Patterns of Dynamic Malalignment, Muscle Activation, Joint Motion, and Patellofemoral-Pain Syndrome

2005 ◽  
Vol 14 (3) ◽  
pp. 216-233 ◽  
Author(s):  
Jennifer E. Earl ◽  
Jay Hertel ◽  
Craig R. Denegar
Keyword(s):  
Discriminant Function ◽  
Muscle Activation ◽  
Onset Time ◽  
Pain Syndrome ◽  
Gluteus Medius ◽  
Patellofemoral Pain ◽  
Iliotibial Band ◽  
Lower Extremity Function ◽  
Predictive Variables ◽  
Multifactorial Approach

Context:Dynamic malalignment (DM), abnormal muscle activation, and static malalignments all might lead to patellofemoral pain (PFP) but have not been examined using a multifactorial approach.Objective:To determine which measures of static malalignment, DM, and muscle-onset times best predict PFP.Design and Setting:Between-subjects, laboratory.Subjects:2 groups (PFP and uninjured) of 16 subjects each.Interventions:EMG and 3-D kinematic data were recorded during a step-down. Five static-alignment assessments were performed.Measurements:Three discriminant analyses using injury as the grouping variable and static measures, joint angles, and EMG onsets as the predictor variables. A final combined discriminant analysis using the most predictive variables from each set.Results:The static-alignment discriminant function was most predictive (81.3% correct), followed by the kinematic (69%) and the EMG (67%) functions. The final discriminant function included iliotibial-band flexibility, navicular drop, pronation, knee flexion, hip adduction, gluteus medius, and vastus medialis obliquus onset time and correctly classified 92.3% of PFP subjects.Conclusions:PFP can most accurately be predicted when multiple measures of lower extremity function are considered together.

No Difference in Gluteus Medius Activation in Women With Mild Patellofemoral Pain

2012 ◽  
Vol 21 (2) ◽  
pp. 110-118 ◽  
Author(s):  
Kieran O’Sullivan ◽  
Ellen Herbert ◽  
David Sainsbury ◽  
Karen McCreesh ◽  
Amanda Clifford
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Weight Bearing ◽  
Pain Syndrome ◽  
Gluteus Medius ◽  
Patellofemoral Pain ◽  
Stair Climbing ◽  
Convenience Sample ◽  
Healthy Participants

Context:The gluteus medius (Gmed) is proposed to consist of 3 functional subdivisions (anterior, middle, and posterior). Gmed weakness and dysfunction have been implicated in numerous lower extremity disorders, including patellofemoral pain syndrome (PFPS). PFPS is a knee condition that frequently occurs in females and is associated with activities such as squatting and stair climbing. There is a lack of evidence for the role of the subdivisions of the Gmed in females with and without PFPS.Objective:To compare muscle activation in the 3 Gmed subdivisions during 4 weight-bearing exercises in women with and without PFPS.Design:Single-session, repeated-measures observational study.Setting:University research laboratory.Participants:Convenience sample of 12 women with PFPS and 12 age- and gender-matched asymptomatic controls.Intervention:Participants performed 4 weight-bearing exercises (wall press, pelvic drop, step-up-and-over, and unilateral squat) 3 times while surface electromyography (sEMG) activity of the Gmed segments was recorded.Main Outcome Measures:sEMG muscle activity for each functional subdivision of the Gmed during each weight-bearing exercise was analyzed using a mixed between–within-subjects ANOVA (post hoc Bonferroni).Results:No statistically significant differences in muscle activation were found between the PFPS and healthy participants (P = .97). Furthermore, there were no statistically significant differences between the exercises (P = .19) or muscle fibers (P = .36) independent of group analyzed. However, the activation of the subdivisions varied according to the exercise performed (P = .003).Conclusions:Similar levels of muscle activation were recorded in the Gmed subdivisions of the PFPS and healthy participants during the different exercises. This is the first study to examine all 3 Gmed subdivisions in PFPS. Future studies using larger sample sizes should also investigate onset and duration of muscle activation in all Gmed subdivisions in both healthy individuals and those with PFPS.

scholarly journals Onset of quadriceps activation and torque variation during stair ascent in individuals with patellofemoral pain

2013 ◽  
Vol 11 (4) ◽  
pp. 642-650 ◽  
Author(s):  
Heloyse Uliam Kuriki ◽  
Fábio Mícolis de Azevedo ◽  
Rúben De Faria Negrão Filho ◽  
Neri Alves
Keyword(s):  
Muscle Activation ◽  
Vastus Lateralis ◽  
Neuromuscular Disorders ◽  
Pain Syndrome ◽  
Patellofemoral Pain ◽  
Control Group ◽  
Stair Ascent ◽  
Simultaneous Activation ◽  
Control Pain ◽  
Motor Recruitment

Introduction: Studies have used surface electromyography (EMG) to understand motor recruitment in individuals with patellofemoral pain syndrome (PFPS); however, there is no consensus in the literature. Objective: To understand if, in addition to neuromuscular disorders, there are changes in rotational patterns in individuals with PFPS. Methods: Twenty-two control pain-free subjects and eleven subjects with PFPS were assessed during stair ascent with respect to the onset of muscle activation and percentage of torque variation (PTV). Result: The PFPS group showed previous activation of vastus lateralis (VL) (21.1 ± 58.1ms), while simultaneous activation was observed in the control group (2.8 ± 30.7ms, p=0.01). The groups also showed differences in relation to the PTV (p=0.02): the control group showed greater variation in torque (26.7 ± 35.3%) compared to the PFPS group (17.5 ± 35.9%). Conclusion: People with PFPS have prior activation of VL and lower tendency towards body rotation, which may suggest patellar lateralization.

scholarly journals A Preliminary Multifactorial Approach Describing the Relationships Among Lower Extremity Alignment, Hip Muscle Activation, and Lower Extremity Joint Excursion

2011 ◽  
Vol 46 (3) ◽  
pp. 246-256 ◽  
Author(s):  
Anh-Dung Nguyen ◽  
Sandra J. Shultz ◽  
Randy J. Schmitz ◽  
Richard M. Luecht ◽  
David H. Perrin
Keyword(s):  
Lower Extremity ◽  
Muscle Activation ◽  
Gluteus Maximus ◽  
Gluteus Medius ◽  
Femoral Anteversion ◽  
Navicular Drop ◽  
Hip Muscle ◽  
Single Leg Squat ◽  
Multifactorial Approach ◽  
Hip Internal Rotation

Context: Multiple factors have been suggested to increase the risk of faulty dynamic alignments that predict noncontact anterior cruciate ligament injury. Few researchers have examined this relationship using an integrated, multifactorial approach. Objective: To describe the relationship among static lower extremity alignment (LEA), hip muscle activation, and hip and knee motion during a single-leg squat. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Thirty men (age = 23.9 ± 3.6 years, height = 178.5 ± 9.9 cm, mass = 82.0 ± 14.1 kg) and 30 women (age = 22.2 ± 2.6 years, height = 162.4 ± 6.3 cm, mass = 60.3 ± 8.1 kg). Main Outcome Measure(s): Pelvic angle, femoral anteversion, quadriceps angle, tibiofemoral angle, and genu recurvatum were measured to the nearest degree; navicular drop was measured to the nearest millimeter. The average root mean square amplitude of the gluteus medius and maximus muscles was assessed during the single-leg squat and normalized to the peak root mean square value during maximal contractions for each muscle. Kinematic data of hip and knee were also assessed during the single-leg squat. Structural equation modeling was used to describe the relationships among static LEA, hip muscle activation, and joint kinematics, while also accounting for an individual's sex and hip strength. Results: Smaller pelvic angle and greater femoral anteversion, tibiofemoral angle, and navicular drop predicted greater hip internal-rotation excursion and knee external-rotation excursion. Decreased gluteus maximus activation predicted greater hip internal-rotation excursion but decreased knee valgus excursion. No LEA characteristic predicted gluteus medius or gluteus maximus muscle activation during the single-leg squat. Conclusions: Static LEA, characterized by a more internally rotated hip and valgus knee alignment and less gluteus maximus activation, was related to commonly observed components of functional valgus collapse during the single-leg squat. This exploratory analysis suggests that LEA does not influence hip muscle activation in controlling joint motion during a single-leg squat.

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