title: Accuracy and inter-observer reliability of visual estimation compared to clinical goniometry of the elbow.
abstract: OBJECTIVE
  To test the hypothesis that visual estimation by a trained observer is as accurate and reliable as clinical goniometry for measuring elbow range of motion.
  
  
  METHODS
  Instrument validity and inter-observer reliability of visual estimation was evaluated on a consecutive series of 50 elbow contractures. Four observers with different levels of elbow experience first estimated extension and flexion of the contracted elbows and then measured them with a blinded goniometer.
  
  
  RESULTS
  Instrument validity for visually-based goniometry was extremely high. ICC scores were 0.97 for both extension and flexion estimations. Systematic error was negligible (1°) with upper limits of agreement being 9° (95% CI: 7°-11°) and 8° (95% CI: 6°-10°), respectively, for extension and flexion. For the expert surgeon, 92% of the visual estimates were within 5° of the value obtained by clinical goniometry. Between experienced observers (elbow surgeon and physician assistant), the ICC's were very high-0.96 for extension and 0.93 for flexion. The systematic errors were low, from -1° to 1° with upper limit of agreement being 11° (95% CI: 8°-14°). However, agreement was poor between an inexperienced study coordinator and the others (ICC's: 0.51-0.38, systematic errors: 8°-18°, upper limit of agreement: 32°-40°). The accuracy of the visual estimations made by the experienced elbow surgeon was as good as the measurements taken with a goniometer by the physician assistant or the clinical fellow and better than those taken by an inexperienced study coordinator.
  
  
  CONCLUSIONS
  The trained human eye is highly capable of accurately estimating the range of motion of the elbow, compared to conventional clinical goniometry, depending on the experience of the observer.
  
  
  METHODS
  Diagnostic study, Level II.
authors.affiliation: Department of Orthopedic Surgery, Center for Sports Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
authors.forename: Davide
authors.initials: D
authors.lastname: Blonna
authors.forename: Peter C
authors.initials: PC
authors.lastname: Zarkadas
authors.forename: James S
authors.initials: JS
authors.lastname: Fitzsimmons
authors.forename: Shawn W
authors.initials: SW
authors.lastname: O'Driscoll
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D053587:Arthrometry, Articular; D002983:Clinical Competence; D003286:Contracture / Q000503:physiopathology; D004551:Elbow Joint / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D014796:Visual Perception; D055815:Young Adult
references.citation: Lancet. 1986 Feb 8;1(8476):307-10
references.pmid: 2868172
references.citation: Lancet. 1995 Oct 21;346(8982):1085-7
references.pmid: 7564793
references.citation: Physiother Res Int. 2010 Sep;15(3):126-34
references.pmid: 20024893
references.citation: J Shoulder Elbow Surg. 2007 Nov-Dec;16(6):788-794.e2
references.pmid: 17967547
references.citation: Stat Methods Med Res. 1999 Jun;8(2):135-60
references.pmid: 10501650
references.citation: Phys Ther. 1991 Feb;71(2):90-6; discussion 96-7
references.pmid: 1989012
references.citation: J Manipulative Physiol Ther. 1991 Mar-Apr;14(3):199-208
references.pmid: 2045731
references.citation: Am J Sports Med. 1990 Jan-Feb;18(1):58-63
references.pmid: 2405721
references.citation: J Manipulative Physiol Ther. 1991 Feb;14(2):119-32
references.pmid: 2019821
references.citation: J Shoulder Elbow Surg. 1998 Nov-Dec;7(6):573-80
references.pmid: 9883416
references.citation: Physiotherapy. 1976 Jun 10;62(7):227-9
references.pmid: 967944
references.citation: Knee. 2007 Jan;14(1):2-8
references.pmid: 17140797
references.citation: Phys Ther. 1987 Dec;67(12):1867-72
references.pmid: 3685114
references.citation: Arch Phys Med Rehabil. 1993 Oct;74(10):1113-8
references.pmid: 8215866
references.citation: Phys Ther. 1983 Oct;63(10):1611-5
references.pmid: 6622536
references.citation: Phys Ther. 1978 Nov;58(11):1355-60
references.pmid: 704684
references.citation: Arch Phys Med Rehabil. 2005 Mar;86(3):571-5
references.pmid: 15759246
references.citation: J Shoulder Elbow Surg. 2012 Jan;21(1):29-35
references.pmid: 21983191
references.citation: Stat Med. 1987 Jun;6(4):441-8
references.pmid: 3629046
references.citation: Clin J Sport Med. 2006 Mar;16(2):155-61
references.pmid: 16603886
references.citation: Arch Phys Med Rehabil. 2001 Mar;82(3):396-402
references.pmid: 11245764
references.citation: Phys Ther. 1985 Nov;65(11):1666-70
references.pmid: 4059329