Bradley S Neal1, Simon D Lack2, Christian J Barton3, Aleksandra Birn-Jeffery4, Stuart Miller5, Dylan Morrissey6. 1. Sports & Exercise Medicine, Queen Mary University of London, United Kingdom; Pure Sports Medicine, London, United Kingdom. Electronic address: b.s.neal@qmul.ac.uk. 2. Sports & Exercise Medicine, Queen Mary University of London, United Kingdom; Pure Sports Medicine, London, United Kingdom. 3. Sports & Exercise Medicine, Queen Mary University of London, United Kingdom; La Trobe Sport and Exercise Medicine Research Centre, La Trobe University, Bundoora, Victoria, Australia; School of Allied Health, La Trobe University, Melbourne, Victoria, Australia. 4. Sports & Exercise Medicine, Queen Mary University of London, United Kingdom; School of Engineering and Materials Science, Queen Mary University of London, United Kingdom. 5. Sports & Exercise Medicine, Queen Mary University of London, United Kingdom. 6. Sports & Exercise Medicine, Queen Mary University of London, United Kingdom; Physiotherapy Department, Barts Health NHS Trust, London, UK.
Abstract
OBJECTIVES: Investigate the validity and reliability of markerless, smart phone collected, two-dimensional (2D) video, analysed using the 'Hudl technique' application, compared to three-dimensional (3D) kinematics during running, in participants with patellofemoral pain (PFP). DESIGN: Validity/reliability study. SETTING: Biomechanics laboratory. PARTICIPANTS: Males/females with PFP (n = 21, 10 males, 11 females, age 32.1 months [±12.9]). MAIN OUTCOME MEASURES: Manually synchronised 2D and 3D measurement of peak hip adduction (HADD) and peak knee flexion (KFLEX) during running. RESULTS: 2D and 3D measures of peak KFLEX (p = 0.02, d = 1.13), but not peak HADD (p = 0.25, d = -0.27), differed significantly. Poor validity was identified for 2D measurement of peak HADD (ICC 0.06, 95% CI -0.35, 0.47) and peak KFLEX ICC 0.42, 95% CI (-0.10, 0.75). Moderate intra-rater reliability was identified for both variables (ICC 0.61-65), alongside moderate inter-rater reliability for peak KFLEX (ICC 0.71) and poor inter-rater reliability for peak HADD (ICC 0.31). CONCLUSIONS: Measurement of peak HADD and KFLEX in runners with PFP using markerless, smart phone collected 2D video, analysed using the Hudl technique Application is invalid, with poor to moderate reliability. Investigation of alternate 2D video approaches to increase precision is warranted. At present, 2D video analysis of running using Hudl Technique cannot be advocated.
OBJECTIVES: Investigate the validity and reliability of markerless, smart phone collected, two-dimensional (2D) video, analysed using the 'Hudl technique' application, compared to three-dimensional (3D) kinematics during running, in participants with patellofemoral pain (PFP). DESIGN: Validity/reliability study. SETTING: Biomechanics laboratory. PARTICIPANTS: Males/females with PFP (n = 21, 10 males, 11 females, age 32.1 months [±12.9]). MAIN OUTCOME MEASURES: Manually synchronised 2D and 3D measurement of peak hip adduction (HADD) and peak knee flexion (KFLEX) during running. RESULTS: 2D and 3D measures of peak KFLEX (p = 0.02, d = 1.13), but not peak HADD (p = 0.25, d = -0.27), differed significantly. Poor validity was identified for 2D measurement of peak HADD (ICC 0.06, 95% CI -0.35, 0.47) and peak KFLEX ICC 0.42, 95% CI (-0.10, 0.75). Moderate intra-rater reliability was identified for both variables (ICC 0.61-65), alongside moderate inter-rater reliability for peak KFLEX (ICC 0.71) and poor inter-rater reliability for peak HADD (ICC 0.31). CONCLUSIONS: Measurement of peak HADD and KFLEX in runners with PFP using markerless, smart phone collected 2D video, analysed using the Hudl technique Application is invalid, with poor to moderate reliability. Investigation of alternate 2D video approaches to increase precision is warranted. At present, 2D video analysis of running using Hudl Technique cannot be advocated.