The Achilles tendon is the thickest and strongest tendon in the human body, located at the back of the lower leg. It connects the large calf muscles—the gastrocnemius and soleus—to the heel bone (calcaneus). The primary function of this structure is to enable plantarflexion, the movement that points the foot downward, which is necessary for walking, running, and jumping. A complete rupture is a severe, acute injury that immediately compromises the ability to push off the ground and requires prompt medical assessment.
Identifying the Immediate Signs of Rupture
The moment an Achilles tendon rupture occurs, an individual commonly experiences a sudden, sharp impact to the back of the ankle. Many people report an audible and palpable “pop” or snapping sound originating from the heel or lower calf area. This sensation is frequently mistaken for being struck by an object.
Following the initial sensation, pain is typically immediate and severe, localized near the heel. The pain may subside slightly into a dull ache, but the functional consequences become quickly apparent. The most consistent sign of a rupture is the sudden inability to perform ankle plantarflexion.
The injured person will find it extremely difficult, if not impossible, to stand up on the toes of the affected leg. Although some individuals may still be able to walk, this is achieved through compensatory movements that bypass the calf muscles. This compromised gait, coupled with noticeable swelling and bruising that develops quickly around the ankle and lower calf, are strong indicators of a tear.
Performing Simple At-Home Diagnostic Checks
An individual can perform a straightforward check, known as the Thompson Test, to assess the likelihood of a complete tear. This check is based on the principle that squeezing the calf muscle should cause the foot to point downward if the tendon is intact. To perform this, the individual should lie face down with the feet hanging relaxed over the edge of a bed or chair.
A second person can then gently but firmly squeeze the calf muscle on the injured leg. If the Achilles tendon is not ruptured, the squeeze will transmit force to the heel bone, causing the foot to point toward the floor (plantarflex). A positive indicator of a full rupture is a complete absence or a significant decrease in this downward foot movement when the calf is squeezed.
The Thompson Test is highly sensitive for detecting complete ruptures, though it is less reliable for partial tears. Another simple check involves gently running a finger along the length of the tendon. In the event of a full rupture, a noticeable gap or depression can often be felt in the soft tissue approximately two inches above the heel bone attachment point. These self-checks are useful indicators but should not be mistaken for a final medical diagnosis, and a professional evaluation is mandatory.
Urgent Steps Following Potential Rupture
Immediate action following a suspected Achilles rupture is focused on minimizing pain and swelling while preparing for urgent medical attention. The initial first aid protocol involves the R.I.C.E. method, which stands for Rest, Ice, Compression, and Elevation. Rest is paramount, and the injured leg should not bear any weight, as attempting to walk can complicate the injury and subsequent treatment.
Applying ice to the injured area for periods of about 15 to 20 minutes can help to reduce both pain and inflammation. Compression, achieved by gently wrapping the ankle and lower calf with an elastic bandage, helps to control the swelling. Care must be taken not to wrap so tightly that it causes numbness or increased pain.
Elevation of the leg is also a key step, as raising the foot above the level of the heart uses gravity to assist in draining excess fluid from the injury site. This reduces throbbing and swelling in the affected area. After these immediate first aid steps, the next action is to seek professional medical confirmation without delay.
Specialists recommend seeking medical attention within 24 hours of the injury, as the timeline for diagnosis influences the optimal treatment path, which may involve surgery or non-surgical immobilization. The medical consultation will typically include a physical examination and may be followed by imaging tests such as an ultrasound or MRI to fully assess the extent of the tear. Timely intervention is important for planning the repair and ensuring long-term recovery.