The effects of different focus cues and motor learning strategies on landing mechanics in male handball players

Anterior Cruciate Ligament (ACL) injuries are a major concern in sports, especially among athletes with limited ankle dorsiflexion, impacting performance and career longevity. Targeting kinetic and kinematic risk factors of high-risk sports actions through effective strategies is crucial for injury mitigation. This study aimed to assess the impact of internal focus (IF), and external focus (EF) within linear (LP) and differential learning (DL) methods on movement quality of a single leg drop jump (SL-DJ) task training in male handball players with restricted ankle dorsiflexion. Sixty-five professional handball players (aged 20-25 years) with ankle dorsiflexion <10 degrees were randomly assigned to five groups: (1) Control group (n=13), (2) EF-LP (n=13), (3) IF with LP (IF-LP) (n=13), (4) EF-DL (n=13), and (5) IF-DL (n=13). A single 30-minute training session comprised four tasks (double-leg squats, single-leg squats, single-leg step-downs, and lateral step-downs). Pre-test, post-test, retention (24 h), and transfer (48 h, elevated task height) assessments measured joint angles (hip, knee, ankle), ground reaction forces (GRF), and moments (hip and knee) of a SL-DJ task using a 3D motion analysis system. The EF-DL demonstrated significant improvements, with increased ankle dorsiflexion angle, decreased knee valgus angle, and lower vertical GRF during SL-DJ (p < 0.001). The IF-DL showed moderate gains, while LP were less effective during retention and transfer phases. The control group did not exhibit significant improvements in any SL-DJ performed. DL combined with an EF led to significant improvements in biomechanical variables associated with ACL injury risk during SL-DJ tasks, suggesting enhanced neuromuscular efficiency and adaptability. This approach is particularly beneficial for short-term interventions and dynamic sports conditions. Future studies should expand to other sports, genders, and long-term training protocols to validate and broaden these findings.