06/16/2026
Your Achilles stopped hurting months ago.
But it may still produce 20% less peak force than the other side.
Here’s what you’re missing after Achilles tendinopathy, a calf strain, or a partial tear: pain resolves faster than tendon stiffness does.
Stiffness is the property that lets your Achilles store and return energy at stride speed — and it lags strength recovery by months. That’s why force production can look normal on a discharge exam while your tendon is still 15–20% below where 1,500 strides per mile demands it. And it’s why recurrence rates after calf and Achilles injuries sit near 30% in the first season back.
The 5-metric panel inside this carousel is what separates “pain-free” from “ready to run”:
→ Seated plantar flexion MVIC at 10° dorsiflexion — the position your Achilles actually loads in mid-stance, not a standing 0° test
→ Heel raise endurance under strict 1010 tempo with a locked knee
→ Reactive Strength Index (RSI) on a drop jump — how fast your tendon returns load
→ Post-endurance peak force — because symmetry at rest is not symmetry at mile 4
→ Single-leg hop distance for global limb output
Most discharge exams check the last one. The other four are where re-injury hides.
Identify what matters. Test what matters. Train what matters.
If this gave you a new lens on your return-to-run:
• Follow Dr. David Waltman, PT for education on testing thresholds and return-to-sport criteria
• Save this for the next time someone tells you they’re “cleared” but their tendon still feels off
• Share it with a runner, lifter, or hooper coming back from Achilles, calf, or tendon issues
For athletes who refuse to plateau.
06/14/2026
Ask yourself these questions if you’ve had a major injury.
Is the injured side at least as strong as it was before the injury?
Is the injured side at least as strong as the uninjured side?
Do you feel as confident in your ability after the injury as before?
if any of these answers are no, why?
Even though we can’t predict a future injury with 100% certainty, the technology and research available now is light years better than it was 20 years ago or even 5–10 years ago.
Notice how I didn’t ask you if you have returned to your sport after your injury.
Playing your sport again after an injury is a low bar to set.
I have a patient now who plays basketball once a week, but couldn’t do a knee extension more than 10 pounds.
How could this be?
Simple. Compensation. Your body learns how to avoid what is weak and use what is strong.
But the result will go one of two ways.
Either you keep playing on a knee that week and be a shell of what you were before the injury.
Or you will likely have another serious injury because of the significant weakness, asymmetry, and compensation that has now developed.
So just because you are playing your sport again does not mean you are ready.
Don’t you want to actually feel good, strong, and confident playing the sport you love, instead of just running around on the court thinking back to how it used to be?
You may be older now, but that sure as s**t does not mean you can’t improve.
Identify what matters. Test what matters. Train what matters.
That’s what the pros do. And that’s what I do here at Dr. David Waltman, PT
06/02/2026
Meet KEZI — your AI assistant for return-to-sport testing and performance programming.
Force plate testing is only as good as what you do with the data.
Hundreds of metrics don’t help you decide if your athlete is ready to play.
KEZI does.
🔹 Auto-syncs your VALD data — ForceDecks, ForceFrame, DynaMo, NordBord — straight in, no getting lost in the Hub
🔹 Reads it in context — pulls in injury history, sport demands, phase of rehab, and the latest research
🔹 Tells you what to do next — clear, criteria-based decisions for return-to-sport and the next training block
🔹 Built for performance coaches — not data scientists
Stop staring at a screen full of numbers wondering what they mean.
Get the decision — backed by evidence, calibrated to your athlete.
KEZI turns your VALD data into something useful.
👉 DM “DEMO” to see KEZI in action.
