| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Bjerke, Joakim, et al.
(author)
-
Compensatory strategies for muscle weakness during stair ascent in subjects with total knee arthroplasty
- 2014
-
In: The Journal of Arthroplasty. - : Elsevier. - 0883-5403 .- 1532-8406. ; 29:7, s. 1499-1502
-
Journal article (peer-reviewed)abstract
- Subjects with total knee arthroplasty (TKA) exhibit decreased quadriceps and hamstring strength. This may bring about greater relative effort or compensatory strategies to reduce knee joint moments in daily activities. To study gait and map out the resource capacity, knee muscle strength was assessed by maximal voluntary concentric contractions, and whole body kinematics and root mean square (RMS) electromyography (EMG) of vastus lateralis and semitendinosus were recorded during stair ascent in 23 unilateral TKA-subjects ~19months post-operation, and in 23 healthy controls. Muscle strength and gait velocity were lower in the TKA group, but no significant group differences were found in RMS EMG or forward trunk lean. The results suggest that reduced walking velocity sufficiently compensated for reduced knee muscle strength.
|
|
| 5. |
- Bjerke, Joakim, et al.
(author)
-
Gait on soft versus hard surface after total knee arthroplasty
-
Other publication (other academic/artistic)abstract
- Asymmetric gait patterns are common following total knee arthroplasty (TKA). Gait on even and hard surface is primarily characterized by reduced peak knee flexion in the prosthetic knee, increased contralateral knee adduction angle, and decreased walking speed compared to controls. Natural conditions may however lead to different strategies. Therefore, the objective of the present study was to explore how gait patterns may differ when walking on a soft surface. Methods: 3D kinematics during gait on hard and soft surface were assessed in 23 unilateral TKA-subjects ~19 months post-operative, and in 23 controls. Results: Gait characteristics in TKA-subjects that differed from controls observed on hard surface were amplified on soft surface. Flexion in the prosthetic knee was further decreased and a tendency towards reduced flexion in the contralateral knee was observed. Knee and hip adduction were not affected by surface conditions nevertheless there was a difference between groups, in particular with regard to the prosthetic side. In addition, step width increased on soft surface in TKA-subjects. Conclusion: Gait on an even and soft surface did not amplify asymmetries in TKA-subjects, but decreased knee flexion and increased step-width, albeit with similar gait speed as the control group suggests that the soft surface provided a small but significant challenge making the TKA-subjects precautious.
|
|
| 6. |
- Bjerke, Joakim, et al.
(author)
-
Peak knee flexion angles during stair descent in TKA patients
- 2014
-
In: The Journal of Arthroplasty. - : Elsevier. - 0883-5403 .- 1532-8406. ; 29:4, s. 707-711
-
Journal article (peer-reviewed)abstract
- Reduced peak knee flexion during stair descent (PKSD) is demonstrated in subjects with total knee arthroplasty (TKA), but the underlying factors are not well studied. 3D gait patterns during stair descent, peak passive knee flexion (PPKF), quadriceps strength, pain, proprioception, demographics, and anthropometrics were assessed in 23 unilateral TKA-subjects ~ 19 months post-operatively, and in 23 controls. PKSD, PPKF and quadriceps strength were reduced in the TKA-side, but also in the contralateral side. A multiple regression analysis identified PPKF as the only predictor (57%) to explain the relationship with PKSD. PPKF was, however sufficient for normal PKSD. Deficits in quadriceps strength in TKA-group suggest that strength is also contributing to smaller PKSD. Increased hip adduction at PKSD may indicate both compensatory strategy and reduced hip strength.
|
|
| 7. |
- Bjerke, Joakim, et al.
(author)
-
Walking on a compliant surface does not enhance kinematic gait asymmetries after unilateral total knee arthroplasty
- 2016
-
In: Knee Surgery, Sports Traumatology, Arthroscopy. - : Springer. - 0942-2056 .- 1433-7347. ; 24:8, s. 2606-2613
-
Journal article (peer-reviewed)abstract
- PURPOSE: To investigate gait asymmetries and the effect of walking on compliant surfaces in individuals with unilateral total knee arthroplasty (TKA), hypothesizing that asymmetries would increase as an effect of the compliant surface.METHODS: Individuals with unilateral TKA ~19 months post-operative (n = 23, median age 59 years) recruited from one orthopaedic clinic and age- and gender-matched healthy individuals without knee complaints (n = 23, median age 56 years) walked at comfortable speed on a hard surface and on a compliant surface. 3D kinematic analyses were made for knee and hip angles in sagittal and frontal planes, stance time, step length, and gait velocity.RESULTS: Shorter stance time (p < 0.01) and less peak knee flexion (p < 0.001) at weight bearing acceptance was found in the prosthetic side compared with the contralateral side. Larger knee (p < 0.01) and hip (p < 0.001) adduction was found compared with healthy controls. Neither asymmetries between the prosthetic and the contralateral side nor differences compared with healthy controls were enhanced when walking on compliant surfaces compared with hard surfaces.CONCLUSION: The TKA group adapted their gait to compliant surfaces similarly to healthy controls. Gait asymmetries in the TKA group observed on hard surface were not enhanced, and adduction in hip and knee joints did not increase further as an effect of walking on compliant surfaces. Thus, unfavourable knee joint loading did not increase when walking on a compliant surface. This implies that recommendations for walking on soft surfaces to reduce knee joint loading are not counteracted by increased gait asymmetries and unfavourable joint loading configurations.LEVEL OF EVIDENCE: III.
|
|
| 8. |
- Dahlgren, A, et al.
(author)
-
Activity performance and upper extremity function in cervical spinal cord injury patients according to the Klein-Bell ADL Scale.
- 2007
-
In: Spinal cord : the official journal of the International Medical Society of Paraplegia. - : Springer Science and Business Media LLC. - 1362-4393. ; 45:7, s. 475-84
-
Journal article (peer-reviewed)abstract
- STUDY DESIGN: Cross-sectional study. OBJECTIVES: (1) To examine whether the Klein-Bell ADL Scale (K-B Scale) discriminates cervical spinal cord injury (SCI) patients in daily activities and to explore its applicability in this group of patients. (2) To examine the association between basic ADL and upper extremity function. (3) To investigate if grip ability can be discerned in the scale. SETTING: Spinal Cord Injury Unit, Sahlgrenska University Hospital, Göteborg, Sweden. METHODS: Fifty-five patients with cervical SCI with no prior reconstructive hand surgery were included in the study. Analyses of the patient's independence were made according to the K-B Scale. Three additional analyses were carried out, the first examined whether the use of assistive devices and house and car adaptations influenced independence. The last two used different approaches to investigate whether arm and grip function could be detected in the K-B scale. RESULTS: Raw score in the K-B Scale can discriminate for independence in daily activities but the scale's weight scheme does not function for cervical SCI patients. Assistive devices and car and house adaptations can compensate for dependence in daily activities. Lack of grip function decreases the patient's ability to become independent. Diagnosis-related activities cannot be assessed in all items. CONCLUSION: The K-B Scale's raw score was useful assessing daily activities in cervical SCI patients. Its reliability in conjunction with arm and grip function in patients with cervical SCI has yet to be proven.
|
|
| 9. |
- Hellström, Mats, et al.
(author)
-
Dll4 signalling through Notch1 regulates formation of tip cells during angiogenesis.
- 2007
-
In: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 445:7129, s. 776-80
-
Journal article (peer-reviewed)abstract
- In sprouting angiogenesis, specialized endothelial tip cells lead the outgrowth of blood-vessel sprouts towards gradients of vascular endothelial growth factor (VEGF)-A. VEGF-A is also essential for the induction of endothelial tip cells, but it is not known how single tip cells are selected to lead each vessel sprout, and how tip-cell numbers are determined. Here we present evidence that delta-like 4 (Dll4)-Notch1 signalling regulates the formation of appropriate numbers of tip cells to control vessel sprouting and branching in the mouse retina. We show that inhibition of Notch signalling using gamma-secretase inhibitors, genetic inactivation of one allele of the endothelial Notch ligand Dll4, or endothelial-specific genetic deletion of Notch1, all promote increased numbers of tip cells. Conversely, activation of Notch by a soluble jagged1 peptide leads to fewer tip cells and vessel branches. Dll4 and reporters of Notch signalling are distributed in a mosaic pattern among endothelial cells of actively sprouting retinal vessels. At this location, Notch1-deleted endothelial cells preferentially assume tip-cell characteristics. Together, our results suggest that Dll4-Notch1 signalling between the endothelial cells within the angiogenic sprout serves to restrict tip-cell formation in response to VEGF, thereby establishing the adequate ratio between tip and stalk cells required for correct sprouting and branching patterns. This model offers an explanation for the dose-dependency and haploinsufficiency of the Dll4 gene, and indicates that modulators of Dll4 or Notch signalling, such as gamma-secretase inhibitors developed for Alzheimer's disease, might find usage as pharmacological regulators of angiogenesis.
|
|
| 10. |
- Lindkvist, Anna, 1976-
(author)
-
Jorden åt folket : nationalföreningen mot emigrationen 1907-1925.
- 2007
-
Doctoral thesis (other academic/artistic)abstract
- This thesis deals with the National Society Against Emigration (Sw.Nationalföreningen mot emigrationen) – referred to as the NE – and its radical right-wing leader Adrian Molin. Th e NE was founded in 1907 in order to stem the tide of emigration from Sweden and facilitate re-immigration by providing jobs and accomodation. Its many bureaus served as employment offi ces, land distribution centres and own-your-own-home companies, mainly aimed at creating smallholdings for Swedish working-class families. The purpose of the study is to investigate the organization, concept and practise of the internal colonization of rural Sweden between 1907 and 1925. By following both the successes and setbacks of the NE during the first decades of the twentieth century, ideas and opportunities circulating in Swedish society in a time of wide-ranging ideological and material change are discussed. Questions in focus include why a society to prevent emigration from Sweden emerged at that particular time; the function it served for both society and the state; the form internal colonization actually took and how it was conducted in comparison with other governmental and private agricultural reforms; and the attitude of the NE toward modernization in general. Theoretically the dissertation takes its point of departure in theories on nation-building and internal colonization (i.e., the establishment of small-scale farming and the cultivation of new land within the national borders), corporatism and attitudes toward modernization. The ideological analysis has been inspired by political scientist Michael Freeden´s theory of the construction of political ideologies via political concepts, as well as an analysis of the view of social categories such as gender, class and ethnicity. The source material is comprised of magazines, newspaper articles, letters and books and offi cial parliamentary publications. The practise of internal colonization has been studied with the aid of preserved accounts of the NE’s small-scale farming colonies, real estate documents, company reports, correspondance and further press materials. The surge of anti-emigration attitudes is explained as a powerful reaction arising at the turn of the century due to the economic upswing in Swedish industry and the social transformations which followed in the 1890s, when the country was seen as a nation with a promising future. That Adrian Molin founded the NE in 1907 is viewed as a consequence of his nationalistic thought. Together with political scientist Prof. Rudolf Kjellén, Molin was one of the country´s foremost advocates of an integrative nationalism. The NE was led by an elite of middle- and upper-class men involved in politics, industry and voluntary associations. Female members and representatives of the lower social classes were mostly absent. In general the NE neglected women in both speeches and plans, being preoccupied with ideas concerning the cultivation of middle-class Swedish men. The NE became a co-actor in a corporative colonization eff ort sanctioned by government financing during the 1910s. In 1920 the NE’s projects were condemned as hierarchical and undemocratic in comparison with other own-home organizations. Many other own-home companies were built on a cooperative foundation, while the NE was run by a national, regional, and local political and financial elite. Suspicions were raised about the raison d´être of the society. The state withdrew its subsidies and loans, and the NE lost it close connections with the government. Though conservative and reactionary in social issues, the NE cannot be characterized as critical of civilization or economic modernization of the country. Its programme intended to aid in the development of both agriculture and industry. The creation of more smallholdings would help bridge the problematic transition between two systems, from agrarian to industrial society.
|
|
