Pregnancy Flashcards
Changes in the centre of gravity
As your baby grows as pregnancy progresses, there is more weight in front of the centre of gravity.
– meaning the posterior chain has to work harder, putting it under more stress, to maintain an upright standing position
– this puts the facts, discs, ligaments and muscle under more pressure
The abdomen will have to expand a lot, putting pressure and stretch through the fascial structures like the lines alba and the semilunaris.
Changes in spinal curves and how the body adapts during different trimesters
12 weeks
– thoracic spine kyphosis increases
—- due to increased anterior weight (breasts become bigger)
– flexion affects discs
– reduced lumbar spine lordosis
—- due to a posterior pelvic tilt that is caused by a shortening of the rectus abdominalis
– affects discs more due to a flatted lordosis, so the spine is slightly more flexed
– compromised TOS
– increased sacral counternutation
– baby is the size of a grapefruit
—- uterus rises above the pelvic rim
Anterior musculature:
– rectus abdomens shortening, which may cause the posterior rotation of the pelvis
– anterior hip muscles need to be stretched
24 weeks
– CSP lordosis increases
– expanding uterus and displaced viscera produce pressure underneath as it elevates up
—– so the TSP needs to extend
– TSP
—- kyphosis increases due to increased anterior weight
—– lower ribs are displaced and need to expand laterally
—– distal sternum elevates
—– TOS may be present due to the viscera being pushed up and there is 1st rib dysfunction
– pelvis still rotated posteriorly, just starting to rotate anteriorly
– so lumbar lordosis still reduced, however anterior rotation of the pelvis will cause an increased lumbar lordosis again
30 weeks
– 80% of women develop a lordotic posture
—- approximating the facets causing facet irritation
– there will be altered head carriage (may be thrown back or forward), to help with posture
– increased kyphosis TSP
—- due to enlarged breasts, belly having more weight
—- this can play a part in the increased lumbar lordosis as well
—- strain at the CT junction
—- thoracic inlet compromisation
– deep lumbar lordosis
—- anterior pelvic rotation and increased TSP kyphosis plays a part in this
—– stretch through the rectus abdominals (60% of cases rectus diastases occurs)
—- there is pubis strain in 89% of cases in 2nd or 3rd trimesters
Pelvis:
– anterior rotation
– increased sacral nutation
– coccyx needs to flex
Hips:
– widened pelvis, leads to lateral rotation of the hips
– leading to an altered orientation of the knee and feet
– leading to a waddling gait
40 weeks
– pelvis rotated posteriorly, so lumbar spine flattened
Fluid dynamics
Pregnancy can affect venous return
How supine position affects the inferior vena cava:
– the positioning of the foetus tends to obstruct venous return, this is due to the uterus compressing the inferior vena cava, reducing sometimes more than 80% of blood flow in the inferior vena cava
– the pregnancy uterus can also partially block the aorta leading to a reduction of about 30% in blood flow through the aorta
Pregnancy is the leading cause of varicose veins:
– women blood during pregnancy usually becomes hypercoagulable (increased tendency to stick together and form clots)
– vein wall tension can decrease leading to the stagnation of blood and this paired with hypercoagulability can predispose women to varicose veins
Internal support- ligaments of the uterus
Form a sling and support the uterus and bladder
Hypermobility vs instability, the role of relaxin
Hypermobility- where someone has a larger range of motion in a joint than normal.
– pts that are pregnant are hyper mobile, can be very difficult to treat. Hypermobile patients should avoid doing yoga.
Instability- where tissues, such as muscles, ligaments and bones weaken. Once they are weak, they no longer hold the bones of the joint in proper place.
Role of relaxin:
– hormone only produced during pregnancy.
– its role is to increase flexibility of the ligaments during pregnancy to help open up the pelvis during labour.
—- it alters the properties of cartilage and tendons by activating collagenase
– 89% of pubic synthesis disorders occur in the 2nd and 3rd trimesters
– peak production at 12 weeks
– relaxin can cause ligament laxity within the body, this may cause instability at certain joints. For example, if there is ligament laxity within the spine it can cause instability at segmental levels of the facets, or the vertebrae
How neurology can be affected by pregnancy
Myalgia parasthetica, due to its position it can be caused by compression on the lateral femoral cutaneous nerve
Sciatic irritation (maybe due to tight muscles due to a tight posterior chain) may cause the sciatic nerve to be compressed (piriformis syndrome)
Spinal curves
Increased TSP kyphosis (due to anterior weight)
– posterior stretching of the discs, leading to an increased likelihood of herniation
– rib head facets are displaced leading to joint surface irritation
Increased CSP lordosis (due to increased TSP kyphosis, so the head orientates itself upwards)
– approximates the facets, leading to an increased likelihood of facet dysfunction
Decreased LSP lordosis (12 weeks, due to posterior pelvic tilt)
– puts facet capsules on stretch, also puts more pressure on discs, leading to an increased likelihood of herniation
Increased LSP lordosis (30 weeks, due to anterior pelvic tilt):
– approximates the facets, leading to an increased likelihood of lumbar facet dysfunction
ligaments
Relaxin causing ligamentous laxity, which can lead to instability at a vertebral level.
Leads to increased range of movement at joints and increased joint irritation.
May also lead to pubic symphysis problems
Muscles
Muscles of the posterior chain have to work harder due to increased anterior centre of gravity.
Increased muscle tone due to ligament instability
Both lead to increased muscle fatigue and chronic pain
Vascularity
Decreased venous return due to pressure on the inferior vena cava due to positioning of the foetus
– worse in the supine position
Reduced blood pressure
Increased likelihood of heamorhoids
Increased chance of varicose veins
Neurology
Myalgia parasthetica due to increased pressure on pelvic bowl, which puts pressure on the lateral femoral cutaneous nerve (L2, L3).
Sciatica due to increased tone and tightness of posterior chain muscles
– especially the piriformis muscle, illiciting sciatic symptoms
Relaxin
Hormone that is only released during pregnancy, intends to increase ligament flexibility in order to open up the pelvis to make it easier for the mother and baby
Increases ligament flexibility by changing the properties of ligaments by releasing collegenase.
Can cause increased ROM and lead to ligament instability at a vertebral level
Ligaments of the pelvic floor
Pubocervical ligament
Inguinal ligament
Transverse cervical ligament
Uterosacral ligament
Retrovaginal septum
Hypermobility and pregnancy
They may be difficult to treat
They may have restrictions in the thoracic spine, with increased tension in the ES muscles to try and stabilise the hyper mobile segments
Hypermobile patients should avoid doing yoga- as they are already mobile enough
Hypermobility vs instability
Relaxin can cause instability of the joints
Hypermobility- having unusual or abnormal ROM at a joint
Instability- When tissues around the joint weaken meaning they cant hold the joint in place properly so they weaken
Hypermobility:
– multiple joints involved
– visceral symptoms
– chronic pain for 3 months
– recurring episodes of pain in the same area
– exercise can improve or exacerbate pain
Instability:
– single joint involved
– pain may resolve itself in days
– no visceral symptoms
