Simmonds test

The Simmonds test is a calf-squeeze test used to assess for an Achilles tendon rupture. The name Simmonds has been widely used in British literature, while Thompson has been widely used in North American literature. Today, the two names are sometimes combined as the Simmonds–Thompson test. Despite the different names, the procedure is essentially the same.

The calf muscles (Gastrocnemius and Soleus) connect to the heel bone through the Achilles tendon. Squeezing the calf muscles shortens them, pulling on the tendon and causing the foot to move slightly downward. If the connection is intact, squeezing the calf produces a slight downward movement of the toes.

In contrast, if the tendon is completely torn, the force of squeezing the muscles is not transmitted to the foot, so the foot is considered to show no movement or a smaller response than usual. The size of the response is compared with that of the opposite foot.

1. Lie face down — Lie face down on an examination table with both feet hanging relaxed over the edge. The test may also be performed while kneeling on a chair with the knees bent to 90 degrees. 2. Squeeze the calf — The examiner grasps the thickest part of the calf and gently squeezes it toward the Achilles tendon. 3. Observe the foot's response — The examiner watches for a slight downward movement of the foot. 4. Compare with the other side — The same procedure is performed on the uninjured foot to compare the responses of both feet.

The person being examined simply lies comfortably and relaxes. There is usually only a feeling of light pressure when the calf is grasped, and the test takes just a few seconds. Immediately after an injury, swelling and pain mean that the examiner proceeds slowly and carefully.

• People who suddenly felt as though someone had kicked them above the heel during exercise and heard a sound
• People who have difficulty standing on tiptoe after jumping or sprinting
• People who feel as though there is a hollow or depression in the Achilles tendon area
• People whose Achilles tendon pain has worsened and who want to have it assessed

A prospective study published in 1998 compared 174 people diagnosed with a complete rupture of one Achilles tendon with 28 people in whom a rupture was suspected but who did not actually have one. This calf-squeeze test had a sensitivity of 0.96 and a specificity of 0.93, and was more sensitive than manually checking for a gap in the tendon.

A systematic review comparing tests for Achilles tendon injuries was published in 2014. It included 3 studies and concluded that the calf-squeeze test had the highest sensitivity and specificity among the tests reviewed. In another study of 66 people with acute complete ruptures confirmed during surgery, this test, reduced resting ankle tension, and a palpable gap all yielded the same results when assessed together.

During an examination, this test is considered alongside the sensation at the time of rupture, swelling and bruising, a palpable gap, and the strength to stand on tiptoe. If needed, ultrasound or MRI is used to identify the location and extent of the rupture.

• Describe how the injury happened. It helps to explain when it happened, what you were doing, and what sound or sensation you noticed.
• Let your foot hang relaxed. Tensing the foot makes it harder to observe the response.
• Mention it even if you can walk. Even with a rupture, other surrounding muscles may allow you to move your foot or walk, so foot movement alone does not give a complete picture of the tendon's condition.
• Avoid overexertion after an injury. Immediately after an injury, resting without putting weight on the foot is more comfortable.