244-S249.
94. Childs JD, Fritz JM, Piva SR, Whitman JM. Proposal of a classifica-tion system for patients with neck pain. J Orthop Sports Phys Ther. 2004;34(11):686-696; discussion 697-700.
95. Fritz JM, Brennan GP. Preliminary examination of a proposed treat-ment-based classification system for patients receiving physical therapy interventions for neck pain. Phys Ther. 2007;87(5):513–524.
96. Goldsmith R, Wright C, Bell SF, Rushton A. Cold hyperalgesia as a prognostic factor in whiplash associated disorders: A systematic review. Man Ther. 2012;17(5):402-410.
97. Koening J, Jarczok MN, Ellis RJ, et al. Two-week test–retest stability of the cold pressor task procedure at two different temperatures as a measure of pain threshold and tolerance. [published online ahead of print November 20, 2013] Pain Pract. doi: 10.1111/papr.12142.
98. Maxwell S, Sterling M. An investigation of the use of a numeric pain rating scale with ice application to the neck to determine cold hyperalgesia. Man Ther. 2013;18(2):172-174.
99. Glynn PE, Weisbach PC. Clinical Prediction Rules: A Physical Therapy Reference Manual. Sudbury, MA: Jones and Barlett Pub-lishers, LLC; 2011.
100. Childs JD, Cleland JA, Elliott JM, et al. Neck pain: clinical prac-tice guidelines linked to the International Classification of Func-tioning, Disability, and Health from the Orthopaedic Section of the American Physical Therapy Association. J Orthop Sports Phys Ther. 2008;38(9):A1-A34.
101. Kamper SJ, Hancock MJ, Maher CG. Optimal designs for predic-tion studies of whiplash. Spine. 2011;36(25S):S268-S274.
102. Carroll LJ, Ferrari R, Cassidy JD, Côté P. Coping and recovery in whiplash-associated disorders: early use of passive coping strate-gies is associated with slower recovery of neck pain and pain-re-lated disability. Clin J Pain. 2014;30(1):1-8.
103. McLean SA. The potential contribution of stress systems to the transition to chronic whiplash-associated disorders. Spine. 2011;36(25S):S226-S232.
104. Cameron ID, Wang E, Sindhusake D. A randomized trial com-paring acupuncture and simulated acupuncture for subacute and chronic whiplash. Spine. 2011;36(26):E1659-E1665.
105. Teasell RW, McClure JA, Walton D, et al. A research synthesis of therapeutic interventions for whiplash-associated disorder (WAD): part 2- interventions for acute WAD. Pain Res Manag. 2010;15(5):295-304.
106. Dehner C, Elbel M, Strobel P, et al. Grade II whiplash injuries to the neck: what is the benefit for patients treated by different phys-ical therapy modalities? Patient Saf Surg. 2009;3(1):2.
107. Conforti M, Fachinetti GP. High power laser therapy treatment compared to simple segmental physical rehabilitation in whiplash injuries (1° and 2° grade of the Quebec Task Force classification) involving muscles and ligaments. Muscles Ligaments Tendons J. 2013;3(2):106-111.
108. Chipchase L. Is there a future for electrophysical agents in muscu-
loskeletal physiotherapy? Man Ther. 2012;17(4):265-266.
109. Dehner C, Hartwig E, Strobel P, et al. Comparison of the rel-ative benefits of 2 versus 10 days of soft collar cervical immo-bilization after acute whiplash injury. Arch Phy Med Rehabil. 2006;87(11):1423-1427.
110. Muzin S, Isaac Z, Walker J, Abd OE, Baima J. When should a cervical collar be used to treat neck pain? Curr Rev Musculoskelet Med. 2008;1(2):114-119.
111. Kongsted A, Qerama E, Kasch H, et al. Neck collar, “act-as-usual” or active mobilization for whiplash injury? A randomized paral-lel-group trial. Spine. 2007;32(6):618-626.
112. Lowry CD, O’Hearn MA, Courtney CA. Resolution of whiplash-as-sociated allodynia following cervicothoracic thrust and non-thrust manipulation. Physiother Theory Pract. 2011;27(6):451–459.
113. Treleaven J. A tailored sensorimotor approach for management of whiplash associated disorders. A single case study. Man Ther. 2010;15(2):206-209.
114. Kondratek M, Creighton D, Krauss J. Use of translatoric mobiliza-tion in a patient with cervicogenic dizziness and motion restric-tion: a case report. J Man Manip Ther. 2006;14(3):140-151.
115. Montfoort I, Van Der Geest JN, Slijper HP, De Zeeuw CI, Frens MA. Adaptation of the cervico- and vestibulo-ocular reflex in whiplash injury patients. J Neurotrauma. 2008;25(6):687-693.
116. Kristjansson E, Treleaven J. Sensorimotor function and dizziness in neck pain: implications for assessment and management. J Or-thop Sports Phys Ther. 2009;39(5):364-377.
117. Castien R, Blankenstein A, van der Windt D, Heymans MW, Dek-ker J. The working mechanism of manual therapy in participants with chronic tension-type headache. J Orthop Sports Phys Ther. 2013;43(10):693-699.
118. Puentedura EJ, Cleland JA, Landers MR, Mintken PE, Louw A, Fernández-de-Las-Pẽnas C. Development of a clinical prediction rule to identify patients with neck pain likely to benefit from thrust joint manipulation to the cervical spine. J Orthop Sports Phys Ther. 2012;42(7):577-592.
119. Bertozzi L, Gardenghi I, Turoni F, et al. Effect of therapeutic exercise on pain and disability in the management of chronic non-specific neck pain: systematic review and meta-analysis of randomized trials. Phys Ther. 2013;93(8):1026-1036.
120. Jull GA. Considerations in the physical rehabilitation of patients with whiplash-associated disorders. Spine. 2011;36(25S):S286-S291.
121. Michaleff ZA, Maher, CG, Jull G, et al. A randomised clinical trial of a comprehensive exercise program for chronic whiplash: trial protocol. BMC Musculoskelet Disord. 2009;10:149.
122. Beer A, Treleaven J, Jull G. Can a functional postural exercise improve performance in the cranio-cervical flexion test?--a pre-liminary study. Man Ther. 2012;17(3):219-224.
123. Peolsson A, Landén Ludvigsson ML, Overmeer T, et al. Effects of neck-specific exercise with or without a behavioural approach in addition to prescribed physical activity for individuals with chron-ic whiplash-associated disorders: a prospective randomised study. BMC Musculoskelet Disord. 2013;14:311.
124. Nijs J, Van Houdenhove B, Oostendorp RA. Recognition of central sensitization in patients with musculoskeletal pain: application of pain neurophysiology in manual therapy practice. Man Ther. 2010;15(2):135-141.
125. Gross A, Forget M, St George K, et al. Patient education for neck pain. Cochrane Database Syst Rev. 2012;3.
126. Szeto GP, Straker LM, O’Sullivan PB. During computing tasks symptomatic female office workers demonstrate a trend to-
wards higher cervical postural muscle load than asymptom-
atic office workers: an experimental study. Aust J Physiother.
2009;55(4):257-262.
127. Johnston V, Jimmieson NL, Jull G, Souvlis T. Contribution of indi-
vidual, workplace, psychosocial and physiological factors to neck
pain in female office workers. Eur J Pain. 2009;13(9):985-991.
128. Fabrizio P. Ergonomic intervention in the treatment of a patient
with upper extremity and neck pain. Phys Ther. 2009;89(4):351-
360.
129. Gordon SJ, Grimmer-Somers K. Your pillow may not guarantee
a good night’s sleep or symptom-free waking. Physiother Can.