Measurement of lower limb volume: agreement between the vertically oriented perometer and a tape measure method.
OBJECTIVE
To investigate the agreement between lower limb volume measurements for the vertically oriented perometer and a tape measure method.


METHODS
Between-methods agreement and test-retest reliability study.


METHODS
University setting.


METHODS
Thirty university staff and students were recruited using convenience sampling with no participant drop-outs.


METHODS
All participants' dominant lower limb volumes were measured using the vertically oriented perometer and a tape measure method.


METHODS
The Bland-Altman difference plot was reported for determining the bias between the two methods and its 95% confidence interval. Test-retest reliability and the measurement error for the perometer method were determined using the ICC(2,1) model and within-subject standard deviation (sw) respectively.


RESULTS
There was a lack of agreement between the tape measure and perometer method. The Bland-Altman difference plot showed that the tape measure method overestimated limb volume by 157ml compared to the perometer method. A 95% confidence interval of -834ml to 519ml was observed. The test-retest reliability of the perometer method was ICC(2,1)=0.99. The measurement error of the perometer method was clinically acceptable (sw=121ml).


CONCLUSIONS
There was a lack of agreement between the two methods investigated. Therefore the perometer and tape measure methods are not interchangeable. It is recommended that future validity and reliability studies for the vertically oriented perometer are conducted on clinical populations.
School of Health Sciences, Queen Margaret University Edinburgh, United Kingdom. ctan@qmu.ac.uk
Chee-Wee
CW
Tan
Fiona
F
Coutts
Cathy
C
Bulley
D000328:Adult; D000886:Anthropometry / Q000295:instrumentation* / Q000379:methods*; D004487:Edema / Q000473:pathology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007866:Leg / Q000033:anatomy & histology* / Q000473:pathology; D008297:Male; D026741:Physical Therapy Modalities / Q000592:standards*; D012016:Reference Values; D015203:Reproducibility of Results; D055815:Young Adult
CV; ICC; Lower extremity; Rehabilitation; Reliability and validity; coefficient of variation; intraclass correlation; s(w); within subject standard deviation (measurement error)