Shape Shifting Lens
The existing evidence suggests that a shape-shifting bi-directional association exits between posture and QOL in youth with scoliosis (aged 8 to 21 years) and adults with osteoporosis (over age 50 years).15 If this remains true in children with cancer, a child’s QOL could be evaluated with a simple, non-invasive clinical measurement tool. The inclinometer may avoid otherwise unnecessary spinal radiographs, and may be more feasible to collect in children with cancer evidenced by the completion rate in our study for the inclinometer measure (68%) was higher than the child report on the PedsQL questionnaire (60%).12
While four studies demonstrated consistently that kyphosis is modifiable with exercise,8,31-33 two of the studies supported that the improvement in kyphosis was in fact accompanied by improved QOL,8,32 a finding not explained by the known improvement in QOL with exercise. Perhaps this concept could be generalized to children with temporary kyphosis due to the effects of cancer and its treatment, whereby measurement of kyphosis over time could be a simpler measure of QOL to more easily tailor supportive care. Furthermore, the scoliosis studies showed that measurement of kyphosis is feasible in the pediatric population, and perhaps the more malleable spines in children without orthopedic disorders could show improvement in kyphosis with improved QOL with cancer treatment. This concept was supported by a recent RCT in children with cystic fibrosis. Although the investigators did not include QOL as an outcome, rendering it ineligible for inclusion here, they demonstrated improved posture with a physical exercise intervention.35 If kyphosis is modifiable, even in elderly adults and patients with orthopedic disorders, and tracks with QOL, it could be an appropriate surrogate measure showing the impact of QOL interventions.
In shape-shifting contrast, the behavioral studies consistently demonstrated an inverse association between QOL (as depression or mood) and posture. Three of the studies used behavioral techniques to evoke positive and negative emotions to demonstrate the association.26,29,30 Additionally, these three studies further supported that by measuring thoracic kyphosis, the assessment of a child’s mood (as an aspect of QOL) could be measured with an inclinometer.36 Similarly, we found correlation between mood measured by the Faces scale and the posture measure in our study in children with cancer (β = 0.26).12 The finding of a statistically significant correlation with a strong effect size between depression and shoulder inclination may also be highly clinically useful.23 If mood is related to posture in older women with osteoporosis, perhaps this finding can be replicated in children with cancer. Indeed, our prospective study did confirm this concept without a significant difference between males and females, specifically in children with cancer.12
The bi-directional relationship between QOL and posture are bi-directionally could be explained physiologically by established connections between the limbic system, shown to govern emotional response, and the postural response seen in major depression. This was recently supported in a study of electroconvulsive therapy for depression and the effects on the neuroplasticity of the limbic system in the brain where brain volumes increased significantly related to symptom improvement (p < .01).37 Similarly, the field of rehabilitation medicine has used the Bobath practice model based in neuroscience to integrate posture by evaluating critical client cues such as postural alignment on the outcomes of pain and function (but not QOL) in the recovery from stroke and spinal cord injury.38