Paediatric Musculoskeletal Development

Intro

And it really is all about this muscle pull and the movement patterns that we participate in throughout growth and development that cause these changes to happen. e expect these muscles to activate in appropriate ways that cause us to have the alignment we do as adults.

trunk

normal: rounded rounded kyphotic spine. We expect to see that. Their rib cage is actually very rigid and barrel-shaped. So their ribs are actually really highly elevated and their ribs are actually perpendicular to their spine. ibs that are at this 90 degree angle with their spine

2 years: old what happens is the sternum, the ribs will actually depress and develop an angulation in relation to their attachment with the spine. And it will also go from this kind of rounded barrel-shaped to a little more oval in its appearance. So there's this lateral expansion that happens to other ribs. o you have this diaphragm that is going to pull the ribs down at its attachment points with breathing. And also our intercostal muscles that are going to help with lateral expansion of our ribs- as a child is sitting for longer periods of time, as they're standing, as they're walking, that force will actually act on the ribcage to cause depression. When you start to have increased use of obliques, when kids are starting to climb and crawl and sit for periods of time, those muscles are going to pull down on the ribs. So all of these developmental actions that we see in typically developing children will cause the rib cage to go from this very rounded perpendicular barrel-shape into a much more oblong with depressed rib shape.

abnormal: ut let's say you have a child that isn't doing those things, it's not typically developing. We are more likely to see them have this persistence of this sort of barrel-shaped rib cage with ribs perpendicular to spine. Because they're not having that appropriate loading due to external gravitational forces and those internal forces from muscle pull and from breathing.

upper trunk: extension from prone push up, posterior chain muscle activation; sitting, posterior chain activation; crawling-co-contraction: o as these muscles pull and activate over time, infants are going to go from this very kyphotic position to a much more neutral spine- abnormal: can actually see a change in this spine position because of abnormal muscle pulls.

lower trunk:increased thoracic spine extension, we're also going to see increased lumbar spine and hip extension over time originally they start with this kind of rounded pelvis with this posterior pelvic tilt. And then as they start to sit and stand and play and activate this posterior chain and activate their core muscles, what we see is that originally they're going to have this anterior pelvic tilt and it's going to increase just a little bit. So at 12 months of age, we expect to see that a child will have around eight to 12 degrees of an anterior pelvic tilt. When they get to 30 months up to age three, you're going to see a continued increase in that anterior pelvic tilt to around 15 degrees. And then from there, as the glutes are able to engage more, we will see that that anterior tilt decreases a little bit through around the age of eight years old. At which point they'll be at about an adult angle, which is around 10 degrees of an anterior pelvic tilt.

lower extremity: lower extremity. So here, what you'll see are some norms. So at birth, we expect that infants should have around a 34 degree hip extension limitation. . As they spend time in prone and they're moving and they're activating their posterior chain and they're in this prone press position, they're going to stretch out that anterior capsule. So by six weeks we'll see that that decreases to 19 degrees of a hip extension limitation. And then really, we're at about seven degrees throughout toddlerhood.

You'll also see that they have a hip adduction limitation at the time of birth. And then as they grow and mature and start to ambulate, we'll see that they're able to bring their leg in and across their body much more. Normalising into the thirties and 20 degrees as they continue to grow and develop through toddlerhood. We see that when infants are born, they have a lot more external rotation and this decreases over time. And that they have this slight limitation in their knee flexion at time of birth with a popliteal angle of 27. And then by five years they should be able to get their knee straight when their hip is flexed at 90 degrees

LE norm: hip: flexion, abduction and lateral rotation, knee: flexion, genu varum, medial rotation of tibia; ankle: dorsiflexion, slight pronation

hip

o in the newborn we expect to see an increased angulation of the hip where it goes in the socket. So increased coxa valga between 140 and 160 degrees in the newborn. That decreases some in the adult to around 126 degrees as an average. We also see a change in the way that the femoral shaft is twisted. o that hip flexion contracture that we have at time of birth we talked a little bit about this. So this iliofemoral and ischiofemoral ligament on the anterior aspects of the hip are tighthis prone position and they continue to kind of push we will actually see those structures start to stretch out.

knee

So that knee flexion contracture as they can get hands to feet and stretch out is really going to allow them to reduce that knee flexion contracture over time.