| 1. |
- Löfstedt, Tommy, et al.
(författare)
-
Dynamic ultrasound imaging : a multivariate approach for the analysis and comparison of time-dependent musculoskeletal movements
- 2012
-
Ingår i: BMC Medical Imaging. - : Springer Science and Business Media LLC. - 1471-2342 .- 1471-2342. ; 12:1, s. 29-
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Muscle functions are generally assumed to affect a wide variety of conditions and activities, including pain, ischemic and neurological disorders, exercise and injury. It is therefore very desirable to obtain more information on musculoskeletal contributions to and activity during clinical processes such as the treatment of muscle injuries, post-surgery evaluations, and the monitoring of progressive degeneration in neuromuscular disorders.The spatial image resolution achievable with ultrasound systems has improved tremendously in the last few years and it is nowadays possible to study skeletal muscles in real-time during activity. However, ultrasound imaging has an inherent problem that makes it difficult to compare different measurement series or image sequences from two or more subjects. Due to physiological differences between different subjects, the ultrasound sequences will be visually different -- partly because of variation in probe placement and partly because of the difficulty of perfectly reproducing any given movement. METHODS: Ultrasound images of the biceps and calf of a single subject were transformed to achieve congruence and then efficiently compressed and stacked to facilitate analysis using a multivariate method known as O2PLS. O2PLS identifies related and unrelated variation in and between two sets of data such that different phases of the studied movements can be analysed. The methodology was used to study the dynamics of the Achilles tendon and the calf and also the Biceps brachii and upper arm. The movements of these parts of the body are both of interest in clinical orthopaedic research. RESULTS: This study extends the novel method of multivariate analysis of congruent images (MACI) to facilitate comparisons between two series of ultrasound images. This increases its potential range of medical applications and its utility for detecting, visualising and quantifying the dynamics and functions of skeletal muscle. CONCLUSIONS: The most important results of this study are that MACI with O2PLS is able to consistently extract meaningful variability from pairs of ultrasound sequences. The MACI method with O2PLS is a powerful tool with great potential for visualising and comparing dynamics between movements. It has many potential clinical applications in the study of muscle injuries, post-surgery evaluations and evaluations of rehabilitation, and the assessment of athletic training interventions.
|
|
| 2. |
- Löfstedt, Tommy, 1982-
(författare)
-
OnPLS : Orthogonal projections to latent structures in multiblock and path model data analysis
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The amounts of data collected from each sample of e.g. chemical or biological materials have increased by orders of magnitude since the beginning of the 20th century. Furthermore, the number of ways to collect data from observations is also increasing. Such configurations with several massive data sets increase the demands on the methods used to analyse them. Methods that handle such data are called multiblock methods and they are the topic of this thesis. Data collected from advanced analytical instruments often contain variation from diverse mutually independent sources, which may confound observed patterns and hinder interpretation of latent variable models. For this reason, new methods have been developed that decompose the data matrices, placing variation from different sources of variation into separate parts. Such procedures are no longer merely pre-processing filters, as they initially were, but have become integral elements of model building and interpretation. One strain of such methods, called OPLS, has been particularly successful since it is easy to use, understand and interpret. This thesis describes the development of a new multiblock data analysis method called OnPLS, which extends the OPLS framework to the analysis of multiblock and path models with very general relationships between blocks in both rows and columns. OnPLS utilises OPLS to decompose sets of matrices, dividing each matrix into a globally joint part (a part shared with all the matrices it is connected to), several locally joint parts (parts shared with some, but not all, of the connected matrices) and a unique part that no other matrix shares. The OnPLS method was applied to several synthetic data sets and data sets of “real” measurements. For the synthetic data sets, where the results could be compared to known, true parameters, the method generated global multiblock (and path) models that were more similar to the true underlying structures compared to models without such decompositions. I.e. the globally joint, locally joint and unique models more closely resembled the corresponding true data. When applied to the real data sets, the OnPLS models revealed chemically or biologically relevant information in all kinds of variation, effectively increasing the interpretability since different kinds of variation are distinguished and separately analysed. OnPLS thus improves the quality of the models and facilitates better understanding of the data since it separates and separately analyses different kinds of variation. Each kind of variation is purer and less tainted by other kinds. OnPLS is therefore highly recommended to anyone engaged in multiblock or path model data analysis.
|
|
| 3. |
- Peolsson, Anneli, et al.
(författare)
-
Preliminary evaluation of dorsal muscle activity during resisted cervical extension in patients with longstanding pain and disability following anterior cervical decompression and fusion surgery
- 2015
-
Ingår i: Physiotherapy. - : Elsevier BV. - 0031-9406 .- 1873-1465. ; 101:1, s. 69-74
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives To compare mechanical activity (deformation and deformation rate) of the dorsal neck muscles between individuals with longstanding symptoms after anterior cervical decompression and fusion (ACDF) surgery and healthy controls.Design Preliminary cross-sectional study.Setting Neurosurgery clinic.Participants Ten individuals {mean age 60 [standard deviation (SD) 7.111 who had undergone ACDF surgery 10 to 13 years previously and 10 healthy age- and sex-matched controls.Main outcomes Mechanical activity of the different layers of dorsal neck muscles, measured at the C4 segment using ultrasonography (speckle tracking analysis) during a standardised, resisted cervical extension task.Results A significant group x muscle interaction was found for muscle deformation (P<0.03) but not for deformation rate (P>0.79). The ACDF group showed significantly less deformation of the semispinalis capitis muscle during the extension task compared with the control group [mean 3.12 (SD 2.06) and 6.64 (SD 4.17), respectively; mean difference 3.34 (95% confidence interval 0.54 to 7.21)].Conclusions As the semispinalis capitis muscle is a powerful neck extensor, the finding of altered activation following ACDF surgery lends support to the inclusion of exercise to train neck muscle performance in the management of these patients.
|
|
| 4. |
- Peolsson, Anneli, et al.
(författare)
-
Ultrasound imaging with speckle tracking of cervical muscle deformation and deformation rate : isometric contraction of patients after anterior cervical decompression and fusion for cervical disc disease and controls
- 2012
-
Ingår i: Manual Therapy. - : Elsevier BV. - 1356-689X .- 1532-2769. ; 17:6, s. 519-525
-
Tidskriftsartikel (refereegranskat)abstract
- There is currently a lack of information regarding neck muscle activity during specific exercises. The purpose of the present study was to investigate deformation and deformation rate in different layers of dorsal and ventral neck muscles during isometric neck muscle contraction in individuals after anterior cervical decompression and fusion and in healthy controls. This study included 10 individuals (mean age 60 years; SD 7.1) with a verified, long-standing neck disorder and 10 healthy, age- and sex-matched controls. Ultrasonography and post-process speckle tracking analysis was used to investigate the degree and the rate of neck muscles motions at the C4 segmental level during sub-maximal, isometric resistance of the head in a seated position. None of the analyses performed showed significant differences between groups (p > 0.05). In the dorsal muscles, both groups exhibited a higher deformation rate in the multifidus than in the trapezius, splenius, and semispinalis capitis (p ≤ 0.01). In the neck disorder group, the multifidus also showed a higher deformation rate compared to the semispinalis cervicis (p = 0.02). In the ventral muscles of patients with neck disorders, the longus colli had a higher deformation rate than the sternocleidomastoid (p = 0.02). Among the healthy controls, the multifidus showed a higher degree of deformation (p = 0.02) than the trapezius. In conclusion, our results showed no significant differences between the two groups in mechanical neck muscle activation. Larger studies with different exercises, preferably with a standardized measure of resistance, are needed to investigate whether patients and controls show differences in deformation and deformation rates in neck muscles.
|
|
| 5. |
- Peolsson, Michael, et al.
(författare)
-
Modelling human musculoskeletal functional movements using ultrasound imaging
- 2010
-
Ingår i: BMC Medical Imaging. - : Springer Science and Business Media LLC. - 1471-2342 .- 1471-2342. ; 10, s. 9-
-
Tidskriftsartikel (refereegranskat)abstract
- Background: A widespread and fundamental assumption in the health sciences is that muscle functions are related to a wide variety of conditions, for example pain, ischemic and neurological disorder, exercise and injury. It is therefore highly desirable to study musculoskeletal contributions in clinical applications such as the treatment of muscle injuries, post-surgery evaluations, monitoring of progressive degeneration in neuromuscular disorders, and so on.The spatial image resolution in ultrasound systems has improved tremendously in the last few years and nowadays provides detailed information about tissue characteristics. It is now possible to study skeletal muscles in real-time during activity.Methods: The ultrasound images are transformed to be congruent and are effectively compressed and stacked in order to be analysed with multivariate techniques. The method is applied to a relevant clinical orthopaedic research field, namely to describe the dynamics in the Achilles tendon and the calf during real-time movements.Results: This study introduces a novel method to medical applications that can be used to examine ultrasound image sequences and to detect, visualise and quantify skeletal muscle dynamics and functions.Conclusions: This new objective method is a powerful tool to use when visualising tissue activity and dynamics of musculoskeletal ultrasound registrations.
|
|
| 6. |
- Peterson, Gunnel, et al.
(författare)
-
Altered ventral neck muscle deformation for individuals with whiplash associated disorder compared to healthy controls : A case-control ultrasound study
- 2015
-
Ingår i: Manual Therapy. - : Elsevier. - 1356-689X .- 1532-2769. ; 20:2, s. 319-327
-
Tidskriftsartikel (refereegranskat)abstract
- Previous studies have shown altered neck muscle function in individuals with chronic whiplash associated disorder (WAD). However, we lack real-time investigations with non-invasive methods that can distinguish between the different ventral neck muscle layers. This study investigated deformations and deformation rates in the sternocleidomastoid (SCM), longus capitis (Lcap), and longus colli (Lco) muscles with real-time ultrasonography. Twenty-six individuals with WAD were compared with 26 controls, matched for age and sex. Ultrasound imaging of the SCM, Lcap, and Lco were recorded during 10 repetitive arm elevations. The first and tenth arm elevations were post-process analyzed with speckle tracking. There were few significant differences in the deformations or deformation rates in the SCM, Lcap, and Lco between the WAD and control group. In controls, deformations and deformation rates showed linear positive relationships between SCM/Lcap, SCM/Lco, and Lcap/Lco which increased from the first arm elevation (R-2 = 0.14-0.70); to the tenth arm elevation (R-2 = 0.51-0.71). The WAD group showed similar or weaker linear relationship (R-2 < 0.19) during the tenth compared to the first (R-2 < 0.44) arm elevation except for deformations in Lcap/Lco (R-2 = 0.13-0.57). This result indicated that deformations and deformation rates in one muscle were correlated by similar deformations and deformation rates in other neck muscles in the control group, but this interplay between muscles was not found in the WAD group. (C) 2014 Elsevier Ltd. All rights reserved.
|
|
| 7. |
- van der Werff, Ross, et al.
(författare)
-
A speckle tracking application of ultrasound to evaluate activity of multilayered cervical muscles
- 2014
-
Ingår i: Journal of Rehabilitation Medicine. - : Medical Journals Sweden AB. - 1650-1977 .- 1651-2081. ; 46:7, s. 662-667
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To evaluate the capacity of the ultrasound-based method of speckle tracking analysis to detect changes in multilayered dorsal neck muscle activity induced by performing a lifting task. Subjects: Twenty-one healthy individuals. Design: Participants performed a loaded lifting task in 3 different postural orientations of the neck (neutral, flexed and forward head posture). Ultrasound images were recorded and speckle tracking analysis was used to quantify muscle deformation and deformation rate over 3 equal time-periods during the lifting sequence (rest, mid-lift and end-lift). Results: Significant main effects of postural orientation for the deformation measure (p<0.05) and time for the deformation rate measure (p<0.05) were observed in all dorsal muscles examined. Significant time by postural interactions for the deformation measure were observed in the trapezius, semispinalis cervicis and multifidus (p<0.05) and in the semispinalis cervicis (p<0.05) for the deformation rate measure. Conclusion: Speckle tracking analysis ultrasound measurements can detect differences in multilayered muscle activity of the dorsal neck induced by postural variations during a lifting task. Findings for the deformation and the deformation rate measures suggest that they quantify a different, albeit related, mechanical event during muscle contraction in a functional task such as lifting.
|
|
