The Acute Effects of Internal, External, and Golf-Specific Attentional Focus Cues on Isometric Trunk Strength in Youth Golfers

<b>Background</b>: Attentional focus strategies, including internal, external, and sport-specific cues, can influence muscle strength by modulating motor control. However, their acute effects on maximal isometric back-extensor strength in youth athletes under controlled laboratory conditions remain unclear. <b>Methods</b>: Fourteen youth golfers (15.8 ± 0.5 years) performed maximal voluntary isometric back-extension tasks under nine cueing conditions: three internal, three external, and three golf-specific. The task involved exerting maximal force against a fixed, immovable resistance while maintaining standardized trunk and hip positions to ensure consistent execution. Cueing was delivered verbally in a standardized manner across participants and sessions. Maximal isometric strength was compared across conditions using repeated-measures analyses. <b>Results</b>: Maximal isometric back-extensor strength was significantly (<i>p</i> = 0.004 η_p² = 0.34) lower with internal cues (57.1 ± 16.0 kg) compared with external (68.2 ± 13.0 kg) and golf-specific (68.1 ± 12.5 kg) cues. Specifically, the internal cues 'engage your glutes and hamstrings', 'tighten your core', and 'maintain a neutral spine' produced lower force than all external cues and the golf-specific cue 'focus on using your lower body to create a stable base for your golf swing'. Among internal cues, 'engage your glutes and hamstrings' resulted in the lowest torque. <b>Conclusions</b>: External and certain golf-specific verbal cues acutely enhance maximal isometric back-extensor force more effectively than internal cues in a controlled laboratory setting. While these results inform how attentional focus can modulate acute force output in youth athletes, the task does not replicate the dynamic, rotational nature of the golf swing, and the findings should not be interpreted as direct indicators of golf performance. Future research should explore long-term adaptations and assess transfer to sport-specific, dynamic movements.