Synopsis
Identify acute Achilles rupture without being falsely reassured by residual plantar flexion, protect the tendon immediately, distinguish rupture from midportion and insertional tendinopathy, and coordinate functional rehabilitation, thrombosis assessment and selective surgery.
- Acute rupture typically feels like being kicked in the heel, with a pop, weak push-off and inability to perform a normal single-leg heel rise; pain may settle quickly and should not reassure.
- The high-yield bedside tests are a reduced resting plantar-flexion angle and absent or markedly reduced plantar flexion when the calf is squeezed with the patient prone and knees flexed.
- Residual active plantar flexion does not exclude rupture because tibialis posterior, toe flexors and peroneal muscles can still point the foot.
Key red flags
A sudden acceleration, jump or push-off followed by a pop, weak gait and positive calf-squeeze test is an acute rupture until proved otherwise, even if the patient can still point the foot.
Investigation priorities
Confirm functional tendon discontinuity and avoid false reassurance from residual active plantar flexion.
Management branches
An acute event produces weak push-off, abnormal resting angle, palpable gap or positive calf-squeeze test.
- Stop further dorsiflexion testing, document skin and neurovascular status and place the ankle in the approved plantar-flexed boot or backslab.
- Give mobility and weight-bearing instructions that match the local acute rupture protocol and check the device before discharge.
Key medicines
Paracetamol for acute rupture painTake 500–1000 mg orally when needed, separated by at least 4 hours and limited to 4 g in 24 hours; use a lower maximum with body weight below 50 kg, frailty, malnutrition or liver risk.
Topical diclofenac for tendinopathy painFor a short trial, place 2–4 g of diclofenac 1.16% gel on intact painful skin at each dose; remain within the product limit of three or four daily applications.