Hamstring muscle architecture using wide field-of-view ultrasound: A reliability study

Kevin Cronin, Radiography and Diagnostic Imaging, School of Medicine, University College Dublin, Ireland


The prevalence of hamstring strain re-injury is high among field sport athletes, and ranges from 14%–34% within the same competitive season. Ultrasound is the most commonly used medical imaging modality to assess the architectural characteristics of skeletal muscle. However, acquisition of hamstring muscle architecture is challenging and operator-dependent.

Aim of investigation

To assess the reliability of wide field-of-view (WFOV) ultrasound (US) to quantify the muscle architecture of the hamstring muscles.


Twenty male athletes were sonographically assessed on two separate occasions. Static ultrasound images were collected by a single sonographer using a 92mm linear transducer to assess the architectural characteristics (muscle length, fascicle length, pennation angle and muscle thickness) from two distinct locations of the BFlh and SM of the left limb. Muscle length and thickness were assessed in the BFsh and ST muscle of the left limb. Intraclass correlation assessed intra-rater reliability.


Both muscle (ICC = 0.99; SEM = 4.3-6.6mm) and fascicle (ICC = 0.92–0.98; SEM = 1.1-2.4mm) length were measured with excellent intra-rater reliability. Muscle thickness was measured with excellent reliability (ICC = 0.9-0.96; SEM = 0.91mm–1.4mm) for all hamstring muscles except for the proximal segments of the BFsh (ICC = 0.85; SEM = 0.84mm) and ST (ICC = 0.88; SEM = 0.82mm) which measured good reliability. Pennation angle was measured with good reliability (ICC = 0.77 – 0.87; SEM = 1-1.6).


Static WFOV is a reliable ultrasound technique to quantify the architectural characteristics of the hamstring muscles.

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