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- Björklund, Martin, et al.
(författare)
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Acute muscle stretching and shoulder position sense
- 2006
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Ingår i: Journal of athletic training. - 1062-6050 .- 1938-162X. ; 41:3, s. 270-274
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Tidskriftsartikel (refereegranskat)abstract
- Context: Stretching is common among athletes as a potential method for injury prevention. Stretching-induced changes in the muscle spindle properties are a suggested mechanism, which may imply reduced proprioception after stretching; however, little is known of this association. Objective: To evaluate whether acute stretching of the shoulder muscles affects position sense. Design: A crossover design with subjects randomized to 3 groups. Setting: A university human research laboratory. Patients or Other Participants: Nine male (age = 24 +/- 3 years) and 9 female (age = 21 +/- 2 years) healthy volunteers. Intervention(s): Stretching of shoulder (1) agonists or (2) antagonists or (3) nonstretching control. Main Outcome Measure(s): We determined position sense acuity of the right shoulder before and after the interventions by having subjects attempt to reproduce arm positions of 15 degrees and 30 degrees (shoulder adduction) while starting at 45 degrees to the sagittal plane. The outcome variables were response variability (variable error) and overall accuracy (absolute error). Results: The relative change in variable error (ie, variable error after/variable error before) was not significantly different between the interventions ( P = .38). Similarly, no change in absolute error was found ( P = .76). Furthermore, no differences were noted regarding test sequence or the interaction of intervention x sequence for either variable error ( P = .73 and .53, respectively) or absolute error ( P = .71 and .67, respectively). Conclusions: We found no effect on shoulder position sense after an acute bout of stretching of either agonist or antagonist shoulder muscles.
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| 3. |
- Crenshaw, Albert G., et al.
(författare)
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Applying near infrared spectroscopy (NIRS) to assess muscular oxygenation during computer mouse use
- 2007
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Ingår i: Sixth International Scientific Conference on Prevention of Work-Related Musculoskeletal Disorders. ; , s. 253-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Chronic trapezius myalgia was shown to be associated with a reduction in microcirculation (via direct measurements of bloodflow). In line with this, morphological data have indicated disturbances in oxidative metabolism. Therefore, data obtained on the muscle oxygenation status could help provide insight into the pathomechanisms behind work related muscle pain. Near-infrared spectroscopy (NIRS) allows for the noninvasive monitoring of continuous changes in skeletal muscle oxygenation (representing the dynamic balance between oxygen delivery and consumption), and for subsequent determinations of changes in blood volume.
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| 4. |
- Crenshaw, Albert G., et al.
(författare)
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Oxygenation, EMG and position sense during computer mouse work : impact of active versus passive pauses
- 2006
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 97:1, s. 59-67
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the effects of active versus passive pauses implemented during computer mouse work on muscle oxygenation and EMG of the forearm extensor carpi radialis muscle, and on wrist position sense. Fifteen healthy female subjects (age: 19-24 years) performed a 60-min mouse-operated computer task, divided into three 20 min periods, on two occasions separated by 3-6 days. On one occasion a passive pause (subjects resting) was implemented at the end of each 20-min period, and on another occasion an active pause (subjects performed a number of high intensity extensions of the forearm) was implemented. Also at the end of each 20-min period, test contractions were conducted and subjective ratings of fatigue and stress were obtained. Another parameter of interest was total haemoglobin calculated as the summation of oxy-and deoxy-haemoglobin, since it reflects blood volume changes. The most interesting findings were an overall increasing trend in total haemoglobin throughout the mouse work (P<0.001), and that this trend was greater for the active pause as compared to the passive pause (P<0.01). These data were accompanied by an overall increase in oxygen saturation (P<0.001), with a tendency, albeit not significant, toward a higher increase for the active pause (P=0.13). EMG amplitude and median frequency tended to decrease (P=0.08 and 0.05, respectively) during the mouse work but was not different between pause types. Borg ratings of forearm fatigue showed an overall increase during the activity (P<0.001), but the perceptions of stress did not change. Position sense did not change due to the mouse work for either pause type. While increasing trends were found for both pause types, the present study lends support to the hypothesis of an enhancement in oxygenation and blood volume for computer mouse work implemented with active pauses. However, a presumption of an association between this enhancement and attenuated fatigue during the mouse work was not supported.
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| 7. |
- Djupsjöbacka, Mats, et al.
(författare)
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Correlation analysis of proprioceptive acuity in ipsilateral position-matching and velocity-discrimination.
- 2005
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Ingår i: Somatosensory & motor research. - : Informa UK Limited. - 0899-0220 .- 1369-1651. ; 22:1-2, s. 85-93
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Tidskriftsartikel (refereegranskat)abstract
- In order to plan and control movements the central nervous system (CNS) needs to continuously keep track of the state of the musculoskeletal system. Therefore the CNS constantly uses sensory input from mechanoreceptors in muscles, joints and skin to update information about body configuration on different levels of the CNS. On the conscious level, such representations constitute proprioception. Different tests for assessment of proprioceptive acuity have been described. However, it is unclear if the proprioceptive acuity measurements in these tests correlate within subjects. By using both uni- and multivariate analysis we compared proprioceptive acuity in different variants of ipsilateral active and passive limb position-matching and ipsilateral passive limb movement velocity-discrimination in a group of healthy subjects. The analysis of the position-matching data revealed a higher acuity of matching for active movements in comparison to passive ones. The acuity of matching was negatively correlated to movement extent. There was a lack of correlation between proprioceptive acuity measurements in position-matching and velocity-discrimination.
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| 8. |
- Djupsjöbacka, Mats
(författare)
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Ospecifika muskuloskeletala besvär : rehabilitering, behandling och träning av senmotorisk funktion
- 2007
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Ingår i: Svensk Rehabilitering. - 1403-4468. ; 8/9:4-1, s. 26-29
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Tidskriftsartikel (refereegranskat)abstract
- Långvarig värk i nacke-skuldra och ländrygg tillhör de vanligaste orsakerna till sjukskrivning. Bakgrunden till dessa tillstånd är vanligen oklara, vilket gör att kausal behandling inte är aktuell. Senare års forskning visar dock att multimodal rehabilitering ger god effekt och är kostnadseffektiv. Forskningen ger även en god grund för att träning av sensomotorisk funktion kan vara effektiv vid dessa tillstånd.
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| 9. |
- Djupsjöbacka, Mats
(författare)
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Proprioception and neck/shoulder pain
- 2008
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Ingår i: Fundamentals of musculoskeletal pain. - Seattle : IASP Press. - 9780931092725 ; , s. 385-399
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Chronic neck/shoulder pain constitutes an extensive health problem. The point prevalence has been estimated to be as high as 18% in the general population (Guez et al., 2003). The symptoms usually involve pain and stiffness in the neck/shoulder area as well as impaired neck mobility. A history of neck or head trauma is rather common. Thus, in the population studied by Guez et al. (2003), more than one fourth of the cases had a history of such trauma. Nevertheless, due to a limited knowledge on the underlying pathomechanisms, the source of the symptoms can only rarely be established. This obviously poses a severe problem for efficient treatment and rehabilitation of this patient group. In order to improve treatment and rehabilitation it is thus important to develop sensitive and specific methods for characterization of patients with chronic neck/shoulder pain. This should obviously entail many different aspects of the patient characteristics. One such aspect that has received increasing attention is sensorimotor functions, for example muscle coordination and proprioception. The growing interest in this area is based on an increasing number of studies reporting atypical, or impaired, sensorimotor functioning in subjects with chronic neck/shoulder pain, along with the fact that several models on the pathophysiology behind musculoskeletal disorders involves various aspects of sensorimotor functioning. This chapter will deal with one of these sensorimotor functions: proprioception. First, a background to the topic and a review on the research on proprioception in relation to chronic neck/shoulder pain is given, along with a discussion on methodology. Lastly, implications for future research as well as clinical implications are discussed.
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| 10. |
- Domkin, Dmitry, et al.
(författare)
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Joint angle variability in 3D bimanual pointing : uncontrolled manifold analysis.
- 2005
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Ingår i: Experimental Brain Research. - : Springer Science and Business Media LLC. - 0014-4819 .- 1432-1106. ; 163:1, s. 44-57
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Tidskriftsartikel (refereegranskat)abstract
- The structure of joint angle variability and its changes with practice were investigated using the uncontrolled manifold (UCM) computational approach. Subjects performed fast and accurate bimanual pointing movements in 3D space, trying to match the tip of a pointer, held in the right hand, with the tip of one of three different targets, held in the left hand during a pre-test, several practice sessions and a post-test. The prediction of the UCM approach about the structuring of joint angle variance for selective stabilization of important task variables was tested with respect to selective stabilization of time series of the vectorial distance between the pointer and aimed target tips (bimanual control hypothesis) and with respect to selective stabilization of the endpoint trajectory of each arm (unimanual control hypothesis). The components of the total joint angle variance not affecting (V(COMP)) and affecting (V(UN)) the value of a selected task variable were computed for each 10% of the normalized movement time. The ratio of these two components R(V)=V(COMP)/V(UN) served as a quantitative index of selective stabilization. Both the bimanual and unimanual control hypotheses were supported, however the R(V) values for the bimanual hypothesis were significantly higher than those for the unimanual hypothesis applied to the left and right arm both prior to and after practice. This suggests that the CNS stabilizes the relative trajectory of one endpoint with respect to the other more than it stabilizes the trajectories of each of the endpoints in the external space. Practice-associated improvement in both movement speed and accuracy was accompanied by counter-intuitive lack of changes in R(V). Both V(COMP) and V(UN) variance components decreased such that their ratio remained constant prior to and after practice. We conclude that the UCM approach offers a unique and under-explored opportunity to track changes in the organization of multi-effector systems with practice and allows quantitative assessment of the degree of stabilization of selected performance variables.
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