Browsing by Author "Green, Tanya"

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    Validation of an evidence-based biomechanical risk factor screening tool for patellofemoral pain
    (Stellenbosch : Stellenbosch University, 2021-12) Green, Tanya; Louw, Quinette A.; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Health & Rehabilitation Sciences. Physiotherapy.
    ENGLISH SUMMARY : Background: Patellofemoral pain (PFP) is a musculoskeletal disorder of the knee commonly known to affect active adolescent and young adult populations. Altered lower-extremity biomechanics is recognised as a contributing factor resulting in increased stress of the patellofemoral joint (PFJ), which may ultimately cause PFP. Two-dimensional (2D) video gait analysis is a practical way to assess gait kinematics in a clinical setting. However, comparisons between 2D clinical observational gait analysis and the ‘gold standard’ three-dimensional (3D) motion analysis using an evidence-based biomechanical risk factor screening tool to identify biomechanical risk factors have not been established yet. Aim and objectives: This study aimed to ascertain agreement between the identification of biomechanical risk factors in individuals with PFP using 2D observational gait analysis (clinical standard) by clinicians and 3D motion analysis (gold standard) by an experienced analyst. The interrater reliability and concurrent validity of 2D clinical observational gait analysis by employing an evidence-based biomechanical risk factor screening tool were investigated. Methods The data were collected using a cross-sectional, descriptive study design. Interrater reliability and concurrent validity of 2D clinical observational gait analysis were investigated by observing walking and running videos of 18 recreational runners. Two physiotherapists (raters) independently reviewed the recordings to identify kinematic risk factors constructed from the evidence-based biomechanical risk factor screening tool. Sixteen frontal, sagittal and transverse hip, knee and ankle kinematic variables were investigated and rated dichotomously (yes/no) at specific phases in the gait cycle. The percentage agreement and Cohen’s kappa statistic were used to calculate agreement within raters and between 2D and 3D kinematic variables. Results: Overall, 2D clinical observational gait analysis demonstrated moderate interrater reliability and concurrent validity based on the percentage agreement. The agreement for interrater reliability ranged widely for walking (percentage agreement = 50%–77.78%; kappa = -0.09–0.27) and running (percentage agreement = 44.44%–77.78%; kappa = -0.15–0.35). Only two of the eight kinematic variables for walking demonstrated a high percentage agreement, namely increased peak knee extension and increased overall ankle dorsiflexion (77.78%). Running showed a high percentage agreement in three of the eight kinematic variables, namely increased peak knee flexion (77.78%), increased ankle dorsiflexion and increased ankle eversion (72.22%). Observed agreement for 2D kinematics versus 3D kinematics observed differed significantly between raters. Rater 1’s mean findings demonstrated a percentage agreement of 60.41% (with kappa = 0.05) in walking and 64.58% (with kappa = 0.09) in running. Rater 2’s mean findings demonstrated a percentage agreement of 76.38% (with kappa = 0.15) in walking and 81.25% (with kappa = 0.20) in running. Conclusion: The study findings invalidated the use of 2D clinical observational gait analysis employed for the identification of lower-extremity biomechanics and constructed from the evidence-based biomechanical risk factor screening tool in recreational runners with PFP. However, there was overall moderate to fair interrater reliability. The results show that 2D clinical observational gait analysis of certain kinematics included in the evidence-based biomechanical risk factor screening tool should be used cautiously, as the reliability and validity are not adequate for all the kinematic factors included. Clinicians should consider both the best available evidence and the reliability of clinical measurements when screening individuals with PFP in clinical practice to ensure that biomechanical analysis is accurate and relevant.