Insufficient Hamstring Strength Compromises Landing Technique in Adolescent Girls

Abstract

Girls with reduced hamstring strength appear to have a decreased capacity to control lower limb frontal plane alignment. This reduced capacity appears to contribute to increased ACL loading and, in turn, increased potential for injury.

Acute Effects of Static Stretching of Hamstring on Performance and Anterior Cruciate Ligament Injury Risk During Stop-Jump and Cutting Tasks in Female Athletes

“…Additionally, the results of this study are not consistent with results reported by Wild et al (54) in which girls with lower hamstring strength displayed greater knee abduction angle and greater ACL loading during landing from a leap compared with girls with higher hamstring strength. Athletes with less hamstring stiffness also displayed greater abduction moment, greater peak anterior tibial shear force, and less knee flexion angle at critical time points during landing than individuals with greater hamstring stiffness (7).…”

“…The time of peak posterior GRF (PPF) was identified as a critical time point for knee loading (32,60). Knee kinematic and kinetic variables at this critical time, including knee flexion angle (17,54), knee extension moment (17,54), knee abduction angle (54), knee adduction moment (54), the peak anterior tibial shear force (10), the peak lateral tibial shear force, hip adduction angle (27), and hip adduction moment (24), were used for evaluating the ACL injury risk. Jump height, which was used for evaluating stop-jump performance, was calculated by subtracting the vertical coordinates of the center of mass during the static trial from the maximum vertical coordinates of the center of mass during the stop-jump trials.…”

“…In addition, the hamstrings could potentially protect the ACL against high abduction strain during high-impact landings by controlling the frontal plane knee motion (33). Girls with lower hamstring strength exhibited significantly reduced hip abduction moments, greater knee abduction alignment, and 76% greater normalized ACL loading during landing compared with girls with higher hamstring strength (54). Additionally, Weinhandl et al (53) reported that fatigue-induced hamstring strength reduction significantly reduced knee flexion angles and increased ACL loading by 36% during sidestep cutting.…”

Strength Training and Metabolic Conditioning for Female Youth and Adolescent Soccer Players

“…Given technical competency progression to Olympic-style weight lifting may bring about desirable adaptions to ligament thickness and timing of muscle contractions in jumping and landing tasks (2,21). Appropriate hamstring strengthening exercises should also be included as part of a balanced program (40), particularly given the potential relationship between hamstring strength and landing control (58). Movement skill mastery and exercise progressions should be individualized, so the above examples serve as general guidelines only.…”

A Review of Recent Perspectives on Biomechanical Risk Factors Associated with Anterior Cruciate Ligament Injury

“…Recent research has attempted to explore the relationships between strength, muscle activity and landing biomechanics. For example, Wild et al (2013) examined lower limb kinematics of the hip, knee and ankle, ACL forces and muscle activity of six lower limb muscles (Medial Gastrocnemius, Tibialis Anterior, Vastus Medialis, Rectus Femoris, Semitendinosis and Biceps Femoris) during a single-leg horizontal landing in high (n = 11) and low (n = 11) concentric hamstring strength groups of pubescent females. The results showed that the low hamstring strength group displayed significantly greater knee valgus angles at the time of maximum vertical and anterioposterior ground reaction forces (GRF), significantly less hip abduction moments at the time of maximum vertical GRF and significantly greater ACL force at the time of maximum anterioposterior GRF compared with the high hamstring strength group.…”