A Prospective Investigation of Biomechanical Risk Factors for Patellofemoral Pain Syndrome The Joint Undertaking to Monitor and Prevent ACL Injury (JUMP-ACL) Cohort

University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
The American Journal of Sports Medicine (Impact Factor: 4.36). 09/2009; 37(11):2108-16. DOI: 10.1177/0363546509337934
Source: PubMed


Patellofemoral pain syndrome is one of the most common chronic knee injuries; however, little research has been done to determine the risk factors for this injury.
Altered lower extremity kinematics and kinetics, decreased strength, and altered postural measurements will be risk factors.
Cohort study (prognosis); Level of evidence, 2.
A total of 1597 participants were enrolled in this investigation and prospectively followed from the date of their enrollment (July 2005, July 2006, or July 2007) through January 2008, a maximum of 2.5 years of follow-up. Each participant underwent baseline data collection during their pre-freshman summer at the United States Naval Academy. Baseline data collection included 3-dimensional motion analysis during a jump-landing task, 6 lower extremity isometric strength tests, and postural alignment measurements (navicular drop and Q angle).
Risk factors for the development of patellofemoral pain syndrome included decreased knee flexion angle, decreased vertical ground-reaction force, and increased hip internal rotation angle during the jump-landing task. Additionally, decreased quadriceps and hamstring strength, increased hip external rotator strength, and increased navicular drop were risk factors for the development of patellofemoral pain syndrome.
Multiple modifiable risk factors for patellofemoral pain syndrome pain have been identified in this investigation. To decrease the incidence of this chronic injury, the risk factors for patellofemoral pain syndrome need to be targeted in injury prevention programs.
Prevention programs should focus on increasing strength of the lower extremity musculature along with instructing proper mechanics during dynamic movements to decrease the incidence of patellofemoral pain syndrome.

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Available from: Michelle C Boling
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    • "It has been suggested that alterations in hip kinetics may lead to patellofemoral pain syndrome (Powers 2003). Increased external hip rotator strength has been identified as a risk factor for the development of patellofemoral pain (Boling et al. 2009), while no evidence was found for the hip abduction moment during a jump landing task as tested in the present experiment. "
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    ABSTRACT: Knee and hip alignment and knee moments during landing are considered risk factors for knee injuries while ankle bracing has been demonstrated to alter landing kinematics and kinetics at these joints. The aim of this study was to investigate whether a semi-rigid ankle brace has an effect on knee and hip kinematics and kinetics during landing on uneven surfaces. Seventeen recreational athletes performed a landing task on a randomly inclined platform with and without an ankle brace. Three different surface alignments were generated: everted, neutral, and inverted. Ground reaction forces (GRF), kinematics, and brace reaction forces were measured. Two independent variables were tested: the brace factor (braced and non-braced) and the inclination factor (everted, neutral, and inverted). Seven separate 2 × 3 repeated measures MANOVAs were employed to compare GRF, knee, and hip initial angles and range of motion (ROM), knee, and hip forces and moments. Participants landed with a more flexed knee and hip during the brace condition, followed by a knee ROM reduction. No differences were observed for the kinetic variables. Landing on the inverted surface resulted in increased peak magnitudes of the vertical and the mediolateral GRF compared to landing on the neutral surface. Landing on the everted surface caused higher knee and hip abduction moments during early contact. Results confirm that ankle bracing may affect the kinematics of the whole lower extremity with no effect on knee or hip loading. Landing on uneven surfaces may increase injury risk, but no adverse effects were shown for wearing the brace.
    Full-text · Article · Jan 2016
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    • "The incidence of PFP reported in the current investigation (10.5%) is slightly higher than that which has been previously reported in prospective investigations of adult populations (Stefanyshyn et al., 2006; Boling et al., 2009). This is probably reflective of the high incidence of PFP in adolescent females as these studies examined adult populations which included males in their analyses. "
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    ABSTRACT: Patellofemoral pain (PFP) is a prevalent lower limb musculo-skeletal injury in adolescent females. Female athletes with PFP display increased frontal plane knee joint motion in comparison to control subjects. The current investigation aimed to determine prospectively whether two-dimensional knee valgus displacement during landing could predict the risk of developing PFP. Seventy-six injury-free adolescent female athletes (age = 12.9 ±0.35 years) participated. At baseline participants performed three drop vertical jump trials from a 31-cm box. A standard video camera was used to record frontal plane knee joint kinematics. Over the 24-month follow-up, eight participants developed PFP, as diagnosed by a Chartered Physiotherapist. Knee valgus displacement was significantly increased in those who developed PFP compared to those who did not (mean difference = 7.79°; P = 0.002; partial eta squared = 0.07). Knee valgus displacement ≥10.6° predicted PFP with a sensitivity of 0.75 and specificity of 0.85. The associated positive likelihood ratio was 5. These results have clinical utility suggesting that two-dimensional analysis could be implemented to screen for increased risk of PFP in adolescent female athletes.
    Full-text · Article · Dec 2015 · Scandinavian Journal of Medicine and Science in Sports
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    • "Patellofemoral pain syndrome (PFPS) is characterized by pain around the patella mainly at activities that load the patellofemoral joint like bending knees, walking stairs, or kneeling. The origin of the complaints is not fully understood although weakness and/or tightness of the extensor muscles, changes in medial and lateral quadriceps muscle reflex time, patellar laxity, and increased navicular drop are suggested to be associated with PFPS (Witvrouw et al. 2000; Boling et al. 2009). "

    Full-text · Dataset · Nov 2015
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