Prone kneeling: strength, coordination, stability and balance requirements

Typically developing infants will usually learn to transition from prone lying or sitting into prone kneeling (quadruped position) over a period of several weeks.

This experience allows them to acquire the basic strength, coordination, stability  and control of balance needed for sustaining the position when they lift one hand to reach for a toy and start to experiment with different ways of moving forwards:

UE strength: ability to support the weight of the upper body with the shoulder in flexion and elbow in extension without locking the elbows into hyperextension.

Trunk and neck muscle strength to maintain stability as the limbs are moved. 

UE flexibility: flex the shoulders to about 900 degrees, with the elbow extended and extend the wrists to close on 900 , with the neck in extension and some capital flexion. 

HIp flexibility: 90 plus degrees of flexion, along with hip adduction and rotation to neutral. 

Coordination required for adjusting weight distribution to maintain balance when the leg or hand are lifted up off the support surface. 

Anticipatory postural responses to stabilize the limbs and trunk in readiness for movement of the limbs. 

Exploring balance and stability in prone kneeling 

This sequence shows Will (6 months) moving from prone to prone kneeling and how he adapts his weight distributions as he works out how to lift his hand to reach for a toy. 

W 6m transition to prone kneeling 1.jpg   W 6m transition to prone kneeling 2.jpg   W 6m transition to prone kneeling 3.jpg   W 6m transition to prone kneeling 4.jpg  W 6m transition to prone kneeling 6.jpg   W 6m transition to prone kneeling 7.jpg  W 6m transition to prone kneeling 8.jpg   W 6m transition to prone kneeling 9.jpg   W 6m transition to prone kneeling 11.jpg   W 6m transition to prone kneeling 12.jpg  W 6m transition to prone kneeling 13.jpg   

Infants with movement difficulties

Infants with developmental delay, joint hypermobility, Down syndrome and preterm infants often lack the strength, flexibility, coordination and effective balance responses needed for active prone kneeling.

Restricted range of shoulder flexion 

Reaching forwards with both UEs requires adequate extensibility of the fascial structures, including the deep fascia, that cross over the upper thoracic regions. This may be associated with the posture of the UE's in supine in preterm birth. 

This restriction can be felt when both shoulders are flexed to 900 and then adducted. The restriction may increase if the neck is flexed. 

2 weeks kicking.jpg 

Restricted range of hip adduction

Infants with joint hypermobility, Down syndrome and preterm infants, often have restricted adduction of the hip, when the hip is flexed or extended. The restriction of adduction is usually the result of the habitual posture of the LEs in supine and sitting. 

2 weeks lying.jpg   Sit wide abduction.jpg

As a result the infant tends to kneel with the hips in abduction, or in abduction combined with lateral rotation. The abduction interferes with the weight shift associated with lifting one hand to reach for a toy, or when crawling. 

Prone kneel hips abducted.jpg    Max 13m sit kneel transition 4.jpg

 

Upper limb strength 

Infants who have not spent time actively moving around in prone and pushing up from prone into prone kneeling have not developed the strength needed to support the body weight. 

Infants with generalized  joint will often lock their elbows into hyperextension when they push into extended arm support. The elbow extensor muscles are minimally engaged and as a result do not develop the strength needed for weight bearing in prone kneeling. 

R 9m prone extended arm support 1.jpg

Head and trunk muscle activation and strength

The ability to stabilize the head and trunk in prone kneeling depends on recruitment of right muscles at the right time and in the right direction.  This is a matter of task specific coordination rather than just a reflection of muscle strength per se.   

Coordination for postural adjustments and stabilization 

The coordination needed for maintaining prone kneeling is learned through experience. 

Infants who have had limited experience actively moving around in prone have not acquired the basic elements of closed chain actions of the limbs, of using the support surfaces for stability, moving the head and shoulder girdle relative to the pelvis, and the intricate redistribution of weight needed for lifting one are to reach for a toy. 

TOMT 0-3 Intervention Strategies 

Active mobilization of tight hip structures 

Training prone kneeling, starting with an adapted physical environment 

Training sitting-prone kneeling transitions - using adapted environment 


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