The impact of rifle carriage on lower body angular kinematics in on-snow biathlon skiing

Abstract Purpose Biathlon is an endurance sport that combines high-intensity cross-country skiing with precision shooting, requiring athletes to carry a rifle while skiing. This study examined the effect of rifle carriage on angular kinematics involving hip and knee range of motion (ROM) in on-snow biathlon skiing. Methods 29 tier 3 level biathletes (11 F; 18 M) skied two maximal effort time trials (2300 m), once with and once without carrying the biathlon rifle. A 3D motion analysis system, comprising of twelve inertial measurement units, was used to measure hip and knee ROM in the sagittal plane. Multilevel linear models, considering slope, stance (dominant/non-dominant), and side (leading/lagging, left/right), were employed to analyze the effects of rifle carriage on knee and hip ROM in gears 2 and 3. Results In gear 2, rifle carriage was associated with reduced knee ( p < .001) and hip ROM. ( p < .001). In gear 3, rifle carriage was associated with reduced knee ROM ( p < .001) but greater hip ROM ( p = .003). Conclusion Biathletes change their skiing kinematics when carrying a rifle during on-snow skiing. Rifle carriage was associated with decreased knee and hip ROM in gear 2, and reduced knee but increased hip ROM in gear 3. Future research should determine the relationships between rifle-induced changes to skiing kinematics with performance.