Although currently unidentified, there is a mechanism of action for deep pressure stimulation follows, which in turn causes therapeutic benefits. This theory postulates that regardless of the deep pressure stimulation intervention used, similar benefits should be experienced by users, assuming that the intervention used to trigger the appropriate skin receptors. Weighted blankets are becoming the most popular deep pressure stimulation intervention, but some people may be resistant to trying weighted blankets for various reasons. They may need persuasion from science, which is where previous evidence-based interventions such as the Wilbarger Protocol can help. The Wilbarger Brushing Protocol – described in more detail below – utilizes a brush to provide deep pressure to certain areas of the body.
Can the Wilbarger Brushing Protocol elicit similar benefits found by weighted blanket users, thus reinforcing the hypothesis of deep pressure stimulation’s reciprocity? Further, can weighted blankets yield therapeutic results observed with the use of the Wilbarger Brushing Protocol, that have not been tested with weighted blankets yet?
Occupational therapists have been trained in the Wilbarger Brushing Protocol for years, but what is it?
Wilbarger Brushing Protocol Process
The Wilbarger Brushing Protocol – based on Ayre’s sensory integration theory (1964, 1965) – emerged in 1965. There has been some controversy surrounding the Wilbarger Brushing Protocol approach because conventional sensory processing disorder treatments allow the participants to choose when and where they would like the sensation to be applied. In contrast, the Wilbarger Brushing Protocol approach prescribes an amount of time and number of repetitions; the participant does not have as much autonomy. During the procedure, deep pressure input is applied to the skin with a non-scratching brush followed by compression to major joints, in this way mimicking deep-pressure stimulation.
A previous post reveals some of the problems associated with touch therapy, including lack of pressure control and the theory of forced helplessness. Advocates of the Wilbarger Brushing Protocol assure that this method is different than other forms of touch therapy due to the controlled pressure and extensive training needed for certification. However, I am unconvinced that manual pressure can be controlled.
Wilbarger Brushing Protocol supporters have argued that those with sensory defensiveness are often skeptical of new experiences, and may not know how the Wilbarger approach would benefit them. Therefore, having an occupational therapist initiate the sensation is beneficial.
The Wilbarger Brushing Protocol approach does have another upside, it can be helpful to those who have sensory defensiveness, but are not able to utilize a weighted intervention for health reasons or safety concerns. The question is, however, Does the Wilbarger Brushing Protocol produce similar benefits as those that we’ve seen with weighted vests and weighted blankets?
Kimball, Lynch, Stewart, Williams, Thomas, & Atwood (2007) looked at the Wilbarger Protocol’s effects on stress in their study, specifically, how the protocol modifies levels of the hormone, cortisol — A stress hormone. While stress has a direct and immediate effect on the sympathetic nervous system, cortisol has a separate, more delayed, and long-term response due to the activation of a hormonal pathway, that leads to the production of cortisol. When the body perceives danger, the autonomic nervous system is the first to respond, heightening our sympathetic nervous system so that we can react to the situation immediately. If the danger continues, the brain will activate the HPA-axis, which releases various hormones such as cortisol to maintain the heightened sympathetic nervous system activity. In sum, if there are high levels of cortisol, the body has been experiencing stress for a prolonged period of time.
Four male children with ages from three to five years old who were diagnosed with a sensory defensiveness disorder were recruited by occupational therapists to participate in this study. Participants needed to have the ability to follow directions; specifically, they needed to have the ability to follow instructions to brush their teeth and spit.
Parents completed the following assessments:
This was distributed to collect data on age, gender, treatment history, etc.
In past studies discussed on this blog, we have seen that stress has been measured primarily using skin conductance, which is the preferred method of measuring the autonomic nervous system, but these researchers utilized a different approach: saliva. Stress can also be measured a blood test. Although not commonly used, testing cortisol levels using saliva is an effective way to measure stress. It’s cheap and noninvasive (Hodgson & Granger, 2013) . The downfall, however, is that due to the delayed production of cortisol, relative to sympathetic activity, we cannot always see when a shift occurs. Therefore, at times, cortisol data can be wonky, which we will see in this study.
Saliva was collected from the participants while they pretended to brush their teeth because the saliva absorbing chews, which are typically used, presented as a safety risk for small children. Saliva was collected at the start of the children’s typical occupational therapy session. Once the saliva was received, the Wilbarger Brushing Protocol was administered. Upon completion, the child engaged in a neutral activity for 15-minutes that involved coloring or completing a puzzle, which allowed for cortisol levels to reach the saliva before collecting the after-session sample. The after-session sample was collected in the same manner as the pre-session collection. Children were administered the Wilbarger approach once a week for four consecutive weeks.
- Cortisol levels for participants 2 & 4 decreased every session. Participant 1’s cortisol levels decreased for three out of the four sessions but increased on the 4th (last) session.
- Participant 1’s cortisol levels were the lowest seen throughout the study on the final day, but upon completion of the Wilbarger Protocol, their cortisol levels increased to an average level.
- Participant 3 started with abnormally low cortisol levels, but after completion of the Wilbarger approach, the cortisol levels increased to an average range. This theme occurred throughout all four sessions. Participant 3 also refused to participate in the post-session neutral activity, and this may have influenced the cortisol levels.
Deep Pressure and Neurophysiology
These results are promising when drawing parallels between stress relief weighted blankets and the Wilbarger Protocol. Also, both stimuli may follow similar ascending neurological pathways, thus providing further evidence that the results from one could be mimicked by the other. But the difference lies within the type of touch. The Wilbarger Brushing Protocol arguably utilizes discriminate (fine) touch due to the brush’s bristles; weighted blankets can arguably be considered as non discriminate (crude) touch, discriminate (fine) touch, or both. Crude and fine touch follow different pathways to the brain, and thus the brain reacts to them differently. Our upcoming literature review will dissect the hypothesized neurophysiology of deep pressure and refine this ideology more. But at this point in our research, we believe that deep pressure sensory input follows both the anterolateral system in the form of crude touch and the dorsal column-medial lemniscal pathway via deep pressure and fine touch.
Insight From our Author(s)
To answer our main question, yes, the Wilbarger Brushing Protocol does produce similar results as those seen in weighted blanket/vest use, but we hypothesize that they have a similar mechanism of action, so this result was expected. A reduction in the amount of cortisol occurred most of the time, which indicates a decrease in stress. However, because the data was collected using saliva, some limitations must be considered. We do not know what the everyday cortisol levels for these children are; we only know of their cortisol level when they enter therapy in the morning. Therefore, we do not have a solid understanding of typical cortisol levels these children have in different environments. It is possible that entering the occupational therapy facility could be stressful for the child, and as habituation occurs, the stress level naturally lowers. These data do not show us the long term effects of the Wilbarger Protocol. The child’s cortisol level could spike again upon leaving the therapy session.
The learned helplessness theory that we discussed in the therapeutic touch article applies to this study, as well. The children may have “given in” to the Wilbarger Brushing Protocol due to no other options being available, and thus their body reacted by reducing the production of cortisol. A reduction in cortisol does not ensure that the children enjoyed the experience, and enjoyment is a predictor for treatment success in the long run. Also, this intervention requires a certification for proper use, thus disallowing many families from practicing at home unless they take the time to become trained. The premise is that over time, long-term changes occur, but what about initially? In weighted blanket research, the participant can use the intervention just about wherever and whenever they need it.
This intervention is promising for those who are unable to use weighted vests due to health concerns or limitations, and in the upcoming weeks, we will explore the sensory integration theory more, to better understand how this can be a useful tool for people.
Given that cortisol levels change relatively slowly to a given stimulus, in this case, the Wilbarger Brushing Protocol, it is impressive that several of the participants showed decreased levels of cortisol after the treatment. While salivary cortisol may fluctuate with levels of anxiety, cortisol levels naturally fluctuate as a circadian (daily) rhythm. In fact, our body’s natural rhythm is to increase cortisol levels early in the morning, to help us wake up, and then the levels taper off throughout the day. A major strength of this study is that the authors accounted for this, by testing the subjects and collecting the salivary cortisol at the exact same time each morning. Overall, this study suggests further research should be performed, however with increased numbers of subjects to account for the body’s delayed production and circadian fluctuations of cortisol.
Hodgson, N., & Granger, D. (2013). Collecting saliva and measuring salivary cortisol and alpha-amylase in frail community residing older adults via family caregivers. Journal of Visualized Experiments, 82, 50815- 50822. doi:10.3791/50815
Kimball, J., Lynch, K., Stewart, K., Williams, N., Thomas, M., & Atwood, K. (2007). Using salivary cortisol to measure the effects of a Wilbarger protocol-based procedure on sympathetic arousal: A pilot study. American Journal of Occupational Therapy, 61, 406-413.