Knee and Hip Isometric Force Steadiness Are Impaired in Women With Patellofemoral Pain.

Ferreira, AS, de Oliveira Silva, D, Ferrari, D, Magalhães, FH, Pappas, E, Briani, RV, Pazzinatto, MF, and de Azevedo, FM. Knee and hip isometric force steadiness are impaired in women with patellofemoral pain. J Strength Cond Res 35(10): 2878-2885, 2021-The purposes were as follows: to compare knee extension and hip abduction force steadiness and maximal strength between women with patellofemoral pain (PFP) and pain-free women; and to investigate whether maximal strength, self-reported pain during force-matching tasks, self-reported knee function, symptoms duration, and physical activity level are associated with knee extension and hip abduction force steadiness.

Relationship between knee abduction moment with patellofemoral joint reaction force, stress and self-reported pain during stair descent in women with patellofemoral pain.

Background: Increased external knee abduction moment has been proposed as a risk factor for patellofemoral pain. This alteration is thought to be associated with elevated patellofemoral joint reaction force and stress, however these relationships remain poorly explored. Therefore, this study aimed at comparing knee abduction moment parameters (peak, rate of moment development and impulse), patellofemoral joint reaction force and stress of women with patellofemoral pain and pain-free controls during stair descent; and investigating the relationship among these variables with self-reported pain.

Reliability and Validity of Frontal Plane Kinematics of the Trunk and Lower Extremity Measured With 2-Dimensional Cameras During Athletic Tasks: A Systematic Review With Meta-analysis.

Background: Two-dimensional (2-D) analysis is commonly used to quantify frontal plane kinematics of the trunk and lower extremity. However, there are conflicting results regarding the reliability and validity of these measurements.

Objective: To synthesize the current literature to determine whether 2-D analysis is a reliable and valid method of measuring frontal plane kinematics of the trunk and lower extremity during squatting, landing, and cutting tasks.

Knee crepitus is prevalent in women with patellofemoral pain, but is not related with function, physical activity and pain.

Objectives: (i) To assess the reliability of knee crepitus measures, (ii) to investigate the association between knee crepitus and PFP; (iii) to investigate the relationship between knee crepitus with self-reported function, physical activity and pain.

Design: Cross-sectional.

Setting: Laboratory-based study.

Which is the best predictor of excessive hip internal rotation in women with patellofemoral pain: Rearfoot eversion or hip muscle strength? Exploring subgroups.

Background: Patellofemoral pain (PFP) has been linked to increased patellofemoral joint stress as a result of excessive hip internal rotation. Lower hip strength and/or excessive rearfoot eversion have been used to explain such altered movement pattern; however, it is unknown which one is the best predictor of excessive hip internal rotation.

Research Question: To investigate if peak rearfoot eversion and/or peak concentric hip abductor strength can predict peak hip internal rotation during stair ascent in women with PFP.

Higher pain level and lower functional capacity are associated with the number of altered kinematics in women with patellofemoral pain.

This study investigated whether women with patellofemoral pain (PFP) present kinematic alterations in proximal, local, and distal factors simultaneously, and determined the association between the number of kinematic alterations, pain level, and functional status. A three-dimensional motion analysis system was used to analyze the peak hip adduction, peak knee flexion, and peak rearfoot eversion, addressing the proximal, local, and distal factors, respectively, in fifty women. Functional status and pain level were assessed using the anterior knee pain scale (AKPS) and a visual analogic scale.

Outpatient versus inpatient anterior cruciate ligament reconstruction: A systematic review with meta-analysis.

Background: Efforts to reduce the financial costs related to anterior cruciate ligament reconstruction (ACLR) include reducing the length of hospitalization of the patient undergoing ACLR. However, it is unclear if inpatient and outpatient ACLR differ in terms of safety, satisfaction, costs and clinical outcomes.

Aim: To systematically review and synthesize the literature that directly compared costs and outcomes after outpatient and inpatient ACLR.

Vastus Medialis Hoffmann Reflex Excitability Is Associated With Pain Level, Self-Reported Function, and Chronicity in Women With Patellofemoral Pain.

Objective: To determine the association between the amplitude of vastus medialis (VM) Hoffmann reflex (H-reflex) and pain level, self-reported physical function, and chronicity of pain in women with patellofemoral pain (PFP).

Design: Cross-sectional study.

Setting: Laboratory of biomechanics and motor control.

Lower Amplitude of the Hoffmann Reflex in Women With Patellofemoral Pain: Thinking Beyond Proximal, Local, and Distal Factors.

Objectives: To investigate whether vastus medialis (VM) Hoffmann reflexes (H-reflexes) differ on the basis of the presence or absence of patellofemoral pain (PFP) and to assess the capability of VM H-reflex measurements in accurately discriminating between women with and without PFP.

Design: Cross-sectional study.

Setting: Laboratory of biomechanics and motor control.

Delayed onset of electromyographic activity of the vastus medialis relative to the vastus lateralis may be related to physical activity levels in females with patellofemoral pain.

The aims of this study were to examine group differences in muscle activation onset of the vastus medialis (VM) in relation to the vastus lateralis (VL) and pain level during stair ascent in females with patellofemoral pain (PFP) who maintain high and moderate levels of physical activity; to determine the association between physical activity level and muscle activation onset. Forty-three females with PFP and thirty-eight pain-free females were recruited and divided into four groups based on their level of physical activity: females with PFP (n=26) and pain-free females (n=26) who practiced a moderate level of physical activity and females with PFP (n=17) and pain-free females (n=12) who practiced an intense amount of physical activity. Participants were asked to ascend a seven-step staircase and the VM and VL activation onset was determined.

Q-angle static or dynamic measurements, which is the best choice for patellofemoral pain?

Background: The elevated Q-angle seems to be one of the most suggested factors contributing to patellofemoral pain. Females with patellofemoral pain are often evaluated through static clinical tests in clinical practice. However, the adaptations seem to appear more frequently in dynamic conditions.

Vertical Ground Reaction Forces are Associated with Pain and Self-Reported Functional Status in Recreational Athletes with Patellofemoral Pain.

Individuals with patellofemoral pain (PFP) use different motor strategies during unipodal support in stair climbing activities, which may be assessed by vertical ground reaction force parameters. Thus, the aims of this study were to investigate possible differences in first peak, valley, second peak, and loading rate between recreational female athletes with PFP and pain-free athletes during stair climbing in order to determine the association and prediction capability between these parameters, pain level, and functional status in females with PFP. Thirty-one recreational female athletes with PFP and 31 pain-free recreational female athletes were evaluated with three-dimensional kinetics while performing stair climbing to obtain vertical ground reaction force parameters.

Reduced knee flexion is a possible cause of increased loading rates in individuals with patellofemoral pain.

Background: Stair ascent is an activity that exacerbates symptoms of individuals with patellofemoral pain. The discomfort associated with this activity usually results in gait modification such as reduced knee flexion in an attempt to reduce pain. Although such compensatory strategy is a logical approach to decrease pain, it also reduces the normal active shock absorption increasing loading rates and may lead to deleterious and degenerative changes of the knee joint.

Comparison of frequency and time domain electromyography parameters in women with patellofemoral pain.

Background: Despite its high incidence, patellofemoral pain etiology remains unclear. No prior study has compared surface electromyography frequency domain parameters and surface electromyography time domain variables, which have been used as a classic analysis of patellofemoral pain.

Methods: Thirty one women with patellofemoral pain and twenty eight pain-free women were recruited.

Reliability and differentiation capability of dynamic and static kinematic measurements of rearfoot eversion in patellofemoral pain.

Background: Excessive rearfoot eversion is thought to be a risk factor for patellofemoral pain development, due to the kinesiological relationship with ascendant adaptations. Individuals with patellofemoral pain are often diagnosed through static clinical tests, in scientific studies and clinical practice. However, the adaptations seem to appear in dynamic conditions.

Diagnostic accuracy of the electromyography parameters associated with anterior knee pain in the diagnosis of patellofemoral pain syndrome.

Objective: To assess the diagnostic accuracy of the surface electromyography (sEMG) parameters associated with referred anterior knee pain in diagnosing patellofemoral pain syndrome (PFPS).

Design: Sensitivity and specificity analysis.

Setting: Physical rehabilitation center and laboratory of biomechanics and motor control.