Achilles tendinopathy shows up as stiffness first thing in the
morning, tenderness a few centimeters above the heel, and a tendon
that complains after faster or hillier sessions. It's among the most
commonly recorded running injuries (Kakouris et al., 2021).
The tendon is a spring. It stores force as you land and releases it
as you push off. It gets irritated when the stride asks it to store
more than it can currently tolerate, more often than it can recover.
That's a load question before it's a strength question, and the load
depends on how you land and how long you stay on the ground.
This page covers what GaitLab Coach looks for when you flag Achilles
pain, and one thing it deliberately won't tell you to do.
A foot that lands well ahead of the hips has to be pulled back under
the body before push-off, which lengthens ground contact and asks
the calf and tendon to work through a longer range. A low cadence
has the same effect: fewer, longer steps, each with more time on the
ground.
Foot strike matters less than the internet debate suggests.
Switching to a forefoot landing shifts load off the knee and onto
the calf and Achilles (LER foot-strike review). If your tendon is already irritated, that's the wrong direction.
GaitLab Coach won't coach you onto your forefoot when you've flagged
Achilles pain.
Fatigue is part of the picture too. A stride that looks fine at the
start of a run can collapse forward at the waist and get slower off
the ground late on, when the tendon is already tired.
Morning stiffness that eases as you walk around
Soreness that rises after speed work, hills, or a sudden increase
in volume
A tendon that feels worse late in long runs, when form tends to
deteriorate
What the video shows
Ground contact time
Longer stance means more time loading the tendon on every
stride. Visible as a foot that lingers before push-off.
Landing position
A foot far ahead of the hip line lengthens contact and adds
braking. Shortening stride length lowers impact loading (stride length and impact review).
Foot strike
Read as one input, not a target. A heel landing under the hips
is fine; a forced forefoot strike adds tendon load.
Cadence and lean
A 5–10% cadence increase shortens stride and contact time
without hurting economy (Sports Health, 2025). A slight lean from the ankles, not the waist, helps.
What GaitLab Coach does with it
Flag Achilles pain before recording and the analysis weights its
findings toward the mechanics that change tendon demand. It also
applies a contraindication: the plan won't include drills that push
you toward a forefoot strike or add plyometric calf load early.
The 4-week plan for an Achilles case typically pairs a small cadence
bump with a landing-position cue, and adds slow eccentric calf work.
That's a focused progression rather than a form rebuild, which is
what the retraining literature supports (Bramah et al., JOSPT 2022).
Findings ranked by tendon load, so foot strike doesn't get flagged
as a problem in isolation
Drills screened against the injury you flagged
Re-film at the end of the plan and compare contact time and
landing position, not how it felt
When form isn't the culprit
Achilles pain is often a training-load story: a jump in speed work,
hills, or volume, or a switch to lower-drop shoes without time to
adapt. Form work doesn't rescue a reckless build. A tendon that is
swollen, has a palpable lump, hurts sharply, or gave way suddenly
needs a clinician before anything else. GaitLab Coach flags movement
patterns linked to overuse risk; it can't assess the tendon itself.
Can a phone video help with Achilles pain in runners?
It can show the patterns that change tendon load: how long your
foot stays on the ground, where it lands relative to your hips,
your cadence, and where your lean comes from. Those are the
coachable variables. It can't measure tendon load directly.
Should I switch to a forefoot strike for Achilles pain?
No. A forefoot landing moves load onto the calf and Achilles. If
the tendon is already irritated, that adds to the problem. Work
on landing position and cadence and let foot strike follow.
How does flagging Achilles pain change the plan?
The findings are ranked by tendon demand and the drill list is
screened for that injury. You won't get hill sprints or forefoot
cues in week one.
Use this guide to understand the movement patterns discussed in a
report. In GaitLab, select the relevant injury context before your
analysis, or skip injury selection for general form feedback.
Start with free form highlights and slow-motion replay. Ranked
findings and the 4-week drill plan require the optional Premium
unlock. A video-based form assessment cannot confirm the cause of
pain.
Record your run, flag Achilles pain, and get the load-related patterns
ranked in order, with drills screened for the tendon. Free to start.
The full report, with the 1–10 score, ranked findings, and 4-week
plan, is a one-time $4.99 unlock.