Linearity of the Scale for Mass and Volume within the Air Displacement Plethysmograph (BOD POD): A Methodological Investigation
Journal Title: Sports and Exercise Medicine – Open Journal - Year 2017, Vol 3, Issue 2
Abstract
Introduction: In order to maintain the accuracy and reliability for both volume and mass measurements of the air displacement plethysmograph (BOD POD) on a day-to-day basis, quality assurance processes are undertaken. Given the importance of accurate estimation of body mass and body volume in determining body composition, the aim of this methodological investigation was to further examine the calibration approaches and to independently determine both the linearity and reliability of mass and volume measurements throughout the potential measurement range. Methods: Routine calibration procedures for mass (sequentially add known masses ranging from 10-30 kg) range and volume (sequentially add known volume of balloons ranging from 49.900 L to 118.40 L) were conducted using BOD POD model 2000A (Life Measurement Inc. (LMI), Concord, CA, USA). Scatter plots between actual (known) against predicted (measurement) mass and volume values and bias and 95% limits of agreement plots were produced to illustrate the agreement, and paired t-tests to determine significant differences between the volumes. Results: Results revealed that for all mass measurements between 10-30 kg the known mass and measured mass were in agreement. With respect to all volume measurements, the predicted (measured) volume differed from the actual (known) volume by as little as 0.2 L and as much as 0.9 L. There was a difference between actual (known) (mean±SD=65.1±35.9 l) and predicted (measured) (64.7±35.8 L), t9=6.35 p<0.01. Conclusion: One might question the relevance of only being able to calibrate mass to a maximum of 30 kg, when body mass of adult participants certainly exceed 30 kg. Results from the adapted volume calibration trial using balloons revealed underreporting of predicted (measured) volumes by 0.4 L. However, on the basis of this methodological investigation, it is possible to be broadly confident with the linearity and reliability of both mass and volume measurement outcomes from the BOD POD involving a reasonable level of rigour.
Authors and Affiliations
Claire Mills
The Interventional Use of Water Treadmill Running During Long Periods of Injury
The aim of this brief study was to establish the efficacy of waist depth water Aquatic treadmill (ATM) running during a 28-day injury period where normal land based training was not possible. Synchronized tri-axial accel...
Social Competence as a Role-Player in the Game between Motor Performance and Organized Sports Participation among School-Age Children
Lifestyle choices from childhood, such as being physically active, track into adulthood. A key factor that influences a child’s likelihood of being healthy is their level of social competence. Social Competence (SC) is t...
Cervical Strain/Whiplash Associated Disorder (WAD) Management
Introduction: “Cervical strain and whiplash” secondary to a motor vehicle accident (MVA) are commonly treated in an emergency room and frequently referred to outpatient physical therapy care. Though, the Quebec Task Forc...
Effects of Resistance Training on Bone and Muscle Mass in Older Women: A Review
Aging is associated with declines of different physiological systems. These reductions are directly related to loss of mobility in older individuals, reducing the independence and quality of life for this population. Reg...
Effectiveness of Compression Garments on Selected Physiological, Perceptual and Performance Measures While Traversing Austere Conditions at Altitude: A Pilot Study
Background Compression garments (CGs) have increased in popularity within recreational and competitive athlete populations. Purpose The purpose of this study was to examine the effect of CGs on physiological, performance...