Anterior cruciate ligament rupture during a cognitively demanding change-of-direction task in football: biomechanical insights from a laboratory injury.

Breast cancer is the most frequently diagnosed malignancy and the leading cause of cancer-related death among women globally, with an annual incidence of 46.8 per 100,000 and a mortality rate of 12.7 per 100,000 (). Its incidence continues to rise, particularly in China, where a growing number of cases are being diagnosed among younger women (). Concurrently, advances in cancer treatment have markedly improved survival outcomes, with breast cancer-specific survival rates now reaching 94% (). Against this backdrop of rising incidence, improved survival, and younger onset age, the quality of life of those affected has become a growing priority. In China, socioeconomic development and increased health awareness have facilitated earlier detection, creating opportunities for timely evidence-based interventions. Despite these advances, clinical management, often involving invasive surgery and intensive treatment, can cause significant physical and psychological distress in patients (), while prolonged caregiving imposes substantial psychological morbidity and emotional burden on family caregivers (). These combined challenges can disrupt family relationships, diminish intimacy, and precipitate a family crisis (). By contrast, some families demonstrate a capacity to adapt effectively and enact positive changes when confronting breast cancer-related challenges (), and evidence confirms that family resilience is critical to this adaptive process (; ). Nevertheless, existing research on family resilience in breast cancer has predominantly focused on identifying associated factors (; ), whereas intervention studies remain scarce. Most available programmes are still at the pre-experimental stage (; ), with only a few randomized controlled trials conducted to date (; ; ). Moreover, these interventions have typically emphasized disease-related knowledge, stress management, and problem-solving skills, delivered in group formats (; ; ) and targeting patients or caregivers separately, thereby overlooking the dyadic unit as an integrated entity. Furthermore, while several dyadic interventions have been developed for chronic illness populations, most have targeted patient-spouse or parent–child dyads (; ; ), assuming a relatively fixed caregiver role. In breast cancer, especially among younger women, caregivers can include parents, spouses, adult children, siblings, and even close friends. To date, this heterogeneity in caregiver identity and relationship has rarely been fully addressed. Whether existing approaches are appropriate for the Chinese breast cancer population therefore remains unclear, underscoring the need for a culturally adapted dyadic intervention.