A non-invasive, 3D, dynamic MRI method for measuring muscle moment arms in vivo: Demonstration in the human ankle joint and Achilles tendon

Clarke, Elizabeth C.; Martin, Joshua H.; d’Entremont, Agnes G.; Pandy, Marcus G.; Wilson, David R.; Herbert, Robert D.

doi:10.1016/j.medengphy.2014.11.003

Cited by 42 publications

(58 citation statements)

References 23 publications

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“…plantar flexor) moment arms at the rotated ankle are more favourable than those at a normal knee (Steenhoff et al , 1993). Previous experimental measurements suggest that the patellar tendon moment arm decreases remarkably from 15° to 0° knee flexion (Tsaopoulos et al , 2006), whereas estimated Achilles tendon moment arm is relatively stable (Clarke et al , 2015) and it tends to be greater in plantarflexed position, which is the same adopted by KRP patients during early stance. There seems to be room, therefore, for speculating that muscle atrophy might well be also the effect, not only the cause, of the decreased power output.…”

Section: Discussionmentioning

confidence: 89%

Knee rotationplasty: motion of the body centre of mass during walking

Rota

Benedetti

Okita

et al. 2016

International Journal of Rehabilitation Research

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Knee rotationplasty (KRP) is a type of surgery in which the rotated ankle serves as a new knee after being removed for bone tumor. Although this limb salvage surgery is rarely indicated in properly selected patients, it may offer functional advantages over transfemoral amputation, and more durable results compared with a prosthesis. The walking mechanics of adult patients after KRP is believed to be close to that of below-knee amputees. In this study, we evaluated steady-state walking of KRP patients from the viewpoint of the overall muscle power needed to keep the body centre of mass in motion. Three adult patients after KRP, all athletes, were evaluated. Ground reactions during walking were recorded during six subsequent strides on a force treadmill. The positive mechanical work and power sustaining the motion of the centre of mass and the recovery of muscle energy due to the pendulum-like mechanism of walking were computed and compared with those obtained in previous studies from above-knee, below-knee amputees and healthy individuals. In KRP patients, walking was sustained by a muscle power output which was 1.4–3.6 times lower during the step performed on the rotated limb than on the subsequent step. The recovery of muscle energy was slightly lower (0.9) or higher (1.3–1.4 times) on the affected side. In two out of the three KRP patients, our findings were more similar to those from above-knee amputees than to those from below-knee amputees. After KRP, the rotated limb does not necessarily provide the same power provided by below-knee amputation. This may have a relevance for the paralympic classification of KRP athletes.

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Section: Discussionmentioning

confidence: 89%

Knee rotationplasty: motion of the body centre of mass during walking

Rota

Benedetti

Okita

et al. 2016

International Journal of Rehabilitation Research

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“…In brief, a sagittal MR image of the lower leg and foot was used to identify the joint (ankle) center of rotation as well as Achilles tendon line of action (the latter marked as a straight line along the center of the tendon). The perpendicular distance of the joint center to the line of action was measured as the Achilles tendon moment arm . The measured muscle force is that generated by the gastrocnemius (lateral and medial) and the soleus muscles.…”

Section: Methodsmentioning

confidence: 99%

Diffusion tensor imaging and diffusion modeling: Application to monitoring changes in the medial gastrocnemius in disuse atrophy induced by unilateral limb suspension

Malis

Sinha

Csapo

et al. 2018

Magnetic Resonance Imaging

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Background Diffusion tensor imaging (DTI) assesses underlying tissue microstructure, and has been applied to studying skeletal muscle. Unloading of the lower leg causes decreases in muscle force, mass, and muscle protein synthesis as well as changes in muscle architecture. Purpose To monitor the change in DTI indices in the medial gastrocnemius (MG) after 4‐week unilateral limb suspension (ULLS) and to explore the feasibility of extracting tissue microstructural parameters based on a two‐compartment diffusion model. Study Type Prospective cohort study. Subjects Seven moderately active subjects (29.1 ± 5.7 years). Field Strength/Sequence 3T, single‐shot fat‐suppressed echo planar spin echo sequence. Assessment Suspension‐related changes in the DTI indices (eigenvalues: λ1, λ2, λ3, fractional anisotropy; coefficient of planarity) were statistically analyzed. Changes in model‐derived tissue parameters (muscle fiber circularity and diameter, intracellular volume fraction, and residence time) after suspension are qualitatively discussed. Statistical Tests Changes in the DTI indices of the MG between pre‐ and postsuspension were assessed using repeated‐measures two‐way analysis of variance (ANOVA). Results All the eigenvalues (λ1: P = 0.025, λ2: P = 0.035, λ3: P = 0.049) as well as anisotropic diffusion coefficient (P = 0.029) were significantly smaller post‐ULLS. Diffusion modeling revealed that fibers were more circular (circularity index increased from 0.55 to 0.95) with a smaller diameter (diameter decreased from 82–60 μm) postsuspension. Data Conclusion We have shown that DTI indices change with disuse and modeling can relate these voxel level changes to changes in the tissue microarchitecture. Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018.

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“…, ; Sheehan ; Clarke et al. ). The line of action was projected onto the orthogonal plane of the talocrural joint axis, and the shortest distance between that projected line and the talocrural joint axis was calculated as the ATMA for the neutral position.…”

Section: Methodsmentioning

confidence: 99%

“…, ; Sheehan ; Clarke et al. ) can overcome the limitations of 2D approaches, this method is not always feasible owing to long scan time and high cost of data collection. Furthermore, the center of rotation method also requires MRI for data collection, whereas data collection for the tendon excursion method can be performed by ultrasonography, which is more feasible.…”

Section: Introductionmentioning

confidence: 99%

Comparison of the Achilles tendon moment arms determined using the tendon excursion and three-dimensional methods

et al. 2016

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The moment arm of muscle‐tendon force is a key parameter for calculating muscle and tendon properties. The tendon excursion method was used for determining the Achilles tendon moment arm (ATMA). However, the accuracy of this method remains unclear. This study aimed to investigate the magnitude of error introduced in determining the ATMA using the tendon excursion method by comparing it with the reference three‐dimensional (3D) method. The tendon excursion method determined the ATMA as the ratio between the Achilles tendon displacement during foot rotation from 15° of dorsiflexion to 15° of plantarflexion and the joint rotation angle. A series of foot images was obtained at 15° of dorsiflexion, the neutral position, and 15° of plantarflexion. The 3D value of the ATMA was determined as the shortest distance between the talocrural joint axis and the line of action of the Achilles tendon force. The ATMA determined by the tendon excursion method was smaller by 3.8 mm than that determined using the 3D method. This error may be explained mainly by the length change in the Achilles tendon due to the change in the force applied to it, as passive plantarflexion torque was different by 11 Nm between 15° of dorsiflexion and 15° of plantarflexion. Furthermore, the ATMAs determined using the 3D and tendon excursion methods were significantly correlated but the coefficient of determination was not large (R 2 = 0.352). This result suggests that the tendon excursion method may not be feasible to evaluate the individual variability of the ATMA.

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A non-invasive, 3D, dynamic MRI method for measuring muscle moment arms in vivo: Demonstration in the human ankle joint and Achilles tendon

Cited by 42 publications

References 23 publications

Knee rotationplasty: motion of the body centre of mass during walking

Knee rotationplasty: motion of the body centre of mass during walking

Diffusion tensor imaging and diffusion modeling: Application to monitoring changes in the medial gastrocnemius in disuse atrophy induced by unilateral limb suspension

Comparison of the Achilles tendon moment arms determined using the tendon excursion and three-dimensional methods

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