"11 months post ACL tear he was unable to dampen impact loads"

Here’s a transcription excerpt of our webinar with Jay Dicharry on this interesting ACL case: 

“I basically stuck a sensor on one of our athletes, who I knew had an ACL tear about 11 months ago. He was the ginny pig of our gait assessments, and we looked at his data and found some things that were really really important. And I said hey, let’s talk about something. I said “how are you doing”, and he said, my ACL tear was 11 months ago”. And, his physiotherapist released him back to running and said, “you’re doing pretty well”. Well, we know from research that things aren’t completely healed after all, 12,13 months, or even a year and a half window—following a tear.  But, if you just look at the range of motion or raw strength numbers, you miss some things“.

I’m not going to get too ‘deep in the weeds’, but I’ll give you really quick some numbers here. On the left side of the screen in the top corner we have ‘Impact Magnitude’, and this is somewhat reflective of the strength your athlete brings to the table when they’re running. So we can measure the amount of impact they have every time. If he’d have a strength imbalance you might see a large asymmetry here, but we don’t see a large asymmetry here. 

If we look at impact duration (top right corner metric), though,  things are actually very large—we see a huge shift. Things are out the green and we’re now around the caution level. We’re almost in the very high number on that left leg. So, what we found was—this runner—11 months post ACL tear, was not able to dampen impact loads. We talk about strength, (i.e., how much force you can put out), but is time a factor? Nope! Power is about how quickly you can put out forces, and because running happens quickly, this is a way you can look stride for stride if you’re seeing adequate power output to dampen these impact loads. So if we find asymmetries here, that’s telling to know what’s really going on. We can see very clearly that he can’t dampen loads very effectively on his left leg, so what he did was threw extra loads over to his right leg. And, even though the therapist told him he was ‘strong’, he lacks the functional ability to dampen loads symmetrically. And we’re releasing him back to running? Would we really do this if we had better tools to say, ‘hey, here is where we are’?

I know that this individual is strong, they just can’t generate this force fast enough. And it comes back to the key aspect of the rate of force development. So I know I’m not going to spend time doing strength work with this individual. I’m going to spend time improving his impact capacity—so how he learns to dampen those loads symmetrically over time, and how I can make sure that translates over to running gait. So, this information is just like a ‘aha this is cool, things are asymmetric’. They’re actually very telling about what you need to work on


Picture of Case insight provided by: Jay Dicharry, MPT, CSCS

Case insight provided by: Jay Dicharry, MPT, CSCS

Jay Dicharry built his international reputation as an expert in biomechanical analysis as Director of the SPEED Clinic at the University of Virginia. Through this innovative venture, Jay was able to blend the fields of clinical practice and engineering to better understand and eliminate the cause of overuse injuries in endurance athletes. His unique approach goes outside the traditional model of therapy and aims to correct imbalances before they affect your performance. Jay wrote a book on running gait assessments: he is author of "Anatomy for Runners", writes columns for numerous magazines, and has published over 30 peer-reviewed journal articles. Having taught in the Sports Medicine program at UVA, he brings a strong bias towards patient education, and continues to teach nationally to elevate the standard of care for Therapists, Physicians, and Coaches working with endurance athletes.

Originally from New Orleans LA, Jay completed the Masters of Physical Therapy degree at Louisiana State University Medical Center and is a Board-Certified Sports Clinical Specialist. Jay has had an active research career, and consults for numerous footwear companies, the US Air Force and USA Track and Field. His research focus on footwear and the causative factors driving overuse injury continues at Rebound, and provides his patients with an unmatched level of innovation and success.

In addition to his clinical distinction, Jay is a certified coach through both the United States Track and Field Association and the United States Cycling Federation, and certified Golf Fitness Instructor through Titleist Performance Institute. He has a competitive history in swimming, triathlon, cycling, and running events on both the local and national level, and has coached athletes from local standouts to national medalists.

Start assessing Functional load capacity in ACL

Speak to a member of our Runeasi team, and learn how Runeasi can improve your client outcomes returning from ACL.

If you already have a full picture of Runeasi, go for a 15min call to quickly chat about the possible next steps. Do you want to go more in detail and learn about our parameters, schedule a 45 min demo.


1. Global movement quality

Track and improve your client’s Runeasi running quality. Identify their weakest link with our advanced visualisation.

2. individual recommendations

Get individual training and cueing recommendations to improve your client’s weakest link.

3. Real-time feedback


4. Session trends

Learn more about your client’s running quality during daily training. Our session trends show when and where the quality drops with fatigue.

5. Quick comparisons

Compare pre-post data to show intervention effects on the movement quality. 


1. No motion artifacts. The Runeasi belt is secured tightly against the body and the skin to capture the actual movements of the body’s center of mass. Attaching or clipping the sensor directly to the pants would allow the sensor to wobble from side to side (i.e., measuring the wobbling of the pants, and not the human body.

2.  Easy to standardize the sensor’s positioning. The Runeasi belt makes it easy to consistently position the sensor close to the center of mass. Attaching the sensor directly to the pants would dramatically affect the reliability of the outputs as the height and tightness of the pants will affect the results. Moreover, these pants attachments often shift sideways while running which further decreases the data quality. 

 3. Comfortable to wear.  Hundreds of runners confirmed that they immediately forget about our belt while running. This allows them to move without any restrictions and allows us to capture movements that are representative of a client’s true biomechanics.



Accurately captures full range of motion and kinetic parameters by leveraging wide sensing range (16 Gs) & high sampling frequency (1000 Hz)


Built to withstand high intensity training and sweating. Suitable for the outdoor elements, come rain or shine. Robust to handle the repetitive and ruthless impact shocks of running.

Lightweight & SLIM

Seamlessly integrates onto the body to support movement without restrictions. Weight: 9.4g/0.33oz with battery. Dimensions (36.6mm/1.44” dia. X 10.6mm/ 0.42” thick)

No charging wireless

Replaceable coin-cell battery with operating time up to months, depending on the usage. Bluetooth® 5.0 radio for effortlessly transmitting data real-time or post-session.