A Q&A with Alan Premasiri, Director, Clinical Research Operations at ALS TDI
ALS TDI’s ALS Research Collaborative (ARC) Study is a remote research study that partners with people with ALS to collect longitudinal data about their disease. Participants contribute various information from home, including surveys and wearable sensor data. One important use of this data is to help researchers better understand how ALS progresses and how to measure that progression more precisely.
In recent years, ARC data has helped fuel important advances in digital biomarker research. A 2023 study led by Dr. Anoopum Gupta collected natural movement data from participants who wore accelerometers for days at a time. The study demonstrated that this data can sensitively track disease progression and may offer advantages over traditional measures like the ALSFRS.
At the same time, the ARC Study only requires participants to complete short, structured exercises while wearing accelerometers, just a few minutes, no more than once a month.
So which approach provides the most meaningful insight: all-day natural movement, or brief prescribed exercises?
A study by researchers at MGH and ALS TDI was recently published in the Journal of NeuroEngineering & Rehabilitation, and it sought to help answer that question.
The findings show that both structured exercise data and natural movement data provide meaningful insight into upper limb function in ALS. And while all-day wear may be advantageous in certain instances, the study demonstrates that short, structured exercises may often be sufficient to generate meaningful data.
In other words, even brief participation can make a measurable difference.
We spoke with ALS TDI’s Director, Clinical Operations, Alan Premasiri, about what the study found, and why small contributions in ARC matter.
Q: What question were you trying to answer with this study?
Alan:
We already knew that accelerometers can capture meaningful changes in movement over time. Previous research, including studies using ARC data, showed that natural, free-living movement data correlates with disease progression.
But most of that work required long wear times, sometimes 16 hours or more in a day. That’s a significant burden.
In this study, we wanted to understand how the short, prescribed exercises ARC participants already perform compared to the ALS Functional Rating Scale (ALSFRS-R), which is still the current standard tool used in clinics and clinical trials.
Specifically, we asked:
Do the movement metrics we extract from these brief exercise sessions track with ALSFRS-R scores- and do they perform comparably to free-living data?
Instead of monitoring movement all day, participants completed about five minutes of structured arm exercises. We wanted to see whether those short sessions could provide measurements that are both meaningful and aligned with ALS FRS.
Q: What did you find?
Alan:
We analyzed exercise data from 329 ARC participants and extracted four metrics from each session:
- Count — how many repetitions were completed
- Duration — how long each movement took
- Intensity — how strong or vigorous the movement was
- Similarity — how consistent the movements were
Three of those four metrics, especially intensity, showed strong associations with ALS progression.
In fact, the intensity metric performed comparably to free-living monitoring approaches that required at least 16 hours of sensor wear time
That tells us short, structured exercises can provide information similar to what might otherwise require nearly a full day of monitoring.
Q: Why is intensity such an important signal?
Alan:
One of the most interesting findings was that even when someone could still complete the same number of repetitions, the quality of those movements changed.
Intensity declined. Movements became slower and less vigorous over time
Traditional clinical tools like the ALS Functional Rating Scale (ALSFRS-R) rely on score changes. Those scores can remain stable for a period before dropping.
Accelerometer data captures subtler shifts in strength and consistency. It doesn’t flatline the same way. That nuance can be especially valuable in research and clinical trials where detecting smaller changes matters.
Q: How much participation does this kind of research actually require?
This is one of the most common questions we hear from ARC participants: Does a small amount of data really matter?
Alan:
This study is proof that you don’t have to submit a massive amount of time or data to make an impact in ARC.
Our sensitivity analysis showed that as few as five arm swings were enough to produce statistically meaningful associations with ALS functional scores.
In practical terms, even one short session can contribute meaningful insight.
Individually, that may not feel like much. Collectively, it becomes transformative.
The ARC Study is impactful not because any one person does everything, but because many people contribute what they can.
Q: What role did ARC participants play in this publication?
Alan:
They made it possible.
All of the exercise data analyzed in this study came directly from ARC participants. ALS TDI contributed the dataset, and our MGH collaborators led the statistical analysis.
Without participants choosing to share their data, there is no study.
It’s rare in ALS research to have this level of longitudinal, at-home movement data. That resource exists because people living with ALS took a few minutes to perform these exercises at least once.
Q: What happens next?
Alan:
We continue validating these findings with newer ARC data as the study grows.
We’re also focused on understanding meaningfulness, how these digital signals align with how participants experience changes in their daily lives.
Digital biomarkers are an area of increasing interest in ALS research and clinical trials. This study helps lay the groundwork for developing tools that are sensitive, objective, and feasible for people to complete at home.
We’re not finished. But this is an important step forward.
Q: If someone wants to contribute to research, what can they do, and how much do they need to do?
Alan:
The most important thing is simply to participate.
People sometimes feel like if they can’t commit to everything, wearing devices all the time, completing every survey, performing every exercise, then it’s not worth joining. That’s not true.
You don’t have to do everything to make an impact. Even a few exercises or surveys can help move ALS research forward. When over a thousand people each share a little, it becomes powerful research.
ARC is designed to be flexible. Participants contribute what they’re able to, when they’re able to. And that collective effort is what makes large-scale, longitudinal research possible.
When many people each do a little, it becomes something powerful.
The Takeaway
This study shows that:
- Short, five-minute exercise sessions can meaningfully track upper limb function.
- Movement intensity may detect subtle changes earlier than traditional measures.
- As few as five repetitions can contribute valuable research data.
- Hundreds of small contributions create powerful, scalable datasets.
To learn more and enroll in the ARC Study, visit www.als.net/arc.