Research Article Open Access
Journal of Novel Physiotherapies
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ISSN: 2165-7025
Cau et al., J Nov Physiother 2016, 6:4
DOI: 10.4172/2165-7025.1000303
Volume 6 • Isue 4 • 1000303
J Nov Physiother
ISSN: 2165-7025 JNP, an open access journal
Circumferential versus Hand-held Laser Scanner Method for the
Evaluation of Lower Limb Volumes in Normal-weight and Obese Subjects
Nicola Cau
1
*, Stefano Corna
2
, Valentina Aspesi
2
, Francesco Postiglione
2
, Manuela Galli
1,3
, Elena Tacchini
2
, Luisa Brugliera
2
, Veronica
Cimolin
1
and Paolo Capodaglio
2
1
Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
2
Rehabilitation Unit and Research Lab in Biomechanics and Rehabilitation, S Giuseppe Hospital, Istituto Auxologico Italiano, Piancavallo (VB), Italy
3
IRCCS “San Raffaele Pisana”, Tosinvest Sanità, Roma, Italy
Keywords: Obesity; Volume measurements; Rehabilitation
Introduction
Diferent measures for lower limbs volume computation are
available in clinical setting. Tese measures can be classifed according
to the equipment used and the data provided. Water displacement is
considered the gold standard for limb volume measurement [1-3]. It
is based on the Archimedes principle according to which the water
volume moved by an object equals the object’s volume and it provides
a direct measure of the limb volume. According to this method, the
lower extremity is submerged in a tank of water whose displacement is
measured to determine the volume of the leg [4]. Despite its accuracy,
this method is not commonly used by clinicians for practical reasons.
Te most widely used method in clinical practice is the
Circumferential Measurement (CM) using a fexible measure tape. Te
leg volume is obtained using a indirect method as it is computed using
a geometrical approximation (Frustum Formula [5]). Te whole leg
is divided into sections - usually ten - with each section representing
a truncated cone. Te fnal volume is determined by summing up
the volumes of the diferent sections. Tis method presents with the
advantages of being simple, inexpensive and accurate; however, it is
operator-dependent and its reliability depends on the operator’s skills
[6]. As the formula used for the volume calculation assumes that
the leg is approximated to a truncated cone, CM does not capture
information regarding leg shape (i.e., gibbousness or localized
swelling). Another indirect volumetric method is perometry, which
consists of a square-shaped sliding frame surrounding the perimeter
of the limb. Tis frame contains rows of infrared light emitters and
sensors on opposite sides. When the leg is placed inside the frame, it
interrupts the emitted infrared beam on two planes. Tis provides two
perpendicular diameter measurements of the limb segment. Tus, it
is possible to estimate for each measuring point the correspondent
diameter and calculate the volume of the limb. Despite its accuracy,
this technique has some limitations in terms of costs and usability. In
fact, the dimension of the frame is not wide enough to accommodate
the leg of extremely large subjects. Another indirect volume measure
is the bio-impedance method, which measures the tissue resistance to
an electrical current in order to determine extra-cellular fuid volume.
When a current is applied to the body through surface electrodes, it
is transmitted through water-containing component within the tissues
and a value of impedance can be calculated. Te latter can be converted
into an index score, which refects volume measurement.
Recent studies support the use of a new technique for an accurate
and reliable measurement of body segments based on 3D laser scanner
method (LS3D) [7-9]. LS3D usually used in orthopaedics and orthoses
design to create three-dimensional models, has been recently tested
to measure body volumes. It has the advantages of being fast and
non-invasive [10]. Comparison with gold standard (WD) method
on upper limb volume measurement [8,9] have already proved good
correlations. LS3D has shown to be accurate, reliable, not operator-
dependent and able to provide a 3D representation of the limb. Besides
this it represents a very good alternative to the WD measurement,
Abstract
Circumferential measurement (CM) for lower limbs volume computation is a simple and accurate method; however,
its reliability depends on the operator’s skills. Recent studies support the use of a new technique for an accurate and
reliable measurement of body segments based on 3D laser scanner method (LS3D).
The detection of the limb volume in obese patients can be tricky, due to the excess of masses that may hamper the
identifcation of anatomical landmarks. In this study, we wanted to compare CM and LS3D in terms of circumferential
measures and volumes of lower limbs in normal-weight and in obese subjects.
We measured lower limb volumes in 21 female obese and in 11 female healthy subjects with both methods.
Our data show statistically signifcant differences in terms of volume as detected by CM and LS3D. In the comparison
between methods, the control group had showed a higher number of parameters statistically different in comparison with
the obese. The reason is related to the shape of the limb: whereas in lean subjects the leg shape is anatomically defned,
in obese subjects the presence of fat layers masks the anatomical landmarks with the leg shape closely resembling a
cone fgure. In this latter case, the Frustum formula seems to better approximate the volume. LS3D presents with the
advantage of detecting gibbousness and uneven limb shapes, i.e. in patients lymphedema, which can be overlooked by
the Frustum formula. Our data suggest that LS3D may represent a suitable tool for clinical applications, especially for
pre-post evaluations.
*Corresponding author: Nicola Cau, Department of Electronics, Information and
Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan,
Italy, Tel: +39 02 23993359; Fax: +39 02 23993360; E-mail: nicola.cau@polimi.it
Received July 19, 2016; Accepted July 30, 2016; Published August 10, 2016
Citation: Cau N, Corna S, Aspesi V, Postiglione F , Galli M, et al. (2016)
Circumferential versus Hand-held Laser Scanner Method for the Evaluation of
Lower Limb Volumes in Normal-weight and Obese Subjects. J Nov Physiother 6:
303. doi: 10.4172/2165-7025.1000303
Copyright: © 2016 Cau N, et al. This is an open-access article distributed under
the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited.