Postural lumbago in pregnancy analysis of a technical aid

Postural lumbago in pregnancy: analysis of a technical aid by Fabio Scoppa and Franziskus Vendrame Abdominal supporters for pregnant women serve the main purpose of reducing the intensity of rachialgia which may arise from modification (due to pregnancy) of the mechanical and articular balance of the system involving the pelvis, sacrum and lumbar section of the spine. The increase in body weight and the volume of the abdomen make the body barycentre move forward, consequently causing a forward thrust of the trunk and anteversion of the pelvis, increasing lumbar lordosis and causing a more marked inclination angle of the sacral plate than normal. The sacrum-iliac articulation adapts to the new situation by nutation (fig. 1). Such adaptations can cause pain due to an increase in the force of rotation on the lumbar articular facets and the sacrum-iliac articulation, stretching of the stabilizing ligament system and phenomena of general discopathy linked to an increase in intradisk pressure. Pregnancy and back pain The aspects described above have been, and still are, the subject of in-depth studies12 ; from an analysis of these contributions, many of which with very long follow-up, it can be seen how back pain increases considerably during pregnancy. In a study by Ostgaard, Zetherstrom and Roos-Hansson2 362 pregnant women were examined; of these 351 were seen three months after childbirth and 303 as many as six years after giving birth. Fig. 1 During pregnancy the body’s centre of gravity moves forward, due to the progressive increase in volume of the abdomen and breasts. To offset this lack of balance pregnant women tend to accentuate their lumbar lordosis by thrusting their head and trunk backwards. The diagram shows the alteration in lordosis during pregnancy. (from Medicina e Salute, vol. 8, Edi. Ermes). The study shows that 18% of the women suffered from lumbago before pregnancy, 71% during pregnancy and 16% six years after giving birth. Those who suffered the most from back pain during pregnancy seem to suffer longer and more intensely also in the period following childbirth. Back pain is specific during pregnancy but not during the postpartum period, when it is defined “common backache”. During pregnancy posterior pelvic pain in the sacroiliac crests involved 47% of the women, whereas episodes of pure sciatica, with exact dermatomic reference occurred only in 1%4-5. Ostgaard’s studies3-5 show other points as the origin of pain, as for example those occurring in the pubic symphysis; however, these are not considered statistically significant. Further elements that could cause back pain in pregnancy appear to be youth and the practise of physically demanding activities, as well as physical and psychological factors. In the end, it is clear that backache in pregnancy is prevalently mechanical and that many women suffer from it. Fig. 2 Abdominal supporter: the blue oval highlights the support given by anterior action (new concept), whereas the red square shows the type of containment actuated by transversal action (Filian and Lebeurier’s concept). Effectiveness of abdominal corsets A Canadian study by Filion and Lebeurier 6 analyses the methods commonly used to solve the problems caused by back pain during pregnancy: administration of medicines, physiotherapy, postural and corrective exercises, massage, joint mobilization and manipulation, use of elastic belts and corsets, rest and bed (table 1). All these can alleviate back pain in pregnancy; good results are obtained especially with the use of abdominal corsets by women in whom the pain causes functional handicaps and limits everyday activities. Table 1 Methods for the alleviation of back pain in pregnancy analysed by Filion and Lebeurier6 √ Administration of medicines √ Postural and corrective exercises √ Physiotherapy √ Massage √ Joint mobilization and manipulation √ Elastic belts and corsets √ Rest – bed and abdominal supporters The corset designed by Filion and Lebeurier is like a panty belt that wraps round the abdomen; real abdominal support is provided by a reinforcing belt that lies over the iliac crest and adheres to the lumbar region with comfortable silicon reinforcement. Bibliographic research to find other studies that verify the effectiveness of abdominal corsets shows that most of the contributions available merely express generally favourable opinions of the use of supporters in pregnancy (recommendations for grade D, EBM). The only studies with a certain scientific importance are those carried out by Weber, Thomas, Ostgaard and Berg, and show a reduction of pain due to the use of ortheses with unspecified elasticity. There are many types of abdominal corsets, but they are all inspired by a single model, which is the one used in the study by Filion and Lebeurier. A new concept for corsets: a supporter Our abdominal supporter is distinguished from those described above in that it comprises two parts: an under part, structurally and functionally similar to the commonly used corset, and a top part which is shaped like a bodice. The two parts are connected to each other at the front sides by two Velcro straps (fig. 2). Unlike the traditional supporter, our abdominal supporter has an auxiliary bodice to use over the final months of pregnancy, when the weight of the belly begins to increase. Weight is an extremely important variable: current abdominal supporters are very useful, but their effectiveness is limited when the volume and weight of the belly grows significantly. Pregnant women in the final weeks of pregnancy refer that a corset does not support the belly as effectively as it did in the previous weeks. The top bodice solves the problem when used at this stage (and until the end of the pregnancy): it assures antigravitary support from the shoulder joints. The idea of a bodice involving the scapulohumeral girdle to support the belly arises from the results of the previously mentioned studies: if back pain in pregnancy is felt mainly in the rear part of the pelvis (and is therefore of mechanical origin), it is preferable to use a mechanical type of support that is more effective than current corsets, the main purpose of which is to support the belly. Reduction of gravitary load on the belly The action of the bodice is to reduce the gravitary load on the belly by producing a thrust upwards and back in order to raise and push back the body barycentre. In this way the sacral plate tends towards its original physiological value, with a reduction in nutation of the sacroiliac joints, which is the main source of rear pelvic pain. This also causes a reduction in lumbar lordosis and spondylosic load on the rear articular facets. Weight on the lumbar intervertebral discs is also distributed more naturally (Fig. 3). Fig. 3 Supporter structure 1. front support belt 2. elastic rear part reinforcement 3. bodice 4. bodice shoulder straps 5. Velcro 6. end of belt 1. with silicon Weight distribution on both shoulders The main objection to this type of supporter is that it could cause excessive pressure on the shoulder joints. Actually, the bodice does not involve the scapulohumeral articulations directly because it wraps around the shoulders, involving the top part of the back. In this way the load is distributed on both shoulders, without specially involving the scapulohumeral joints and without creating obstacles for normal kinetics (Fig. 4). Fig. 4 Abdominal supporter with bodice: the rear view clearly shows distribution of the load on both shoulders. It will be useful to carry out thorough research in order to define more carefully the work done by the muscles that stabilize the scapula from the back and the anterior loads on the sterno-costo-clavicular system. Reduction of sliding forces With our type of supporter axial load on the spine increases, as does the work of the back and lumbar muscles: in any case these muscles are very strong and are therefore able to support an increase in the axial load. There is also likely to be greater involvement of the paravertebral and multifid muscles, which are important stabilizers especially in the lumbar region. In any case there is a reduction in the forward-sliding forces in the region of the lumbar vertebrae. The cyrtosis action of the rectus abdominis muscle and the belly load on the spinal area is offset by the wide back belt and the lower lateral position of the corset shoulder straps (Fig. 5). Fig. 5 Abdominal supporter with bodice: the wide back belt and the lower lateral position of the shoulder straps offset the cyrtosis action of the rectus abdominis muscle. Taking the strain off abdominal muscles The rectus abdominis muscle tends to curve the bust forward, the transverse muscle increases intra-abdominal pressure and the oblique muscles are the true lateral ‘containers’ of the belly. In this context, the supporter should not activate the abdominal muscles, but support the belly in a ‘neutral’ way. The supporter, therefore, has an important role because it substitutes the rectus abdominis muscle without activating it and without involving the transverse muscle of the abdomen. Also important is the possibility to regulate the tension of the corset shoulder straps to maintain a suitable ratio between support and muscle activity. The shoulder straps also aid the action of the oblique muscles, so improving belly containment. Aesthetic and proprioceptive effects Our abdominal supporter, apparently more voluminous than the more common supporters, has been well accepted by the pregnant women who have worn it: many of them reported that they felt better and perceived greater support and protection for the belly. This may contribute to better sensorial perception and acceptance from the aesthetic point of view of the transformations the body undergoes in pregnancy, reducing pain symptoms also with a placebo effect. Table 2 Use of abdominal supporter * Effects on the experimental group EFFECT Greater support Diminished pain Disappearance of pain PERCENTAGE OF SUBJECTS 22.2% 33.3% 44.5% * Worn for an average of 6.5 hours a day. Investigations with an experimental group and a control group For the purpose of assessing the effectiveness of our abdominal supporter, an investigation was carried out which showed correspondence of the data presented in a study by Ostgaard14 : 24% of the subjects investigated suffered from lumbago, both before pregnancy (43% episodes) and during pregnancy (68%), with 20% episodes of bedridden patients. With regard to the types of pain suffered in pregnancy (measured by the VAS scale), 65% of patients suffered pain in the lumbar region and 48% in the pelvic region (pubalgia). Only 20% of the subjects was asymptomatic. In any case, pain before pregnancy affects pain and ‘postural autonomy’ also during pregnancy. As a solution to the pain, lateral decubitus has been suggested. The investigation was carried out on an experimental group made up of seven pregnant women, five of whom attended during pregnancy by the Obstetrics Dept. of Conegliano Hospital and two by a private structure. The patients were between the 36th week and the end of pregnancy and had been prescribed the abdominal supporter. As a control group, 15 pregnant women were chosen from those attended by the Obstetrics Dept. of Vittorio Veneto Hospital. The patients were between the 28th and 40th week of pregnancy and had not been advised to use supporters or body belts. Both groups were given a questionnaire aimed at checking the pain- killing effects of using the supporter in pregnancy, whereas only the patients in the experimental group underwent a check by stability measurement test analysis on the postural effects of using the supporter. Stability measurement test analysis Stability measurement test analysis was carried out by Romberg position tests in three series of two tests: one with open eyes and one with closed eyes. The first series took place without the supporter, the second with the full supporter and the third with just the under part of the supporter. The following indices were assessed: - bundle surface; distance covered by pressure centres; front-rear movements on the abscissa axis (x); lateral movements on the ordinate axis (y); Romberg index. Results – with regard to the results obtained, the following observations apply: bundle surface (smallest surfaces): three patients without the supporter, two with the full supporter and two patients with the under part of the supporter. distance from pressure centres (least distance): five patients without the supporter and two with the full supporter. front-rear movements: without the supporter, five patients moved their pressure centres towards the forefoot; with the full supporter five patients moved their pressure centres towards the back of the foot; lateral movements (symmetrical lateral movements): three patients with the full supporter, three patients with the under part of the supporter, none without supporter; for the other two patients there was no variation; Romberg index: the index was within the reference parameters (100 and 250) for three patients without the supporter, six patients with the full supporter and two patients with just the under part of the supporter. Although this was a preliminary investigation, the antalgic effect of using the supporter (Table 2) was shown, notwithstanding the lack of a real comparison with the use of other similar items. Furthermore, any relationship to gynaecological problems (e.g. hypercontractility of the uterus) has yet to be demonstrated. Once the supporter was worn, it gave a deep sensation of comfort in all the women. An evident proprioceptive influence and mechanical effect on posture was also found: alteration of posture necessarily arising from an increase in weight and body volume, with the body’s barycentre and podalic pressure centres pushed back, reequilibrium of the lateral oscillations of pressure centres and improvement in postural perception (Romberg index progress). STABILITY MEASUREMENT TEST ANALYSIS Romberg test – the subject stands on the stability measurement platform with the forefeet approximately 30° apart and the eyes on the horizon for 51”2’ (standard time used by the computer to gather the data). Bundles – graphic rendering of pressure centre movements, read by sensors placed inside the stability measurement platform. Distance covered by pressure centres – unwinding of the bundle. expressed in mm. The lower the value the better the result. Generally - - - Romberg index – relationship between the surface of the bundles obtained with patients with closed eyes and the surface of the bundles obtained with patients with open eyes: the figures between 1 (or 100%) and 2.5 (or 250%) are to be considered within the standard. Coadjuvant against pain From medicine and anatomy we learn that the morphological transformation of women during pregnancy causes a physiological biochemical defence response, such as, for example, greater elasticity of the aponeurosis and ligament tissues following an increase in hormone stimulation and production. It must not be forgotten that pregnancy and childbirth are absolutely natural states that the female organism is physiologically able to withstand in normal conditions. This does not alter the fact that during pregnancy back pain is more common, due mainly to mechanical factors. There are many ways to face the problems of vertebral pain in pregnancy. The use of abdominal supporters may generally help to relieve pain through three factors: mechanical reduction of the load on the sacrum-iliac joints, the main source of rear pelvic pain; effect on the spinal erector muscles, which are subjected to a sort of ‘passive exercise’. increased sensation of protection for the foetus and belly by means of a proprioceptive effect. Fabio Scoppa Scientific and didactic co-ordinator Master in Posturology Università degli Studi “La Sapienza”, Rome Franziskus Vendrame Kinesiologist Conegliano Veneto (TV)