1. MUSCULOSKELETAL CHANGES
ASSOCIATED WITH PERINATAL PERIOD.
BY
AMRIT KAUR

2. MUSCULOSKELETAL CHANGES DURING
PREGNANCY
One of the most obvious changes
in pregnancy is the alteration of
the woman's body. Mechanical
changes related to the weight of
growing breasts, uterus and
fetus, as well as an increase in
lumbar lordosis, result in a shift
in the woman's center of gravity,
which may cause problems with
balance.

3. • Pregnancy wt. gain - 9 to 14kg.
• Stretching of abdominal muscles
• Decrease in ligamentous tensile strength.
• Hyper mobility of joints due to ligamentous laxity.
• Pelvic floor drops as much as 2.5 cm
• COG shifts upwards & forwards.
• posture – shoulder girdle becomes rounded,
scapular protraction,
increase in cervical lordosis.
knee hyperextension.
increase in lumber lordosis.
balance – pt. walks with wider BOS.

4. NEUROMUSCULAR AND ARTICULAR
RELATIONSHIP
• The musculoskeletal system is composed of 3 sub
systems- the muscular, articular and neural
system.
• Changes in degree of passive restraint offered by
the collagenous tissue surrounding the
articulation.
• Oestrogen causes proliferation of connective
tissue and that relaxin acts to provide
vascularization and softening of this connective
tissue.
• Increase in joint laxity in multiple joints during
pregnancy.

5. • Such a changes in passive restraint of any joint
is bound to have significant influences on the
afferent input to the to the spinal cord and
higher cortical centers.
• Muscle stiffness is also reduced, leading to
decrease in muscle responsiveness to
pertubations.
• Increase in articular pressure, sometimes
pinching of articular capsule.
• Proprioceptive acuity of hypermobile joints is
having lesser sensitivity than normal.

6. • Injury of the capsule and /or ligament influences
muscle activity not only in the muscle which cross
the injured joint, but also in those which are
remote from it.
• Interruption of the flow of impulses from the
mechanoreceptor in a joint capsule into central
nervous system result in clinically evident
disturbances of the perception of joint position and
movement and of the reflexes concerned with
posture and gait.
• The arthrokinetic reflex might be considered as a
triggering factor which would initiate a whole chain
of adaptation reactions, eventually resulting in a
changed movement pattern .

7. POSTURAL CHANGES ASSOCIATED
WITH PREGNANCY
• The most obvious physical features in pregnancy
influencing the women's posture are the
alterations in body mass and the consequent
changes in the center of gravity.
• The physiotherapist must place emphasis on
directing and training women to ensure that their
newly assumed posture does not overstress any
body segment since the outcome of this could be
fatigue , micro trauma and pain.

8. • There is tendency to an increased anterior
displacement of the line of gravity
• This natural tendency to anterior displacement may be
counterbalanced by a number of options such as
increased activation of gastrocnemius and soleus
muscle, an active posterior displacement of the body
,extension of hip joint or posterior displacement of
upper trunk.
• The mechanism that may be used to achieve an active
posterior displacement of the body may include
increase of the lumbosacral angle, and increase in
lumbar curvature or a displacement of pelvis anteriorly
and shoulder posteriorly, which may be reflected in
greater degree of thoracic kyphosis.

9. SPINAL INSTABILITY DURING
PREGNANCY
3 subsystems
• Control subsystem –neural feedback from various
forces and motion transducers, located in
ligaments, tendon and muscles, and neural
control centers.
• Passive subsystem –vertebrae, facet
articulations, inter vertebral discs, spinal
ligaments and joint capsules.
• Active subsystem- muscles and tendons
surrounding vertebral column .

10. • In pregnancy there is rapid change in passive
sub system, due to the change in circulating
hormones.
• Possible cause for spinal instability is either
increase ROM not restrained by the passive
subsystem (the neutral zone) or a decrease
control in this area by the active subsystem.
• In either situation , a portion of the normal
range of motion is not controlled and this may
lead to increased shear forces, micro trauma
and pain.

11. SPINAL PAIN DURING PREGNANCY
CAUSES
• Weight gain
• Rapid postural changes
• Vascular effects
• Previous h/o back pain
• Repetitive lifting /banding
• Pelvic insufficiency due to hormonal changes

12. 3 major region
• Pain above lumbar region only
• Pain in lumbar region with or without
radiation to one or both legs.
• Pain over the sacroiliac area sometimes with
radiation to the legs.

13. BIOMECHANICS OF THE BODY
• Biomechanics includes the bones and muscles, and how
they work together to make the body move. The brain
receives a continuous supply of information about the
changing posture of the pregnant body and eventually
accepts the altered arrangement and balance of body parts.
Feedback from the skin, joints, and muscles are involved in
this process. By the end of pregnancy, the brain has re-
configured its image of the body in balance.
• The major changes that occur with respect to biomechanics
include:
• The change in the center of gravity as the baby grows in size
during the second half of pregnancy.The center of gravity
changes from the center of the pelvis with surrounding body
weight evenly distributed in all directions to a point forward
and slightly up from the center of the pelvis. The increased
weight positioned forward of the pelvic midpoint causes
forward gravitational pull.

14. • Movement of joints due to changes in weight distribution.
• Balance of muscle strength changes around the joint to
accommodate the new weight distribution. To compensate for
the forward gravitational pull, the posture changes to
maintain a balanced erect position. The back of the waist
curves in, the top of the pelvis tilts forward and the curves in
the upper spine increase. These changes put stress on
muscles and joints.
• Spinal curves increase, placing a greater load on the
vertebrae.
• Joint laxity causes a greater risk for injury. Hormone changes
(increased levels of relaxin and elastin) that affect the
looseness of ligaments and tendons make the joints more
mobile. Although this helps with the birth of the baby, it can
stress joints and muscles during movement.
• There can be more structural discomfort such as low back
pain.
• There is increased potential for nerve compression and blood
vessel entrapment, such as sciatica or carpal tunnel
syndrome.

15. Uterus and uterine ligaments
• In pregnancy, the uterus grows to a weight of about 2.5
pounds and has a capacity of approximately 1.5 to 2.5
gallons. It enlarges through the stretching of muscle fiber to
the size of a watermelon. The muscle fibers lengthen 7-11
times and widen 2-7 times. It also increases the number
and size of its blood vessels and nerves.
• After the first trimester (first 13 weeks of pregnancy), the
uterus begins to prepare for labor and delivery by
contracting involuntarily and irregularly. These are called
Braxton-Hicks contractions. They are: prelabor contractions
that work toward shortening and widening the cervix and
stretching the bottom of the uterus ,soften the cervix and
prepare it for labor
• usually are not painful but can be uncomfortable
• In labor, the uterus contracts with increasing frequency and
intensity and pushes the baby through the birth canal.

16. • The uterine ligaments hold the uterus in place
and undergo prolonged stretching during
pregnancy.
• The round ligaments attach the uterus to the
pubic bone in the front and help maintain the
uterus in the center of the pelvis. Either a sharp
pain or a dull ache near the hip joint is common
when they are stretched upward.
• The broad ligaments connect the uterus to the
sacrum and are often involved in backaches
during pregnancy. Pain in the low back is the
result of weak abdominal muscles, poor posture,
and the weight of the abdomen pulling on the back
ligaments.

17. MUSCLE CHANGES
• As the uterus enlarges the abdominal muscles
are stretched. The top layer of the abdominal
muscles are the rectus abdominal muscles.
They run from the rib cage to the pelvic bone.
As the abdomen gets larger these muscles
can separate. This abdominal muscle
separation is called a diastasis, and can lead
to a loss of abdominal strength.
• Strectching of pelvic floor muscles.
• Some muscle will go for tightness, some will
be lengthen.

18. • Overstretching and weakening of gluteal
muscles and hamstrings (buttocks and back
of leg).
• Overstretching and weakening of abdominal
muscles and pelvic floor muscles.
• Overstretching and weakening of upper back
muscles (shoulders forward).
• Shortening and tightening of hip flexor
muscles.
• Shortening of upper back flexors and
pectoral muscles (chest caves in).