The Knee That Is Complaining About the Ankle
Tom, 24, plays recreational soccer twice a week and runs 5 km on weekends. He has sprained his right ankle twice in the past 18 months, most recently five months ago, and did no rehabilitation either time. For six weeks he has had left anterior knee pain that appears with running and descending stairs and reaches 4/10 at worst. His right ankle feels stiff and occasionally gives way on uneven ground. Assessment shows right ankle dorsiflexion of 6° versus 14° on the left, single-leg heel raise of 18 on the right versus 25 on the left, and a single-leg squat where the right heel lifts and, when standing on the left, the left knee drifts medially with the right side of the pelvis dropping. Balance on the right with eyes closed is markedly worse than on the left. He wants to keep playing and asks whether the knee is the real problem.
1. Explain how a right ankle problem could produce left knee pain, and identify what you would screen to confirm the chain.
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The chain in plain terms. Tom's right ankle has limited dorsiflexion and poor calf endurance, so during running and landing he cannot get the tibia to travel over the foot on that side. He compensates by pushing off early, altering his stride, and shifting load to the left leg. The left leg then absorbs more impact and more single-leg stance time, and on the left he already has a frontal-plane control problem: the pelvis drops on the right and the left knee drifts inward. That combination - more load on a limb that cannot control its own alignment - is a plausible route to anterior knee pain without anything being wrong with the knee itself. This is regional interdependence: the site of symptoms is not the site of the driver.
Also consider the sensorimotor side. Two sprains without rehabilitation, plus worse eyes-closed balance on the right, suggests altered proprioception and ankle stability, which changes landing strategy before the knee ever complains.
Screens to confirm:
- Re-test ankle dorsiflexion with the heel flat and knee over the second toe; note the end-feel.
- Single-leg squat with the right heel lifted to see whether the left knee drift is partly driven by the right limb's contribution to his overall strategy - less useful here, so instead test left single-leg squat after right ankle mobilization to see if the pattern shifts.
- Single-leg hop and landing on each side, watching for knee position and confidence.
- Right ankle stability: anterior drawer and talar tilt, plus single-leg balance eyes open and closed.
- Training and playing load over the past eight weeks, and footwear on both feet.
2. Write Tom's first four weeks of work in ILEA order, including how you would manage his soccer and running.
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Inhibit (daily, 8 minutes)
- Right calf and soleus self-release, 60–90 s.
- Peroneal and lateral calf ball release, 45 s, if the ankle feels guarded.
Lengthen (daily)
- Knee-to-wall ankle mobilization with a band, 3 x 10, 2-second hold at end range.
- Bent-knee soleus stretch, 30 s x 3.
Activate (three times a week)
- Single-leg heel raise on the right, 3 x 10, building toward 3 x 15, then adding load. Right baseline is 18 vs 25, so calf capacity is a clear target.
- Left side-lying hip abduction and single-leg bridge, 3 x 10 each, to address the pelvic drop.
- Right single-leg balance, eyes open for 30 s, progressing to eyes closed with a counter nearby, 3 x 20 s.
Integrate (three times a week)
- Left step-down with the knee tracking over the second toe, 3 x 8, slow.
- Split squat with a heel lift on the right, 3 x 8.
- Single-leg hop and stick on the right, low height, 3 x 5, only once heel raises are symmetrical.
Load management. He can keep playing, but not as-is. Drop to one soccer session plus one run per week for weeks 1–2, keep pain at or below 3/10 during activity and back to baseline within 24 hours, and remove downhill running and uneven-surface play. Add the second soccer session back at week 3 only if the left knee pain has not increased and the ankle range has improved.
Re-test ankle dorsiflexion and heel raise count at weeks 2 and 4.
3. What are the referral triggers for Tom, and how would you answer his question about whether the knee is the real problem?
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Refer if:
- The right ankle gives way more often or feels unstable in daily life, or he rolls it again - repeated giving way with no rehabilitation progress needs a proper ankle assessment.
- New locking, catching, swelling, or a true giving-way episode at the left knee.
- Left knee pain that rises above 5/10, persists at rest, or disturbs sleep.
- Numbness, tingling, or weakness in the foot, or a calf that is hot and swollen.
- No change in the single-leg squat or running pain after four weeks of consistent work.
Answering his question. The knee is where he feels it, and it is real, but it is probably not the origin. His right ankle is stiff and his right calf is weak; his left hip does not control his pelvis in single-leg stance. The knee sits between those two problems and takes the load. If you treat only the knee - tape it, rub it, strengthen the quadriceps - you may settle the symptom while leaving the reason he has it in place, and it will come back when he returns to full training.
That said, keep measuring the knee. It is the outcome that tells you whether the plan is working: if the left knee pain is unchanged at week 4 while ankle range improves, the hypothesis needs revisiting and he needs a referral rather than another block of the same work.
End with the honest framing: this is a load-and-movement problem until proven otherwise, and the fact that his ankle has never been rehabilitated is the most fixable thing in the picture.