Association between preparatory muscle activation and peak valgus knee angle

Palmieri-Smith, Riann M.; Wojtys, Edward M.; Ashton‐Miller, James A.

doi:10.1016/j.jelekin.2007.03.007

Cited by 70 publications

(62 citation statements)

References 24 publications

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“…Appropriate precontact muscle activations are also deemed more critical than muscle activations during landing because a muscle's response latency is generally considered too long to reactively stabilize a joint during landing. 40,41 We originally hypothesized that executing movement tasks under unanticipated conditions would deleteriously alter lower extremity neuromechanics. This proposal was based on observations by other authors 9,14,15 of greater knee-joint and ACL loading during unanticipated conditions.…”

Section: Discussionmentioning

confidence: 99%

Anticipatory Effects on Lower Extremity Neuromechanics During a Cutting Task

Meinerz

Malloy

Geiser

et al. 2015

Journal of Athletic Training

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Context Continued research into the mechanism of noncontact anterior cruciate ligament injury helps to improve clinical interventions and injury-prevention strategies. A better understanding of the effects of anticipation on landing neuromechanics may benefit training interventions. Objective To determine the effects of anticipation on lower extremity neuromechanics during a single-legged land-and-cut task. Design Controlled laboratory study. Setting University biomechanics laboratory. Participants Eighteen female National Collegiate Athletic Association Division I collegiate soccer players (age = 19.7 ± 0.8 years, height = 167.3 ± 6.0 cm, mass = 66.1 ± 2.1 kg). Intervention(s) Participants performed a single-legged land-and-cut task under anticipated and unanticipated conditions. Main Outcome Measure(s) Three-dimensional initial contact angles, peak joint angles, and peak internal joint moments and peak vertical ground reaction forces and sagittal-plane energy absorption of the 3 lower extremity joints; muscle activation of selected hip- and knee-joint muscles. Results Unanticipated cuts resulted in less knee flexion at initial contact and greater ankle toe-in displacement. Unanticipated cuts were also characterized by greater internal hip-abductor and external-rotator moments and smaller internal knee-extensor and external-rotator moments. Muscle-activation profiles during unanticipated cuts were associated with greater activation of the gluteus maximus during the precontact and landing phases. Conclusions Performing a cutting task under unanticipated conditions changed lower extremity neuromechanics compared with anticipated conditions. Most of the observed changes in lower extremity neuromechanics indicated the adoption of a hip-focused strategy during the unanticipated condition.

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Section: Discussionmentioning

confidence: 99%

Anticipatory Effects on Lower Extremity Neuromechanics During a Cutting Task

Meinerz

Malloy

Geiser

et al. 2015

Journal of Athletic Training

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“…[38][39][40] Studies of GMED activation in combination with dynamic kneevalgus measures are in agreement with our findings. [16][17][18] Russell et al 18 did not observe differences in either kneevalgus angle or GMED activation between men and women during a single-legged drop landing. Palmieri-Smith et al 17 and Hollman et al 16 reported no association between GMED activity and knee-valgus alignment during singlelegged landings or step-down tasks, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…14,15 Surprisingly, few authors [16][17][18] have investigated the role of proximal muscle activation in dynamic knee-valgus motion. Given this limited body of evidence, the relationship between MKD and hip muscle activation is unclear and requires further study.…”

mentioning

confidence: 99%

Neuromuscular Characteristics of Individuals Displaying Excessive Medial Knee Displacement

Padua

Bell

Clark

2012

Journal of Athletic Training

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Context: Knee-valgus motion is a potential risk factor for certain lower extremity injuries, including anterior cruciate ligament injury and patellofemoral pain. Identifying neuromuscular characteristics associated with knee-valgus motion, such as hip and lower leg muscle activation, may improve our ability to prevent lower extremity injuries.Objective: We hypothesized that hip and lower leg muscleactivation amplitude would differ among individuals displaying knee valgus (medial knee displacement) during a double-legged squat compared with those who did not display knee valgus. We further suggested that the use of a heel lift would alter lower leg muscle activation and frontal-plane knee motion in those demonstrating medial knee displacement.Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: A total of 37 healthy participants were assigned to the control (n ¼ 19) or medialknee-displacement (n ¼ 18) group based on their double-legged squat performance.Main Outcome Measure(s): Muscle-activation amplitude for the gluteus maximus, gluteus medius, adductor magnus, medial and lateral gastrocnemius, and tibialis anterior was measured during 2 double-legged squat tasks. The first task consisted of performing a double-legged squat without a heel lift; the second consisted of performing a double-legged squat task with a 2-in (5.08-cm) lift under the heels.Results: Muscle-activation amplitude for the hip adductor, gastrocnemius, and tibialis anterior was greater in those who displayed knee valgus than in those who did not (P , .05). Also, use of heel lifts resulted in decreased activation of the gluteus maximus, hip adductor, gastrocnemius, and tibialis anterior muscles (P , .05). Use of heel lifts also eliminated medially directed frontal-plane knee motion in those displaying medial knee displacement.Conclusions: Medial knee displacement during squatting tasks appears to be associated with increased hip-adductor activation and increased coactivation of the gastrocnemius and tibialis anterior muscles.

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“…There is some evidence that the amount of knee valgus during single-leg landing in female athletes corresponds with a gender-specific increase in cocontraction from the lateral knee muscles compared to the medial muscles. 23 Thus, female athletes may utilize an undesirable pattern of muscle recruitment that could promote greater dynamic knee valgus during landing.…”

Section: Muscle Strength In the Lower Extremity Does Not Predict Postmentioning

confidence: 99%