Influence of Anticipation on Movement Patterns in Subjects With ACL Deficiency Classified as Noncopers

Abstract

t MetHoDS anD MeaSuReS: The study included 16 subjects who are ACL deficient, classified as noncopers, and 20 healthy controls. Data were collected using an Optotrak Motion Analysis System and force plate integrated with Motion Monitor Software to generate knee joint angles, moments, and power. Each testing session included anticipated tasks, straight walking task (ST), and 45° side-step cutting tasks (SSC), followed by a set of unexpected straight walking (STU) and unexpected sidestep cutting (SSCU) tasks in a random order. For all tasks speed was maintained at 2 m/s. Peak knee angle, moment, and power variables during early stance were compared using 2-way mixed-effects ANOVA models.t ReSultS: For both the straight and sidestep tasks, the noncoper group did not show a dependence on whether the task was anticipated or unanticipated (group-by-condition interaction) for the knee angle (straight, P = .067; side-step cutting, P = .103), moment (straight, P = .079; side-step cutting, P = .996), and powers (straight, P = .181; side-step cutting, P = .183) during the loading response phase. However, during both straight and side-step cutting tasks, the subjects in the noncoper group used significantly lower knee flexion angles (straight, P = .002; side-step cutting, P = .019), knee moments (straight, P = .005; sidestep cutting, P,.001), and knee powers (straight, P = .013; side-step cutting, P,.001).t concluSionS: This study suggests subjects that are ACL deficient and classified as noncopers use a common abnormal movement pattern of lower knee extensor loading even during unanticipated tasks.

Identifying Individuals With an Anterior Cruciate Ligament-Deficient Knee as Copers and Noncopers: A Narrative Literature Review

“…Noncopers seem to utilize a common abnormal movement pattern of lower knee extensor loading even during unanticipated tasks. 33 Functional outcomes further suggest that a subgroup of noncopers require additional supervised rehabilitation to pass stringent criteria to return to sports. 28 Studies have revealed significant differences in angle-specific knee torque values between potential copers and noncopers (P<.05).…”

“…Individuals in the coper group preferentially used a particular vastus lateralis and medial hamstrings activation pattern at a frequency more than twice that observed in the control group. 33,34 The noncoper group, compared to the control group, also preferentially used a medial hamstrings activation pattern more than twice as often and utilized a distinct medial hamstrings and lateral hamstrings activation pattern.…”

Reliability and measurement precision of concentric-to-isometric and eccentric-to-isometric knee active joint position sense tests in uninjured physically active adults

“…With regard to the knee, injury can result in destruction of mechanoreceptors (Bali, et al, 2012). Loss of mechanoreceptors after knee injury is associated with impaired joint-muscle reflexes and abnormal movement patterns (Beard, Kyberd, O'Connor, Fergusson, & Dodd, 1994;Houck, De Haven, & Maloney, 2007;Wojtys & Huston, 1994). Consequently, authors have described how impaired proprioception is a potential contributing factor to first-time joint injury, repetitive joint injury, and the onset and progression of osteoarthrosis (OA) (Borsa, Sauers, & Lephart, 1999;Felson, et al, 2009;MV Hurley, 1997;Roos, Herzog, Block, & Bennell, 2011;Segal, et al, 2010).…”

Differences in EMG–moment relationships between ACL‐injured and uninjured adults during a weight‐bearing multidirectional force control task

“…The purpose of this study was to identify differences in the relationship of individual muscle activations and internal joint moments between ACLi participants and uninjured CON using a reliable isometric weight‐bearing force matching protocol . Consider that (1) greater knee abduction angles and internal moments; (2) greater knee rotation angles and internal moments; and (3) reduced knee flexion angles and greater knee extension internal moments are defining factors in the non‐contact ACL injury mechanism, and are associated with reports of ACLi knee instability . Therefore, compared to CON, ACLi muscle activations that have a greater relationship with internal knee abduction, rotation, and extension moments can be considered strategies that reduce knee joint stability, while muscle activations that have a greater relationship with internal knee adduction and flexion moments are considered strategies that increase knee joint stability.…”