Search Results

You are looking at 1 - 10 of 384 items for :

  • "ultrasound" x
  • Refine by Access: All Content x
Clear All
Restricted access

Steven J. Obst, Lee Barber, Ashton Miller, and Rod S. Barrett

joint torque to AT force and can be measured in vivo using the ‘tendon-excursion method’ 1 or a ‘geometric method’. 2 The simplest geometric methods use 2D medical imaging (eg, sagittal magnetic resonance imaging [MRI] or B-mode ultrasound) in combination with anthropometric measurements 3 , 4 or 3D

Restricted access

Sabrina S.M. Lee, Gregory S. Lewis, and Stephen J. Piazza

The accuracy of an algorithm for the automated tracking of tendon excursion from ultrasound images was tested in three experiments. Because the automated method could not be tested against direct measurements of tendon excursion in vivo, an indirect validation procedure was employed. In one experiment, a wire “phantom” was moved a known distance across the ultrasound probe and the automated tracking results were compared with the known distance. The excursion of the musculotendinous junction of the gastrocnemius during frontal and sagittal plane movement of the ankle was assessed in a single cadaver specimen both by manual tracking and with a cable extensometer sutured to the gastrocnemius muscle. A third experiment involved estimation of Achilles tendon excursion in vivo with both manual and automated tracking. Root mean squared (RMS) error was calculated between pairs of measurements after each test. Mean RMS errors of less than 1 mm were observed for the phantom experiments. For the in vitro experiment, mean RMS errors of 8–9% of the total tendon excursion were observed. Mean RMS errors of 6–8% of the total tendon excursion were found in vivo. The results indicate that the proposed algorithm accurately tracks Achilles tendon excursion, but further testing is necessary to determine its general applicability.

Restricted access

Stephen J. Pearson, Tim Ritchings, and Ahmad S.A. Mohamed

The work describes an automated method of tracking dynamic ultrasound images using a normalized cross-correlation algorithm, applied to the patellar and gastrocnemius tendon. Displacement was examined during active and passive tendon excursions using B-mode ultrasonography. In the passive test where two regions of interest (2-ROI) were tracked, the automated tracking algorithm showed insignificant deviations from relative zero displacement for the knee (0.01 ± 0.04 mm) and ankle (–0.02 ± 0.04 mm) (P > .05). Similarly, when tracking 1-ROI the passive tests showed no significant differences (P > .05) between automatic and manual methods, 7.50 ± 0.60 vs 7.66 ± 0.63 mm for the patellar and 11.28 ± 1.36 vs 11.17 ± 1.35 mm for the gastrocnemius tests. The active tests gave no significant differences (P > .05) between automatic and manual methods with differences of 0.29 ± 0.04 mm for the patellar and 0.26 ± 0.01 mm for the gastrocnemius. This study showed that automatic tracking of in vivo displacement of tendon during dynamic excursion under load is possible and valid when compared with the standardized method. This approach will save time during analysis and enable discrete areas of the tendon to be examined.

Restricted access

Mark A. Sutherlin, L. Colby Mangum, Jay Hertel, Susan A. Saliba, and Joseph M. Hart

abdominis muscle. ▸ Height times mass was the most consistent normalization variable for the lumbar multifidus muscle. Low back pain (LBP) is a condition of global significance that influences deeper musculature in the body, 1 – 19 but assessing these muscles is challenging. Ultrasound imaging (USI) is one

Restricted access

Walaa M. Elsais, Stephen J. Preece, Richard K. Jones, and Lee Herrington

muscle architecture. For example, ultrasound has been used to measure muscle thickness 15 and elongation of muscle and soft tissue structures during maximal 16 , 17 and submaximal contraction. 18 Two previous studies have used ultrasound to identify the boundaries of the individual adductor muscles

Restricted access

Dale R. Wagner and James D. Cotter

). Accuracy of estimating %BF is 2–3% for laboratory methods and 3–4% for field methods ( Lohman et al., 2020 ). Ultrasound spans the laboratory and field method categories of body composition assessment. High-frequency (12–18 MHz) B-mode (brightness modulation) ultrasound combined with specialized software

Restricted access

Jared R. Fletcher and Brian R. MacIntosh

option in many cases. Consequently, a series of hybrid measurements similar to the MRI center of rotation method have been developed. These include measuring the perpendicular distance from the apparent center of rotation to Achilles tendon midpoint using motion analysis and ultrasound to detect the

Restricted access

Benoit R. Lafleur, Alyssa M. Tondat, Steven P. Pretty, Marina Mourtzakis, and Andrew C. Laing

having direct measurements of TSTT in future studies. Ultrasound imaging is a practical tool that has previously been employed to enable direct measurement of TSTT. 22 , 35 – 38 This noninvasive approach offers several advantages including real-time imaging, high patient acceptability, as well as low

Restricted access

Brett S. Pexa, Eric D. Ryan, Elizabeth E. Hibberd, Elizabeth Teel, Terri Jo Rucinski, and Joseph B. Myers

last longer in muscles subjected to eccentric activity compared with concentric muscle action. 18 Anatomical muscle cross-sectional area (CSA), a 2-dimensional outline of the muscle belly as measured with musculoskeletal ultrasound, significantly increases following eccentric exercise 19 and remains

Restricted access

Laura C. Slane, Stijn Bogaerts, Darryl G. Thelen, and Lennart Scheys

, 6 with lower peak stress and yield stress 7 than anterior (superficial) fascicles. However, many questions remain, including how such regional variations in tendon geometry and material properties may affect in vivo tendon behavior. Cine ultrasound imaging has emerged as a powerful tool for