Unlearning prohibition: the de-implementation of HIV breastfeeding restrictions in the United States.

Flexible flatfoot presents as a normal medial arch in the non-weight-bearing position but collapses under load, often causing medial foot pain, forefoot abduction, hindfoot valgus, subtalar instability and gait abnormalities []. If unmanaged, it may progress to posterior tibial tendon (PTT) degeneration, spring ligament laxity and other secondary deformities. Achilles or gastrocnemius tightness frequently coexists and accelerates deformity progression []. Conservative measures—including anti-inflammatory medication, rehabilitation, arch supports and orthopaedic footwear—may relieve symptoms, but failure can lead to worsening deformity and eventual transition to rigid flatfoot requiring surgical management []. Historically, flatfoot deformity has been attributed to posterior tibial tendon (PTT) insufficiency, which leads to progressive medial arch collapse and secondary deformities. In 2020, the term progressive collapsing foot deformity (PCFD) was introduced to more accurately represent its multi-structural and progressive nature. Subtalar arthroereisis with HyProCure restricts pathological subtalar motion, corrects hindfoot valgus, prevents talar lateral subluxation and reduces strain on the PTT, making it an important option for flexible flatfoot management []. Medial soft-tissue stabilisation, including PTT repair or reconstruction, spring ligament (SL) reinforcement and accessory navicular procedures, further restores medial arch support, with some cases requiring adjunctive bony procedures such as talonavicular fusion or Cotton osteotomy [, ]. Gastrocnemius or Achilles contracture frequently coexists in PCFD, increasing hindfoot valgus and contributing to arch collapse. Although surgical release may improve dorsiflexion, it carries risks such as sural nerve injury, postoperative weakness, adhesions and cosmetic concerns []. Extracorporeal shock wave therapy (ESWT) has recently gained attention for its ability to reduce myofascial contracture and improve tendon elasticity, showing therapeutic potential in flexible flatfoot management []. However, no study has evaluated ESWT in combination with HyProCure and medial column stabilisation (DSP). This study therefore aimed to assess the clinical efficacy of ESWT combined with DSP in patients with PCFD.