title: Physical Activity Level and Symptom Duration Are Not Associated After Concussion.
abstract: BACKGROUND
  Physical rest after a concussion has been described as a key component in the management of the injury. Evidence supporting this recommendation, however, is limited.
  
  
  OBJECTIVE
  To examine the association between physical activity and symptom duration in a cohort of patients after a concussion.
  
  
  METHODS
  Cohort study; Level of evidence, 2.
  
  
  METHODS
  This study included 364 patients who were diagnosed with a concussion, were seen by a physician within 3 weeks of injury, and completed a questionnaire at the initial clinic visit. The questionnaire assessed the postconcussion symptom scale (PCSS) score, previous number of concussions, presence of the loss of consciousness or amnesia at the time of injury, and prior treatment for headaches. During each follow-up clinic visit, physical activity level was self-reported. A Cox proportional hazard model was constructed to determine the association between symptom duration, initial clinic visit responses, and self-reported physical activity level after the injury.
  
  
  RESULTS
  Study participants ranged in age from 8 to 27 years (mean age, 15.0 years) and had sustained a mean of 0.8 prior concussions; 222 patients (61%) were male. On initial examination, the mean PCSS score was 34.7. The mean symptom duration was 48.9 days after the injury. Among the variables included in the model, initial PCSS score and female sex were independently associated with symptom duration, while physical activity level after the injury was not. For participants aged between 13 and 18 years, however, higher levels of physical activity after the injury were associated with a shorter symptom duration.
  
  
  CONCLUSIONS
  Results from this study indicate that physical activity after the injury may not be universally detrimental to the recovery of concussion symptoms.
authors.affiliation: The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts, USA Sports Concussion Clinic, Division of Sports Medicine, Department of Orthopaedics, Boston Children's Hospital, Boston, Massachusetts, USA Brain Injury Center, Boston Children's Hospital, Boston, Massachusetts, USA David.Howell2@childrens.harvard.edu.
authors.forename: David R
authors.initials: DR
authors.lastname: Howell
authors.affiliation: Brain Injury Center, Boston Children's Hospital, Boston, Massachusetts, USA Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA Department of Pediatrics, Harvard Medical School, Harvard University, Boston, Massachusetts, USA.
authors.forename: Rebekah C
authors.initials: RC
authors.lastname: Mannix
authors.affiliation: Sports Concussion Clinic, Division of Sports Medicine, Department of Orthopaedics, Boston Children's Hospital, Boston, Massachusetts, USA.
authors.forename: Bridget
authors.initials: B
authors.lastname: Quinn
authors.affiliation: Cardiovascular Research Laboratory, Spaulding Hospital Cambridge, Cambridge, Massachusetts, USA Department of Physical Medicine and Rehabilitation, Harvard Medical School, Harvard University, Boston, Massachusetts, USA.
authors.forename: J Andrew
authors.initials: JA
authors.lastname: Taylor
authors.affiliation: Cardiovascular Research Laboratory, Spaulding Hospital Cambridge, Cambridge, Massachusetts, USA Department of Physical Medicine and Rehabilitation, Harvard Medical School, Harvard University, Boston, Massachusetts, USA.
authors.forename: Can Ozan
authors.initials: CO
authors.lastname: Tan
authors.affiliation: The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts, USA Sports Concussion Clinic, Division of Sports Medicine, Department of Orthopaedics, Boston Children's Hospital, Boston, Massachusetts, USA Brain Injury Center, Boston Children's Hospital, Boston, Massachusetts, USA Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA Department of Pediatrics, Harvard Medical School, Harvard University, Boston, Massachusetts, USA Department of Orthopaedics, Harvard Medical School, Harvard University, Boston, Massachusetts, USA.
authors.forename: William P
authors.initials: WP
authors.lastname: Meehan
mesh_terms: D000293:Adolescent; D000328:Adult; D001265:Athletic Injuries / Q000150:complications; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D038223:Post-Concussion Syndrome / Q000209:etiology*; D057566:Self Report; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
keywords: brain concussion; mild traumatic brain injury; physical activity; rehabilitation
references.citation: Pediatrics. 2015 Feb;135(2):213-23
references.pmid: 25560444
references.citation: Am J Sports Med. 2015 Mar;43(3):625-32
references.pmid: 25540297
references.citation: Neurosurgery. 2014 Oct;75 Suppl 4:S24-33
references.pmid: 25232881
references.citation: Neurology. 2014 Dec 9;83(24):2204-10
references.pmid: 25381296
references.citation: Am J Sports Med. 2011 Nov;39(11):2304-10
references.pmid: 21969181
references.citation: Can Fam Physician. 2014 Jun;60(6):e310, e312-5
references.pmid: 24925965
references.citation: Clin Sci (Lond). 2013 Feb;124(3):177-89
references.pmid: 22913765
references.citation: J Head Trauma Rehabil. 2013 Jul-Aug;28(4):241-9
references.pmid: 23249769
references.citation: Brain Res. 2009 Sep 29;1291:53-9
references.pmid: 19635466
references.citation: J Neurotrauma. 2011 Sep;28(9):1727-38
references.pmid: 21355816
references.citation: Med Sci Sports Exerc. 2015 Apr;47(4):673-80
references.pmid: 25100340
references.citation: Brain Inj. 2009 Sep;23(10):809-14
references.pmid: 19697169
references.citation: Ann Biomed Eng. 2012 Jan;40(1):106-13
references.pmid: 21997390
references.citation: Brain Inj. 1999 Mar;13(3):173-89
references.pmid: 10081599
references.citation: J Neurosurg Pediatr. 2015 Jun;15(6):589-98
references.pmid: 25745949
references.citation: Sports Med. 2015 Jul;45(7):1027-40
references.pmid: 25971368
references.citation: JAMA. 2003 Nov 19;290(19):2556-63
references.pmid: 14625332
references.citation: Brain Inj. 2015;29(1):58-63
references.pmid: 25279423
references.citation: Res Q Exerc Sport. 1994 Dec;65(4):347-54
references.pmid: 7886284
references.citation: J Pediatr. 2003 May;142(5):546-53
references.pmid: 12756388
references.citation: Am J Sports Med. 2014 Jul;42(7):1710-5
references.pmid: 24739186
references.citation: J Athl Train. 2008 May-Jun;43(3):265-74
references.pmid: 18523563
references.citation: JAMA Pediatr. 2015 Feb;169(2):163-8
references.pmid: 25531065
references.citation: J Int Neuropsychol Soc. 2014 Jan;20(1):64-80
references.pmid: 23375058
references.citation: Pediatrics. 2014 Feb;133(2):e299-304
references.pmid: 24394679
references.citation: J Appl Physiol (1985). 1993 Jun;74(6):3046-51
references.pmid: 8366006
references.citation: Clin Sports Med. 2015 Apr;34(2):213-31
references.pmid: 25818710
references.citation: Gait Posture. 2014;39(1):611-4
references.pmid: 23810088
references.citation: Am J Physiol Heart Circ Physiol. 2009 Dec;297(6):H2084-95
references.pmid: 19820196
references.citation: Neurology. 2014 Oct 28;83(18):1665-72
references.pmid: 25274845
references.citation: Clin J Sport Med. 2010 Jan;20(1):21-7
references.pmid: 20051730
references.citation: Med Sci Sports Exerc. 2013 Jun;45(6):1030-7
references.pmid: 23274602
references.citation: J Athl Train. 2013 Jul-Aug;48(4):554-75
references.pmid: 23855364
references.citation: J Pediatr. 2013 Sep;163(3):721-5
references.pmid: 23628374
references.citation: J Appl Physiol (1985). 1997 Dec;83(6):2139-45
references.pmid: 9390992
references.citation: J Head Trauma Rehabil. 1998 Aug;13(4):58-67
references.pmid: 9651240
references.citation: J Int Neuropsychol Soc. 2013 Jan;19(1):22-33
references.pmid: 23058235
references.citation: J Neurotrauma. 2013 Apr 15;30(8):657-70
references.pmid: 23062081
references.citation: Clin J Sport Med. 2003 Jul;13(4):222-9
references.pmid: 12855924