Focus of attention during landing in young female volleyball players

Mgr. Lukáš SLOVÁK

Doctoral thesis

Abstract:

Landing is a fundamental motor skill critical for safely absorbing impact and preventing injuries during physical activities. Specifically, frequent landings in sports such as volleyball represent a significant risk for the knee joint, with cartilage damage and anterior cruciate ligament (ACL) injuries commonly occurring. As a result, previous research has addressed the impact of attentional focus instructions during landings to reduce the load on the knee joint and the likelihood of ACL injuries. Although existing evidence demonstrates the beneficial effect of attentional focus instructions that are externally focused (EF - when an individual's focus of attention is directed toward the movement effects or movement goals) compared to those that are internally focused (IF - when an individual's focus of attention is directed at body-related movements), further exploration into attentional focus instructions that are related to the injury risk of the knee during different phases of landing is necessary. Furthermore, young female team sport athletes are at greater risk of ACL injuries compared to their male counterparts. Therefore, a comprehensive examination of spatiotemporal biomechanical risk factors, the acute response of the soft tissues (i.e., ACL and cartilage) of the knee joint, and the influence of various externally focused attentional focus instructions during the landing phase in young female athletes is critical to developing more effective and targeted injury prevention. Consequently, the main purpose of this thesis is to enhance our understanding of how attentional focus instructions during landing can contribute to reducing the load on the knee joint, which could aid in the prevention of ACL injuries and osteoarthritis. To fulfill the main purpose of this dissertation, three separate studies were conducted, aiming to thoroughly explore and understand the relationship between attentional focus instructions and the risk of knee-related injuries during the drop landing. In this regard, the first study showed that an EF cue ´Focus on landing as soft as possible' was biomechanically beneficial for reducing knee loading during a critical initial window for ACL injuries (i.e., 30% of the landing time), particularly in the sagittal plane, relative to an IF cue 'Focus on bending your knees when you land' and no-focus condition. This was evidenced by reduced vertical ground reaction force (VGRF) and loading rates during the drop landing from a 50cm height box. No significant differences were found in the frontal and horizontal (transverse) planes across the conditions during the risk interval for ACL injuries, suggesting that these attentional focus instructions had no significant influence on the biomechanical forces along the frontal and horizontal planes, which load ACL. The second study revealed that, during repeated landings from a 50 cm height box, the EF cue ´Focus on landing as softly as possible´ led to the least acute reduction in T2 relaxation time and the lowest decrease in cartilage volume within the lateral compartment of the femorotibial cartilage, compared to the IF cue ´Focus on bending your knees when you land´ and no-focus condition. No significant alterations were found in the medial compartment of the cartilage or the ACL across attentional focus conditions after repeated drop landings from a 50cm height box. The third study demonstrated that all EF cues investigated (i.e., ´Focus on landing as quiet as possible´; ´Focus on landing as safe as possible´, and ´Focus on landing as soft as possible´) were biomechanically beneficial in reducing knee loading from a 50 cm height box, potentially decreasing the likelihood of ACL injury as evidenced by lower VGRF and internal rotation angles, and increased knee flexion angles, compared to a no-focus condition. No significant differences were found in the frontal plane across attentional focus and no-focus conditions.

Abstract:

Landing is a fundamental motor skill critical for safely absorbing impact and preventing injuries during physical activities. Specifically, frequent landings in sports such as volleyball represent a significant risk for the knee joint, with cartilage damage and anterior cruciate ligament (ACL) injuries commonly occurring. As a result, previous research has addressed the impact of attentional focus instructions during landings to reduce the load on the knee joint and the likelihood of ACL injuries. Although existing evidence demonstrates the beneficial effect of attentional focus instructions that are externally focused (EF - when an individual's focus of attention is directed toward the movement effects or movement goals) compared to those that are internally focused (IF - when an individual's focus of attention is directed at body-related movements), further exploration into attentional focus instructions that are related to the injury risk of the knee during different phases of landing is necessary. Furthermore, young female team sport athletes are at greater risk of ACL injuries compared to their male counterparts. Therefore, a comprehensive examination of spatiotemporal biomechanical risk factors, the acute response of the soft tissues (i.e., ACL and cartilage) of the knee joint, and the influence of various externally focused attentional focus instructions during the landing phase in young female athletes is critical to developing more effective and targeted injury prevention. Consequently, the main purpose of this thesis is to enhance our understanding of how attentional focus instructions during landing can contribute to reducing the load on the knee joint, which could aid in the prevention of ACL injuries and osteoarthritis. To fulfill the main purpose of this dissertation, three separate studies were conducted, aiming to thoroughly explore and understand the relationship between attentional focus instructions and the risk of knee-related injuries during the drop landing. In this regard, the first study showed that an EF cue ´Focus on landing as soft as possible' was biomechanically beneficial for reducing knee loading during a critical initial window for ACL injuries (i.e., 30% of the landing time), particularly in the sagittal plane, relative to an IF cue 'Focus on bending your knees when you land' and no-focus condition. This was evidenced by reduced vertical ground reaction force (VGRF) and loading rates during the drop landing from a 50cm height box. No significant differences were found in the frontal and horizontal (transverse) planes across the conditions during the risk interval for ACL injuries, suggesting that these attentional focus instructions had no significant influence on the biomechanical forces along the frontal and horizontal planes, which load ACL. The second study revealed that, during repeated landings from a 50 cm height box, the EF cue ´Focus on landing as softly as possible´ led to the least acute reduction in T2 relaxation time and the lowest decrease in cartilage volume within the lateral compartment of the femorotibial cartilage, compared to the IF cue ´Focus on bending your knees when you land´ and no-focus condition. No significant alterations were found in the medial compartment of the cartilage or the ACL across attentional focus conditions after repeated drop landings from a 50cm height box. The third study demonstrated that all EF cues investigated (i.e., ´Focus on landing as quiet as possible´; ´Focus on landing as safe as possible´, and ´Focus on landing as soft as possible´) were biomechanically beneficial in reducing knee loading from a 50 cm height box, potentially decreasing the likelihood of ACL injury as evidenced by lower VGRF and internal rotation angles, and increased knee flexion angles, compared to a no-focus condition. No significant differences were found in the frontal plane across attentional focus and no-focus conditions.

Keywords

anterior cruciate ligament, injury risk, drop landing, kinetic, kinematic, magnetic resonance imaging, T2 relaxation time, femorotibial cartilage, statistical parametric mapping, vertical ground reaction force, external focus of attention, motor control

Language used: English

Date on which the thesis was submitted / produced: 10. 5. 2024

Thesis defence

• Date of defence: 17. 6. 2024
• Supervisor: doc. Mgr. David Zahradník, Ph.D., doc. Mgr. David Zahradník, Ph.D.

University of Ostrava

Pedagogical Faculty

Doctoral programme / field:
Kinanthropology / Kinanthropology