561 research outputs found
Acta kinesiologiae Universitatis Tartuensis. 17
http://www.ester.ee/record=b1227224*es
Acta kinesiologiae Universitatis Tartuensis. 5
http://www.ester.ee/record=b1227224*es
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Muscle activation patterns in shoulder impingement patients
Introduction: Shoulder impingement is one of the most common presentations of shoulder joint problems 1. It appears to be caused by a reduction in the sub-acromial space as the humerus abducts between 60o -120o – the 'painful arc'. Structures between the humeral head and the acromion are thus pinched causing pain and further pathology 2. Shoulder muscle activity can influence this joint space but it is unclear whether this is a cause or effect in impingement patients. This study aimed to observe muscle activation patterns in normal and impingement shoulder patients and determine if there were any significant differences.
Method: 19 adult subjects were asked to perform shoulder abduction in their symptomatic arm and non-symptomatic. 10 of these subjects (age 47.9 ± 11.2) were screened for shoulder impingement, and 9 subjects (age 38.9 ± 14.3) had no history of shoulder pathology. Surface EMG was used to collect data for 6 shoulder muscles (Upper, middle and lower trapezius, serratus anterior, infraspinatus, middle deltoids) which was then filtered and fully rectified. Subjects performed 3 smooth unilateral abduction movements at a cadence of 16 beats of a metronome set at 60bpm, and the mean of their results was recorded. T-tests were used to indicate any statistical significance in the data sets. Significance was set at P<0.05.
Results: There was a significant difference in muscle activation with serratus anterior in particular showing a very low level of activation throughout the range when compared to normal shoulder activation patterns (<30%). Middle deltoid recruitment was significantly reduced between 60-90o in the impingement group (30:58%).Trends were noted in other muscles with upper trapezius and infraspinatus activating more rapidly and erratically (63:25%; 60:27% respectively), and lower trapezius with less recruitment (13:30%) in the patient group, although these did not quite reach significance.
Conclusion: There appears to be some interesting alterations in muscle recruitment patterns in impingement shoulder patients when compared against their own unaffected shoulders and the control group. In particular changes in scapula control (serratus anterior and trapezius) and lateral rotation (infraspinatus), which have direct influence on the sub-acromial space, should be noted. It is still not clear whether these alterations are causative or reactionary, but this finding gives a clear indication to the importance of addressing muscle reeducation as part of a rehabilitation programme in shoulder impingement patients
Investigation into the prevalence, spinal kinematics and management of adolescent male rowers with low back pain
This thesis investigated back pain in adolescent rowers. A high prevalence of low back pain was found in adolescent male rowers. Differences in lumbar spine movement patterns during ergometer rowing were observed between genders and in adolescent males with back pain compared to those without. A cognitive functional intervention was tested in a randomized controlled trial and was demonstrated to reduce pain and disability, improve muscle endurance and alter sitting spinal postures in adolescent male rowers
Different sitting positions influence cross country sit skiers performance: Sitting position influence on force generation and cycle characteristics
Cross country sit skiing is a Paralympic discipline in which athletes due to physical impairment ski sitting on a sit-ski. The impairment influences performance directly and also through sitting position. Athletes with a better trunk control usually adopt a sitting position called “kneeing” in which the hip joints are higher than the knee joints. In contrast, athletes with high impact of impairment prefer a sitting position called “knee high” in which the hip joints are lower than the knee joints. Able bodied athletes skiing on the ergometer in these two sitting positions showed different performance. However, to the best of authors’ knowledge, no studies have examined performance, force production, and cycle characteristics of athletes with physical impairment who ski using different sitting positions. Therefore, the aim of the present study is to assess if athletes with physical impairment sitting in “kneeing” and “knee high” position perform differently while skiing. To obtain this purpose, a k-means cluster analysis was used to group ten male athletes according to their skiing performance in terms of maximal speed, generated force, and cycle characteristics. Cluster analysis results showed athletes aggregation in two clusters and a very high agreement between clusters analysis outcome and real athletes sitting position. Maximal speed and generated force were the most relevant variables for grouping athletes. Despite some limitations, these results suggest that the cluster analysis can be used to discriminate athletes according to their performance
Development of a human-powered watercraft for people with lower-body disabilities
Spinal cord injuries (SCI) or other lower-body disabilities can change the life of a person significantly both physically and psychologically. Chapter 1 describes how physical activity is associated with improved physical fitness, health and psychological well-being for people with lower-body disabilities but also that a number of limitations exist to potentially discourage this population from exercising. One of these limitations is a lack of exercise water activities as traditional aquatic sports such as rowing, kayak and canoe requires a level of trunk muscle activation that is often missing for people with SCI. The main aim of this dissertation has been to develop a human-powered watercraft that could be maneuvered by people with lower-body disabilities. This process is described in chapter 2 including the results of a study, which showed the metabolic expenditure when using the watercraft to be similar to other physical activities performed by people with lower-body disabilities. Moreover, the mechanical efficiency was found to be comparable to other human-powered watercrafts and could, as a result, be an alternative fitness tool especially for people with lower-body disabilities, who seek water activities. Chapter 3 describes the development of an improved version of the watercraft, and the results of testing that shows improved hydrodynamic resistance and relationship between mechanical power output and speed. Chapter 4 investigates how velocity fluctuations may affect the speed of the watercraft and if different propulsion modes have an influence. No significant differences are found but several ideas for further research are given. Finally, the interface pressure is evaluated in a setting that mimics the one on the watercraft. It is known that high interface pressure for long periods of time increases the risk of pressure ulcer development for people with SCI. Chapter 5 describes a case-study of an Italian handcycling champion arm cranking on an arm ergometer at two difference backrest inclinations while interface pressure and oxygen uptake was measured. The results showed a difference in pressure between backrest inclinations and from arm cranking and resting. This could help people with SCI to still be able to exercise even if suffering from pressure ulcers
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