scholarly journals Automated regional analysis of B-mode ultrasound images of skeletal muscle movement

2012 ◽  
Vol 112 (2) ◽  
pp. 313-327 ◽  
Author(s):  
John Darby ◽  
Emma F. Hodson-Tole ◽  
Nicholas Costen ◽  
Ian D. Loram
Keyword(s):  
Skeletal Muscle ◽  
Cross Correlation ◽  
Regional Analysis ◽  
Length Change ◽  
Medial Gastrocnemius ◽  
Average Error ◽  
Ultrasound Images ◽  
Joint Rotation ◽  
Field Representation ◽  
Local Movement

To understand the functional significance of skeletal muscle anatomy, a method of quantifying local shape changes in different tissue structures during dynamic tasks is required. Taking advantage of the good spatial and temporal resolution of B-mode ultrasound imaging, we describe a method of automatically segmenting images into fascicle and aponeurosis regions and tracking movement of features, independently, in localized portions of each tissue. Ultrasound images (25 Hz) of the medial gastrocnemius muscle were collected from eight participants during ankle joint rotation (2° and 20°), isometric contractions (1, 5, and 50 Nm), and deep knee bends. A Kanade-Lucas-Tomasi feature tracker was used to identify and track any distinctive and persistent features within the image sequences. A velocity field representation of local movement was then found and subdivided between fascicle and aponeurosis regions using segmentations from a multiresolution active shape model (ASM). Movement in each region was quantified by interpolating the effect of the fields on a set of probes. ASM segmentation results were compared with hand-labeled data, while aponeurosis and fascicle movement were compared with results from a previously documented cross-correlation approach. ASM provided good image segmentations (<1 mm average error), with fully automatic initialization possible in sequences from seven participants. Feature tracking provided similar length change results to the cross-correlation approach for small movements, while outperforming it in larger movements. The proposed method provides the potential to distinguish between active and passive changes in muscle shape and model strain distributions during different movements/conditions and quantify nonhomogeneous strain along aponeuroses.

scholarly journals Information from dynamic length changes improves reliability of static ultrasound fascicle length measurements

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4164 ◽  
Author(s):  
Jeroen Aeles ◽  
Glen A. Lichtwark ◽  
Sietske Lenchant ◽  
Liesbeth Vanlommel ◽  
Tijs Delabastita ◽  
...  
Keyword(s):  
Length Change ◽  
Medial Gastrocnemius ◽  
Ultrasound Images ◽  
Initial Image ◽  
Fascicle Length ◽  
Mean Squared Errors ◽  
Length Measurements ◽  
Length Changes ◽  
Dynamic Length ◽  
Effectiveness Studies

PurposeVarious strategies for improving reliability of fascicle identification on ultrasound images are used in practice, yet these strategies are untested for effectiveness. Studies suggest that the largest part of differences between fascicle lengths on one image are attributed to the error on the initial image. In this study, we compared reliability results between different strategies.MethodsStatic single-image recordings and image sequence recordings during passive ankle rotations of the medial gastrocnemius were collected. Images were tracked by three different raters. We compared results from uninformed fascicle identification (UFI) and results with information from dynamic length changes, or data-informed tracking (DIT). A second test compared tracking of image sequences of either fascicle shortening (initial-long condition) or fascicle lengthening (initial-short condition).ResultsIntra-class correlations (ICC) were higher for the DIT compared to the UFI, yet yielded similar standard error of measurement (SEM) values. Between the initial-long and initial-short conditions, similar ICC values, coefficients of multiple determination, mean squared errors, offset-corrected mean squared errors and fascicle length change values were found for the DIT, yet with higher SEM values and greater absolute fascicle length differences between raters on the first image in the initial-long condition and on the final image in the initial-short condition.ConclusionsDIT improves reliability of fascicle length measurements, without lower SEM values. Fascicle length on the initial image has no effect on subsequent tracking results. Fascicles on ultrasound images should be identified by a single rater and care should be taken when comparing absolute fascicle lengths between studies.

scholarly journals The Application of Deep Convolutional Neural Networks to Ultrasound for Modelling of Dynamic States within Human Skeletal Muscle

2017 ◽  
Author(s):  
Ryan J. Cunningham ◽  
Peter J. Harding ◽  
Ian D. Loram
Keyword(s):  
Skeletal Muscle ◽  
Joint Angle ◽  
Region Of Interest ◽  
Image Understanding ◽  
Joint Torque ◽  
Medial Gastrocnemius ◽  
Ultrasound Images ◽  
Deep Convolutional Neural Networks ◽  
Segmented Images

AbstractThis paper concerns the fully automatic direct in vivo measurement of active and passive dynamic skeletal muscle states using ultrasound imaging. Despite the long standing medical need (myopathies, neuropathies, pain, injury, ageing), currently technology (electromyography, dynamometry, shear wave imaging) provides no general, non-invasive method for online estimation of skeletal intramuscular states. Ultrasound provides a technology in which static and dynamic muscle states can be observed non-invasively, yet current computational image understanding approaches are inadequate. We propose a new approach in which deep learning methods are used for understanding the content of ultrasound images of muscle in terms of its measured state. Ultrasound data synchronized with electromyography of the calf muscles, with measures of joint torque/angle were recorded from 19 healthy participants (6 female, ages: 30 ± 7.7). A segmentation algorithm previously developed by our group was applied to extract a region of interest of the medial gastrocnemius. Then a deep convolutional neural network was trained to predict the measured states (joint angle/torque, electromyography) directly from the segmented images. Results revealed for the first time that active and passive muscle states can be measured directly from standard b-mode ultrasound images, accurately predicting for a held out test participant changes in the joint angle, electromyography, and torque with as little error as 0.022°, 0.0001V, 0.256Nm (root mean square error) respectively.

Intensity- and muscle-specific fascicle behavior during human drop jumps

2007 ◽  
Vol 102 (1) ◽  
pp. 382-389 ◽  
Author(s):  
F. Sousa ◽  
M. Ishikawa ◽  
J. P. Vilas-Boas ◽  
P. V. Komi
Keyword(s):  
Length Change ◽  
Medial Gastrocnemius ◽  
Ground Contact ◽  
Contact Phase ◽  
Drop Jumps ◽  
Synergistic Muscles ◽  
Braking Phase ◽  
Whole Muscle ◽  
Specific Length

The present study was designed to examine fascicle-tendon interaction in the synergistic medial gastrocnemius (MG) and soleus (Sol) muscles during drop jumps (DJ) performed from different drop heights (DH). Eight subjects performed unilateral DJ with maximal rebounds on a sledge apparatus from different DH. During the exercises, fascicle lengths (using ultrasonography) and electromyographic activities were recorded. The results showed that the fascicles of the MG and Sol muscles behaved differently during the contact phase, but the whole muscle-tendon unit and its tendinous tissue lengthened before shortening in both muscles. The Sol fascicles also lengthened before shortening during the ground contact in all conditions. During the braking phase, the Sol activation increased with increasing DH. However, the amplitude of Sol fascicle lengthening was not dependent on DH during the same phase. In the MG muscle, the fascicles primarily shortened during the braking phase in the lower DH condition. However, in the higher DH conditions, the MG fascicles either behaved isometrically or were lengthened during the braking phase. These results suggest that the fascicles of synergistic muscles (MG and Sol) can behave differently during DJ and that, with increasing DH, there may be specific length change patterns of the fascicles of MG but not of Sol.

scholarly journals Mild Hypobaric Hypoxia Effects on Murine Skeletal Muscle Morphology and Macrophages and Well-Being

2019 ◽  
Vol 90 (12) ◽  
pp. 1050-1054 ◽  
Author(s):  
Liyuan Zhang ◽  
Julia Soulakova ◽  
Barbara St. Pierre Schneider
Keyword(s):  
Skeletal Muscle ◽  
Hypobaric Hypoxia ◽  
Well Being ◽  
Primary Objective ◽  
Medial Gastrocnemius ◽  
Muscle Morphology ◽  
Cellular Effects ◽  
Hindlimb Muscles ◽  
Murine Skeletal Muscle ◽  
Macrophage Populations

BACKGROUND: In the last 10 yr, the number of ultra-haul flights—defined as flights greater than 12 h of flying time—has increased. While the medical complications of these flights are well-known, the underlying cellular effects are less clear. The primary objective of this study was to test the effects of extended mild hypobaric hypoxia on overall well-being and skeletal muscle morphology and macrophage populations.METHODS: A total of 22 male C57BL/6 mice were assigned to a normobaric (NB) or hypobaric (HB) chamber for 14–17 h. Overall mouse well-being and the general morphology and resident macrophage number in hindlimb muscles were compared between the two pressure conditions.RESULTS: During mild hypobaric hypoxia, the mice behaved normally and no changes were observed in general muscle morphology. Regarding resident macrophages, the mean antigen area of CD206 in the hindlimb muscles, lateral gastrocnemius (LG, 33.8 ± 2.0 vs. 35.3 ± 1.6), medial gastrocnemius (MG, 32.4 ± 1.6 vs. 32.6 ± 1.5), and quadriceps femoris (QF, 36.3 ± 1.2 vs. 34.3 ± 1.1) were similar between NB and HB conditions, and the number of CD68-positive cells in the LG and QF were similar between the two conditions. Significantly fewer CD206-positive cells were counted in the LG muscle under the HB condition.CONCLUSION: Our findings indicate that extended exposure to mild hypobaric hypoxia, similar to that of an ultra-long-haul flight, does not adversely affect healthy skeletal muscle.Zhang L, Soulakova J, St. Pierre Schneider B. Mild hypobaric hypoxia effects on murine skeletal muscle morphology and macrophages and well-being. Aerosp Med Hum Perform. 2019; 90(12):1050–1054.

scholarly journals Acute skeletal muscle wasting and dysfunction predict physical disability at hospital discharge in patients with critical illness

Critical Care ◽  
2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Kirby P. Mayer ◽  
Melissa L. Thompson Bastin ◽  
Ashley A. Montgomery-Yates ◽  
Amy M. Pastva ◽  
Esther E. Dupont-Versteegden ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Critical Illness ◽  
Physical Function ◽  
Hospital Discharge ◽  
Muscle Power ◽  
Muscle Size ◽  
Ultrasound Images ◽  
Icu Admission ◽  
Percent Change ◽  
Icu Discharge

Abstract Background Patients surviving critical illness develop muscle weakness and impairments in physical function; however, the relationship between early skeletal muscle alterations and physical function at hospital discharge remains unclear. The primary purpose of this study was to determine whether changes in muscle size, strength and power assessed in the intensive care unit (ICU) predict physical function at hospital discharge. Methods Study design is a single-center, prospective, observational study in patients admitted to the medicine or cardiothoracic ICU with diagnosis of sepsis or acute respiratory failure. Rectus femoris (RF) and tibialis anterior (TA) muscle ultrasound images were obtained day one of ICU admission, repeated serially and assessed for muscle cross-sectional area (CSA), layer thickness (mT) and echointensity (EI). Muscle strength, as measured by Medical Research Council-sum score, and muscle power (lower-extremity leg press) were assessed prior to ICU discharge. Physical function was assessed with performance on 5-times sit-to-stand (5STS) at hospital discharge. Results Forty-one patients with median age of 61 years (IQR 55–68), 56% male and sequential organ failure assessment score of 8.1 ± 4.8 were enrolled. RF muscle CSA decreased significantly a median percent change of 18.5% from day 1 to 7 (F = 26.6, p = 0.0253). RF EI increased at a mean percent change of 10.5 ± 21% in the first 7 days (F = 3.28, p = 0.081). At hospital discharge 25.7% of patients (9/35) met criteria for ICU-acquired weakness. Change in RF EI in first 7 days of ICU admission and muscle power measured prior to ICU were strong predictors of ICU-AW at hospital discharge (AUC = 0.912). Muscle power at ICU discharge, age and ICU length of stay were predictive of performance on 5STS at hospital discharge. Conclusion ICU-assessed muscle alterations, specifically RF EI and muscle power, are predictors of diagnosis of ICU-AW and physical function assessed by 5x-STS at hospital discharge in patients surviving critical illness.

Effects of thyroidectomy on development of skeletal muscle in fetal sheep

1991 ◽  
Vol 261 (5) ◽  
pp. R1300-R1306 ◽  
Author(s):  
D. I. Finkelstein ◽  
P. Andrianakis ◽  
A. R. Luff ◽  
D. Walker
Keyword(s):  
Skeletal Muscle ◽  
Thyroid Gland ◽  
Extensor Digitorum Longus ◽  
Relaxation Times ◽  
Medial Gastrocnemius ◽  
Fetal Sheep ◽  
Twitch Contraction ◽  
Slow Twitch ◽  
Contraction And Relaxation ◽  
Fast Twitch

The influence of the thyroid gland on the functional and histochemical development of fast- and slow-twitch skeletal muscle of fetal sheep has been studied in euthyroid fetal sheep (n = 6) and athyroid fetuses (n = 4) surgically thyroid-ectomized at 70-75 days of gestation. Two fast-twitch muscles, the medial gastrocnemius and extensor digitorum longus, and the slow-twitch soleus muscle were studied at the fetal age of 140 days gestation. The athyroid fetuses had significantly slower twitch contraction and relaxation times in both the medial gastrocnemius and extensor digitorum longus muscles compared with the euthyroid fetuses. Twitch contraction and relaxation times of the soleus were not different in the two groups. Thyroidectomy resulted in an increase in the proportion of fast (type II) muscle fibers and myosin, as shown histochemically and by gel electrophoresis of heavy-chain myosins. These results indicate that the functional maturation of the fast-twitch muscles of sheep is influenced by the presence of an intact thyroid gland from at least 70 days of gestation. In contrast, the slow-twitch soleus muscle fiber diameter and twitch contraction and relaxation times were not different in the two groups.

scholarly journals Intergenic bidirectional promoter and cooperative regulation of the IIx and IIb MHC genes in fast skeletal muscle

2008 ◽  
Vol 295 (1) ◽  
pp. R208-R218 ◽  
Author(s):  
Chiara Rinaldi ◽  
Fadia Haddad ◽  
Paul W. Bodell ◽  
Anqi X. Qin ◽  
Weihua Jiang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Antisense Rna ◽  
Bidirectional Promoter ◽  
Regulatory Elements ◽  
Feedback Mechanism ◽  
Medial Gastrocnemius ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Dynamic Regulation ◽  
Mhc Genes

This study investigated the dynamic regulation of IIx-IIb MHC genes in the fast white medial gastrocnemius (WMG) muscle in response to intermittent resistance exercise training (RE), a model associated with a rapid shift from IIb to IIx expression ( 11 ). We investigated the effect of 4 days of RE on the transcriptional activity across the skeletal MHC gene locus in the WMG in female Sprague-Dawley rats. Our results show that RE resulted in significant shifts from IIb to IIx observed at both the pre-mRNA and mRNA levels. An antisense RNA (xII NAT) was detected in the intergenic (IG) region between IIx and IIb, extending across the entire IIx gene and into its promoter. The expression of the xII NAT was positively correlated with IIb pre-mRNA ( R = +0.8), and negatively correlated with IIx pre-mRNA ( R = −0.8). Transcription mapping of the IIx–IIb IG region revealed the generation of sense IIb and xII NATs from a single promoter region. This bidirectional promoter is highly conserved among species and contains several regulatory elements that may be implicated in its regulation. These results suggest that the IIx and the IIb genes are physically and functionally linked via the bidirectional promoter. In order for the IIx MHC gene to be regulated, a feedback mechanism from the IG xII NAT is needed. In conclusion, the IG bidirectional promoter generating antisense RNA appears to be essential for the coordinated regulation of the skeletal muscle MHC genes during dynamic phenotype shifts.

Determinants of work produced by skeletal muscle: potential limitations of activation and relaxation

1997 ◽  
Vol 273 (3) ◽  
pp. C1049-C1056 ◽  
Author(s):  
V. J. Caiozzo ◽  
K. M. Baldwin
Keyword(s):  
Skeletal Muscle ◽  
Length Change ◽  
Small Strain ◽  
Mechanical Work ◽  
Slow Skeletal Muscle ◽  
Loop Technique ◽  
Force Velocity ◽  
The Difference ◽  
Kinetics Of ◽  
Work Loop

The objective of this study was to estimate the limitations imposed by the kinetics of activation and relaxation on the ability of slow skeletal muscle to produce mechanical work. These estimates were made by the following methods: 1) using the work loop technique and measuring the actual mechanical work (WA) produced by rat soleus muscles (n = 6) at four different frequencies (0.5, 1, 2, and 4 Hz) and seven different amplitudes of length change (1, 2, 3, 4, 5, 6, and 7 mm); 2) determining the force-velocity relationships of the soleus muscles and using this data to quantify the theoretical mechanical work (WT) that could be produced under the work loop conditions described above; and 3) subtracting WA from WT. The difference between WT and WA was interpreted to represent limitations imposed by activation and relaxation. Under certain conditions (high frequency, small strain), factors controlling the kinetics of activation and relaxation reduced the mechanical work of the soleus muscle by approximately 60%. Hence, activation and relaxation collectively represent important factors limiting the production of mechanical work by slow skeletal muscle.

scholarly journals Increased Ankle Plantar Flexor Stiffness Is Associated With Reduced Mechanical Response to Stretch in Adults With CP

2021 ◽  
Vol 9 ◽  
Author(s):  
Jakob Lorentzen ◽  
Rasmus Feld Frisk ◽  
Jens Bo Nielsen ◽  
Lee Barber
Keyword(s):  
Ankle Joint ◽  
Stretch Reflex ◽  
Gastrocnemius Muscle ◽  
Length Change ◽  
Medial Gastrocnemius ◽  
Reflex Response ◽  
Plantar Flexor ◽  
Flexor Muscle ◽  
Muscle Fascicles ◽  
Medial Gastrocnemius Muscle

Hyperexcitable stretch reflexes are often not present despite of other signs of spasticity in people with brain lesion. Here we looked for evidence that increased resistance to length change of the plantar flexor muscle-fascicles may contribute to a reduction in the stretch reflex response in adults with cerebral palsy (CP). A total of 17 neurologically intact (NI) adults (mean age 36.1; 12 female) and 13 ambulant adults with CP (7 unilateral; mean age 33.1; 5 female) participated in the study. Subjects were seated in a chair with the examined foot attached to a foot plate, which could be moved by a computer-controlled electromotor. An ultrasound probe was placed over the medial aspect of the leg to measure the length of medial gastrocnemius muscle fascicles. Slow (7 deg/s) and fast (200 deg/s) stretches with amplitude 6 deg of the plantar flexors were applied over an ankle range of 70 deg at 10 deg intervals between 60 and 130 deg plantarflexion. It was checked by EMG electrodes that the slow stretches were sufficiently slow not to elicit any activity and that the fast stretches were sufficiently quick to elicit a maximal stretch reflex in both groups. The torque elicited by the stretches was measured together with changes in the length of medial gastrocnemius muscle fascicles. Muscle fascicles increased significantly in length with increasing dorsiflexion position in both populations (p &lt; 0.001), but the fascicles were shorter in the CP population at all positions. Slow stretches elicited significantly larger torque and significantly smaller length change of muscle fascicles as the ankle joint position was moved more towards dorsiflexion in CP than in NI (p &lt; 0.001). Fast stretches elicited larger torque responses at ankle joint positions of 80–100 deg in the NI than in the CP group (p &lt; 0.01). A significant negative correlation was observed between the torque response and muscle fascicle length change to slow stretch in CP (p &lt; 0.05), but not in NI. These findings support that increased passive resistance of the ankle plantar flexor muscle-tendon unit and development of contractures may conceal stretch reflex response in adults with CP. We argue that this should be taken into account in the neurological examination of spasticity.

Sign in / Sign up

Export Citation Format

Share Document