Document Detail

Validation of a Novel Smartphone Accelerometer-Based Knee Goniometer.
MedLine Citation:
PMID:  23150162     Owner:  NLM     Status:  Publisher    
Loss of full knee extension following anterior cruciate ligament surgery has been shown to impair knee function. However, there can be significant difficulties in accurately and reproducibly measuring a fixed flexion of the knee. We studied the interobserver and the intraobserver reliabilities of a novel, smartphone accelerometer-based, knee goniometer and compared it with a long-armed conventional goniometer for the assessment of fixed flexion knee deformity. Five healthy male volunteers (age range 30 to 40 years) were studied. Measurements of knee flexion angle were made with a telescopic-armed goniometer (Lafayette Instrument, Lafayette, IN) and compared with measurements using the smartphone (iPhone 3GS, Apple Inc., Cupertino, CA) knee goniometer using a novel trigonometric technique based on tibial inclination. Bland-Altman analysis of validity and reliability including statistical analysis of correlation by Pearson's method was undertaken. The iPhone goniometer had an interobserver correlation (r) of 0.994 compared with 0.952 for the Lafayette. The intraobserver correlation was r = 0.982 for the iPhone (compared with 0.927). The datasets from the two instruments correlate closely (r = 0.947) are proportional and have mean difference of only -0.4 degrees (SD 3.86 degrees). The Lafayette goniometer had an intraobserver reliability ± 9.6 degrees. The interobserver reliability was ± 8.4 degrees. By comparison the iPhone had an interobserver reliability ± 2.7 degrees and an intraobserver reliability ± 4.6 degrees. We found the iPhone goniometer to be a reliable tool for the measurement of subtle knee flexion in the clinic setting.
Matthew Ockendon; Robin E Gilbert
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-5-3
Journal Detail:
Title:  The journal of knee surgery     Volume:  25     ISSN:  1538-8506     ISO Abbreviation:  J Knee Surg     Publication Date:  2012 Dec 
Date Detail:
Created Date:  2012-11-14     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101137599     Medline TA:  J Knee Surg     Country:  -    
Other Details:
Languages:  ENG     Pagination:  341-346     Citation Subset:  -    
Copyright Information:
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Department of Sports Surgery, Robert Jones and Agnes Hunt Orthopaedic Hospital, Gobowen, Oswestry, United Kingdom.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Quadriceps Tendon Rupture: A Biomechanical Comparison of Transosseous Equivalent Double-Row Suture A...
Next Document:  Computer Navigated Versus Conventional Total Knee Arthroplasty.