As a school-based OT, you’re probably familiar with weighted vests. But as ubiquitous as these items are, many questions still remain about their use. Is there evidence behind weighted vests? How much weight should be utilized? How often should an individual wear one to see effects? Are weighted vests safe? What do weighted vests improve? Let’s take a closer look at the research and find the answers to some of these questions.
What are weighted vests purported to do?
In practice, weighted vests are trialed for many reasons. In this 2004 article on perspectives from OTs on weighted vests, staying on task, staying seated, and attention span were the most common areas targeted. Sometimes weighted vests are also utilized in an attempt to curb stimming or fidgeting behaviors, which we now know serve important functions for neurodivergent individuals and should not be “managed” just for the sake of it. Weighted vests have been utilized for other functions such as decreasing self-injurious or aggressive behavior. In practice, weighted vests are often trialed for non-specific functions and are sometimes thought to improve a child’s general ability to process sensory information, self-regulate, socialize, and learn.
Who uses weighted vests?
Occupational therapists tend to be the most common professionals to utilize weighted vests for the purposes listed above, though teachers, school counselors, and other professionals working with children may use them too. Weighted vests tend to be used with neurodivergent children, such as those who are autistic or have ADHD. They are also used with other students with developmental disorders.
Weighted vests are also used for fitness and other health reasons by a variety of professionals. For our purposes, we won’t be looking at that segment today.
What are the risks of weighted vests?
Weighted vests are not a completely benign intervention; they do come with risks. One major risk involves situations in which the weight is too heavy for the wearer to control, such as the cases in which children have died due to suffocating under weighted blankets. While the typical use of weighted vests is not done while children sleep, this is still an important factor to consider when introducing any weighted item. Even if the child will not be sleeping in the vest, being so weighed down that movement is impacted has other risky implications, not least of which is the child’s autonomy. As frustrating as movement in the classroom can be for some teachers, the idea behind weighted items isn’t that students are literally so weighed down that they have difficulty getting up.
Weight may also be an issue for children who have comorbid conditions that impact their back, neck, and spine, or for children who have respiratory and circulatory conditions. Don’t use weighted vests with these children without clearing it with their pediatrician.
Another major risk of weighted vests is temperature control. Since these vests are often heavy and thick, children can become sweaty, overheated, and dehydrated. Always monitor for signs of this, especially if a child is engaged in active movement while wearing the vest.
One other risk with weighted vests is skin integrity – always inspect the skin for damage after use, especially if the child has gotten sweaty.
What is the recommended weight and wearing schedule for weighted vests?
While many OTs recommend 5 – 10% of the child’s body weight, this percentage does not appear to be based on any evidence or research. Instead, this appears to be tribal knowledge, potentially based on similar guidance for backpack weight. Similarly, no evidence exists that a particular wearing schedule has shown to be more beneficial than others. In practice, it appears that OTs typically decide these factors based on trial and error.
What does the research say about weighted vests?
In short, the research base for weighted vests for the aforementioned concerns isn’t great. There is a real lack of high-level evidence. This simply means that not many studies have been done, and the ones that have tend to be small, have weak research designs, or have other limitations. Beyond that, many of these studies did not actually find weighted vests to be effective in addressing the issues they were targeting. This doesn’t mean that weighted vests don’t work – but it does mean we don’t have much evidence to say that they do.
Let’s take a deeper dive into some of the research:
This 2014 article was the strongest piece of evidence I could find in favor of weighted vests. The authors used a randomized, two-period crossover design to study 110 children with ADHD to see if weighted vests improved their attention, impulse control, and on-task behavior. They concluded that children who wore weighted vests did show significant improvement in inattention, speed of processing and responding, consistency of executive management, and three of the four on-task behaviors they were measuring. They did not find significant improvements in impulse control and automatic vocalizations.
While this study offers a higher level of evidence than many others on weighted vests, it does come with significant limitations. While 110 children is a bigger sample size than most existing weighted vest studies, it is still a relatively small number when considering generalization. Second, the researchers chose to measure attentional factors through the use of a 14-minute computer-based test called the CPT-II, given in a quiet room, one-on-one with the lead researcher. While this test is a valid way to test attentional skills, it is only one measure, and one that may not be generalizable to a noisy and busy classroom environment.
The children in this study were also recruited from clinics, which again makes it difficult to extrapolate these findings to a more general population. Additionally, this study only examines the efficacy of weighted vests for children with ADHD – which means the results may not be applicable to other conditions.
Lastly, something that rubbed me the wrong way about this study was the behaviors themselves that they were targeting – such as movement out of seat, fidgeting, looking away from the computer screen, and what they called “meaningful and meaningless utterances,” which I assume means talking and vocally stimming. While obviously we want children to be able to pay attention, some of these behaviors seem based on neurotypical classroom standards and maybe aren’t best practice for how children with ADHD actually learn.
The rest of the research is less favorable.
This 2015 article looks at many of those previously mentioned smaller descriptive and qualitative studies. In total, 32 studies met inclusion criteria for this review. Of the 32, four (12%) were rated as “meets evidence standards” and six (19%) were rated as “meets evidence standards with reservations”. Twenty-two (69%) studies were rated as “does not meet evidence standards”. All four of the studies rated as “meets evidence standards” indicated that there was “no evidence” to support the use of weighted with autistic individuals. Two studies rated as “meets evidence standards with reservations” also showed “no evidence” to support the use of weighted vests with autistic individuals. Three studies rated as “meets evidence standards with reservations” showed “moderate support” for the use of weighted vests. One study rated as “meets evidence standards with reservations” showed “strong evidence” for the use of weighted vests.
The author concluded that it appears that using weighted vests with autistic individuals is not an evidence-based practice. Obviously, a huge limitation of this study is a lack of high-quality research articles to systematically review.
If you’re interested in reading more research directly, I recommend looking in the reference sections for the above articles to analyze the individual articles. You can also conduct a small literature review of your own using a platform like Google Scholar. But to summarize, most of the other research articles you will find as of October 2022 are similar to what has been described in these two – small sample sizes, no or minimal positive effects, and sometimes even negative effects.
Should weighted vests be recommended?
So, what should we take away from this for clinical practice? Should we never recommend weighted vests?
It’s a lot easier to prove a positive than it is a negative. Do we have strong evidence that weighted vests are effective? No. But we also don’t have strong evidence that they’re ineffective, either. And we also don’t have strong evidence that they are a harmful intervention, risks and contraindications notwithstanding.
So what should we do?
In my own practice, I don’t tend to recommend weighted vests. As school-based OTs, we have an ethical and legal duty to choose strong, evidence-based interventions. So when I am addressing the skills discussed above, I turn to other strategies.
However, I’ve worked with many other therapists, teachers, and other professionals who are interested in trialing a weighted vest. And I’m not one to gatekeep sensory interventions, so I tend to encourage teachers to try a strategy they think might be beneficial, as long as they are aware of the risks and lack of evidence.
One thing I do recommend to school teams in these cases is to take data. While we don’t have strong evidence that weighted vests are successful interventions for everyone, that doesn’t mean they couldn’t be helpful to an individual. Many of the studies referenced report that children, parents, and teachers anecdotally report liking the vest, and that’s not nothing.
So, if you or someone on your student’s team wants to trial a weighted vest, first decide the needs that you’re actually targeting. I find that all too often school teams are just hoping that a student will be “better” as a result of the weighted vest without getting specific as to what that actually looks like. Then, have someone who will work with the child regularly take data on those targets to see if there are any changes when utilizing the vest.
The other thing I really impress on school teams is to never force a child to wear a weighted vest. We want to protect children’s autonomy, and no one is going to get good work done when they’re made to wear clothing they don’t enjoy.
Further Questions and Implications for Occupational Therapy Practice
Obviously, we need a lot more research on this topic, and in pediatric OT in general! Here are some questions and musings that I’d love to get clearer answers on:
- Are weighted vests truly effective? If so, with what population(s)?
- Are the behaviors we’re addressing actually worth targeting, or are they based on outdated neurotypical classroom norms that don’t really support student learning?
- Is a particular amount of weight more or less effective in weighted vests?
- Is there a particular wearing schedule that is more or less effective with weighted vests?
- Can weighted vests be harmful even for children without comorbidities?
- What are the strongest interventions for attention, self-regulation, and readiness to learn?
All of this to say, if you’re passionate about weighted vests, I encourage you to get out there and do the research! I’ve known many therapists who report anecdotal success with this intervention, and I’d love it if we had a greater evidence base to draw from. In the meantime, hopefully, this provides some clarification and guidance for school-based occupational therapists wondering how they should or shouldn’t utilize weighted vests in their practice.
If you’re looking for more evidence-based strategies to utilize in your school-based practice, come join us in The Dynamic School OT Course. You’ll learn research-based interventions to utilize, as well as strategies for finding and applying evidence to your practice.