Exacerbating patellofemoral pain alters trunk and lower limb coordination patterns and hip-knee mechanics.

The exacerbation of patellofemoral pain (PFP) may lead to compensatory trunk and lower limb movement patterns in order to minimize patellofemoral joint loading. However, joint kinematics are often analysed in isolation, which limits the understanding of how the underlying segments were coordinated to produce limb postures and distribute load across the limb. In this study we used a dynamical systems approach to investigate how women with PFP coordinate trunk, hip, and knee motion and distribute hip-knee moment demands following symptom exacerbation. Coordination patterns and coordination variability of the trunk, hip, and knee from 61 women with PFP were obtained during stair descent, ascent, and step down tasks, before and after a pain exacerbation protocol. Hip-knee extensor moment impulse ratio was also calculated. Following the exacerbation of PFP, women utilized knee dominant coordination patterns less often (p = 0.039-0.027; d = 0.51-0.53), while coordination patterns with the trunk leaning forward were utilized more during stair negotiation (p = 0.043-<0.001; d = 0.52-0.96). Although no significant differences in hip-knee coordination patterns were found, there was an increase in the hip-knee impulse ratio during stair negotiation (p = 0.014-<0.001; d = 0.27-0.36). These findings seem to display a movement strategy utilized by women with PFP in order to distribute more load to the hip joint and less to the knee joint, possibly in an attempt to avoid/manage pain.

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 (n = 144) and control individuals (n = 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). Follow-up assessments will be identical to the baseline and will be performed after a minimum of 15 months. Generalized linear mixed model (GLMM) will be used to investigate group-by-time differences. Linear regression models will be used to determine 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, HRQOL, and physical activity level. Discussion: Physical and non-physical features have been previously associated with PFP. However, the present study will be the first to investigate their integrated evolution as part of the natural history of PFP and its progression. In doing so, we will be able to determine their behavior in the long-term, as well as how they prospectively associate with each other and with clinical outcomes. Ultimately, this will provide a greater understanding of predictors of long-term outcome and possible targets for interventions.

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. PARTICIPANTS: 39 women and 36 men with PFP. MAIN OUTCOME MEASURES: Knee flexor strength, RTD, and flexibility; performance in the SLBT, current, and worst pain level. RESULTS: Moderate to strong significant negative relationships were identified between the current pain level with knee flexor strength (r = -0.57 to -0.34) and flexibility (r = -0.44 to -0.35); and between knee flexor strength and RTD with the performance in the SLBT (r = 0.34 to 0.57) in women and men with PFP. Knee flexor RTD was not related to any pain level and no significant relationships were identified between the worst pain level with knee flexor strength and flexibility in women and men with PFP. CONCLUSIONS: Our results support the potential value of assessing knee flexor strength and flexibility in women and men with PFP. The SLBT may be a useful tool to assess knee flexor muscle capacity in individuals with PFP in a clinical setting.

Comportamento cardiovascular em hemiparéticos crônicos durante a fisioterapia de grupo no formato de circuito de treinamento / Cardiovascular behavior in chronic hemiparesis during group therapy in circuit training format

Introdução: A Fisioterapia de Grupo em Circuito de Treinamento (FGCT) é um modelo de terapia para hemiparéticos, mas ainda são necessários mais estudos para avaliar seus efeitos sobre o sistema cardiovascular e a funcionalidade. Objetivo: Avaliar o comportamento cardiovascular e a funcionalidade de hemiparéticos crônicos submetidos à FGCT. Métodos: Estudo transversal, (n = 13), consiste em 10 estações de FGCT. Foi calculada a frequência cardíaca média (FCmed), frequência cardíaca máxima (FCmáx) e classificada a frequência cardíaca de treinamento. Os testes funcionais foram realizados no início da sessão. Foi realizada correlação entre os testes funcionais e as FCmed, FCmáx e a comparação da frequência cardíaca (FC) durante as estações e os intervalos entre elas. Resultados: 92,3% dos voluntários foram classificados como intensidade de treinamento muito leve ou leve. Houve significância estatística entre FCMed da 1ª estação quando comparada com a última (p < 0,01). Conclusão: A intensidade de treinamento de hemiparéticos submetidos à FGCT foi de muito leve a leve, com diferença significante entre a FCmed da 1ª estação quando comparada com a última. Não foi observada correlação da FCmed com a funcionalidade. (AU)

Introduction: Physiotherapy Group in Circuit Training (PGCT) is a model of hemiparetic therapy, but further studies are needed to assess its effects on the cardiovascular system and functionality. Objective: To evaluate the cardiovascular behavior and the functionality of chronic hemiparetics submitted to PGCT. Methods: A cross-sectional study, (n = 13), consists of 10 PGCT stations. Mean heart rate (HRM), maximum heart rate (HRmax) and heart rate of training were calculated. Functional tests were performed at the beginning of the session. A correlation was performed between the functional tests and HRM, HRmax and heart rate (HR) comparison during the seasons and intervals between them. Results: 92.3% of the volunteers were classified as very light or light training intensity. There was statistical significance between HRM of the 1st station when compared with the last station (p < 0.01). Conclusion: The intensity of hemiparetic training submitted to PGCT was very light to light, with a significant difference between the FCmed of the 1st station when compared to the last one. No correlation of HRM with the functionality was observed. (AU)

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. Adolescent non-athletes were recruited from upper secondary schools. PARTICIPANTS: 108 adolescents diagnosed with PFP: 42 adolescent athletes and 66 adolescent non-athletes. MAIN OUTCOME MEASURES: To evaluate the level of pain, a visual analog scale (VAS) was used and to evaluate the overall function, the Knee Outcome in Osteoarthritis Survey (KOOS) was used. RESULTS: The adolescent athletes scored significantly higher in the VAS (Mean difference = 0.97 (95% CI = 0.35; 1.60) p = 0.003) compared to adolescent non-athletes. Adolescent athletes scored lower in the KOOS - Symptoms, Pain, Knee-related quality of life and Sport and recreation dimensions - than the non-athletes, however, the minimally clinically important difference was not achieved in Pain dimension. There was no significant difference in the Activities of daily living dimension of the KOOS. CONCLUSIONS: Adolescent athletes presented higher levels of pain and lower physical function status compared with physically active non-athletes. This provides an important insight to the management of PFP in adolescent athletes as worst functional status is linked with poor prognosis in patients with PFP.