Pelvic Girdle Pain

Pelvic Girdle Pain (PGP).

What PGP is, its cause and treatment.

PGP is an umbrella term for pain originating from and presenting around the pelvis, see pictures below for pain distribution. It used to be called SPD (symphysis pubic dysfunction), but this was a term incorrectly suggesting that only one joint is involved. PGP is a subcategory of lumbopelvic pain, which can present in both men and women and generally arises in relation to pregnancy, trauma, arthritis or osteoarthritis (Vleeming et al., 2008).

Picture from: https://pelvicpartnership.org.uk/what-is-pgp-symptoms-of-pgp/

Risk factors for developing PGP during pregnancy are a history of previous low back pain (LBP) and/or trauma to the pelvis. It can occur separately or in conjunction with LBP, and is mostly referred to as a pregnancy related condition, however, it can continue into or start during or after giving birth.

The symptoms may be noticeable during everyday activities, but are worse when walking, standing on one leg (e.g. when putting trousers or socks on or walking up and down the stairs), movement with your legs apart (e.g. when getting in or out of your car or a bath), or turning in bed. The level of pain can vary from mild to extreme.

It is estimated that 1 in 5 women (20%) experience PGP during their pregnancy (Vleeming et al., 2008). It is quite common, BUT NOT NORMAL, and should be raised as soon as the symptoms start with your midwife, GP or a health visitor.

Historically, PGP was believed to be hormonally driven, and women were incorrectly advised to “bear with the pain” as it would go away post labour. Although the majority of women recover spontaneously soon after labour, approximately 20% report pain lasting for years post-birth (in Stuge et al., 2017). This “traditional” approach, when women are given advice, painkillers, belts, crutches and wheel chairs without hands-on treatment results in a cascade of issues. These include unnecessarily prolonged pain and fatigue during pregnancy, inability to care for their family, becoming housebound and socially isolated, and dependant on others. There is also psychological distress, leading to deteriorating mental and physical wellbeing, affecting not only the woman but also her whole family.

Although the current research acknowledges that hormonal changes play a role in this process, PGP is now widely understood to be a mechanical issue, and as such, the large majority of cases can be treated with manual therapy.

The Royal College of Obstetricians and Gynaecologist recommend manual (hands-on) therapy as a treatment method for PGP. This should be performed by physiotherapists, osteopaths or chiropractors who specialise in PGP in pregnancy (RCOG, 2015). If the NHS route is not available, or your appointment is too far in the future, you can always opt to go privately.

Talk to your midwife, GP or a health visitor for an appropriate referral. They will discuss your symptoms with you and once other causes are excluded, they will refer you to women’s health physiotherapist. Other potential issues that they will consider include gynaecological, urological, gastrointestinal, musculoskeletal, neurological, psychological and other causes, such as abuse.

Late treatment can prolong recovery time, increase the number of treatments needed, and increase the need for pain relief. The aim is not only to prevent PGP from worsening, but to relieve it quickly and definitely. Relief will help leave you pain free going into labour, as women with PGP are more likely to be considered for induced labour, which is unnecessary for PGP alone. Research suggests that induction may be less efficient and more painful than spontaneous labour, with epidural analgesia and assisted delivery more likely to be required. When induced using pharmacological methods, about 15% of women have instrumental births (foreceps/ ventouse) and 22% emergency caesarean sections. Induction therefore has to be clearly clinically justified (NICE, 2008).

PGP can be especially problematic for women who are on the hypermobility spectrum or have been diagnosed with hypermobility Ehlers-Danlos Syndrome (hEDS). These women are 3 times more likely to develop PGP (in Pezaro et al., 2018).

One cause of PGP is Diastasis Symphysis Pubis, when the joint at the front of your pelvis separates more than 1cm. This can be a complication in pregnancy as well as during and after labour. Other processes that need to be considered include degenerative, metabolic, genetic and biomechanical factors (in Verstraete et al., 2013). And in some cases, PGP can result from how the baby lies in utero and exerts pressure on some abdominal/pelvic structures. Again, these structures can be worked on with manual therapy to offer relief. If you are experiencing PGP in your first pregnancy, you are in a higher risk for your future pregnancies, but that doesn’t correlate with its intensity.

How the female body changes and how Osteopathy can help.

The female body goes through an incredible series of changes during pregnancy. The baby is growing every day in the uterus, which grows upward and outward in the abdomen rearranging organs to the sides, changing the centre of gravity to the front and creating a larger curve in the lower back. The breasts are also enlarging, creating further weight on the front and therefore increasing tension in the upper body and upper back and neck. In some women these changes can lead to thoracic outlet syndrome, causing symptoms in their arms, hands and fingers. At the same time, there is an increase in hormones that enable the tissues to go through such changes, such as relaxin and progesterone.

Rest assured, a woman’s body has the ability to adapt to the physiological changes during pregnancy. These changes affect your body from your feet all the way to the neck and how you hold your head. However, there can be residual effects from earlier injuries, which your body could not resolve fully but managed to compensate for well so that you felt you recovered. Now that your body has to adapt to new demands within a relatively short period of time, it may be struggling a little. It could also be as simple as that you lifted a shopping bag in an unfavourable position or angle, sat in a chair at work for too long, or slept awkwardly and created some tension or imbalance in your pelvis that your body cannot resolve by itself, and that is just getting worse.

Being an Osteopath with special training in women’s health, I find that there are no two women with PGP who have exactly the same cause. Some women I only treated once and they were pain free for the rest of their pregnancy, although most needed between 3-5 treatments. On some occasions I treated them regularly throughout their pregnancy, such as those with shift work and physically demanding jobs. Sometimes, women book because their NHS appointment is in some weeks in the future and they want to relieve the pain immediately.

The first appointment is 70 minutes long, I will be asking questions about your concerns and your medical history, including your general health, accidents, injuries, operations, etc. You may be asked to dress down to your underwear at the start of the examination, please feel free to bring shorts and a vest to change into for your comfort. A physical examination will follow consisting of some guided active and passive movements and hands-on palpation. I will examine your feet, knees, hips, pelvis, pelvic floor (externally only) and lower back on your first appointment.

We will then discuss my findings. I will explain how I can help and over what period of time, outlining a treatment plan and any possible side effects. Once agreed and consent is given, you will also be treated. I will refer you to another specialist if necessary.

After the treatment, you will be given some advice on what you can do to help yourself and what to avoid (see below). I am likely to give you some exercises later, but that will only take place once I am happy that your body is well balanced and it is appropriate to start strengthening. For this reason, I will not be covering exercise in this article.

What you can do.

This section provides helpful tips on how to manage your symptoms doing everyday tasks. But I must stress, it does not replace manual therapy, which addresses the cause of your pain.

Rest & pacing - Stay active but also acknowledge your limits. This means that you might have to sit down more often, change activities regularly to avoid sitting or standing for longer periods of time, or leave some tasks for the following day. Avoid activities that aggravate your symptoms, and always ask yourself “Does this really have to be done today?”. Most of the time, it doesn’t, it is just the pressure women tend to put upon themselves. Generally, you need to be mindful and really concentrate on what works for you and what doesn’t.
No standing on one leg - Sit down when putting underwear, socks, trousers, skirt, or shoes on. Avoid any activity that involves you standing on one leg. This can get challenging when you have stairs in the house. When your PGP is severe, you might have to take one step at a time, rather than walking the stairs as you were used to. The advice is to go upstairs with your less painful leg and downstairs with the more painful one, or go upstairs backwards, or on your bottom.
Help & housework - You will need help, please don’t be afraid to ask for help from your partner, friends, family, neighbours. Especially when it gets to “normally easy” tasks such as vacuum cleaning, getting the groceries into or out of the car, general housework, and childcare. If finance is not an issue, pay for the services when you can, order groceries online and have them delivered. If you do have to carry anything, ensure you have the weight evenly distributed and carry bags in both arms.
Lifting - Avoid bending, twisting, and lifting anything heavy, such as shopping or wet laundry. If you already have a child, you may find it helpful to train your child to climb on you whilst you’re sitting for a cuddle rather than lifting them up to you. Pushing a pram up the hill or a heavy shopping trolley should also be avoided.
Sitting - When sitting upright, you can use a small pillow or towel to support the curve in your lower back. Please see the link in the “Further Resources” section below for pictures demonstrating the movement/positioning advice described in this article. Keep your legs hip width apart, no wider, with your pelvis neutral. Sitting on a Swiss ball can be more comfortable than a chair, but notice if you are "gripping" around the ball, if you are, you may need to use the stabilising stand that comes with it to prevent you gripping. Avoid sitting on very soft surfaces, such as sofas and armchairs, as well as sitting on the floor with your legs straight in front of you, or crossing your legs, whether knees or ankles.
Knees together - Keep your knees together, for example when getting in and out of your car. You can put a plastic bag on the seat and then swivel with your knees together into the car in a single movement. The plastic bag must then be removed, otherwise you risk an injury during sudden breaks. If you only have a bath or a shower in your bath, a similar principle applies; try to keep your knees together, even better if your partner can help you. When getting in your bed, sit down first, and lower yourself onto your side while bringing your legs up at the same time. On getting out of bed, shuffle towards the edge of the bed while lying on your side, and lower your legs over the edge at the same time as you push yourself up with your hands. Ideally, all "bracing" movements would be performed on an out-breath, engaging your pelvic floor/ abdominal/ core muscles at the same time for support.
Driving – Limit the time you spend driving, especially in a manual car. Driving an automatic car is easier, so if you have a choice from a company or family car that is an automatic, use that one.
Planning - Plan your day ahead and if there are stairs in the house, you can bring everything down in the morning in a backpack so that you make the fewest possible trips up and back down the stairs.
Sleeping - Ensure you use enough pillows to support you at night, between your knees and ankles, behind your back, etc. Play with them to find the right support. Something that worked last week may need to change this week as your body is also changing. When turning in bed, keep your knees together (see point 6.). Consider buying a satin bed sheet and/or pyjamas, or fold a silk scarf and put it under your abdomen/pelvis/ hips so that it helps you glide rather than drag your hips when turning in bed. Satin is certainly more affordable than silk. It may take you a couple of nights to get used to the new sliding sleeping experience.
Sex - Try positions during sexual intercourse that do not involve your legs being apart, such as the “spoon” position, ideally with a pillow between your knees for support. Being on all fours or kneeling with your upper body being supported on a sofa or a bed might also be more comfortable. Play with positions, communication with your partner is key, and let’s not forget that intimacy may not always need to involve penetration. If you find sexual intercourse painful for reasons other than PGP, please consult your healthcare professional. As for PGP, painful intercourse is common but NOT normal, and needs to be addressed.
Support belts - The NHS generally recommends the TubiGrip support belt, but I have no clinical experience with it. The support belt recommended by many manual therapists is the Serola belt. I have had a number of patients test the original Serola and similar alternatives and the feedback was always the same: the Serola belt provided the best support. It comes in different sizes and I found their staff very helpful with sizing and ordering. Belts are only to be worn during activities to support you during the most demanding times, not when sitting or lying down or resting. I never suggest that you wear a belt before you receive manual therapy, after which your body is more balanced and tension released. Misuse can lead to more irritation or general muscle weakness, which is the opposite of what we are trying to achieve. https://appliedbiomechanics.co.uk/pregnancy/
Bump wrapping - A temporary relief can also be achieved with bump wrapping. Again this is helpful when you are really struggling and you need extra support. This might be before you find an experienced manual therapist, before the treatment starts having the desired effect, or towards the very end of your pregnancy. I can recommend Madeline Boot from Sheen Slings who is a sling specialist, she provides Zoom appointment and feedback from my patients has always been wonderful. For a tutorial on how to wrap your bump, have a look at the following video #9 Pregnancy Support on her website.
Kinesiotape - An experienced manual therapist can also apply Kinesiotape as an extra support. The tape can last for about 3-4 days before it should be taken off or comes off by itself. You can shower with it so it doesn’t need any extra care. I teach my patients how they can apply it themselves between treatments as they find it very helpful. Tape is not suitable for all and some women can have a skin reaction to it. If you experience uncontrollable itching, please take it off immediately.
Other aids & occupation therapy - Severe symptoms should be preventable with early diagnosis and treatment with manual therapy. But should your PGP become severe, your NHS physiotherapist should be able to provide you with crutches or a wheel chair. Also, your NHS physiotherapist or GP should refer you to an occupational therapist (you can also request this), who will help you adapt your home, provide advice and suggest aids to help with everyday tasks.
Exercise - Exercise during pregnancy is very important. From my clinical experience, women who were doing regular exercise prior to pregnancy and maintained their exercise routine during pregnancy usually recovered quicker than those who did not. Swimming front crawl is suggested rather than breast stroke which puts extra pressure on the hips and pelvis, and on the whole spine if goggles are not used. But simply walking in the water, aquanatal classes (there are classes held at the Pickaquoy Centre), or hydrotherapy are a great form exercise for women during pregnancy. Some women report that cycling on an easy gear is asymptomatic, but be mindful when getting on and off your bike and do remain seated, don’t stand up cycling as it creates strain on your pelvis. Pregnancy yoga with an experienced practitioner is also recommended- Sara from Orkney Bump to Baby Support https://www.orkneybumptobabysupport.com/yogarelaxationservices. Abdominal breathing exercises with awareness on pelvic floor are also very useful, but it is best to discuss these with an experienced practitioner or at least follow a reputable online tutorial if you have no direct access to face-to-face advice. Maintaining good muscle tone and strength during pregnancy is vital even without PGP.
Pain & acupuncture - Acupuncture is recommended for pain management alongside manual therapy. In Orkney, we have Bel from Five Element Acupuncture who is an acupuncturist working in women's health. She's a member of the Acupuncture for Childbirth Team down south working in the field of fertility including IVF support, pregnancy & postpartum care. She's been attending many births over the past 20 years as a "Doula with needles". https://www.facebook.com/westoxfordacupuncture
Pain & medication - For pain management with medication, please consult your GP as some medications can cause harm to you and/or your foetus at different stages of pregnancy. For example prolonged use of NSAIDs (non steroidal anti-inflammatory drugs such as Aspirin, Ibuprofen or Naproxen) during early pregnancy can increase the risk of miscarriage and congenital malformations. In late pregnancy, they increase the risk of premature closure of a structure related to foetal heart circulation, which is a medical emergency (Antonucci et al., 2012). This is not to scare you, but to make sure that you do not self-medicate during pregnancy with over the counter medication. On the contrary, some women have conditions that require long-term use of anti-inflammatories, and taking them helps with carrying the pregnancy to full-term. You can also look at BUMPS (Best use of medication in pregnancy) at https://www.medicinesinpregnancy.org/Medicine--pregnancy/
Pain & cold/heat – cold and heat packs are seen as a safe method for managing pain, however cold/heat therapy safety has not been researched in pregnant women. I advise on cold/heat therapy only once I have assessed and treated the patient. In general terms, cold treatment reduces inflammation and heat promotes blood flow and helps muscles relax. But we have to remain cautions, and you should NEVER put a cold/heat pack on your abdomen. Always wrap your pack in a tea towel or similar material before application and ensure that you have full skin sensation in the area prior to application. Leave on the affected area for 5-10 minutes, do not exceed 10 minutes at a time. Heat – hot water bottle, wheat pack or jelly heat pack applied over muscles in your back, buttocks, or thighs. Some prefer a hot shower directed on the affected area. Cold – jelly ice pack applied over irritated and inflamed joints; leave about 2 hours between applications.
Hypermobility & hEDS – Those on the Hypermobility spectrum or diagnosed with hEDS (hypermobility Ehlers-Danlos Syndrome) should seek healthcare providers with interest or experience in their condition. Should you have difficulties finding someone, please print the research paper by Perazo et al. (2018) below and give a copy to your provider. The content will help you understand all major factors of your condition in relation to pregnancy, labour and recovery and should help you assess your situation and make informed decisions about your care.https://www.magonlinelibrary.com/doi/pdf/10.12968/bjom.2018.26.4.217 It is also worth reading ‘A midwife’s guide to pregnancy, birth, feeding and EDS’ on the EDS Support UK website for further considerations: https://www.ehlers-danlos.org/information/a-midwifes-guide-to-pregnancy-birth-feeding-and-eds/
Anxiety & depression - Prolonged pain and fatigue may lead to anxiety and have a negative effect on mental wellbeing. Anxiety and depression during pregnancy and post-natally is a complex topic that requires more in-depth consideration, please refer to my next article on Postnatal Depression for further details. For practical advice to support your mental health, please visit my second article Postnatal Depression Part II.
Birth plan - In preparation for labour, ensure that all practitioners involved and your birthing partner(s) are aware of the fact that you suffer from PGP (or hEDS), this also needs to be clearly noted in your birth plan. There is currently no evidence that elective C-section is indicative for PGP alone. If natural birth is your choice, you will not need to be induced because of PGP before your due date - as explained above it is likely to lead to further interventions. But the benefits and risks of both modes of labour are best to be considered with your midwife or obstetrician, taking into consideration your personal needs, preferences, and circumstances. Whichever you choose, when possible ask for a room that is near the toilets or has an en-suite, so that if you have any complications during delivery, you do not have to walk far to use the facilities.
Pain free range - Ensure that you know your “pain free range”, which is how far you can spread/separate your knees before pain starts. Knowing this range is important as if you are given analgesia or have an epidural, you may not feel any pain beyond this range but it can cause more damage in the long-term; your knees should not be separated beyond this range during labour. When your legs are separated, such as for vaginal examination, assisted delivery or stitching (unless there are complications, your midwife/ or obstetrician should be able to do these side-lying), ensure that they are brought up together into the position and then are kept symmetrical and comfortable, not exceeding the pain free range. If you are sitting to push DO NOT put your feet up on your midwife’s or partner’s hips or allow anyone to pull your legs in any direction either.
Labour positions - Ideally you would take the advantage of gravity during labour in your positioning, such as staying upright, kneeling, or on all fours. Side-lying may also be comfortable with appropriate support of your upper leg. But lying on your back should be avoided (unless it is necessary for your or your baby’s safety) as it restricts the natural pelvic opening during labour and tends to slow labour. Water birth is reported to be another helpful way of giving birth. But your midwife or obstetrician should take this into account, as long as they are aware of your PGP; you may need to remind them. Some parents may opt for hiring a doula for this extra support. To see what doulas do, see https://doula.org.uk/. Sara, from Orkney Bump to baby is also a qualified doula https://www.orkneybumptobabysupport.com/doulaservices. You might also find helpful to have a look at ‘Tell me a good birth story’ website, which is a website set up by an experienced doula Natalie Meddings http://www.tellmeagoodbirthstory.com/.
The fourth trimester - After giving birth, women enter their “fourth” trimester. This is the time when all women need extra support, let alone in cases of persistent or returning PGP. It is the custom of many countries around the world that the mum and baby are looked after by their families during that time. Unfortunately, in the current society, we tend to live in different cities, countries and sometimes continents, which makes this impossible. Should your pain persist or return, please continue with your manual therapy and consult your midwife and GP. All the above measures apply post-partum. But most importantly, rest, you just brought a new life into the world.
Caring for a new born - When caring for your new born, try not to bend or twist when lifting your baby. Change her/his nappies on a high (but safe) surface at waist height, or ask your midwife to teach you how to do it on your lap. When bathing, prepare everything you need at arm’s reach beforehand. If you can, bathe your baby at waist height so you don’t have to bend at all, such as in a sink or basin, or in a bath bucket placed in your kitchen sink, or bath tub on the kitchen counter. Always follow safety measures, such as non-skid strips or mat under the tub, and never leave your baby unattended, even for just one second. If you have your partner at home at the same time, you can arrange to take a bath with your baby and have some skin-to-skin time or feed at the same time.
Feeding - For feeding (whether breast or bottle), refer to the sitting principles above (point 5.), make sure you are comfortable and well supported. Ideally, you will have visited your nearest feeding support clinic before you give birth. There are weekly feeding support sessions in Kirkwall where you'll be supported by Lou Brewer, a health visitor and Infant feeding specialist, and also by a team of peer supporters, who had their own breastfeeding journey and attended additional training in feeding support, as well as by other mums. Sadie and Sarah are also available for feeding support at Home-Start Orkney. You can also work with IBCLC certified consultant via Zoom, to find a consultant see https://www.lcgb.org/find-an-ibclc/. I used to work with Anna Page and I am very happy to recommend her, you can contact her directly on [email protected] or 07963 800 243. Lastly, you can also follow some consultants on Facebook, such as Lucy Webber Feeding Support - IBCLC (formerly LMJ Infant Feeding Support) or Lucy Ruddle IBCLC. If you have an unsettled baby, please read my article on Unsettled baby.
Carrying your baby - Women are advised not to lift and carry their baby as much as possible. This can be very difficult advice to follow, not only from an emotional point of view but also if the baby is unsettled and requires contact, or needs to be upright because of reflux. In this case, slings and front carries can help. Contact your local Sling Library - Sadie from Home-Start is managing our one in Orkney. For a Zoom fitting session, you can contact Madeleine form Sheen Slings - she will check if your sling is being used correctly in relation to your baby’s age, hip development and your own posture and comfort https://sheenslings.com/.
Car seats - When you lift and carry your baby, keep her/him as close to you as possible, especially when getting her/him in or out of their cot or a car seat, for which it would be best to get assistance. Keep your car seat on the table, so that you do not need to bend down to the floor getting your baby in or out. If you are seeing me for treatment, ask me to show you how to handle a carseat, hopefully I will add a video here soon. I will not cover prams or pushchairs, as designs, weight and accessibility vary too much, but all the above-mentioned principles in relation to posturing apply.
Slow increase of activity - It is a good idea to gradually increase your level of activity within your pain free limit. You can start doing some gentle breathing exercise soon after birth, but I will not be discussing these here as they are woman specific and you can hurt yourself if you start too early. Especially, avoid high impact activities for some weeks and even months to come, or any activities exacerbating your symptoms. Ensure that your home is safe and clutter free so you prevent falls, trips and slips.
Breathing – Don’t forget to breathe. Breathing is taken for granted, but breathing awareness is very important. Whenever you are about to move, such as stand up from sitting, lifting your baby, or turning in bed, try to do it on your outbreath only. First breathe in, become aware of your pelvic floor and your abdominal muscle, and then undertake the actual movement on an outbreath whilst engaging your muscles.

This is not an exhaustive guide, and I encourage you to use the further resources below.

Further Resources.

The Pelvic Partnership is a wonderful UK charity that provides a lot of information and support for women with PGP. They provide extra tips and the information is based on feedback from thousands of women.
https://pelvicpartnership.org.uk/

You can also find a list of practitioners in the UK, who work with women with PGP. The list only contains practitioners who were recommended by women whom were helped with PGP by those practitioners:
http://pelvicpartnership.org.uk/list-of-recommended-practitioners/
A list of osteopaths, who completed a 2-year postgraduate diploma in women's health can be found here:
https://www.molinari-institute-health.org/news

This link has demonstrations on movement and positioning, please do have a look.
http://brochures.mater.org.au/brochures/mater-mothers-private-brisbane/pelvic-girdle-pain-physiotherapy-hints-to-relieve

And lastly, a short information leaflet by the Royal College of Obstetricians and Gynaecologists for women with PGP. https://www.rcog.org.uk/globalassets/documents/patients/patient-information-leaflets/pregnancy/pi-pelvic-girdle-pain-and-pregnancy.pdf

If you have any comments or recommendations in relation to my articles, please do get in touch, your feedback is always appreciated.

Please note that the above is only general information and is not intended to diagnose, that can only be done after a detailed case history and examination. The information is accurate at the time of writing in May 2020 with minor updates due to location change in March 2023. I have no financial or other interests in any of the practitioners or products mentioned above.

References.

Antonucci, R., Zaffanello, M., Puxeddu, E., Porcella, A., Cuzzolin, L., Pilloni, M., D. & Fanos, V. (2012). Use of Non-steroidal Anti-inflammatory Drugs in Pregnancy: Impact on the Fetus and Newborn. Current Drug Metabolism, 13 (474).

Bergström, C., Persson, M., & Mogren, I. (2014). Pregnancy-related low back pain and pelvic girdle pain approximately 14 months after pregnancy - pain status, self-rated health and family situation. BMC pregnancy and childbirth, 14 (48).

NICE, National Institute for Health and Care Excellence. (2008). Clinical Guideline CG70: Inducing Labour. NICE: Manchester.

Pezaro, S., Pearce, G., & Reinhold, E. (2018). Hypermobile Ehlers-Danlos Syndrome during pregnancy, birth and beyond. British Journal of Midwifery, 26(4), 217-223.

RCOG. Royal College of Obstetricians and Gynaecologists. (2015). Information for you: Pelvic girdle pain and pregnancy. RCOSG: London.

Stuge, B., Krogstad, H. & Grotle, M. (2017). The Pelvic Girdle Questionnaire: Responsiveness and Minimal Important Change in Women With Pregnancy-Related Pelvic Girdle Pain, Low Back Pain, or Both. Physical Therapy, 97(11), 1103–1113.

Tinkle, B., Castori, M., Berglund, B. et al. (1017). Hypermobile Ehlers–Danlos syndrome (aka Ehlers–Danlos syndrome Type III and Ehlers–Danlos syndrome hypermobility type): Clinical description and natural history. Am J Med Genet C Semin Med Genet, 175(1), 48-69.

Verstraete, E. H., Vanderstraeten, G., & Parewijck, W. (2013). Pelvic Girdle Pain during or after Pregnancy: a review of recent evidence and a clinical care path proposal. Facts, views & vision in ObGyn, 5(1), 33–43.