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Structural changes during pregnancy Presentation Title Presentation title (Date)

Explain correct posture and how to transfer safely and effectively between different postural positions and during different daily activities Explain the structure and detail the structural changes that occur in the spine and pelvis Explain the muscle, ligament and bone density implications of the ante state Lesson objective

Weight Gain • Average total gain: 12-13 kg / 27-30 lbs Activity 1 • In small groups label the weight distribution diagram given to you by your tutor • 5 minutes

Activity 1 • Group 1 - Explain what is meant by correct posture and consider the effect pregnancy may have on correct posture? • Group 2 - What effect does pregnancy have on the pelvis and what effect does gravity have on pregnancy? • Group 3 - What effect does pregnancy have on muscles, which lengthen, which shorten?

Posture • Feet approx hip distance apart • Feet comfortably placed, distributing weight evenly between feet • Knees slightly bent • Locate a neutral pelvic position • Bring shoulder blades down and closer together, lifting rib cage away from hips • Lengthen back of neck, chin at right angles to shoulders & looking straight ahead

Effects of Pregnancy on the Spine • Centre of gravity changes • Abdonimal muscles Lengthen & weaken • Reduced support for the spine • Increased ligament & intervertebral disc elasticity • Increased lordosis • Increased kyphosis

Centre of gravity shifts downwards & outwards Lumbar lordosis increases Thoracic kyphosis increases Effects of Pregnancy on Posture

Correct Posture Dependent on: • Flexibility in: • hip flexors • hamstrings • pectorals • lower back • Strength in: • gluteals • abdominals • upper back

The Pelvis • 4 bones: • 2 hip bones • sacrum • coccyx • Each hip bone consists of 3 fused bones: • ilium • ischium • pubis

All fixed (fibrous) joints Front - symphysis pubis (pain) gap 4mm pre-pregnancy (up to9mm during pregnancy) Back - sacroiliac allows for slight forwards, backwards & sideways movements when spine flexes or extends Joints of the Pelvis

Muscle, Ligament & Bone Adaptations to Exercise (non pregnant population) • Muscle mass increases • Force & velocity of contraction increases • Improved muscle co-ordination • Increased ligament strength • Increased bone density

No research to suggest force or speed of muscle contraction is any different throughout pregnancy. Muscle mass & strength increase in response to weight gain. Specific increase to lower body muscles Abdominal muscles become stretched, thinned and weaker as a result. Other postural muscles may become shortened as a result of poor postural adaptation. Muscle Adaptation when Pregnant

Muscle lengthens width ways & separates Muscles ability to contract weakens Can separate at the linea alba (diastasis recti) Effects of Pregnancy on the Rectus Abdominus

Centre of gravity changes stretches ligaments supporting pelvis, hips and lower back leading to decreased mobility & increased mechanical stress. Release of relaxin loosens ligaments throughout pregnancy & up to 6 months postnatal. Ligament Adaptation to Pregnancy

Maternal bone mineral density is maintained Maternal bone turnover increases Calcium absorption through intestinal walls increases Bone Adaptations when Pregnant

Muscle, ligament & bone adaptations to exercise during pregnancy Results do not appear to be additive with respect to: • lean muscle mass • remodeling • bone density • Regular weight bearing exercise should have positive effect on: • muscle strength & tone • improve posture, abs & back strength • mechanical stress from centre of gravity changes & back pain

Postural awareness and correction can be the single most important skill a pregnant woman can learn. Discomfort and pain around the pelvis should be addressed through alternative positions, exercises and referral to health professionals when persistent Muscle function and bone density remains unaltered, whilst ligaments loosen during pregnancy Summary

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