What is a sDHT and why should I care as a stroke survivor?
How sDHT could prevent the “Slinky Effect” in Stroke Recovery
Why Longitudinal Physical Activity Monitoring is Critical for Lifelong Stroke Aftercare to Achieve Balance
Call to Action: Why we need industry to receive input by stroke survivors and clinicians to build digitally enabled care pathways
By David Dansereau, MSPT from my upcoming new book, Closure After Stroke
Key terms:
Digital Health: Learning the Lingo- What is a sDHT anyway?
The abbreviation "sDHT" typically refers to sensor-based digital health technology. The U.S. Food and Drug Administration (FDA) uses this term to identify medical devices that incorporate sensors and digital health technologies, which are authorized for marketing in the US, according to the FDA. It's also used in the context of medical devices to describe those that utilize sensors to collect and transmit health data digitally.
The sDHT medical device list is a resource intended to identify sDHT medical devices that are authorized for marketing in the United States.
This article references these terms and tools so providing this as helpful information before we dive into how these tools have the potential to transform stroke care.
Background
After a stroke, recovery doesn’t end at hospital discharge or the last outpatient therapy visit—it’s only just beginning in an often long journey back to achieve balance. Yet for many stroke survivors, the abrupt withdrawal of structured support creates a precarious drop-off that can set the stage for physical and emotional decline.
This often invisible transition I’ve coined the “Slinky Effect”, a term I use to describe the downward spiral that many survivors experience when they’re discharged from care and left without the tools, guidance, or accountability to sustain their recovery journey.
Closure After Stroke by David Dansereau,MSPT,CAPS
In too many cases, the momentum built during inpatient and outpatient rehabilitation unravels. Survivors return home without consistent guidance, the correct rehab equipment and programs for, in-home and/or community-based support, or clear metrics to track their progress—if they’re even told what to look for at all.
Without a long-term plan for physical activity and mobility oversight, gains can erode quickly, leading to sarcopenia, increased fall risk, heightened depression and anxiety, and ultimately, a diminished ability to return to work or community life.-Source: Closure After Stroke Book
The Problem: A Fragmented Stroke Recovery Continuum
Stroke survivors are often thrust into a health care void the moment they leave formal care. After nearly 88 episodes on the Know Stroke Podcast, the bulk of most ‘magic wand’ answers given by guests on how to improve the current stroke care pathway identify these after discharge deficits as areas in need of improvement.
Thanks for reading Know Stroke! Subscribe for free to receive new posts and support my work.
A 2021 study published in BMJ Open offers further evidence and found that most stroke survivors reported a lack of long-term, coordinated care and inadequate community-based rehabilitation services, particularly for managing physical activity and mental health [1]. The average length of physical therapy post-stroke is often constrained to a few months, if not weeks—leaving the majority of stroke survivors without structured movement-based interventions long before their recovery plateaus.
The result?
In all my years in PT clinical practice, it is not uncommon to hear stories similar to this one. A survivor may initially walk out of therapy with a cane, but months later struggle to climb stairs or even forget the correct safety sequence to do so, lose confidence, or even sustain a fall and become homebound. This slow but devastating regression—the “Slinky Effect”—often goes unnoticed until a host of preventable secondary health events occur. Read this post for more examples of the Slinky Effect.
You Can’t Manage What You Aren’t Measuring!
A New Digitally Enabled Playbook For Recovery is Possible
There is a Better Path Forward: The Case for Longitudinal Measurement of Physical Activity
Physical activity is a critical biomarker of recovery. Longitudinal tracking of movement—especially in real-world settings—offers valuable insights into function, endurance, fatigue patterns, fall risk, and emotional well-being.
In stroke rehabilitation, consistent measurement of mobility can:
Detect early signs of decline or stagnation, prompting timely intervention
Support tailored goal setting and behavior change, increasing survivor motivation
Offer data-driven insights to healthcare teams to adjust interventions
Reduce rehospitalization, which is common in the first year after stroke
A review in Archives of Physical Medicine and Rehabilitation emphasizes that physical activity post-stroke is often drastically reduced—well below recommended guidelines for cardiovascular health [2]. And yet, very few stroke programs track or support physical activity past the acute or subacute phases.
The same is true for the near endless supply of new rehab technology innovations that receive university funding for feasibility trials, get to clinical testing stages, begin recruiting and reporting initially positive data but eventually don’t make it to market because they can not measure and sustainably report on success and engagement beyond a year or so. They fail to launch out of the lab, attract startup investment or show a ROI for early investors looking for more outcome data. Ultimately they close their doors and leave eager stroke survivors who helped them launch wondering what happened.
Yet, we know better is out there. Fellow stroke survivor Rory Polera found better by monitoring his health data in recovery. His story is a perfect case study on how you can take charge of your own stroke recovery using personal health data generated from readily available wearable technologies. I’ll also be sharing other survivors who have thrived by taking charge of their recovery in my new soon to be released book, Closure After Stroke.
Thanks for reading Know Stroke! This post is public so feel free to share it.
Digital health technologies—especially wearable activity monitors, remote patient monitoring platforms, and AI-enhanced analytics—have opened the door to a new era of health and medical monitoring.
These tools have the potential to also allow stroke survivors and their care teams to track daily steps, gait quality, heart rate variability, sedentary behavior, and more, beyond the clinic walls.
But the tech alone isn’t enough.
What’s needed is a clinical overlay powered by trained physical therapists, occupational therapists and care navigators who understand stroke-specific patterns of mobility, compensatory movements, and post-stroke fatigue and can support tech enabled longitudinal care surveillance for stroke.
When wearable data is interpreted by a stroke-savvy PT/OT or other rehab care team member, it becomes actionable—enabling the design of personalized movement prescriptions, early detection of regression, and real-time therapy and coaching for survivors and care partners.-David Dansereau,MSPT,CAPS
AI further amplifies this model by:
Learning individual mobility baselines and flagging deviations
Triggering nudges or reminders to move, hydrate, or perform home exercises
Identifying potential safety risks or decline trends
Enabling predictive analytics that could prevent future strokes
Did you know?
A pilot program published in Journal of NeuroEngineering and Rehabilitation found that stroke survivors who engaged in telerehabilitation paired with wearable tech had greater adherence and mobility outcomes than those with traditional care models alone [3]. I was fortunate to be at ISC in 2020 when Steve Cramer from UCLA reported on these findings in his keynote presentation about the potential for the future of stroke rehabilitation being in the home. See my blog post about my takeaways from this conference.
Rebuilding Confidence, Reducing Risk, and Returning to Life
Longitudinal mobility tracking, combined with digital tools and expert guidance, empowers survivors to reclaim agency over their health. This approach addresses not only the physical barriers to recovery but also the emotional toll—providing reassurance, reducing anxiety, and promoting accountability.
It also supports forward thinking return-to-work initiatives by:
Quantifying functional capacity over time
Allowing occupational therapists and vocational counselors to tailor return-to-work plans
Providing employers and insurers with objective recovery data
A Call to Action
If we’re serious about reducing the lifelong burden of stroke, we must invest in connected, person-centered ecosystems of care that extend far beyond hospital discharge.
‘Physical activity should be treated not as a short-term therapy goal, but as an essential medicine, and with its correct dosing can become a measurable component of long-term brain and body health to restore a body in balance after stroke. Sensor-based digital health technologies (sDHT) have the potential to connect this care pathway in stroke.’-Closure After Stroke Book
The tools are here. The data is telling us what we’ve long suspected: stroke recovery is not linear, true stroke plateaus have been debunked and are often a term used to prohibit more time in therapy.
The leveling off of progress should rather be viewed as an opportunity as the body is simply recalibrating and looking for more or sometimes less input, and when we leave survivors to navigate this maze alone, we risk pushing them into the Slinky Effect—where gains unravel with each missed opportunity to intervene and recalibrate for the next phase of recovery.
‘A New Digitally Enabled Playbook for Stroke Recovery is Possible’-Dansereau Closure After Stroke
It’s Time to Rethink Stroke Care
It’s time to call out national organizations and let them know survivors are not their product, they should be their customer, so serve them what they are looking for on your menu. Invest in innovation for them and with them by your side, guiding your next executive moves.
Let’s move beyond episodic therapy models and build a new infrastructure of ongoing movement, measurement, and motivation—one step, one wearable, one industry leader and tech innovator at a time.
As you have learned in this article, with the FDA’s recent release of a new category to its lists of medical devices that incorporate digital health technologies, it now includes sensor-based digital health technologies (sDHTs). These are the tools that capture real-world mobility and health data.
The capture of this previously missing high-resolution data like movement, glucose levels, heart rate, voice, and sleep patterns in stroke recovery using sensors embedded in technologies you can affordably wear, keep in your pocket, and have in your home have the potential to offer meaningful insights for care teams and to advance real world stroke care and research. These actionable insights are what was previously missing in care plans. The missing link between in-clinic data and real world data in the home is no longer the excuse not to connect better care.
A CALL TO ACTION
To Oura, Apple, Whoop and others innovating in this sDHT ecosystem, we need you to help us and build solutions that support us, one survivor at a time.
Stroke support organizations should also step up, involve the stroke survivor and caregiver patient voice and involve us in research, product design and programs that matters to us throughout our recovery.
If you don’t know, ask us.
Help us with designing specific digital pathways and tools to address stroke survivors and care partners' unique needs. We are tired of being the product to be displayed for your fundraising campaigns, or at your annual conferences we aren’t invited to nor can we afford to attend.
We are unfortunately your customer and you are not serving us well at this moment in time. The stroke recovery plateau myth has been debunked after all, yet we are still treating stroke after care like we did 20 years ago and far too many stroke survivors are still being sent home with the message, this is ‘as good as it gets’.
It is beyond time for stroke to get its digitally enabled break out moment to offer better care options. Neuroplasticity is simply a terrible thing to waste.
References:
Andrew NE, Kilkenny MF, Naylor R, et al. Long-term unmet needs after stroke: Systematic review of evidence from qualitative and quantitative studies. BMJ Open. 2021;11:e041912. doi:10.1136/bmjopen-2020-041912
Tieges Z, Mead G, Allerhand M, et al. Sedentary behavior and physical activity after stroke: A systematic review. Archives of Physical Medicine and Rehabilitation. 2015;96(1):30-38.
Cramer SC, Dodakian L, Le V, et al. A Feasibility Study of Expanded Home-Based Telerehabilitation After Stroke. Journal of NeuroEngineering and Rehabilitation. 2020;17:25. doi:10.1186/s12984-020-00653-1
David, this is a brilliant and incredibly important piece. The "Slinky Effect" is a perfect and frankly, devastatingly accurate, metaphor for the gap in longitudinal care that so many people fall into.
As a biochemist focused on healthspan, your central argument, "You Can’t Manage What You Aren’t Measuring", resonates deeply. We see this not just in stroke recovery, but across the entire spectrum of aging. The slow, silent erosion of muscle mass (sarcopenia) and metabolic function often goes unnoticed until a crisis hits, precisely because it isn't being tracked.
Your advocacy for using sensor-based digital health technology (sDHT) to monitor real-world physical activity is the clear path forward. It's about moving from a system of acute, episodic interventions to one of continuous, data-driven oversight. This is how we can finally start to proactively manage, and even reverse, the downward slide.
A vital and necessary call to action. Fantastic work.
David, this is a brilliant and incredibly important piece. The "Slinky Effect" is a perfect and frankly, devastatingly accurate, metaphor for the gap in longitudinal care that so many people fall into.
As a biochemist focused on healthspan, your central argument, "You Can’t Manage What You Aren’t Measuring", resonates deeply. We see this not just in stroke recovery, but across the entire spectrum of aging. The slow, silent erosion of muscle mass (sarcopenia) and metabolic function often goes unnoticed until a crisis hits, precisely because it isn't being tracked.
Your advocacy for using sensor-based digital health technology (sDHT) to monitor real-world physical activity is the clear path forward. It's about moving from a system of acute, episodic interventions to one of continuous, data-driven oversight. This is how we can finally start to proactively manage, and even reverse, the downward slide.
A vital and necessary call to action. Fantastic work.