Female Athletes Exhibit Greater Trial-to-Trial Coordination Variability When Provided with Instructions Promoting an External Focus.

The purpose of this study was to examine how instructions promoting different attentional foci influence joint coordination patterns and trial-to-trial coordination variability during landing. Sixteen females performed drop landings with their typical technique (baseline) and after receiving instructions promoting an internal focus and an external focus. The coordination patterns, and trial-to-trial coordination variability, of the sagittal plane hip-knee, hip-ankle, and knee-ankle angle pairings were compared across conditions. While there was no difference in the joint coordination patterns among the conditions, subjects exhibited greater hip-ankle and knee-ankle trial-to-trial coordination variability for the external focus condition, vs. the baseline and internal focus conditions, which may help to explain the improved motor learning outcomes for athletes who train with an external focus.

Kinetic Asymmetry During a Repetitive Tuck Jump Task in Athletes with a History of Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Athletes who have undergone anterior cruciate ligament reconstruction typically exhibit relatively high/rapid loading of their uninvolved limb during bilateral landing and jumping (vs. their limb that underwent reconstruction), which may place their uninvolved limb at risk for injury. However, previous studies have only examined forces and loading rates for tasks involving an isolated land-and-jump. PURPOSE: The purpose of this study was to examine bilateral landing and jumping kinetics during performance of a repetitive tuck jump task in athletes who had undergone anterior cruciate ligament reconstruction and completed rehabilitation. STUDY DESIGN: Cross-sectional study. METHODS: Nine athletes (four males, five females) participated in this study. All participants had undergone successful unilateral anterior cruciate ligament reconstruction, had completed post-operative rehabilitation, and were in the process of completing return-to-sport testing. Athletes performed a repetitive tuck jump task for 10 seconds, while ground reaction forces were recorded for their uninvolved and involved limbs via separate force platforms. Two-way analysis of variance, for within-subjects factors of limb and cycle, was performed for the impact forces, loading rates, and propulsive forces from the first five land-and-jump cycles completed. RESULTS: There was not a limb-by-cycle interaction effect or main effect of cycle for the impact forces, loading rates, or propulsive forces; however, there was a main effect of limb for the impact forces (F(1, 8) = 14.64; p=0.005), loading rates (F(1, 8) = 5.60; p=0.046), and propulsive forces (F(1, 8) = 10.38; p=0.012). Impact forces, loading rates, and propulsive forces were higher for the uninvolved limb, compared to the involved limb, over the five land-and-jump cycles analyzed. CONCLUSION: The athletes in this study consistently applied higher and more rapid loads to their uninvolved limb over multiple land-and-jump cycles. This may help to explain the relatively high injury rates for the uninvolved limb in athletes who have returned to sport following anterior cruciate ligament reconstruction.

Neuromuscular training programs predominantly include instructions that promote an internal focus.

Neuromuscular training programs that include movement pattern retraining and strengthening, plyometric, and balance exercises are recommended for anterior cruciate ligament injury prevention. Recent evidence suggests that the effectiveness of these programs may be enhanced when athletes train with an external focus; however, clinicians typically rely predominantly on instructions encouraging an internal focus. The aim of this study was to examine the types of instructions provided as part of popular neuromuscular training programs used for anterior cruciate ligament injury prevention. The technique-related instructions provided as part of the FIFA 11+, HarmoKnee, Knakontroll, and Prevent Injury and Enhance Performance programs were categorized as either promoting an internal focus or an external focus. Instructions provided during movement pattern retraining tasks and strengthening, plyometric, and balance training exercises were specifically examined. Next, the percentage of technique-related instructions that promoted an internal focus, versus the percentage that promoted an external focus, were compared for the various program components. Across all programs examined, the vast majority of technique-related instructions for the movement pattern re-training tasks (≥83.3%) and the strengthening, balance, and plyometric exercises (≥75.0%) appeared to promote an internal focus. Despite evidence suggesting that the effectiveness of neuromuscular training programs may be enhanced by encouraging an external focus, most technique-related instructions provided as part of popular neuromuscular training programs appear to promote an internal focus. Modifying neuromuscular training programs to promote a more external focus could help to improve the effectiveness of these programs for anterior cruciate ligament injury prevention.

THE INFLUENCE OF ATTENTIONAL FOCUS ON LANDING STIFFNESS IN FEMALE ATHLETES: A CROSS-SECTIONAL STUDY.

BACKGROUND: Anterior cruciate ligament injury prevention often involves instructing athletes to reduce landing stiffness. Instructions promoting an external focus appear to result in superior motor performance for a wide range of tasks; however, the effect of attentional focus on landing stiffness has not been examined. HYPOTHESIS/PURPOSE: The purpose of this study was to compare the influence of instructions promoting an internal focus vs. those promoting an external focus on landing stiffness. It was hypothesized that both types of instructions would reduce landing stiffness vs. landings performed prior to instruction. It was also hypothesized that participants would demonstrate a greater reduction in landing stiffness when provided with instructions promoting an external focus. STUDY DESIGN: Cross-sectional, quasi-experimental. METHODS: Sixteen female athletes (basketball, soccer, volleyball) completed drop landings while force and kinematic data were collected. Participants first performed drop landings with their typical technique (baseline). They then received instructions promoting an internal focus and an external focus before performing additional drop landings. Peak force, time-to-peak force, leg stiffness, and hip, knee, and ankle sagittal plane angles were analyzed. RESULTS: Both types of instructions resulted in lower landing forces, less leg stiffness, and greater hip and knee flexion versus at baseline. However, athletes demonstrated more knee flexion at the time of the peak force (59.4 ± 9.6 ° vs. 56.0 ± 9.5 °) and less leg stiffness (69.5 ± 17.9 Nkg-1/m vs. 84.0 ± 38.1 Nkg-1/m) when provided with instructions promoting an external focus, compared to when they were provided with instructions promoting an internal focus. CONCLUSION: Instructions promoting an external focus appear to result in a greater reduction in landing stiffness. Clinicians should consider providing instructions promoting an external focus when training athletes to reduce lower extremity stiffness during drop landings. The findings from this study may help to inform clinicians involved in movement pattern re-training for female athletes. LEVEL OF EVIDENCE: Level 3b.