The incorporation of resistance training with young athletes remains controversial among individuals who are not up to date on the current body of literature. Too often, resistance training is viewed as a means of simply making athletes bulkier. However, it’s quite clear that young athletes simply don’t produce enough endogenous anabolic hormones to facilitate significant muscular hypertrophy. Rather, resistance training serves to physically prepare young athletes for the demands of sport; to produce and reduce forces safely and efficiently. In fact, it may be irresponsible to not mind the strength needs of our athletes if keeping them injury free is a priority.
Various hops and jumps are common movements that occur in sport practice and competition. It’s not uncommon for some coaches to recklessly incorporate high intensity plyometric training with young athletes prematurely. The rapid eccentric contractions that occur during these drills and exercises require a requisite amount of strength to enable proper mechanics. A recent study by Wild et al (2013) demonstrates the importance of foundational strength levels in safely performing a simple landing task. A total of 33 female athletes aged 10-13 were assessed for eccentric and concentric isokinetic hamstring and quadriceps strength. Based on peak concentric hamstring torque, the athletes were divided into a low and high strength group. Then, athletes performed a simple leap and land task where ground reaction forces, lower limb electromyography and kinematic data were assessed. The results showed that the female athletes with lower hamstring strength displayed significantly greater knee abduction, reduced hip abduction (collectively creating knee valgus) and greater ACL loading at peak ground contact compared with the stronger hamstring group.

Unfortunately, excessive knee valgus during landing goes largely unnoticed by those not previously trained in functional anatomy. Appropriate strength training should be seriously considered for athletes of all ages as basic movements such as landing from a leap require a sufficient level of strength and neuromuscular control for safe landing. Lack of equipment or facilities is no excuse as plenty of bodyweight movements can be performed to improve strength levels in young athletes. Nordic hamstring curls, bilateral and unilateral hip hinging, supine single and double leg hip extension, and multi-planar lunge variations are excellent exercises that can be utilized to strengthen the lower body. Performed correctly and progressed intelligently, strength training can play a critical roll in reducing injury potential.
Reference:
Wild, C. Y., Steele, J. R., & Munro, B. J. (2013). Insufficient Hamstring Strength Compromises Landing Technique in Adolescent Girls. Medicine and Science in Sports and Exercise, 45(3), 497-505.