Implicit video feedback produces positive changes in landing mechanics

Abstract

BackgroundImplicit (IF) and explicit (EF) feedback are two motor learning strategies demonstrated to alter movement patterns. There is conflicting evidence on which strategy produces better outcomes. The purpose of this study was to examine the effects of reduced IF and EF video feedback on lower extremity landing mechanics.MethodsThirty participants (24 ± 2 years, 1.7 ± 0.1 m, 70 ± 11 kg) were randomly assigned to three groups: IF (n = 10), EF (n = 10), and control (CG) (n = 10). They performed twelve box-drop jumps three times a week on the training sessions for six weeks. Only IF and EF groups received video feedback on the training sessions. IF was cued to focus their attention on the overall jump, while EF was cued to focus on position of their knees. 3D lower extremity biomechanics were tested on testing sessions with no feedback. All sessions were at least 24 h apart from another. Testing sessions included baseline testing (pretest), testing after 3 training sessions with 100% feedback (pst1), testing after 6 training sessions with 33.3% feedback (pst2), testing after 6 training sessions with 16.6% feedback (Pst3), and testing 1 month after with no feedback (retention – ret). ANOVA compared differences between groups and time at initial contact and peak for hip flexion (HF, °) and abduction angle (HA, °), hip abduction moment (HAM, Nm/kgm), knee flexion (KF, °) and abduction angle (KA, °), knee abduction moment (KAM, Nm/kgm) and VGRF (N) (p < 0.05).ResultsA significant main effect for group was found between IF and EF groups for HA (IF = − 6.7 ± 4; EF = − 9.4 ± 4.1) and KAM (IF = 0.05 ± 0.2; EF = − 0.07 ± 0.2) at initial contact, and peaks HA (IF = − 3.5 ± 4.5; EF = − 7.9 ± 4.7) and HAM (IF = 1.1 ± 0.6; EF = 0.9 ± 0.4). A significant main effect for time at initial contact for HF (pre = 32.4 ± 3.2; pst2 = 36.9 ± 3.2; pst3 = 37.9 ± 3.7; ret. = 34.1 ± 3.7), HAM (pre = 0.1 ± 0.1; pst1 = 0.04 ± 0.1; pst3 = 0.1 ± 0.01), KA (pre = 0.7 ± 1.1; pst1 = 0.2 ± 1.2; pst3 = 1.7 ± 1), and KAM (pre = 0.003 ± 0.1; pst3 = 0.01 ± 0.1) was found.Discussion/conclusionWe found that implicit feedback produced positive changes in landing mechanics while explicit feedback degraded motor learning. Our results indicate that implicit feedback should be used in programs to lower the ACL injury risk. We suggest that implicit feedback should be frequent in the beginning and not be reduced as much following the acquisition phase.

Visual Perturbation to Enhance Return to Sport Rehabilitation after Anterior Cruciate Ligament Injury: A Clinical Commentary

“…An external visual focus of attention can ensure visuospatial demands during training and implicit learning can reduce the cognitive demands for motor control to potentially enhance training. [37][38][39][40]…”

“…121 While few studies have examined the behavioral impacts of implicit cues for sports medicine, Popovic et al demonstrated improved landing biomechanics with implicit feedback relative to explicit/no feedback. 40 Thus, instructional language informed by implicit learning may augment visual perturbation training by modulating sensorimotor neural activity and potentially increasing neural efficiency by reducing the cognitive load of learning injury-resistant movement strategies. The newly freed cortical resources may enable athletes to more readily attend to visual distractors during high-level sport (e.g., the ball, opponents) while maintaining neuromuscular control.…”

“…36 Additionally, the application of key motor learning principles may support visual perturbation training, such as 1) an external visual focus of attention or cueing to help ensure visuospatial demands during training and 2) implicit learning to reduce the cognitive requirements for motor control and promote movement automaticity. [37][38][39][40] The following commentary details an example of a sensory reweighting protocol that combines the use of stroboscopic glasses and key motor learning principles.…”

Estratégias de prevenção neuromuscular para lesões do ligamento cruzado anterior sem contato em jogadoras de basquete. Revisão narrativa

“…El tercer aspecto importante en el programa PNM de lesiones LCS-SC es la educación y la retroalimentación en el aterrizaje. La instrucción de estímulos verbales, visuales, de video o retroalimentación de manera implícita mediante una proyección visual pueden facilitar el aprendizaje del gesto motor (Gilchrist et al, 2008;Olsen et al, 2005;Popovic et al, 2018;Steffen et al, 2008). Este factor resulta muy importante debido a la elevada complicación de la tarea, que adicionalmente se incrementa por los factores intrínsecos de la mujer (p.ej.…”

Real‐time biofeedback integrated into neuromuscular training reduces high‐risk knee biomechanics and increases functional brain connectivity: A preliminary longitudinal investigation

“…Risk of musculoskeletal injury, specifically anterior cruciate ligament (ACL) injury, is associated with decreased neuromuscular control and coordination during dynamic activities (Griffin et al, ; Hewett et al, ; Hewett, Torg, & Boden, ; Ireland, ; Krosshaug, Slauterbeck, Engebretsen, & Bahr, ; Zazulak, Hewett, Reeves, Goldberg, & Cholewicki, ). Advances in 3D motion analyses and force platforms have permitted the assessment of neuromuscular coordination using the drop vertical jump (DVJ) (Chaudhari et al, ; Cruz et al, ; DiCesare, Kiefer, Bonnette, & Myer, ; Doherty et al, ; Earl, Monteiro, & Snyder, ; Etnoyer, Cortes, Ringleb, Van Lunen, & Onate, ; Ford, Myer, & Hewett, , ; Hewett et al, ; Limroongreungrat & Boonkerd, ; McLean et al, ; Paterno et al, ; Popovic et al, ; Schmitz et al, ; Taylor et al, ). During the landing phase of the DVJ, tri‐planar hip, knee, and ankle motion that results in the knee collapsing toward the midline, or “dynamic valgus,” is quantified via an external peak knee abduction moment (pKAM) (Carson & Ford, ; Ford, Myer, & Hewett, ; Ford et al, ; Ford, Shapiro, Myer, Van Den Bogert, & Hewett, ; Galloway et al, ; Hewett et al, ; Malfait et al, ; Myer et al, , , ).…”