scholarly journals Neuromuscular Characteristics of Individuals Displaying Excessive Medial Knee Displacement

2012 ◽  
Vol 47 (5) ◽  
pp. 525-536 ◽  
Author(s):  
Darin A. Padua ◽  
David R. Bell ◽  
Micheal A. Clark
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Frontal Plane ◽  
Gluteus Maximus ◽  
Lower Leg ◽  
Knee Valgus ◽  
Medial Knee ◽  
Lower Extremity Injuries ◽  
Leg Muscle ◽  
Extremity Injuries

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 muscle-activation 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 = 19) or medial-knee-displacement (n = 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.

Relationships between Knee Valgus, Hip-Muscle Strength, and Hip-Muscle Recruitment during a Single-Limb Step-Down

2009 ◽  
Vol 18 (1) ◽  
pp. 104-117 ◽  
Author(s):  
John H. Hollman ◽  
Barbara E. Ginos ◽  
Jakub Kozuchowski ◽  
Amanda S. Vaughn ◽  
David A. Krause ◽  
...  
Keyword(s):  
Muscle Strength ◽  
External Rotation ◽  
Frontal Plane ◽  
Gluteus Maximus ◽  
Knee Valgus ◽  
Outcome Measurements ◽  
Hip Muscle ◽  
Hip Abduction ◽  
Step Down ◽  
Rotation Strength

Context:Reduced strength and activation of hip muscles might correlate with increased weight-bearing knee valgus.Objective:To describe relationships among frontal-plane hip and knee angles, hip-muscle strength, and electromyographic (EMG) recruitment in women during a step-down.Design:Exploratory study.Setting:Laboratory.Participants:20 healthy women 20 to 30 years of age.Interventions:Frontal-plane hip and knee angles were measured. Gluteus maximus and medius recruitment were examined with surface EMG. Hip-abduction and -external-rotation strength were quantified with handheld dynamometry.Main Outcome Measurements:The authors analyzed correlation coefficients between knee and hip angles, gluteus maximus and medius EMG, and hip-abduction and -external-rotation strength.Results:Hip-adduction angles (r = .755, P = .001), gluteus maximus EMG (r = −.451, P = .026), and hip-abduction strength (r = .455, P = .022) correlated with frontal-plane projections of knee valgus.Conclusions:Gluteus maximus recruitment might have greater association with reduced knee valgus in women than does external-rotation strength during step-down tasks. Gluteus medius strength might be associated with increased knee valgus.

Adductor Longus Activation During Common Hip Exercises

2014 ◽  
Vol 23 (2) ◽  
pp. 79-87 ◽  
Author(s):  
Robert J. Delmore ◽  
Kevin G. Laudner ◽  
Michael R. Torry
Keyword(s):  
Muscle Activation ◽  
Emg Activity ◽  
Ranking System ◽  
Physically Active ◽  
Lower Extremity Injuries ◽  
Longus Muscle ◽  
Extremity Injuries ◽  
Rehabilitation Exercises ◽  
Adductor Longus ◽  
Swiss Ball

Context:Hip-adductor strains are among the most common lower-extremity injuries sustained in athletics. Treatment of these injuries involves a variety of exercises used to target the hip adductors.Objective:To identify the varying activation levels of the adductor longus during common hip-adductor exercises.Design:Descriptive study.Setting:Laboratory.Participants:24 physically active, college-age students.Intervention:None.Main Measurement Outcomes:Peak and average electromyographic (EMG) activity of the adductor longus muscle during the following 6 hip-adductor rehabilitation exercises: side-lying hip adduction, ball squeezes, rotational squats, sumo squats, standing hip adduction on a Swiss ball, and side lunges.Results:The side-lying hip-adduction exercise produced more peak and average activation than any other exercise (P < .001). Ball squeezes produced more peak and average activation than rotational squats, sumo squats, and standing adduction on a Swiss ball (P < .001). Ball squeezes had more average activation than side lunges (P = .001). All other variables for peak activation during the exercises were not statistically significant (P > .08). These results allowed the authors to provide an overall ranking system (highest to lowest muscle activation): side-lying hip adduction, ball squeezes, side lunges, standing adduction on a Swiss ball, rotational squats, and sumo squats.Conclusion:The study provides a ranking system on the activation levels of the adductor longus muscle for 6 common hip-adductor rehabilitation exercises, with the side-lying hip-adduction and ball-squeeze exercises displaying the highest overall activation.

Kinematic Differences Between Those With and Without Medial Knee Displacement During a Single-leg Squat

2014 ◽  
Vol 30 (6) ◽  
pp. 707-712 ◽  
Author(s):  
Timothy C. Mauntel ◽  
Barnett S. Frank ◽  
Rebecca L. Begalle ◽  
J. Troy Blackburn ◽  
Darin A. Padua
Keyword(s):  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Control Group ◽  
Knee Valgus ◽  
Medial Knee ◽  
Lower Extremity Injuries ◽  
Valgus Angle ◽  
Peak Knee ◽  
Single Leg Squat

A greater knee valgus angle is a risk factor for lower extremity injuries. Visually observed medial knee displacement is used as a proxy for knee valgus motion during movement assessments in an attempt to identify individuals at heightened risk for injury. The validity of medial knee displacement as an indicator of valgus motion has yet to be determined during a single-leg squat. This study compared three-dimensional knee and hip angles between participants who displayed medial knee displacement (MKD group) during a single-leg squat and those who did not (control group). Participants completed five single-leg squats. An electromagnetic motion tracking system was used to quantify peak knee and hip joint angles during the descent phase of each squat. MANOVA identified a difference between the MKD and control group kinematics. ANOVA post hoc testing revealed greater knee valgus angle in the MKD (12.86 ± 5.76) compared with the control (6.08 ± 5.23) group. There were no other differences between groups. Medial knee displacement is indicative of knee valgus motion; however, it is not indicative of greater knee or hip rotation, or hip adduction. These data indicate that clinicians can accurately identify individuals with greater knee valgus angle through visually observed medial knee displacement.

scholarly journals Association between frontal plane knee control and lower extremity injuries: a prospective study on young team sport athletes

2018 ◽  
Vol 4 (1) ◽  
pp. e000311 ◽  
Author(s):  
Anu M Räisänen ◽  
Kati Pasanen ◽  
Tron Krosshaug ◽  
Tommi Vasankari ◽  
Pekka Kannus ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Injury Risk ◽  
Screening Tool ◽  
Characteristic Curve ◽  
Area Under The Curve ◽  
Frontal Plane ◽  
Ankle Injuries ◽  
Lower Extremity Injury ◽  
Lower Extremity Injuries ◽  
Extremity Injuries

Background/aimPoor frontal plane knee control can manifest as increased dynamic knee valgus during athletic tasks. The purpose of this study was to investigate the association between frontal plane knee control and the risk of acute lower extremity injuries. In addition, we wanted to study if the single-leg squat (SLS) test can be used as a screening tool to identify athletes with an increased injury risk.MethodsA total of 306 basketball and floorball players participated in the baseline SLS test and a 12-month injury registration follow-up. Acute lower extremity time-loss injuries were registered. Frontal plane knee projection angles (FPKPA) during the SLS were calculated using a two-dimensional video analysis.ResultsAthletes displaying a high FPKPA were 2.7 times more likely to sustain a lower extremity injury (adjusted OR 2.67, 95% CI 1.23 to 5.83) and 2.4 times more likely to sustain an ankle injury (OR 2.37, 95% CI 1.13 to 4.98). There was no statistically significant association between FPKPA and knee injury (OR 1.49, 95% CI 0.56 to 3.98). The receiver operating characteristic curve analyses indicated poor combined sensitivity and specificity when FPKPA was used as a screening test for lower extremity injuries (area under the curve of 0.59) and ankle injuries (area under the curve of 0.58).ConclusionsAthletes displaying a large FPKPA in the SLS test had an elevated risk of acute lower extremity and ankle injuries. However, the SLS test is not sensitive and specific enough to be used as a screening tool for future injury risk.

Effects of joint preserving realignment surgery for ankle osteoarthritis on foot kinematics and lower leg muscle activation

2014 ◽  
Vol 39 ◽  
pp. S97-S98
Author(s):  
Corina Nüesch ◽  
Cora Huber ◽  
Geert Pagenstert ◽  
Victor Valderrabano
Keyword(s):  
Muscle Activation ◽  
Lower Leg ◽  
Ankle Osteoarthritis ◽  
Foot Kinematics ◽  
Leg Muscle

scholarly journals Neuromuscular Responses of Elite Skaters During Different Roller Figure Skating Jumps

2014 ◽  
Vol 41 (1) ◽  
pp. 23-32
Author(s):  
Patrícia Dias Pantoja ◽  
André Mello ◽  
Giane Veiga Liedtke ◽  
Ana Carolina Kanitz ◽  
Eduardo Lusa Cadore ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Figure Skating ◽  
Vastus Medialis ◽  
Lateral Gastrocnemius ◽  
Neuromuscular Activity

AbstractThis study aimed to describe the neuromuscular activity of elite athletes who performed various roller figure skating jumps, to determine whether the muscle activation is greater during jumps with more rotations and in which phase the muscles are more active. This study also aimed to analyze if there is any difference in the muscle activity pattern between female and male skaters. Four elite skaters were evaluated, and each participated in two experimental sessions. During the first session, anthropometric data were collected, and the consent forms were signed. For the second session, neuromuscular data were collected during jumps, which were performed with skates at a rink. The following four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. The neuromuscular activity of the following seven muscles was obtained with an electromyograph which was fixed to the waist of each skater with a strap: biceps femoris, lateral gastrocnemius, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis and gluteus maximus. The signal was transmitted wirelessly to a laptop. During the roller figure skating jumps, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation during the jumps with more rotations, and the activation mainly occurred during the propulsion and flight phases. Female skaters demonstrated higher muscle activities in tibialis anterior, vastus lateralis, vastus medialis and gluteus maximus during the landing phase of the triple Mapes, when compared to their male counterparts. The results obtained in this study should be considered when planning training programs with specific exercises that closely resemble the roller figure skating jumps. This may be important for the success of elite skaters in competitions.

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