Individuals with patellofemoral pain have impaired self-reported and performance-based function: Systematic review with meta-analysis and meta-regression.

Objective: To determine impairments on self-reported/performance-based function in individuals with patellofemoral pain (PFP) as well as physical and non-physical factors potentially related with these impairments.

Data Sources: We searched MEDLINE, Embase, CINAHL, Web of Science, and SPORTDiscus databases from inception until January 2024.

Study Selection: We included studies comparing self-reported/performance-based measures of function between individuals with PFP and their pain-free limbs or pain-free individuals.

Patellofemoral pain over time: Protocol for a prospective, longitudinal study investigating physical and non-physical features.

Background: This is a protocol for a prospective longitudinal study that aims to investigate: (1) group-by-time changes over a minimum of 15 months follow-up in patellofemoral pain (PFP) symptoms, biomechanical, muscle function, pain processing, and psychological features; (2) the extent to which changes in biomechanical, muscle function, pain processing, and psychological features are associated with changes in self-reported pain, physical performance measures, self-reported function, health-related quality of life (HRQOL), and physical activity level.

Methods: Individuals with PFP ( = 144) and control individuals ( = 85) without PFP were assessed at baseline. Outcomes assessed included: 3D kinematics and kinetics during single leg squat, step-down and single leg hop; maximal torque and rate of torque development of hip abductors and knee extensors/flexors; force steadiness of hip abductors and knee extensors; anterior and lateral trunk endurance; pressure pain thresholds at the center of patella and contralateral shoulder; kinesiophobia (Tampa Scale for Kinesiophobia); pain catastrophizing (Pain Catastrophizing Scale); worst self-reported pain (Visual Analogue Scale); physical performance measures (Single Leg Hop Test and Forward Step-Down Test); self-reported function (Anterior Knee Pain Scale); HRQOL (Medical Outcome Short-Form 36), and physical activity level (Baecke's Questionnaire).

Depth of single-leg squat influences the two-dimensional analysis of knee, hip, and pelvis frontal plane motion in pain-free women.

Background: The single-leg squat (SLS) is often used to measure two-dimensional frontal plane motion; however, there is a variability in the SLS depth across studies.

Research Question: Are knee abduction (KABD), hip adduction (HADD), pelvic drop (PD), and lateral trunk flexion (LTF) angles different at greater knee flexion angles during a SLS?

Methods: Twenty pain-free females (age=22.3 ± 1.

Relationship between vastus medialis Hoffmann reflex excitability and knee extension biomechanics during different tasks in women with patellofemoral pain.

Background: Impaired knee extension biomechanics and spinal excitability have been reported in women with patellofemoral pain, but their relationship has not been explored. A significant relationship between them could indicate the need for investigating the potential benefits of disinhibitory interventions for women with patellofemoral pain. Thus, this study aimed to investigate the relationship between vastus medialis Hoffmann reflex and (1) maximal isometric, concentric and eccentric knee extensor strength and rate of torque development; (2) knee extensor torque steadiness; and (3) knee extensor moment during functional tasks; in women with patellofemoral pain.

Trunk muscle endurance in individuals with and without patellofemoral pain: Sex differences and correlations with performance tests.

Objectives: To compare trunk muscle endurance among females and males with and without patellofemoral pain (PFP), and to investigate the correlations between trunk muscle endurance and performance of the single leg hop test (SLHT) and forward step-down test (FSDT).

Design: Cross-sectional.

Setting: Laboratory-based study.

Knee flexor strength, rate of torque development and flexibility in women and men with patellofemoral pain: Relationship with pain and the performance in the single leg bridge test.

Objectives: To investigate the relationship between: (1) knee flexor strength, rate of torque development (RTD), and flexibility with pain level; (2) knee flexor strength and RTD with the performance in the single leg bridge test (SLBT) in women and men with patellofemoral pain (PFP).

Design: Cross-sectional.

Setting: Laboratory-based study.

Women with patellofemoral pain and knee crepitus have reduced knee flexion angle during stair ascent.

Objectives: To compare trunk and knee biomechanics of women with and without patellofemoral pain (PFP) and knee crepitus during stair ascent.

Design: Cross-sectional.

Setting: Laboratory-based study.

Influence of the exacerbation of patellofemoral pain on trunk kinematics and lower limb mechanics during stair negotiation.

Background: Although it is assumed that the presence of patellofemoral pain (PFP) may result in compensatory behaviors that can alter trunk kinematics and lower limb mechanics, the influence of the exacerbation of patellofemoral pain on trunk kinematics and lower limb mechanics during stair negotiation has not been established.

Research Question: Does the exacerbation of PFP symptoms lead to altered trunk kinematics and lower limb mechanics during stair negotiation?

Methods: Three-dimensional kinematics and kinetics were obtained from 45 women with PFP during stair descent and ascent. Data were obtained before and after a pain exacerbation protocol.

Lower Trunk Muscle Thickness Is Associated With Pain in Women With Patellofemoral Pain.

Objectives: To compare trunk muscle thickness of women with and without patellofemoral pain (PFP) and to assess the association of trunk muscle thickness with self-reported pain of women with PFP.

Methods: Forty-four women were recruited and divided into 2 groups: a PFP group (n = 22) and a pain-free group (n = 22). The thickness of the following trunk muscles was obtained by B-mode ultrasound imaging: transversus abdominis, obliquus internus (OI), obliquus externus (OE), rectus abdominis, and multifidus.

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.

Patellar Tendon Reflex and Vastus Medialis Hoffmann Reflex Are Down Regulated and Correlated in Women With Patellofemoral Pain.

Objectives: The aims of this study were threefold: (1) to compare the amplitude of patellar tendon reflex (T-reflex) between women with patellofemoral pain (PFP) and pain-free controls; (2) to compare the amplitude of vastus medialis Hoffmann reflex (VM H-reflex) between women with PFP and pain-free controls; (3) to investigate the association between the amplitude of patellar T-reflex and VM H-reflex in women with PFP and pain-free controls.

Design: Cross-sectional observational study.

Setting: Laboratory of biomechanics and motor control.

Differences in pain and function between adolescent athletes and physically active non-athletes with patellofemoral pain.

Objectives: To investigate pain level and function limitation in adolescent athletes and physically active non-athletes with PFP.

Design: Cross-sectional study.

Setting: Adolescent athletes were recruited at a sport center complex.

Association between increase in vertical ground reaction force loading rate and pain level in women with patellofemoral pain after a patellofemoral joint loading protocol.

Background: The etiology of patellofemoral pain (PFP) is thought to be the result of increased patellofemoral joint (PFJ) load and aberrant lower extremity mechanics, including altered vertical ground reaction forces (VGRF). However, few studies have investigated the association between an increase in pain and VGRF loading rates in the context of PFP. Thus, this study aimed to investigate the immediate effects of PFJ loading on pain and VGRF loading rate, and to see if there is a link between modification of both pain and VGRF loading rate during stair negotiation.