When we think of autism spectrum disorder (ASD), we automatically think of the stereotypical behaviours and mental health aspect (of culturally Caucasian cis male people).
For the most part this is the important place to focus: learning to manage the dissonance between 'neurodivergent' thinking patterns and the reality of existing in a world angled towards 'neurotypical' people is a hugely difficult task.
Managing differences in behaviour and perspectives also has an impact on physical health - the two are immensely closely related.
As an example, think of a feeling of anxiousness. A classic experience of anxiety is an elevated heart rate. That is a physical experience.
Physical experiences are present in every "mental health" condition, and "mental" experiences are present in every "physical health" condition. The two cannot be separated.
That said, as a physiotherapist, I am best able to help with the physical symptoms.
Many people with ASD experience significant physical differences that influence emotional regulation, mental health, participation, fatigue, and pain. These features are not "secondary" issues. They are integral to how the nervous system experiences and responds to the world.
The main differences that influence this are: low muscle tone, ability to sense our body, and ability to read out internal cues.
Low Muscle Tone (Hypotonia)
Low muscle tone (hypotonia) is a somewhat foreign concept to most people. It relates to the natural tension in which a muscle holds itself.
Think of a rubber band - if you put your two pointer fingers in the loop and pull it tight, it goes tight. Likewise if you bring your fingers together, the band will go loose.
Muscles also have the ability to be loose and be tight - that's how they move you.
But what do they do when they aren't trying to move you?
Think again of our rubber band - if you are holding your two fingers still, what does the rubber band do? It stays the same level of stretchiness.
Everyone has a different distance between their fingers, i.e. different tension in their muscles when the muscles aren't doing anything. In hypotonia, the muscles are floppier than the average person's.
Hypotonia is commonly observed in autistic children and adults, yet it is frequently ignored beyond early childhood.
Hypotonia can present as:
- Poor postural endurance
- Early fatigue
- Delayed motor milestones
- Joint instability
- Increased effort required for everyday tasks
From a mental health perspective, hypotonia matters because holding oneself upright, breathing efficiently, and maintaining postural control all demand cognitive and emotional energy. When baseline physical effort is high, emotional regulation becomes harder, not easier. Also, these tasks are essential for our physical function - it's hard to do anything if you can't breathe!
Motor differences and reduced postural control are consistently reported in ASD across the lifespan. [jetir.org]
Sense of Body (Proprioception)
Proprioception—our sense of body position, movement, and force—is frequently altered in individuals with ASD. Many describe feeling:
- Clumsy or uncoordinated
- Unsure where their body is in space
- Prone to collisions, falls, or over‑using force
Research consistently shows that autistic individuals experience distinct proprioceptive processing differences, affecting motor planning, postural control, and emotional regulation. [ocde.us], [advancedautism.com]
Clinically, poor proprioception can contribute to:
- Anxiety in unpredictable environments
- Avoidance of movement or physical activity
- Heightened sympathetic nervous system activation
When the body feels unreliable, the world feels unsafe.
Interoception: Difficulty Reading the Internal World
Interoception refers to the brain’s ability to interpret internal bodily signals, such as heartbeat, hunger, pain, breath, temperature, and visceral sensations.
People with ASD may experience:
- Difficulty recognising hunger, thirst, or fatigue
- Delayed awareness of distress or pain
- Challenges identifying emotions rooted in body signals
Recent large‑scale reviews indicate that while interoceptive ability varies across autistic individuals, differences in interoceptive integration are strongly linked to emotional regulation, anxiety, and mental health outcomes. [pmc.ncbi.nlm.nih.gov], [frontiersin.org]
In mental health settings, this has profound implications. If someone struggles to interpret bodily cues, emotions can feel sudden, overwhelming, or confusing—not because of poor insight, but because the signal itself is distorted.
The Emerging Link Between Autism and Ehlers‑Danlos Syndromes (EDS)
One of the most important advances in recent years is the growing evidence linking autism with connective tissue disorders, particularly Ehlers‑Danlos Syndromes (EDS) and Hypermobility Spectrum Disorders (HSD).
A landmark review by Casanova and colleagues highlights overlapping features between ASD and EDS/HSD, including:
- Joint hypermobility
- Chronic pain
- Autonomic dysfunction
- Proprioceptive impairment
- Psychiatric and neurodevelopmental overlap
The authors suggest EDS/HSD may represent a distinct neurodevelopmental subtype within the autism spectrum, rather than a coincidental comorbidity. [pmc.ncbi.nlm.nih.gov]
More recent systematic reviews report that:
- Around 30–40% of autistic individuals meet criteria for joint hypermobility or EDS/HSD
- A similar proportion of people with EDS/HSD meet criteria for autism
These rates are far higher than would be expected by chance. [ehlers-danlos.com]
The overlap between ASD and EDS reframes many mental health presentations:
- “Treatment‑resistant anxiety” may reflect autonomic dysregulation
- Persistent distress may relate to chronic pain or joint instability
- Emotional shutdown may follow physical exhaustion or sensory overload
Physiotherapy and ASD
For physiotherapists working alongside psychologists, psychiatrists, and occupational therapists, recognising these bodily contributors allows for more humane, accurate, and effective care.
Movement‑based interventions, proprioceptive strengthening, breath work, pacing, and body awareness training are not optional extras: they are foundational supports for mental health. It's hard to feel emotionally regulated without a good ability to breathe!
When we understand hypotonia, proprioception, interoception, and connective tissue health as core components of the autistic experience, we can connect our mind and body better, improving not only the physical experience, but the emotional, social and behavioural one as well.
References
- Casanova et al., Journal of Personalized Medicine, 2020 [pmc.ncbi.nlm.nih.gov]
- Loureiro et al., Psychology Research and Behavior Management, 2024 [pmc.ncbi.nlm.nih.gov]
- Klein et al., Frontiers in Psychiatry, 2025 [frontiersin.org]
- The Ehlers‑Danlos Society, 2025–2026 [ehlers-danlos.com]
The healing paingel does not endorse any links nor guarantee the accuracy of the information contained within them. This blog is for informational purposes only and does not constitute medical advice.