Tennis Leg

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Expert Patient Guide · Foot & Ankle Surgeon · London & North London

Tennis Leg (Calf Muscle Tear)

A patient guide to calf muscle tears, how they differ from an Achilles tendon rupture, and how they are treated — by Mr Matthew Welck, Consultant Orthopaedic Foot & Ankle Surgeon, Royal National Orthopaedic Hospital (RNOH) Stanmore and UCL, London.

At a Glance: Tennis Leg

Condition	Tennis leg — a tear where the inner calf muscle (medial gastrocnemius) joins its tendon.
Who it affects	Typically active adults around 40; around four times more common in men than women.
Usual mechanism	Pushing off, lunging or sprinting with the knee straight and the ankle bent upwards.
Classic symptom	Sudden calf pain with a “pop”, often described as feeling kicked from behind.
Diagnosis	Clinical examination; ultrasound is first-line imaging, MRI for complex or high-grade tears.
Key differentials	Achilles tendon rupture, deep vein thrombosis (DVT), ruptured Baker’s cyst.
Treatment	Almost always non-surgical: early loading, compression and structured rehabilitation.
Recovery	Most people return to sport within 6–12 weeks; re-tear is uncommon (around 1%).
Specialist	Mr Matthew Welck — Consultant Orthopaedic Foot & Ankle Surgeon, RNOH Stanmore & UCL, London.

Introduction

“Tennis leg” is a sudden tear of the calf muscle, first described in a tennis player in 1883. It was long blamed on the small plantaris muscle, but we now know that almost always the tear occurs where the inner (medial) head of the calf muscle hands over to its tendon — the myotendinous junction. It is one of the more common sports injuries seen in foot and ankle practice, affecting runners, racquet and court sports players, footballers and recreational athletes alike. The great majority heal fully without surgery, provided the diagnosis is right and rehabilitation starts early.

Anatomy

The calf has three muscles. The gastrocnemius has two heads crossing both knee and ankle; the deeper soleus crosses the ankle only and provides about a third of push-off power. Both merge into the Achilles tendon. A slender fourth muscle, the plantaris, is present in around nine people in ten but contributes under 1% of push-off force. The inner head of the gastrocnemius is the largest and most powerful, rich in fast-twitch fibres suited to sprinting and jumping. Where its fibres become tendon, the tissue stretches more than muscle or tendon alone — an efficient spring, but a mechanical weak point.

Pathophysiology

The tear happens when the muscle contracts while being forcibly lengthened — an eccentric load. The classic position is knee straight with the ankle bent upwards: lunging for a drop shot, accelerating, or pushing off uphill. Crossing two joints and built from short, powerful fibres, the inner calf head takes the greatest strain. Calf elasticity declines after the age of 40, and men have a stiffer, less forgiving junction than women — which helps explain why tennis leg is about four times more common in men and peaks in middle age. Repeated minor strains leave scar tissue that tolerates load less well.

Diagnosis

Clinical Assessment

Most people describe sudden, sharp calf pain with an audible “pop” and the sensation of being kicked from behind. Weight-bearing becomes difficult immediately. Swelling and bruising appear over 24–72 hours and track down the leg under gravity, sometimes reaching the ankle or heel — bruise position reflects how blood spreads between tissue planes and is not a guide to the site or severity of the tear. Examination shows tenderness over the inner calf, occasionally a palpable gap or firm lump of clot. A calf-squeeze (Simmonds–Thompson) test is done in every case: normal in tennis leg, abnormal in Achilles tendon rupture.

Imaging

Ultrasound is first-line — quick, inexpensive and able to assess the calf as it moves, showing the tear and any blood collection between the two muscles. MRI is the reference standard for mapping the injury and is used in severe, atypical or high-level sporting cases. Tears are graded 1 to 3: swelling only, partial tear, or complete tear. Those involving tendon tissue take longer to settle than tears confined to muscle.

Differential Diagnosis

Achilles tendon rupture — the most important alternative. Pain sits 2–6 cm above the heel, tiptoe standing is impossible and the calf-squeeze test is abnormal. A distinct injury needing prompt specialist assessment.
Deep vein thrombosis (DVT) — calf pain and swelling without clear injury warrants urgent Doppler ultrasound.
Ruptured Baker’s cyst — fluid leaking from behind the knee closely mimics a calf tear.

Complications

Complications are uncommon. DVT is the most frequent, favoured by reduced mobility, inflammation and pressure from a blood collection. Compartment syndrome — dangerously high pressure within the calf — is extremely rare but a surgical emergency, and has been reported after blood-thinning treatment given for a wrongly diagnosed clot. Muscle retraction is exceptional and described after prolonged splinting without rehabilitation. All are best prevented by accurate early diagnosis and keeping the leg moving.

Treatment

Treatment is graded to the injury. Grade 1 is swelling and stretch of the muscle with no tearing; grade 2 is a partial tear, usually with a collection of blood between the calf muscles; grade 3 is a complete tear, often involving the tendon sheet (aponeurosis). The principles are the same at every grade — protect briefly, then load progressively — but the timescales differ. Grade boundaries are not sharp, and involvement of tendon tissue predicts a slower recovery more reliably than the grade itself.

Medical Management

Care starts promptly, without waiting for a scan, once Achilles rupture and DVT are reasonably excluded. Common to all grades: ice in the first days, elevation, weight-bearing as comfort permits, and anti-inflammatories for a day or two only, as prolonged use may hinder muscle healing. Draining a blood collection, casting the ankle down and strict immobilisation are all avoided — they delay recovery and raise clot risk. Routine blood thinners are not indicated, and platelet-rich plasma (PRP) has no direct evidence in tennis leg.

Grade 1: simple analgesia, ice and a compression sleeve for a few days. Walk normally from the outset; crutches and a heel raise are rarely needed.
Grade 2: elastic compression for two to four weeks to limit bleeding, a temporary heel raise for one to two weeks, and crutches for the first few days if you are limping. Expect visible bruising to track down the leg.
Grade 3: the same measures held longer — compression up to four weeks, heel raise for three to four weeks, crutches until walking is even. MRI is usually obtained, review is closer, and vigilance for DVT and (very rarely) compartment syndrome is higher.

Rehabilitation

Rehabilitation is the treatment that matters most. Every grade follows the same sequence — pain-free movement and gentle stretching, then progressive eccentric calf strengthening, then running and sport-specific work — but each stage is entered on ability, not on the calendar. Outcomes depend more on graded loading and adherence than on supervision.

Grade 1: stretching and pain-free movement within a day or two, calf raises within the first week, running usually at one to three weeks. A home programme is generally enough.
Grade 2: gentle stretching, massage and drainage in week one; eccentric loading introduced from around two weeks and built steadily; running once you walk without limping and manage repeated calf raises comfortably, typically three to six weeks. Supervised physiotherapy is advisable.
Grade 3: protected early movement, avoiding stretching into pain for the first two to three weeks; strengthening from around three to four weeks; running rarely before eight weeks. Supervised physiotherapy with objective strength testing is recommended, and longer still where tendon tissue is involved.

Surgical Management

Surgery is exceptional — only a handful of cases appear in the published literature, and there is no established indication.

Grades 1 and 2: no role. These heal reliably with rehabilitation.
Grade 3: still very rarely required, and considered only for persistent pain, significant loss of push-off strength, or muscle retraction confirmed on MRI after well-conducted rehabilitation has failed — usually three weeks to six months after injury. Scar tissue is cleared, with or without direct repair, followed by brief protection and structured rehabilitation. Reported results are good, with return to work at around three months and sport by six.

Recovery and Return to Activity

Structural healing usually completes between three and sixteen weeks depending on grade, and most people walk comfortably by three to four weeks. Return to sport broadly follows the pattern above: around 1–3 weeks for grade 1, 3–6 weeks for grade 2, and 8–12 weeks or longer for grade 3, extending to three or four months where tendon tissue is involved. Scan appearances lag behind recovery, so repeat imaging is not needed before returning to sport when progress is good — decisions rest on symptoms, strength and tolerance of loading. Re-tear is uncommon, reported at under 1%.

Conclusion

Tennis leg is a common and generally benign calf injury in active people. The priorities are to confirm the diagnosis, exclude an Achilles tendon rupture and a DVT, avoid unnecessary immobilisation, and rehabilitate early and progressively. Managed this way, recovery is usually complete within three months and recurrence is rare.

Why Choose Mr Welck?

Mr Matthew Welck is a Consultant Orthopaedic Foot & Ankle Surgeon at the Royal National Orthopaedic Hospital (RNOH) Stanmore, one of the UK’s leading tertiary orthopaedic centres, and Honorary Associate Clinical Professor at UCL. His specialist practice covers total ankle replacement, complex foot and ankle reconstruction, revision surgery, Weight-Bearing CT, and sports foot and ankle injuries including calf tears, Achilles tendinopathy and Achilles tendon rupture. He has authored more than 50 peer-reviewed publications and is research-active in imaging and outcome measurement. Patients are seen across London and North London with access to ultrasound, MRI and Weight-Bearing CT, and every plan is agreed through shared decision making.

Frequently Asked Questions

Is tennis leg the same as an Achilles rupture?

No. Tennis leg is a tear in the calf muscle itself. An Achilles rupture is a tear of the tendon, usually 2–6 cm above the heel — a different injury needing different treatment. The two are separated at examination, supported by ultrasound if needed.

Do I need a scan?

Not always — the diagnosis is usually clinical. Ultrasound confirms the tear, gauges severity and helps exclude a clot. MRI is reserved for severe, atypical or high-performance cases.

Should I be worried about a blood clot?

Deep vein thrombosis both mimics tennis leg and is a recognised complication of it. Calf pain and swelling without clear injury, or worsening swelling after a few days, should be assessed urgently.

Can I walk on it?

Yes, as comfort allows — early controlled loading speeds recovery. Crutches may help briefly, but prolonged immobilisation in a boot or cast is discouraged.

How long until I can run again?

Typically once you can walk without limping and perform repeated calf raises with minimal discomfort — often 3–6 weeks for a moderate tear.

Will I need surgery?

Very rarely — only a handful of cases are published, for persistent weakness or confirmed muscle retraction after rehabilitation has failed.

Does having tennis leg mean I will need an ankle replacement later?

No. Tennis leg is a muscle injury and does not cause ankle arthritis. Total ankle replacement is a separate operation for a worn ankle joint, most often following previous fracture.

Where can I see a foot and ankle surgeon in London for a calf or Achilles injury?

Mr Welck consults across London and North London, with NHS practice at the Royal National Orthopaedic Hospital (RNOH) Stanmore. Appointments: 07547 395 270 or secretary@matthewwelck.com.

Book a Consultation

If you have torn a calf muscle, or you are unsure whether your calf pain is a muscle tear, an Achilles injury or something else, specialist assessment early gives you the clearest plan and the widest range of options.

Email: secretary@matthewwelck.com Call: 07547 395 270

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Written by: Matthew Welck | Consultant Orthopaedic Foot & Ankle Surgeon London — last updated 26 July 2026

Adapted for patients from Schwach M, Gaulin B, Vermorel P-H, Horteur C, Tourné Y. Tennis leg: diagnosis and management — a state-of-the-art review. The Foot 2026;68:102267. This guide is general information and does not replace individual medical advice.