March 10, 2013
The Yin and Yang of Postural Control
Last month I attended a presentation regarding torticollis at the APTA CSM. The presenters noted that a greater than average percentage of kids who have had torticollis as babes go on to present later in childhood with motor delays (1). Then several days ago a study popped up on my PubMed feed regarding the effects of birth brachial plexus injury on postural control. I read with interest that the findings they documented all had to do with asymmetry (2). It got me thinking about the development of symmetry and midline. And postural control, naturally.
We know that it is part of typical development to go through a period of movement asymmetry between 1 and 3 months. The influence of the ATNR is present and the baby experiences the stability that comes with this position. It’s as if they need to experience the extremes of range individually and then they can discover the middle.
The development of midline comprises a balance of left and right, front and back as well as upper and lower body. It is a first step to complex postural control (3). This symmetry requires balanced activation of both extensor and flexor components. And that’s where postural control can go astray. Our clients, born with low tone and/or decreased physiological flexion, tend to fall into slight extension against gravity. Activation of extension can naturally occur in this alignment. But any issue or intervention that causes prolonged asymmetry favours extension and thus can interfere with the development of those flexor components. This consequently interferes with midline and postural control.
When asymmetry is present, the information to the visual system is altered. And as asymmetry impacts the position of the head, this impacts the vestibular system as well. And proprioceptive information transmitted through the neck musculature to and from the body is also disrupted by asymmetry in this area of the body (4). Further, issues in either the visual system or the vestibular system are also known to create asymmetry in the body as the systems try to cope. So the cycle feeds back on itself; everything really is connected.
As much as we might like treatment to be straightforward, when we practice in pediatrics, any problem must be considered in light of multiple systems because of the speed and complexity of development. And especially with babies, we don’t have the luxury of time nor can we think just in terms of the musculoskeletal system; we need to consider all the systems. Then we can provide truly “balanced” treatment.
Place a folded receiving blanket under a baby’s head during treatment. This brings the head and cervical spine (and possibly the thoracic spine) out of extension and into slight flexion allowing the baby to activate the neck flexors bilaterally. Make sure the blanket isn’t too thick. You want to encourage midline in all planes and the balanced activity of flexors and extensors is a good place to begin.
Are you interested in combining different theories (including attachment, visual-vestibular, sensory processing, reflex patterns/integration and Dynamic Core) to create an holistic model of assessment and treatment of postural control? Join Kim Barthel, OTR and Shelley Mannell, PT, for Expanding Your Toolbox: Integrating Therapeutic Approaches in Pediatrics, a 3-day integrated learning experience Sept 21-23, 2015.
1. Oledzka M, Suhr M. (2013). Clinical approach to the evaluation and treatment of congenital torticollis (presentation). APTA CSM, San Diego, CA.
2. Ridgeway E, Valicenti-McDermott M, Kornhaber L, Kathirithamby R, Wieder H. Effects of birth brachial plexus injury and postural control. J Pediatr. 2013; doi: 10.1016/j.jpeds.2012.12.073
3. Bly L. Motor skills acquisition in the first year of life. An illustrated guide to normal development. Arizona, Therapy Skill Builders, 1994.
4. Johnson MB, Emmerik MB. Is Head-on-Trunk Extension a Proprioceptive Mediator of Postural Control and Sit-to-Stand Movement Characteristics? J Motor Behav. 2011; 43(6): 491-8.