Tennis leg, also known as a torn "monkey muscle", is a rupture of the medial head of the gastrocnemius muscle where it merges with the Achilles tendon. It is commonly seen in middle-aged tennis and squash players during sudden knee extension with the foot dorsiflexed. Patients experience immediate pain and swelling in the calf with difficulty walking. Diagnosis can be confirmed with Simmonds' test and imaging if needed to differentiate from other causes of calf pain like deep vein thrombosis. Initial treatment focuses on RICE therapy followed by mobilization and physiotherapy to regain range of motion and strength.

1. Tennis leg
Prepared by: Dr. Ahmed Ibrahim Eldesouky Abouelela
Family Medicine Registrar
MBbcH, MSc.FAM , MRCGP.int

2. Tennis leg
Tennis leg or Torn
‘monkey muscle’
is a rupture of the
medial head of
gastrocnemius at
the musculo-
tendinous junction
where the Achilles
tendon merges with
the muscle

3.  It is not a torn plantaris muscle as
commonly believed.
 The “calf muscle” or triceps surae consists
of three separate muscles (the
gastrocnemius, soleus, and plantaris)
whose aponeuroses unite to form the
Achilles tendon.
 This painful injury is common in middle
aged tennis and squash players who play
infrequently and are unfit.

4. Gastrocnemius
 Calf strains are most commonly found in the
medial head of the gastrocnemius.
 This injury was first described in 1883 in
association with tennis and is commonly
called tennis leg.
 The classic presentation is of a middle-aged
male tennis player who suddenly extends the
knee with the foot in dorsiflexion, resulting in
immediate pain, disability, and swelling.
 Pain and disability can last months to years
depending on the severity and effectiveness
of initial treatment.

5. Plantaris
 The plantaris also crosses the knee and ankle
joints prior to its common Achilles tendon
insertion on the calcaneus. However, the
plantaris is considered largely vestigial and
rarely involved in calf strains.
 Isolated strains are difficult to distinguish
clinically from strains of the gastrocnemius
and can only be identified through imaging.
 If identified recommended treatment is
similar to gastrocnemius strains.

6. Soleus
 Strains of the soleus vary in reported occurrence from rare
to common.
 Soleus muscle injury may be underreported due to
misdiagnosis as thrombophlebitis or lumping of soleus
strains with strains of the gastrocnemius.
 Unlike the gastrocnemius the soleus is considered low risk
for injury. It crosses only the ankle and is largely
comprised of type one slow twitch muscle fibers.
 Soleus strains also tend to be less dramatic in presentation
and more subacute when compared to injuries of the
gastrocnemius.
 The classic presentation is of calf tightness, stiffness, and
pain that worsen over days to weeks.
 Walking or jogging tends to provoke symptoms. Swelling
and disability are generally mild.

7. Clinical presentation of Tennis leg
 A sudden sharp pain in the calf (the
person thinks he/she has been struck
from behind, e.g. a thrown stone)
 Unable to put heel to ground
 Walks on tiptoes
 Localized tenderness and hardness
 Dorsiflexion of ankle painful
 Bruising over site of rupture

8. Differential diagnosis
 Rupture Achilles tendon.
 DVT.
 Sciatica.
 Diabetic peripheral neuropathy.
 Compartment syndrome.

9. Simmonds' test (Thompson
test or Simmonds-Thompson test)

10. Management
 RICE treatment for 48 hours.
 Ice packs immediately for 20 minutes and then
every 2 hours when awake (can be placed over
the bandage).
 A firm elastic bandage from toes to below the
knee.
 Crutches can be used if severe.
 A raised heel on the shoe aids mobility. Women
should wear high heels.
 Commence mobilization after 48 hours rest, with
active exercises.
 Physiotherapist supervision for gentle stretching
massage and then restricted exercise.

11. Thank you
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