This article reviews research on political repression by social movement scholars. Four topics are discussed: (a) debates over the conceptualization of repression, the breadth of the concept, whether ...distinctions within the concept are productive and/or forms of repression are directly comparable, and the relationship between repression and political opportunities; (b) recent research on different types of repression, particularly protest policing; (c) an evaluation of research on different explanations of repression; and (d) an evaluation of research on the consequences of repression. Attention is also paid to areas where future research effort might be most productively spent, including identifying substantial gaps where more research is needed, where important debates exist that need research to push toward their resolution, where robust results exist but could be furthered by refinements, and where a more inclusive conceptualization of repression may link the study of repression to other significant literatures.
Background: It is hypothesized that patients with patellofemoral pain syndrome (PFPS) have hip and core muscle weakness leading to dynamic malalignment of the lower extremity. Thus, hip strengthening ...is a common PFPS treatment approach.
Purpose: To determine changes in hip strength, core endurance, lower extremity biomechanics, and patient outcomes after proximally focused rehabilitation for PFPS patients.
Study Design: Case series; Level of evidence, 4.
Methods: Nineteen women (age, 22.68 ± 7.19 years; height, 1.64 ± 0.07 m; mass, 60.2 ± 7.35 kg) with PFPS participated in an 8-week program to strengthen the hip and core muscles and improve dynamic malalignment. Paired t tests were used to compare the dependent variables between prerehabilitation and postrehabilitation. The dependent variables were pain; functional ability; isometric hip abduction and external rotation strength; anterior, lateral, and posterior core endurance; joint range of motion (ROM; rearfoot eversion, knee abduction and internal rotation, and hip adduction and internal rotation); and peak internal joint moments (rearfoot inversion, knee abduction, and hip abduction and external rotation) during the stance phase of running.
Results: Significant improvements in pain, functional ability, lateral core endurance, hip abduction, and hip external rotation strength were observed. There was also a significant reduction in the knee abduction moment during running, although there were no significant changes in joint ROM.
Conclusion: An 8-week rehabilitation program focusing on strengthening and improving neuromuscular control of the hip and core musculature produces positive patient outcomes, improves hip and core muscle strength, and reduces the knee abduction moment, which is associated with developing PFPS.
To investigate the effectiveness of computing body-size-independent hip strength measures using muscle-specific allometric scaling and ratio standard normalization methods.
Cross-sectional study.
...University laboratory.
A convenience sample of healthy participants (N=113; 42 men, 71 women).
Not applicable.
Anthropometric measurements of the leg and thigh were obtained, and maximal hip strength was tested (medial and lateral rotation, abduction, adduction, flexion, extension). Strength was measured isometrically as force (kg) and then converted to torque (Nm).
The allometric scaling analysis resulted in exponents for normalizing body mass (BM) in each muscle group assessed. In addition, a 6-muscle average exponent was also computed (bavg) for force (men, .554; women, .335) and torque (men, .792; women, .482). The nonsignificant results of the linear regression analysis revealed that normalizing hip strength to BM(bavg) (hip strength/BM(bavg)) effectively removed the influence of BM on force and torque. However, sex should be factored into analyses of allometric scaling because men have higher b-values than women for both force and torque. The linear regression analyses also demonstrated that force normalized to BM (P=.162-.895) and torque normalized to BM × Height (P=.146-.889) were body-size-independent measures. Force normalized to BM⁰·⁶⁷ (P=.001-.191) and body mass index (BMI) (P=<.001-.066), and torque normalized to BM (P=.004-.415) and BMI (P<.001) were significantly related to BM and therefore were not body-size independent.
Normalizing force and torque to BM(bavg) is the most effective method of removing body-size dependence and allowing comparisons of persons with differing body sizes.
Social movement scholars have long considered organizations (social movement organizations SMOs) vital to the success of a movement. SMOs organize events, mobilize participants, and recruit new ...activists into the movement. In the case of youth activism, SMOs can also play a vital role in the political socialization of youth. However, a substantial line of research finds that most SMOs do a poor job of encouraging and facilitating youth engagement in offline, face-to-face contexts. With the growing use of digital media by both social movements and youth, online activism presents another avenue through which SMOs can recruit youth participation. The extent to which SMOs are doing any better at this online than offline is an open and surprisingly new question, however. Using a unique dataset, we explore the extent to which SMOs are encouraging youth participation in social movement activity online. Based on our findings, we argue that engaging with and recruiting youth into SMOs is vital for the future health of these organizations as well as the political socialization of youth, and that SMOs are not doing enough to recruit youth online, mirroring their failure offline.
Studying collective action with newspaper accounts of protest events, rare only 20 years ago, has become commonplace in the past decade. A critical literature has accompanied the growth of protest ...event analysis. The literature has focused on selection bias—particularly which subset of events are covered—and description bias—notably, the veracity of the coverage. The "hard news" of the event, if it is reported, tends to be relatively accurate. However, a newspaper's decision to cover an event at all is influenced by the type of event, the news agency, and the issue involved. In this review, we discuss approaches to detecting bias, as well as ways to factor knowledge about bias into interpretations of protest event data.
Anterior cruciate ligament injuries and patellofemoral pain syndrome are both common and significant injuries to the knee that have been associated with hip weakness. Prospective studies have linked ...the risk of experiencing either injury to alterations in the frontal plane knee angle and moment during activity. These components of knee mechanics are theorized to be affected by hip abductor weakness. The purpose of this study was to identify the effects of isolated hip abductor fatigue-induced weakness on lower extremity kinematics and kinetics in recreationally active women.
Twenty participants performed cut, jump, and run tasks off a raised platform while three-dimensional motion analysis data were collected.Participants then performed an isolated hip abductor fatigue protocol in side lying against isokinetic resistance, followed immediately by repeated biomechanical data collection. Separate repeated-measures ANOVA (P G 0.05) were used for each dependent variable.
After the hip fatigue protocol, regardless of task, the knee angle at initial ground contact was more adducted (pre = 0.7 degrees +/- 3.4 degrees, post = 1.2 degrees +/- 3.9 degrees, F(1,19) = 5.3, P = 0.032), the knee underwent greater range of motion into abduction (pre = 0.7 degrees +/- 1.5 degrees, post = 2.1 degrees +/- 1.6 degrees, F(1,19) = 73.2, P < 0.001), and there was a greater internal knee adductor moment (pre = -2.6 +/- 13.3 N x m, post = 4.7 +/- 14.1 N x m, F(1,19) = 41.0, P < 0.001) during the weight acceptance phase of stance.
This study demonstrates that simulated hip abductor weakness causes small alterations of frontal plane knee mechanics. Although some of these alterations occurred in directions associated with increased risk of knee injury, changes were small in magnitude, and the effect of these small changes on knee injury risk is unknown.
Abstract Background Movement and muscle activity of the hip have been shown to affect movement of the lower extremity, and been related to injury. The purpose of this study was to determine if ...increased hip strength affects lower extremity mechanics during running. Methods Within subject, repeated measures design. Fifteen healthy women volunteered. Hip abduction and external rotation strength were measured using a hand-held dynamometer. Three-dimensional biomechanical data of the lower extremity were collected during running using a high-speed motion capture system. Measurements were made before, at the mid-point, and after a 6-week strengthening program using closed-chain hip rotation exercises. Joint range of motion (rearfoot eversion, knee abduction, hip adduction, and internal rotation), eversion velocity, eversion angle at heel strike, and peak joint moments (rearfoot inversion, knee abduction, hip abduction, and external rotation) were analyzed using repeated measures analysis of variance ( P ⩽ 0.05). The independent variable was time (pre-, week 3, and week 6). A separate analysis of variance was conducted with the dependent variables of peak hip abduction and external rotation strength. Findings Hip abduction ( P = 0.009) and external rotation strength ( P < 0.0005) increased by 13% and 23%, respectively. Eversion range of motion decreased ( P = 0.05), hip adduction range of motion increased ( P = 0.05), and a trend of decreased hip internal rotation range of motion ( P = 0.08) were found. Rearfoot inversion moment ( P = 0.02) and knee abduction moment ( P = 0.05) decreased by 57% and 10%, respectively. Interpretation The hip abductors and external rotators were strengthened, leading to an alteration of lower extremity joint loading which may reduce injury risk. These exercises could be used in the rehabilitation, or prevention, of lower extremity injuries.
Abstract Background A key to understanding potential anterior cruciate ligament injury mechanisms is to determine joint loading characteristics associated with an injury-causing event. However, ...direct measurement of anterior cruciate ligament loading during athletic tasks is invasive. Thus, previous research has been unable to study the association between neuromuscular variables and anterior cruciate ligament loading. Therefore, the purpose of this study was to determine the influence of movement anticipation on anterior cruciate ligament loading using a musculoskeletal modeling approach. Methods Twenty healthy recreationally active females were recruited to perform anticipated and unanticipated sidestep cutting. Three-dimensional kinematics and kinetics of the right leg were calculated. Muscle, joint and anterior cruciate ligament forces were then estimated using a musculoskeletal model. Dependent t-tests were conducted to investigate differences between the two cutting conditions. Findings ACL loading significantly increased during unanticipated sidestep cutting (p < 0.05). This increase was primarily due to a significant increase in the sagittal plane ACL loading, which contributed 62% of the total loading. Frontal plane ACL loading contributed 26% and transverse plane ACL loading contributed 12%. Interpretation These results suggest that anterior cruciate ligament loading resulted from a multifaceted interaction of the sagittal plane shear forces (i.e., quadriceps, hamstrings, and tibiofemoral), as well as the frontal and transverse plane knee moments. Additionally, the results of this study confirm the hypothesis in the current literature that unanticipated movements such as sidestep cutting increase anterior cruciate ligament loading.
To investigate the effects of an exhaustive run on trunk and lower extremity strength and mechanics in patients with and without patellofemoral pain (PFP), we hypothesized that strength would ...decrease and mechanics would change after the exhaustive run.
Nineteen subjects with PFP and 19 controls participated (10 men and 9 women per group). Lower extremity and trunk mechanics during running, body mass-normalized strength, and pain assessments before and after an exhaustive run were quantified. A repeated-measures ANOVA was used to assess group differences and exhaustion-related changes (P < 0.05), with t-test post hoc analyses performed when significant interactions were identified (P < 0.0125).
Pain significantly increased with the exhaustive run in the PFP group (P = 0.021). Hip strength was reduced after the exhaustive run, more so in those with PFP (abduction: before = 0.384 ± 0.08, after = 0.314 ± 0.08, P < 0.001; external rotation: before = 0.113 ± 0.02, after = 0.090 ± 0.02, P < 0.001). Persons with PFP also demonstrated increased knee flexion (before = 41.6° ± 5.5°, after = 46.9° ± 7.5°, P < 0.001), hip flexion (before = 30.4° ± 6.8°, after = 42.5° ± 9.7°, P < 0.001), and anterior pelvic tilt (before = 7.2° ± 5.1°, after = 13.3° ± 6.7°, P = 0.001) after the exhaustive run compared to controls. Trunk flexion increased in both PFP (before = 13.09° ± 6.2°, after = 16.31° ± 5.3°, P < 0.001) and control (before = 1393° ± 4.7°, after = 15.99° ± 5.9°, P < 0.001) groups. Hip extension (before = -2.09 ± 0.49 N · m · kg(-1), after = -2.49 ± 0.54 N · m · kg(-1), P = 0.002) moments increased only in subjects with PFP.
Exhaustive running results in reduced hip strength in subjects with PFP; however, this did not result in changes to hip internal rotation or adduction kinematics. Kinematic and kinetic changes after the exhaustive run are more indicative of compensatory changes to reduce pain. Increasing trunk flexion during running might provide pain relief during running; however, reducing anterior pelvic tilt may also warrant attention during treatment.
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