**3.2. Endopelvic fascia**

12 Injury and Skeletal Biomechanics

lateral direction (figure 7).

930

**m)**

**pozice (mm) position (mm)**  940

950

960

970

**pozice (mm) position (mm)**  980

990

1000

direction (figure 8).

pregnant women in the third trimester.

**Figure 7.** The navel motion (a) caudo-cranial; b) latero-lateral.

this respect, because the change of those frequencies was not found.

For the acquisition of the kinematic data, the Qualisys system was used. The force (dynamic) effects were detected by the Kistler equipment. The experiment was conducted on two

In the first phase of the experiment, the normal gait was analyzed. The analysis was focused on the movements of the marker that was placed on the navel in cranio-caudal and latero-

**a)** 

**b)** 

The data evaluation was based on mutual comparison of the displayed curves for the measurements without the belt, with the belt and with the belt and braces for both participants. The observed phenomenons were the significant frequencies characterized by the highest amplitudes. The results showed that the belts had a totally negligible effect in

0 50 100 150 200 250 300 350 400 450 500

**time (s)** 

0 50 100 150 200 250 300 350 400 450 500 **čas (frames)**

**time (s)** 

In the second stage of the experiment, the vibrations of the participant's gravid abdomen were observed after the fall on heels after standing on tiptoe. The caudo-cranial movement of the navel marker was recorded. The evaluation was performed separately for each

The last stage of the experiment contained a questionnaire investigation which was designed to explore the participant's feelings about the belts and the connection between the lumbar pain and wearing the belts. In the final part 11 pregnant women in the third trimester participated. The selected belt type was worn for 14 days except for sleeping. The endopelvic fascia is the soft tissue surrounding the vagina. It is attached to the pelvic walls and supports the pelvic viscera - urethra, bladder, cervix, uterus and rectum. Because the fascia is a relatively shape-complicated organ and its various parts are exposed to different mechanical loading, it can be reasonably assumed, that their mechanical properties will vary according to the appropriate field. Regarding the complex structure of the endopelvic fascia, some strength tests through its whole length are difficult to perform. The research is then focused on the areas where the fascia is relatively accessible and where some of its parts can be removed during standard surgeries without causing any inconvenience for patients. The main monitored parameters are elasticity and viscosity, which are represented by the identifiable proteins (e. g. collagen, elastin, etc.) and their mutual arrangement.

Our current work has mainly targeted the issue of long-term postnatal complications in terms of biomechanics, which are largely caused by the processes occurring during birth. The specific goal of the research was the endopelvic fascia and its properties in relation to its

### 14 Injury and Skeletal Biomechanics

intimate relationship to the vaginal mucosa. The changes occurring during birth are also characterized by the greater or minor damaged of tissues. It may also results in a functional failure of the pelvic floor. The damage usually has a multifunctional character and also diverse consequences, however, they are never beneficial for the health of the patient.

The Women's Pelvic Floor Biomechanics 15

FP P F F F F, (2)

K . l K . l K . l, FP <sup>P</sup> <sup>F</sup> (3)

K K K p FP F (4)

*KP KF KFP* 

where *FFP* is the force detected by the measuring head of the device, *FP* is the reaction force

given by properties of the vaginal wall and *FF* is the force from endopelvic fascia.

Using the formula (1), the equation (2) can be arranged to the next shape:

and after rearrangement, the relation for rigidity of the vaginal wall is obtained:

Regarding the data obtained from the performed experiments, this relationship can be used to calculate the rigidity of the vaginal wall at the moment of its rupture, when the rigidity of

For each dependency between the force and extension (figure 10), several particular

The yellow marked area in figure 10a is the record of the cyclic "preload" of the sample in order to stabilize its mechanical properties. The slight vacillations of measured curves (figure 10b, red marked area) showed that the prolongation without the further presumed force increase may be interpreted e.g. as moments, where some minor damages had happened in the tissue without influence on overall stability of tested sample's response. The major breakthrough in the sample response's course was the vaginal wall rupture (figure 10b, yellow marked area). The following graph course (figure 10b, area 8 and 9) was then formed only by the endopelvic fascia response. The moment of the vaginal wall rupture and also endopelvic fascia rupture was well detectable even on the synchronous

The curve (figure 10b) was further divided into the particular sections with a linear character, which were assigned rigidities characterizing the vaginal wall with endopelvic fascia as a whole (figure 10b, areas 1 to 7) and rigidities of the endopelvic fascia separately

**Figure 9.** The tissue structure layout chart.

**vaginal wall endopelvic fascia** 

the separated endopelvic fascia is known.

video recording of the experiment.

magnitudes of the rigidity of the used model were obtained.

The birth is initiated by uterine activity which leads to the gradual extending of the lower uterine segment and cervix. The mechanism of the expansion is allowed by the muscular cell organization. At each contraction the uterus is straightened to the middle line. The uterus is fixed by the suspensory apparatus (especially uteroingvinal chorda) so the fundus is limited in its movement. In the distal direction, the uterus is fixed by sacrouterine ligaments, the muscles and ligaments of the pelvic floor and by its insertion of the vagina. Thanks to the experience that is based on the above mentioned facts, the birth duration and complications, and the other well-known factors it is possible to predict the injury of related tissues and organs. The main recognized causes include injuries such as problematic vaginal birth, chronic increase of the intra-abdominal pressure (obesity, coughs), aging and changed mechanical properties of the suspensory apparatus including the endopelvic fascia.

The mechanical properties of the fascia have been investigated only very marginally and there is still a lack of the valid biomechanical characteristics in world literature. Due to the development of surgical techniques that replace the endopelvic fascia by allogen implants that often result into over rigid spare septa. That is the main reason to increase the knowledge of the mechanical properties of autogenous tissues. From the medical point of view, the biomechanical approach is irreplaceable. Because of the continuing "material disagreement" between the operated tissue and the implant, the foreign material is often refused, which is rather a question of immune response and this can be pharmacologically suppressed. A more serious problem is often the unclear response of the implant to mechanical loading. This is the main factor that influences the success of the surgery, because complicated thermo-visco-plasto-elastic properties of living tissues cannot be substituted by a purely mechanical replacement.

Within the latest phase of our research, 16 samples of vaginal wall with fascia were measured by standardized uni-axial tensile test to determine their "referenced" properties. Next, 6 samples of the implants were measured by the same procedure. The following text presents the proposed and used methods of processing and evaluating of the measured data. At the end, the obtained findings associated with the monitored parameters such as pregnancy, number of completed pregnancies and age of the donor women are listed.

For description of observed materials, we used the linear elastic modulus, which is defined by following formula:

$$\mathbf{F} = \mathbf{K} \, . \,\mathrm{d}\mathbf{l}\,\mathrm{d}\,\mathrm{s}\tag{1}$$

where *K* is stiffness (rigidity) (N/mm), *F* force (N) and *Δl* relative extension (mm).

Regarding the real organization of both tissue structures in the samples (figure 9), we created a complete model of the tested samples by parallel junction of two rigidities, which can be described by the following equation of the force balance:

$$\mathbf{F\_{FP}} = \mathbf{F\_{P}} + \mathbf{F\_{F'}} \tag{2}$$

where *FFP* is the force detected by the measuring head of the device, *FP* is the reaction force given by properties of the vaginal wall and *FF* is the force from endopelvic fascia.

**Figure 9.** The tissue structure layout chart.

14 Injury and Skeletal Biomechanics

intimate relationship to the vaginal mucosa. The changes occurring during birth are also characterized by the greater or minor damaged of tissues. It may also results in a functional failure of the pelvic floor. The damage usually has a multifunctional character and also

The birth is initiated by uterine activity which leads to the gradual extending of the lower uterine segment and cervix. The mechanism of the expansion is allowed by the muscular cell organization. At each contraction the uterus is straightened to the middle line. The uterus is fixed by the suspensory apparatus (especially uteroingvinal chorda) so the fundus is limited in its movement. In the distal direction, the uterus is fixed by sacrouterine ligaments, the muscles and ligaments of the pelvic floor and by its insertion of the vagina. Thanks to the experience that is based on the above mentioned facts, the birth duration and complications, and the other well-known factors it is possible to predict the injury of related tissues and organs. The main recognized causes include injuries such as problematic vaginal birth, chronic increase of the intra-abdominal pressure (obesity, coughs), aging and changed

diverse consequences, however, they are never beneficial for the health of the patient.

mechanical properties of the suspensory apparatus including the endopelvic fascia.

substituted by a purely mechanical replacement.

by following formula:

The mechanical properties of the fascia have been investigated only very marginally and there is still a lack of the valid biomechanical characteristics in world literature. Due to the development of surgical techniques that replace the endopelvic fascia by allogen implants that often result into over rigid spare septa. That is the main reason to increase the knowledge of the mechanical properties of autogenous tissues. From the medical point of view, the biomechanical approach is irreplaceable. Because of the continuing "material disagreement" between the operated tissue and the implant, the foreign material is often refused, which is rather a question of immune response and this can be pharmacologically suppressed. A more serious problem is often the unclear response of the implant to mechanical loading. This is the main factor that influences the success of the surgery, because complicated thermo-visco-plasto-elastic properties of living tissues cannot be

Within the latest phase of our research, 16 samples of vaginal wall with fascia were measured by standardized uni-axial tensile test to determine their "referenced" properties. Next, 6 samples of the implants were measured by the same procedure. The following text presents the proposed and used methods of processing and evaluating of the measured data. At the end, the obtained findings associated with the monitored parameters such as pregnancy, number of completed pregnancies and age of the donor women are listed.

For description of observed materials, we used the linear elastic modulus, which is defined

Regarding the real organization of both tissue structures in the samples (figure 9), we created a complete model of the tested samples by parallel junction of two rigidities, which

where *K* is stiffness (rigidity) (N/mm), *F* force (N) and *Δl* relative extension (mm).

can be described by the following equation of the force balance:

F K . l, (1)

Using the formula (1), the equation (2) can be arranged to the next shape:

$$\mathbf{K}\_{\rm FP}.\mathrm{\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm}}\,+\,\mathbf{K}\_{\rm P}.\mathrm{\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm}\,+\,\mathbf{K}\_{\rm F}.\mathrm{\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm\rm}\,\mathrm{\rm\rm\rm\rm\rm\rm\rm\rm}\,\tag{3}$$

and after rearrangement, the relation for rigidity of the vaginal wall is obtained:

$$\mathbf{K}\_{\rm p} = \mathbf{K}\_{\rm FP} - \mathbf{K}\_{\rm F} \tag{4}$$

Regarding the data obtained from the performed experiments, this relationship can be used to calculate the rigidity of the vaginal wall at the moment of its rupture, when the rigidity of the separated endopelvic fascia is known.

For each dependency between the force and extension (figure 10), several particular magnitudes of the rigidity of the used model were obtained.

The yellow marked area in figure 10a is the record of the cyclic "preload" of the sample in order to stabilize its mechanical properties. The slight vacillations of measured curves (figure 10b, red marked area) showed that the prolongation without the further presumed force increase may be interpreted e.g. as moments, where some minor damages had happened in the tissue without influence on overall stability of tested sample's response. The major breakthrough in the sample response's course was the vaginal wall rupture (figure 10b, yellow marked area). The following graph course (figure 10b, area 8 and 9) was then formed only by the endopelvic fascia response. The moment of the vaginal wall rupture and also endopelvic fascia rupture was well detectable even on the synchronous video recording of the experiment.

The curve (figure 10b) was further divided into the particular sections with a linear character, which were assigned rigidities characterizing the vaginal wall with endopelvic fascia as a whole (figure 10b, areas 1 to 7) and rigidities of the endopelvic fascia separately

### 16 Injury and Skeletal Biomechanics

(figure 10b, areas 8, 9). Applying the above formulas, the rigidity of the vaginal wall can be calculated.

The Women's Pelvic Floor Biomechanics 17

According to the measurement curve analysis and comparison of calculated rigidities the

1. The vaginal wall endures lesser prolongation compared to the endopelvic fascia. This conclusion is valid for all our experiments performed so far, independently on patient

2. Samples rigidity increases with deformation and after reaching maximum decreases while heading for the rupture (figure 11). The curve has a concave characteristic and it

**Figure 11.** Rigidity – prolongation relation of fascia + vagina complex (an example).

3. After the vaginal wall rupture the rigidity of the endopelvic fascia decreases with increasing deformation. This decrease can be considered linear with satisfying

From the current results it can be concluded that the endopelvic fascia has relatively stable properties that are changed significantly only in pregnancy and stabilized again after it. In terms of long-term changes associated with a decrease of mechanical properties of the fascia the crucial parameter is the age of a woman. The number of completed pregnancies exhibits

The processing and evaluating of the data from the second phase of the experiment corresponded to the methods described above. The data were arranged into graphs (figure

12) and the dependence of rigidity on extension of the samples was evaluated.

following can be stated:

anamnesis.

precision.

no significant influence.

is visible on all tested samples.

**Figure 10.** Measurement record (a) and evaluated section (b).

According to the measurement curve analysis and comparison of calculated rigidities the following can be stated:

16 Injury and Skeletal Biomechanics

**Figure 10.** Measurement record (a) and evaluated section (b).

calculated.

(figure 10b, areas 8, 9). Applying the above formulas, the rigidity of the vaginal wall can be


**Figure 11.** Rigidity – prolongation relation of fascia + vagina complex (an example).

3. After the vaginal wall rupture the rigidity of the endopelvic fascia decreases with increasing deformation. This decrease can be considered linear with satisfying precision.

From the current results it can be concluded that the endopelvic fascia has relatively stable properties that are changed significantly only in pregnancy and stabilized again after it. In terms of long-term changes associated with a decrease of mechanical properties of the fascia the crucial parameter is the age of a woman. The number of completed pregnancies exhibits no significant influence.

The processing and evaluating of the data from the second phase of the experiment corresponded to the methods described above. The data were arranged into graphs (figure 12) and the dependence of rigidity on extension of the samples was evaluated.

The Women's Pelvic Floor Biomechanics 19

The comparison of the graphs 12a and 12b shows that the response of samples of vaginal wall with the endopelvic fascia and samples of used implants is similar. The question is, whether these values of the implants rigidity are convenient for their purpose. A reliable answer to this question tasks for an extensive study, however, it must be fulfilled that the implant should compensate for the differences between rigidity of the healthy and damaged

*Charles University, FSPE, Department of Anatomy and Biomechanics, Prague, Czech Republic* 

This work has been supported by grants from the Grant Agency of the Czech Republic

Atkinson, B., Stirling, C., Sukhtankar, A. *Gait Differences Between Pregnant and Non-pregnant* 

Bird, A.R., Menz, H.B., Hyde, C.C. The effect of pregnancy on footprint parametres. A prospective investigation. In *Journal of the American Podiatric Medical Association,* 1999,

Butler, E. et al. An investigation of gait and postural balance during pregnancy. In *Gait &* 

Foti, T., Davids, J.R., Bagley, A. A Biomechanical Analysis of Gait During Pregnancy. In

Golomer, E., Ducher, D., Arfi, Gs., Sud, R. A study of pregnant women while walking and while carrying a weight. In *Journal de Gynecologie Obstetrique et Biologie de la* 

Kovalčíková, J. *Dynamika chrbtice a statika panvy žien počas fyziologickej gravidity*. Bratislava :

Kušová, Sabina. *Dynamika vybraných parametrů axiálního systému gravidních žen a žen do jednoho roku po porodu*. Praha, 2004, 230 s. Disertační práce na FTVS UK, Katedra

Lymbery J.K., Gilleard, W. The Stance Phase of Walking During Late Pregnancy. In *Journal of* 

Karel Jelen, František Lopot, Daniel Hadraba and Martina Lopotova

*Women* [on-line]. ©1996, last revised 9/99 [cit. 2008-03-20].

*Journal of Bone and Joint Surgery,* 2000, vol. 82-A, no. 5, p. 625-632.

Univerzita Komenského v Bratislavě, 1990. ISBN 80223-0208-2.

anatomie a biomechaniky. Vedoucí práce Doc.Karel Jelen, CSc.

*the American Podiatric Medical Association*, 2005, vol. 95, no. 3, p. 247-253.

*Institute of the Care of Mother and Child, Prague, Czech Republic* 

tissues.

**Author details** 

Hynek Herman

**4. References** 

**Acknowledgement** 

provided for the period 2010-2013.

vol. 89, no. 8, p. 405-409.

*Posture*, 2006, vol. 24, no. 2, p. S128-S129.

*Reproduction*, 1991, vol. 20, no. 3, p. 406-412.

**Figure 12.** a) Measurement record and rigidity; b) prolongation relation of the implant.

The comparison of the graphs 12a and 12b shows that the response of samples of vaginal wall with the endopelvic fascia and samples of used implants is similar. The question is, whether these values of the implants rigidity are convenient for their purpose. A reliable answer to this question tasks for an extensive study, however, it must be fulfilled that the implant should compensate for the differences between rigidity of the healthy and damaged tissues.

### **Author details**

18 Injury and Skeletal Biomechanics

**Figure 12.** a) Measurement record and rigidity; b) prolongation relation of the implant.

Karel Jelen, František Lopot, Daniel Hadraba and Martina Lopotova *Charles University, FSPE, Department of Anatomy and Biomechanics, Prague, Czech Republic* 

Hynek Herman *Institute of the Care of Mother and Child, Prague, Czech Republic* 

### **Acknowledgement**

This work has been supported by grants from the Grant Agency of the Czech Republic provided for the period 2010-2013.

### **4. References**


Moore, K., Dumas, G.A., Raid, J.G. Postural changes associated with pregnancy and their relationship with low-back pain. In *Clinical Biomechanics*, 1990, vol. 5, no. 3, p. 169-174.

**Chapter 0**

**Chapter 2**

**Locomotion Transition Scheme of**

Tadayoshi Aoyama, Taisuke Kobayashi, Zhiguo Lu, Kosuke Sekiyama,

There are researches aiming to give a high environmental adaptability to robots. Until now stable locomotion of robots in complex environment such as outside rough terrain or steep slope has been realized [1–7]. Locomotion in the most of researches adapted to complex environment has been realized by single type of locomotion form. On the other hand, we have proposed Multi-Locomotion Robot (MLR) that can perform several kinds of locomotion and has high mobility as shown in Fig. 1 [8]. By using MLR, we have realized independently biped and quadruped walking, brachiation, and climbing motion so far [9–15]. Next research issue of MLR is to develop a systematic transition system from one locomotion form to the

Aoi et al. proposed transition motion from biped to quadruped walking by changing the parameters of the nonlinear oscillator and conducted experimental verification [16, 17]. These works focuse on realization of a stable motion transfer and the transition according to external environment has not been discussed. Meanwhile, Asa et al. discussed the dynamic motion transition using the bifurcation of control parameters and realized motion transition between biped and quadruped walking [18]. These conventional researches aimed to realize a motion transfer between biped and quadruped walking. The transition motion of control system is constructed by using the Central Pattern Generator (CPG); the motion transfer of is realized

On the other hand, we aim to select suitable motion pattern for robots based on external environment and internal state of the robots and realize motion transfer from current motion to the other. In this chapter, we focus on biped and quadruped walking as motion patterns and report the suitable motion selection between biped and quadruped walk considering the walking stability and efficiency. Motion and recognition uncertainty is focused as factors to effect a realization of walking; then walking stability is evaluated from stability

and reproduction in any medium, provided the original work is properly cited.

©2012 Aoyama et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0),which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly

© 2012 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

**Multi-Locomotion Robot**

Yasuhisa Hasegawa and Toshio Fukuda

http://dx.doi.org/10.5772/49997

by attractor transfer mechanism.

cited.

**1. Introduction**

other.

Additional information is available at the end of the chapter

Osman, N.A., Ghazali, M.R. Biomechanical evaluation on gait patterns of pregnant subjects. In *Journal of Mechanics*

#### **Chapter 0 Chapter 2**
