Effects of Ice Hockey Stick Shaft Flex on Shooting Velocity and Snap-Shot Accuracy in Junior Ice Hockey Players: A Counterbalanced Crossover Study

Background/Objectives: Shaft stiffness (“flex”) is the only routinely individualised ice hockey stick specification, yet evidence on its effect on shooting is inconsistent; this is because previous studies have used fixed stiffness levels for players of different sizes and strengths. We determined the effect of deviating, in either direction, from the player’s habitual flex, congruent with the body mass reference flex, on on-ice shooting velocity and snap-shot accuracy in junior players. Methods: Thirty male junior players (18–19 years) whose habitual effective flex was within ±10 units of the body mass reference flex completed a complete counterbalanced (Williams-type) crossover with three sticks differing only in nominal shaft flex—the habitual flex (FLEX0), a shaft 15 units more compliant (FLEX−15), and one 15 units stiffer (FLEX+15)—each preceded by three familiarisation sessions. Wrist- and snap-shot velocity (radar) and snap-shot accuracy in an externally paced target task were analysed with linear mixed models. Results: Flex affected wrist-shot velocity (ηp2 = 0.35), snap-shot velocity (ηp2 = 0.68) and snap-shot accuracy (ηp2 = 0.34), with all three outcomes highest at FLEX0. The wrist shot lost 2.9% with both deviations, whereas the snap shot lost 5.6% with the compliant shaft, but only 1.6% with the stiff shaft (Flex × Technique ηp2 = 0.29). Snap-shot accuracy fell by 9.1 and 14.4 percentage points. Conclusions: In players fitted within ±10 units of the body mass reference flex, deviations of ±15 flex units from the habitual flex were associated with lower shooting velocity and snap-shot accuracy; for the snap shot, an over-compliant shaft was the costlier deviation.