Reliability of ultrasound to measure morphology of the toe flexor muscles

Abstract

BackgroundMeasuring the strength of individual foot muscles is very challenging; however, measuring muscle morphology has been shown to be associated with strength. A reliable method of assessing foot muscle atrophy and hypertrophy would therefore be beneficial to researchers and clinicians. Thus, the aim of this study was to evaluate the test-retest intra-observer reliability of ultrasound to measure the morphology of the primary toe flexor muscles.MethodThe abductor hallucis, flexor hallucis brevis, flexor digitorum brevis, quadratus plantae and abductor digiti minimi muscles in the foot, and the flexor digitorum longus and flexor hallucis longus muscles in the shank were assessed in five males and five females (mean age = 32.1 ± 10.1 years). Muscles were imaged using a GE Venue 40 ultrasound (6-9 or 7.6-10.7 MHz transducer) in a random order, and on two occasions 1-6 days apart. Muscle thickness and cross-sectional area were measured using Image J software with the assessor blinded to muscle and day of scan. Intraclass correlation coefficients (ICC) and limits of agreement were calculated to assess day-to-day repeatability of the measurements.ResultsThe method was found to have good reliability (ICC = 0.89-0.99) with limits of agreement between 8-28% of the relative muscle size.ConclusionThe protocol described in this paper showed that ultrasound is a reliable method to measure morphology of the toe flexor muscles. The portability and advantages of ultrasound make it a useful tool for clinical and research settings.

Morphology of the Toe Flexor Muscles in Older Adults With Toe Deformities

“…Images of the muscles were obtained using a standardized procedure that has been shown to have high intra-and interrater reliability (14,15). Ultrasound coupling gel was applied over the transducer and skin at each of the measurement sites.…”

Effect of antipronation foot orthosis geometry on compression of heel and arch soft tissues

“…For the heel area, the calcaneal tuberosity was selected as the reference anatomical landmark, viewed in the frontal plane. Due to its superficial location, shape, and tissue properties, it is easily identified and has demonstrated high reliability [19].…”

“…Ultrasound is becoming increasingly popular for quantifying soft tissue characteristics [18][19]. As well as being noninvasive, it is portable so, unlike MRI [20], can be used to quantify tissue characteristics in a weightbearing prone position.…”

“…Ultrasound has been used to measure foot muscles [21] and skin and plantar aponeurosis [22]. Furthermore, it demonstrates good intra-and interobserver reliability with foot structures [19]. However, to date, only one study has used ultrasound to study the effect of orthotic designs focusing on the heel, and no APFO was included [23].…”

Does Function Determine the Structure? Changes in Flexor Hallucis Longus Muscle and the Associated Performance Related to Dance Modality: A Cross-Sectional Study

“…Ultrasound imaging is a non-invasive, safe, and valid method for examining soft tissue and musculoskeletal structures [11,12]. Prior studies have focused on the thickness and CSA of the FHL muscle in healthy subjects [13] and subjects with pes planus [14].…”