Neuromuscular electrical stimulation (NMES) has been shown to be effective for recovery of motor function following injury or pathology, however, NMES can impart rapid fatigue and the specific parameters of stimulation that maximize force output and delay the onset of fatigue remain unclear. Frequency, intensity, and pulse pattern are a few of the parameters that can be manipulated to achieve desired outcomes. Strong evidence supports the use of higher frequencies of stimulation to maximize performance of fatigued or paralyzed muscle. Likewise, several studies advocate the use of varied pulse patterns, rather than constant pulses, to maximize force output as well. Much of the research literature regarding NMES use with a pathological population involves spinal injured individuals. Much less is known about the effect of NMES on motor recovery, especially when delivered through varied pulse patterns, in the post-stroke population. The three studies contained herein addressed these issues. In Study 1, submaximal and supramaximal intensities of two variable frequency stimulation patterns and one constant frequency pattern were applied to the thenar muscles of a young healthy population. Results showed marked differences in force output between the two intensities. Submaximal stimulation enhanced the effect of the variable pulses and a greater force response was produced. In Study 2, the same three patterns were applied to the thenar muscles of a post-stroke group and an age-matched able-bodied group at submaximal intensities. Again, differences in force output were evident between the healthy and pathological group, and the variable pulses may have further depressed already weakened hemiplegic muscle. Study 3 compared the effects of a NMES rehabilitation program using a high (40 Hz) and a low (20 Hz) frequency to determine if task-specific improvements were related to frequency used. Results showed that those in the high frequency condition demonstrated greater improvements in strength, dexterity and force accuracy; those in the low frequency condition showed improvements in motor endurance. The results of this work suggest that the intensity, frequency and stimulation pattern of NMES used have a significant impact on the resultant muscle contraction and functional skills gained following stroke and should be carefully considered when implementing a clinical regimen for motor recovery.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

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No description available.

A total laryngectomy (TL) affects the quality of life (QoL) of individuals who have undergone this surgical procedure, as changes are seen in respiration, swallowing and communication. The aim of this study was to gather perspectives of the hallmarks of successful alaryngeal voice rehabilitation by tracheo-esophageal puncture (TEP) with voice prosthesis of laryngectomy patients from key role players based at a public hospital in Gauteng Province, South Africa. A qualitative method of inquiry was used, namely a single-program, collective case study. A focus group, comprising of four individuals who had undergone a total laryngectomy, was held to identify the participants‟ views about successful voice rehabilitation. From this focus group, one successful communicator was identified to be interviewed individually. Five semi-structured, face-to-face individual interviews using open-ended questions were conducted with five key role players in alaryngeal voice rehabilitation. The interviewees comprised of the successfully rehabilitated person with total laryngectomy (PWTL), his caregiver, an ear, nose and throat surgeon, speech-language pathologist and specialist nurse, to gather their perspectives on the factors that contributed to successful alaryngeal voice rehabilitation using TES. The Thematic Framework Approach was used to qualitatively analyze the data. Factors identified as contributing to success included patient selection for tracheo-esophageal puncture, information provision, support in the form of support groups, spiritual as well as family support, stomal care, the skill of the team and key management issues. Issues related to finance adversely affect the provision of voice prostheses and/or the provision of correctly sized prostheses and accessories. Systems have been implemented at the hospital to provide the option of TEP with voice prosthesis without much consideration to the other two alaryngeal options; namely esophageal speech and electrolarynx speech. Implications for clinical practice have been identified especially the need to provide more social support services to persons with TL. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.

Adequate recovery from intense exercise is essential to optimise performance and reduce the associated symptoms of tiredness, fatigue and lethargy. The purpose of the study was to :- i. investigate the effects of massage and stretching in delaying the development of fatigue during repeated bouts of dynamic activity and, ii. to investigate the relative effects of massage and stretching on delayed onset muscle soreness (DOMS). Eighteen volunteer males participated in this study. They were randomly allocated into one of six groups of an Orthogonal Latin square design. Subjects performed five repetitions of as many heel raises as possible in 45 seconds. Each repetition was followed by a recovery technique of three minutes duration. This was repeated weekly until each group has had all three recovery techniques. A fatigue index % was calculated from the decline in the number of repetitions from stage 1 to stage 5. Muscle soreness ratings were retrospectively assessed at 12-36 hour after each session. An analysis of variance showed a significant difference in the fatigue indices. Post hoc intergroup comparison using paired T-tests with the Bonferroni adjustment showed a significant difference between rest and massage (p=0.0001) and rest and stretching (p=0.0006). The differences between massage and stretching were not significant. Fourteen (77.8%) and Fifteen (83.3%) subjects showed an improvement in performance following massage and stretching respectively. Massage is associated with significantly less muscle soreness than stretching (p<0,001). DOMS was most frequently found in the stretching group while the lowest incidence and lowest mean ratings of muscle soreness associated with DOMS was found in the massage group. The difference between massage and stretching was marginal (p=046I) and showed a trend that massage is associated with less DOMS than stretching. This suggests that rest is the least beneficial recovery technique, and that massage may be superior to stretching as there is less muscle soreness. / Thesis (M.Med.Sc.)-University of Natal, 1997.

Due to the lack of morphological data on prepubertal Indian male soccer players in South Africa, this study was undertaken on ninety male prepubertal subjects. The subjects were divided into three groups of thirty subjects each: Experienced "E" (those playing organized soccer for more than two years), beginners "8" (those playing organized soccer for less than two years) and sedentary "S" (those not participating in organized soccer). All subjects were measured according to Heath - Carter anthropometric somatotype methods. Fitness tests comprising power and strength tests (vertical jump height and standing broad jump) and muscle endurance tests (push - ups and sit - ups) were also done. The three groups were first compared to each other and then to available international data. There were no statistical differences among the three groups for: height, weight, age, triceps, subscapular, suprailiac, calf and total skinfolds, humerus and biceps girth, ectomorphy, mesomorphy and endomorphy, suggesting a general homogenicity between groups. For fitness tests the "E" group performed significantly better than the others for standing broad jump and sit - ups (p = 0.005 and p = 0.036 respectively). For push - ups the "8" and "E" were significantly better than the "S" group, (p = 0.013, for "8" versus "S" group), indicating that in soccer muscle strength and explosive strength are important. The lack of difference between the groups for anthropometric criteria in this study may be explained by the experienced players' inadequate training. Other factors may include the lack of parental involvement, inadequate knowledge on fitness aspects and poor training methods. Furthermore, the sedentary group may be participating in unorganized activities which renders them at a level similar to the experienced group. Data on non - Indian South African junior players is required to help us understand the lack of significant Indian talent in the National team. Other factors such as diet, cultural differences, training methods, level of coaching, environmental factors and sport facilities need investigation and be addressed if we want to see an improvement in the South African Indian soccer players. / Thesis (M.Med.Sc.)-University of Natal, Durban, 1997.

Different events usually contain similar elements that can contribute to interference during memory encoding and retrieval. The hippocampus (HPC), a structure that is critically involved in some forms of memory, has been hypothesized to reduce interference between memories with overlapping content, thus facilitating correct recall. Pattern separation is one hypothetical process whereby input ambiguity is reduced. Here we test the hypothesis that the HPC and/or dentate gyrus (DG) are important for pattern separation by measuring performance by rats with damage in tasks that require discrimination between visual stimuli that share systematically varying numbers of common elements. Rats with HPC damage were slower to resolve discriminations with minimal degrees of overlap. Lesions of the DG did not affect the ability of rats to deal with overlap, suggesting a dissociation between the HPC and DG. Our results provide partial support for the idea that the HPC contributes to the pattern separation process. / ix, 84 leaves : ill. ; 29 cm.

All sentient organisms use contextual information to assess the amount of reward associated with a particular behavior. Human beings have arguably evolved the most sophisticated of these mechanisms and are capable of integrating information over a long duration of time to accurately assess the expected outcome of a chosen action. This thesis used electroencephalography (EEG) to measure how the human brain processes rewarding and punishing feedback in a gambling-type game with variable risk and reward. Experiment 1 determined that phase-locked (evoked) and non-phase-locked (induced) electroencephalographic activity share only partially overlapping generators in human mediofrontal cortex. Experiment 2 determined that the magnitude of certain evoked EEG components during reward processing tracked subsequent changes in bets placed in the next round. These results extend the body of literature by assessing the overlap between induced and evoked EEG components and the role of evoked activity in affecting future decision making. / xii, 76 leaves : ill. (chiefly col.) ; 29 cm

Insulin-like growth factor-I (IGF-I) and its principle binding protein (IGFBP-3) are believed to play a role in mediating the anabolic effects of exercise. The purpose of this study was to assess the effect of 4 months of training on IGF-I and IGFBP-3, and to determine if changes in IGF-I or IGFBP-3 were related to changes in training status. Twelve varsity swimmers (5 males, 7 females) were tested pre-season, and again after 8 and 16 weeks of training. Measures included: VO2 max, nutritional status, athletic performance, subjective symptoms of overtraining, and serum levels of IGF-I and IGFBP-3. There was no significant change across time in VO2 max, athletic performance, IGF-I or IGFBP-3. Resting IGFBP-3 was positively correlated to symptoms of overtraining at week 0 (p=0.017), however, this relationship did not persist at week 8 or 16. These findings can not confirm that resting levels of IGF-I and IGFBP-3 are sensitive markers of training status. / ix, 105 leaves : ill. ; 29 cm.