Development and evaluation of a knowledge transfer scheme-based foot core training program for male amateur football players

Lower extremity injuries are common among amateur football players, resulting in reduced performance and a prolonged absence from the sport. While most injury prevention programmes focus on the knee, hip and trunk, comparatively little attention has been given to multimodal foot–ankle and lower-limb training programmes incorporating the foot core framework. This study aimed to develop a foot core-based training programme using the Knowledge Transfer Scheme (KTS) and evaluate changes in lower extremity performance outcomes in male amateur football players compared with a control group. This study employed a two-phase design based on the KTS. In the first phase, a six-week foot core-based training programme was developed through expert consultation and a structured evidence synthesis conducted specifically to support intervention development. In the second phase, male amateur football players were allocated to a foot core training group (FCTG; n = 34) or a control group (CG; n = 47) according to their own voluntary choice of training arm. All participants completed pre- and post-intervention assessments, which included vertical and horizontal jump tests, 10-, 20- and 30-metre sprint tests, the 505 agility test, the Y-Balance test and the navicular drop test. In the FCTG, vertical jump performance increased by 8.55% from baseline (time × group interaction: p < 0.001, partial η² = 0.350), horizontal jump performance increased by 3.8% ( p = 0.049, partial η² = 0.048), and right navicular drop decreased by 15.44% (13.19% on the left; p < 0.001, partial η² = 0.513). Significant time × group interactions were also observed for Y-Balance Test scores ( p < 0.001, partial η² = 0.439) and for all sprint distances (10, 20, and 30 m). Changes in the control group were minimal. Given the quasi-experimental design, these findings should be interpreted with caution and do not establish causality. The multimodal foot core-based training programme was associated with greater pre–post changes in lower-extremity performance outcomes and a greater reduction in navicular drop (an indirect, static measure of medial longitudinal arch behaviour) than routine training alone in male amateur football players. These findings are hypothesis-generating: they do not establish that the programme caused these differences, and randomised controlled trials are needed to test whether such programmes are useful.