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.
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.
Authors: Timothy E Hewett; Gregory D Myer; Kevin R Ford; Robert S Heidt; Angelo J Colosimo; Scott G McLean; Antonie J van den Bogert; Mark V Paterno; Paul Succop Journal: Am J Sports Med Date: 2005-02-08 Impact factor: 6.202
Authors: Tron Krosshaug; Atsuo Nakamae; Barry P Boden; Lars Engebretsen; Gerald Smith; James R Slauterbeck; Timothy E Hewett; Roald Bahr Journal: Am J Sports Med Date: 2006-11-07 Impact factor: 6.202