VERTEBRAL METRICS

Application of a Mechanical Instrument to Evaluate the Spinal Column in

Pregnant Women

Cláudia Quaresma, Mário Forjaz Secca

CEFITEC, Dep. of Physics, Faculdade de Ciências e Tecnologia, UNL

Quinta da Torre, P-2829-516, Caparica, Portugal

João Goyri O’Neill

Faculdade de Ciências Médicas, UNL, Quinta da Torre, P-2829-516, Lisboa, Portugal

Jorge Branco

Faculdade de Ciências Médicas, UNL / Maternidade Dr. Alfredo da Costa, Lisboa, Portugal

Keywords: Biomechanics, Spinal Column, Non-invasive instrument, Evaluation, Standing position, Pregnant women.

Abstract: The incidence of problems related to rachialgiae is so frequent and usual that it must be studied as if it were

an epidemic and social disease (Knoplich, 2003). It was built a completely mechanically and non-invasive

system, designed as Vertebral Metrics, which is able to identify the position x, y and z of each spine

apophysis, from the first cervical vertebra to the first sacral vertebra in standing position. The measuring

part is the “body” of the instrument, and the “support”. This devise was applied in a pregnant woman in four

moments of the pregnancy: 12; 20, 32 and 37 weeks. In the second moment of the evaluation of the spine

the curvatures decrease when compared with the other moments of the evaluation, where an increase of

these curvatures, related to rachialgie, is evident.

1 INTRODUCTION

Rachialgiae constitute a relevant problem in modern

society (Alexandre & Moraes, 2001). In many

women, this problem. appears for the first time

during pregnancy. 80% of pregnant women have

rachialgiae . where 50% of those remains affected

for the rest of their lives. This situation causes

serious troubles of absenteeism and consequently a

great loss for the labour market, under an economic

perspective.

In view of the number of women affected, and of

the economic implications of the problem, the

development an instrument that evaluates, in a

global way, the spinal column in standing position,

as become important in order to better understand

the behaviour of the spine during the gestational

period.

For that purpose a completely mechanical and

non-invasive instrument registered as Vertebral

Metrics, was built, which is able to identify the x, y

and z positions of each vertebra, from the first

cervical vertebra to the first sacral vertebra

(Quaresma et al 2009). After entering these data into

a mathematical model of the spine, the curvatures

and lateral deviations in the standing position can be

calculated (

Forjaz Secca et al, 2008).

The credibility of the instrument has been

recognized by means of the register of the patent as

well as the acceptance of the study with pregnant

women by the Ethics Committees of the

Maternidade Dr Alfredo da Costa and Regional

Health Administration of Lisboa and Vale do Tejo

(Quaresma et al 2009).

The validation process was successfully

.performed at Biomechanics Laboratory, of the

Faculty of Human Kinetics, at the

Technical

University of Lisbon, Portugal (Quaresma, 2009).

Vertebral Metrics provided evidence to be a

reliable, consistent and valid instrument in

comparison with an optoelectronic system, when

performed by one examiner (Quaresma, 2009).

143

Quaresma C., Forjaz Secca M., O’Neill J. and Branco J. (2010).

VERTEBRAL METRICS - Application of a Mechanical Instrument to Evaluate the Spinal Column in Pregnant Women.

In Proceedings of the Third International Conference on Biomedical Electronics and Devices, pages 143-146

DOI: 10.5220/0002759301430146

 SciTePress

Figure 1: Image of Vertebral Metrics.

The main components of the apparatus (Figure 1)

are the “body” and the “support” (Forjaz Secca, et

al, 2008)

The “body” has a vertical piece, mounted in the

support, with 18 horizontal pieces called “2D

Positioner”. Each “2D Positioner” slides along the

scaled ruler attached on the vertical piece.

The “support” has two pieces, one vertical,

where the body of the instrument fits, and one

horizontal piece where the person to be evaluated

stands up.

All the 18 2D Positioners are identical and

adjustable, allowing the identification of the x, y,

and z positions of each vertebra (Quaresma, 2009)

The component 1 of the 2D Positioners is a

square sectioned rod, cone shaped, which is the

contact point for each vertebra (Figure 2)..

Figure 2: The “2D Positioner”.

Three of the “2D Positioner” are used in four

different ways (Quaresma et al 2009)..

The first is placed in the occipital region and is

used as a reference point during the data collection;

The second piece collects the data of the cervical

vertebrae:

The third, which is piece number fifteen,

collects the data from the first, second and third

lumbar vertebra;

Finally, the remaining horizontal pieces will

identify the position of all other vertebra of the

spinal column.

The x, y and z positions of each “2D P” are then

obtained and the 3 coordinates can be read using

different rulers on the device.

2 VERTEBRAL METRICS:

APLICATION

In order initiate the evaluation process the horizontal

pieces of the instrument are roughly adjusted,

according to the height of each woman

The examiner, starts by marking on the skin the

vertebral apophyses, from the first cervical vertebra

to the first sacral vertebra, using a washable pen

(Figure 3).

Figure 3: Marking the vertebral apophyses with a

washable pen.

Each pregnant woman stands up then on the

“support” of the apparatus with the posterior face of

the trunk facing the “body” of the Vertebral Metrics,

followed by adjustment of each “2D Positioner” to

each mark on the various points along the spinal

column(Quaresma et al 2009).

The evaluation starts by placing the first

horizontal piece in the occipital region.

Immediately afterwards the second, fourteenth

and the last “2D Positioner” are adjusted to the

seven cervical vertebra, twelve dorsal vertebra and

the first sacral vertebra. This points are used as

reference points to stabilize to position of the spine.

Subsequently the remaining “2D Positioner” are

adjusted

The x, y and z positions of each “2D Positioner”

are then obtained (Quaresma et al 2009).

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Figure 4: Example of application of Vertebral Metrics.

Despite the apparent complexity of the device and of

the respective measurements, each data collection

only lasts seven minutes (Figure 4).

The collected data are then recorded and

transferred to a specific data basis which includes

correction factors associated with the instrument

3 PREMILINARY RESULTS

This study is part of a broader analysis where we

intend to identify and describe the biomechanical

changes of the spinal column that occur throughout

pregnancy.

This paper presents the application of Vertebral

Metrics to one pregnant woman. Data collection was

made in three periods of the pregnancy:12, 20, 32

and 37 weeks of the gestation.

As can be observed in figures 5 to 8.in the

corresponding diagrams 1 to 4 .the curvatures of the

spine change during pregnancy. In the second

moment of the evaluation of the spine the curvatures

decrease when compared with the other moments of

the evaluation, where an increase of these

curvatures, related to rachialgie, is evident.

4 CONCLUSIONS

Vertebral Metrics is a non-invasive mechanical

instrument, which is able to identify the position x, y

and z of each vertebra in standing position

(Quaresma et al 2009).

Figure 5: Pregnant woman- 12 weeks of gestations.

Figure 6: Pregnant woman - 20 weeks of gestations.

Figure 7: Pregnant woman - 32 weeks of gestations.

Figure 8: Pregnant woman - 37 weeks of gestations.

VERTEBRAL METRICS - Application of a Mechanical Instrument to Evaluate the Spinal Column in Pregnant Women

145

Diagram 1: Spine - 12 weeks of gestations.

Diagram 2: Spine - 20 weeks of gestations.

Diagram 3: Spine -32 weeks of gestations.



Diagram 4: Spine - 37 weeks of gestations.

This instrument allows a global simultaneous

assessment of the spine. Thus, identification of

dysfunctions and / or diseases of the spinal column

in pregnant women, will be shown on a full

diagnosis. Intervention programs, directly connected

to specific problems of each pregnant woman, may

then be elaborated and implemented (Quaresma et al

2009).

Vertebral Metrics was originally planned and

built to be applied to pregnant women, althout it can

be easily applied to the general population

(Quaresma et al 2009). This device can also be

applied in other situation, including the orthopaedic,

neurosurgical and rehabilitation area.

A automatic system to speed up the process of the

data collection is currently being developed.

Besides the mentioned importance of Vertebral

Metrics, it should be provided out that the present

instrument is easily carried making feasible its use in

any health institution.

REFERENCES

Alexandre, N.; Moraes, M. 2001. Modelo de avaliação

fisio-funcional da coluna vertebral. Rev. Latino-am

Enfermagem Março, 9 (2); 67-75.

Knoplich, J. 2003. Enfermidades da coluna vertebral..,

Robe Editorial. São Paulo, 3ªed

Forjaz Secca, M; Quaresma, C.; Santos, F.. 2008. A

Mechanical Instrument to Evaluate Posture of the

Spinal Column in Pregnant Women. Proc. IFMBE 4th

European Congress for Med. and Biol. Eng., Antwerp,

Belgium; 1781-1784

Quaresma, C.; Forjaz Secca, M.; O’Neill, J.; Branco, J.,

2009. Development a mechanical instrument to

evaluate biomechanically the spinal columnin

pregnant women. Proc. Internacional Conference

Biodevice, 310-113.

Quaresma, C.; Forjaz Secca, M.; O’Neill, J.; Branco.

2009. Métrica Vertebral: Intrumento de Avaliação

Biomecânica da Coluna Vertebral. III Congresso

Nacional de Biomecânica

Quaresma, C.; João, F. Fonseca, M. Forjaz Secca, M.

Veloso, A.; O’Neill, J.; Branco, J., 2009. Validação do

Métrica Vertebral Através de um Sistema

Optoeléctrico de Esterogrametria. Actas do

III.Congresso Nacional de Biomecânica

Quaresma, C.; João, F. Fonseca, M. Forjaz Secca, M.

Veloso, A.; O’Neill, J.; Branco, J., 2009. Validations

of Vertebral Metrics: a mechanical instrument to

evaluate posture osf the spinal column. O. Dössel and

W.C. Schlegel (Eds.): WC IFMBE Proceedings

25/VII, 711–713

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