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Journal Article (Refereed)
January 2012

Reliability of Two-Dimensional video assessment of frontal plane dynamic knee valgus during common athletic screening tasks

Munro, A & Herrington, L & Carolan, M 2012, 'Reliability of Two-Dimensional video assessment of frontal plane dynamic knee valgus during common athletic screening tasks', Journal of Sport Rehabilitation, 21(1), pp.7-11.


Context: Two-dimensional (2D) video analysis of frontal-plane dynamic knee valgus during common athletic
screening tasks has been purported to identify individuals who may be at high risk of suffering knee injuries
such as anterior cruciate ligament tear or patellofemoral pain syndrome. Although the validity of 2D video
analysis has been studied, the associated reliability and measurement error have not. Objective: To assess the
reliability and associated measurement error of a 2D video analysis of lower limb dynamic valgus. Design:
Reliability study. Participants: 20 recreationally active university students (10 women age 21.5 ± 2.3 y, height
170.1 ± 6.1 cm, weight 66.2 ± 10.2 kg, and 10 men age 22.6 ± 3.1 y, height 177.9 ± 6.0 cm, weight 75.8 ± 7.9
kg). Main Outcome Measurement: Within-day and between-days reliability and measurement-error values
of 2D frontal-plane projection angle (FPPA) during common screening tasks. Interventions: Participants
performed single-leg squat and drop jump and single-leg landings from a standard 28-cm step with standard
2D digital video camera assessment. Results: Women demonstrated significantly higher FPPA in all tests
except the left single-leg squat. Within-day ICCs showed good reliability and ranged from .59 to .88, and
between-days ICCs were good to excellent, ranging from .72 to .91. Standard error of measurement and smallest
detectable difference values ranged from 2.72° to 3.01° and 7.54° to 8.93°, respectively. Conclusions: 2D
FPPA has previously been shown to be valid and has now also been shown to be a reliable measure of lower
extremity dynamic knee valgus. Using the measurement error values presented along with previously published
normative data, clinicians can now make informed judgments about individual performance and changes in
performance resulting from interventions.


SEEK Members

External Authors

M Carolan

A Munro

Publication Details

Journal Name
Journal of Sport Rehabilitation