When children have sensory integration and processing challenges that affect their daily participation, occupational therapists often recommend sensory-based interventions. These are distinct from Ayres Sensory Integration therapy—they’re typically practitioner-led or adult-led interventions involving passive sensory input applied to the child. Think weighted vests, therapy balls for seating, wearing ear defenders, sensory rooms, or teaching parents sensory strategies to use at home.

These interventions are incredibly popular in schools and homes, but previous systematic reviews have indicated a limited evidence base. The researchers wanted to update the evidence by examining studies published between 2015 and 2024. Their specific question was: “What is the effectiveness of specific sensory-based interventions (including sensory techniques, caregiver-focused sensory interventions, and sensory environmental modifications) to support functioning and participation for children and youth (0–21 years old) with sensory integration and processing challenges that interfere with everyday life participation?”

The authors defined three distinct types of sensory-based interventions: sensory techniques (like weighted items or passive swinging), caregiver-focused interventions (training parents or teachers to support sensory needs), and sensory environmental modifications (changing the physical environment, like lighting or noise levels).

Methods

The review followed PRISMA guidelines, I’ve spoken about PRISMA before and have included the link in the show notes. The research team comprised occupational therapists with expertise in sensory integration and processing, working alongside a health science librarian.

They searched six databases: MEDLINE, CINAHL Complete, PsycINFO, OTseeker, Cochrane Reviews, and ERIC. Search terms built upon previous systematic reviews and included variations on sensory processing, sensation disorders, sensory integration disorder, and related concepts. The search strategy was incredibly comprehensive, covering not just the conditions but also specific interventions like weighted blankets, therapy balls, massage, and environmental modifications.

Studies had to meet strict inclusion criteria. They needed to be peer-reviewed articles published in English between May 2015 and January 2024. Participants had to be children aged birth to 21 years with documented sensory integration and processing challenges, identified through psychometrically sound assessments. Diagnoses included children with conditions commonly associated with these challenges—autism, ADHD, developmental coordination disorder—as long as sensory challenges were documented.

Finally, studies had to include participation or occupation-based outcomes. The researchers deliberately excluded studies focusing solely on symptom reduction—they weren’t interested in whether interventions made children “less sensory” but whether they helped children do more in their daily lives. If studies mentioned “sensory integration” but didn’t reference the ASI Fidelity Measure, they were considered sensory-based interventions rather than true Ayres Sensory Integration and were included in this review. There is a second review which was considered articles which meant fidelity for ASI, it’s below.

The review used Hopkins Levels to describe levels of evidence. Strong evidence was classed as two or more Level I studies; this is typically a randomised controlled trial. Moderate evidence includes one or more Level 1 studies and multiple high-quality Level 2 studies. Low evidence is when the study quality is low or there is insufficient evidence.

Ultimately 21 studies met the inclusion criteria. Settings varied considerably and included schools, therapy clinics, home and a dental clinic. Eight of the studies were conducted in the USA, three in Canada and India, and one each from Iran, Turkey, Sweden, Taiwan, Finland, Israel, and Japan. Participant diagnoses included autism (seven studies), ADHD (seven studies), developmental delay (two studies), and sensory processing disorder or concerns (eight studies).

Outcome measures varied widely, including attention, task completion, quality of life, motor skills, occupational performance, sleep, knowledge of sensorimotor strategies, behaviour and emotional functioning, and goal attainment. Five studies were Hopkins Level I (randomised controlled trials) and 16 were Level II, six of them being single-subject designs.

The Results

Personally, I found some of the groupings slightly misleading, and I think it is important to consider the individual studies within the groups, rather than the overall conclusion. The article itself leaves out a lot of details on the studies, for example a table describing the included studies. However, this data is available in the supplementary data, so if you want to take a deeper dive, I’d suggest looking at the supplementary table alongside the article.

Strong Evidence: Deep Pressure Tactile Input

Four studies provided strong evidence that deep pressure tactile input positively impacts functional outcomes. Two examined massage and two examined weighted items.

One found that massage in addition to routine rehabilitation significantly improved motor skills in young children. Two studies focused specifically on sleep, both showing statistically significant improvements. The first used massage with joint compressions before bedtime and found improvements in overall sleep and decreased daytime sleepiness. The second used weighted blankets and found improved sleep quality for children with ADHD. Interestingly the broader literature on weighted blankets does not support this finding, I’ve included the link to a systematic review specifically on this topic.

One study examining weighted vests worn at school didn’t show significant improvements in attention, body perception, coping skills, or learning. Importantly, this study didn’t specify what activities children engaged in whilst wearing vests, so this aligns with the recommendations from Unwin in 2024 that there is insufficient evidence to support the use of weighted vests.

Moderate Evidence: Alternative Seating Does Not Improve Attention

Three studies indicated that alternative seating doesn’t significantly improve functional behaviour. For me this is reported as a double negative almost and what they are saying is that there is a lack of evidence to support the use of alternative seating for attention – essentially the studies which included stability balls, cube chairs and the-stools, indicated they didn’t help.

Moderate Evidence: Targeting Multiple Sensory Systems

Five studies provided evidence that sensory techniques targeting multiple sensory systems can impact functional behaviours more than if the intervention only targets one sense.

For example, one trial examined treadmill walking with vibration and found statistically significant results for quality of life, attention, and executive functioning, but the improvements were not seen for participants who used the treadmill or vibration alone.

And one study looking at fidget spinners concluded they actually had a negative effect—participants showed worse attention rather than improvements. This is an example of where I found the groupings unhelpful. This section included articles on sensory motor strategies, sensory activity schedule, sensory integration and toileting, sensory diet, sensory garden, treadmill and vibration, fidget spinners, and headphones. I think it would have been more helpful to report on specific equipment, rather than making a conclusion which groups very different sensory supports together.

Strong Evidence: Caregiver Training

Five studies showing strong evidence that sensory based interventions provided following caregiver education and home-based strategies as effective in improving functional performance and participation. One study showed statistically significant improvements in occupational performance for children with sensory concerns following parent training.

Two studies demonstrated significant increases in caregiver knowledge of sensory strategies following training, though neither demonstrated impact on functional outcomes. This distinction is important, although parents learned more, but that knowledge didn’t necessarily translate to improved outcomes for children.

One study found that standard therapy combined with home-based sensory interventions following caregiver training resulted in statistically significant improvements in quality of life and behavioural and emotional functioning. Another study with moderate risk of bias showed that a programme focusing on caregiver sensory knowledge, coaching, and support had statistically significant improvements in functional performance.

Insufficient Evidence: Sensory Environmental Modifications

Only one study examined sensory environmental modifications, and this was specific to dental procedures. So overall, due to the lack of studies reporting on environmental modifications they concluded that the evidence is low.

Practical Takeaways

If you’re working in schools, the evidence is quite clear about what doesn’t work: alternative seating like therapy balls or cube chairs don’t improve attention or productivity. This finding contradicts common practice, where these interventions remain popular despite lack of evidence. I think these are an easy go to in schools, but the number of times I see children sitting on bumpy plastic circles, aka deflated wobble cushions, indicates to me how poorly they are understood!

The authors recommended incorporating parent or teacher education as part of your intervention plan rather than relying solely on direct therapy. They caveated this recommendation by saying that whilst parents gain knowledge through training, this doesn’t automatically translate to improved child outcomes, so you need to continue to support implementation, not just provide information. This ties in nicely with Sue Allen’s parent coaching work that I reviewed in episode 3, if you haven’t listened to that you will be able to find it wherever you’re listening to this episode.

Whilst the authors concluded that deep pressure tactile input has good evidence, particularly for sleep, I think we need to look at these studies more specifically. Massage seemed to have better outcomes than weighted products and the two were grouped together. I’ve also included the link to the other systematic review on weighted blankets for a broader view on the topic.

The review also indicated that sensory techniques target multiple sensory systems matched to a child’s unique needs, they may be more effective than targeting a single system. A lot of different approaches were grouped together here, so for me I think it’s more helpful to look at the individual tools. For instance, ear defenders helped with auditory-related goals whilst fidget spinners worsened attention, so it’s not completely clear cut.

The near absence of research on sensory environmental modifications is striking given how popular sensory rooms, lighting changes, and noise modifications have become in schools and community spaces. Whilst these modifications may be beneficial, we simply don’t have the evidence yet. If you’re advocating for environmental changes, acknowledge this evidence gap whilst explaining the theoretical rationale. I also think we need to be more specific about the difference between adjustments that support modulation in the environment, for example reducing noise or changing lighting, and sensory rooms with equipment like bubble tubes. As for me they really are two different things.

Finally, one limitation across studies is the absence of children’s perspectives. Many outcome measures relied on observable behaviours or adult reports. If a child reports that sitting on a therapy ball helps them concentrate, even if observable behaviour doesn’t change, that perception matters. Consider incorporating child perspectives into your outcome measurement, not just relying on what adults observe.

This review reminds us that popularity doesn’t equal effectiveness. Some of our most used interventions, like therapy balls and weighted vests, lack supporting evidence.  Caregiver training currently has the strongest research base, but again we need to remember training doesn’t equal implementation. As always, comprehensive assessment and matching interventions to individual sensory needs and monitoring outcomes remains essential.

This systematic review examined the impact of sensory activity schedules on school performance and behaviour of students with sensory processing differences. For those not familiar with SAS, they are similar to a sensory diet, but instead of linking the sensory supports to a time of the day, they link them more to specific tasks for example doing their activity schedule before maths if that was a more challenging tasks for the student. The authors conclude that although sensory activity schedules have potential to benefit students’ school performance or behaviour, the current strength of evidence is low, requiring clinical reasoning and individualised progress monitoring.

This systematic review of 12 studies found strong evidence supporting Ayres Sensory Integration for individual goal attainment and occupational performance in children with sensory processing challenges. Moderate strength of evidence supports ASI in improving daily living and self-care skills, as well as social, communication, and play skills. For those of you listening to the podcast from the beginning, you will know that in episode 1 I discussed another systematic review on ASI which reached similar conclusions. It had fewer articles because is only looked at studies up to 12 years of age and only included RCTs. This review includes Level 1 and 2 evidence and a wider age group up to 21 years. They quantify the studies using the Johns Hopkins Nursing levels of evidence. What I found interesting was that they don’t discuss the sample sizes within the studies, for example one of the randomised control trials only included 9 participants in each group and how these small samples could impact the risk of errors in the statistical analysis or the strength of their final conclusions. Again, much of the detail in tables that are included in the supplementary data, so if you are reading this article please make sure you also access the supplement data and cross reference as you’re going. This will give you a fuller picture of the study results.

This narrative review synthesised literature on sensory integration challenges in children and developed the Sensory Integration Decision Guide to fill a gap in resources for primary care providers. The guide provides a systematic process for detecting sensory integration challenges and referring to specialised occupational therapy services to support clinical decision-making. The guide is a simple decision tree which is included in the article. There is no discussion or information on how authors developed the guide, the article explores results from the literature review indicates the need for it, but not how it was developed and the authors noted that it requires empirical or real-world testing.

This study of 10,735 5-year-olds from a French birth cohort found that approximately 1 in 10 infants experienced definite sensory difficulties, and this group had significantly higher rates of clinical mental health symptoms at age 5. This suggests that infant sensory difficulties may be predictive of later child mental health. This study supports the need for early identification, and it could sensory differences in infancy could be a useful red-flag that health visitors could use to initial referral.

This study explored the impact of a 7 month virtual occupational therapy professional development and mentorship program called Sensory Approaches to Infant/Toddler Learning (SAIL) and the impact of the SPM-2 SPARK online database. This programme supports therapists to use a coaching based approach with parents. The results indicated that whilst participants significantly improved in all knowledge and confidence domains from pretest to post-test; no significant change occurred from post-test to follow-up which was when the SPARK tool was available. Participants also found both the professional development and online database appropriate and feasible.

https://www.spm2SAIL.com