Browsing by Author "West, Sacha"

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    Association of Perceived Neighbourhood Walkability with Self-Reported Physical Activity and Body Mass Index in South African Adolescents
    (Multidisciplinary Digital Publishing Institute, 2023-01-30) Wayas, Feyisayo A.; Smith, Joanne A.; Lambert, Estelle V.; Guthrie-Dixon, Natalie; Wasnyo, Yves; West, Sacha; Oni, Tolu; Foley, Louise
    Adolescence is a life stage critical to the establishment of healthy behaviours, including physical activity (PA). Factors associated with the built environment have been shown to impact PA across the life course. We examined the sociodemographic differences in, and associations between, perceived neighbourhood walkability, PA, and body mass index (BMI) in South African adolescents. We recruited a convenience sample (n = 143; 13–18 years; 65% female) of students from three high schools (middle/high and low-income areas). Participants completed a PA questionnaire and the Neighbourhood Environment Walkability Scale (NEWS)-Africa and anthropometry measurements. Multivariable linear regression was used to examine various relationships. We found that, compared with adolescents living in middle/high income neighbourhoods, those living in low-income neighbourhoods had lower perceived walkability and PA with higher BMI percentiles. The associations between neighbourhood walkability and PA were inconsistent. In the adjusted models, land use diversity and personal safety were associated with club sports participation, street connectivity was positively associated with school sports PA, and more favourable perceived walkability was negatively associated with active transport. Overall, our findings suggest that the perceived walkability of lower income neighbourhoods is worse in comparison with higher income neighbourhoods, though the association with PA and BMI is unclear.
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    Conjugated linoleic acid versus high-oleic acid sunflower oil: effects on energy metabolism, glucose tolerance, blood lipids, appetite and body composition in regularly exercising individuals
    (2007) Lambert, Estelle V; Goedecke, Julia H; Bluett, Kerry; Heggie, Kerry; Claassen, Amanda; Rae, Dale E; West, Sacha; Dugas, Jonathan; Dugas, Lara; Meltzer, Shelly; Charlton, Karen; Mohede, Inge
    The aim of this study was to measure the effects of 12 weeks of conjugated linoleic acid (CLA) supplementation on body composition, RER, RMR, blood lipid profiles, insulin sensitivity and appetite in exercising, normal-weight persons. In this double-blind, randomised, controlled trial, sixty-two non-obese subjects (twenty-five men, thirty-seven women) received either 3.9 g/d CLA or 3.9 g high-oleic acid sunflower oil for 12 weeks. Prior to and after 12 weeks of supplementation, oral glucose tolerance, blood lipid concentrations, body composition (dual-energy X-ray absorptiometry and computerised tomography scans), RMR, resting and exercising RER and appetite were measured. There were no significant effects of CLA on body composition or distribution, RMR, RER or appetite. During the oral glucose tolerance tests, mean plasma insulin concentrations (0, 30, 120 min) were significantly lower (P= 0.04) in women who supplemented with CLA (24.3 (SD 9.7) to 20.4 (SD 8.5) microU/ml) compared to high-oleic acid sunflower oil control (23.7 (SD 9.8) to 26.0 (SD 8.8) microU/ml). Serum NEFA levels in response to oral glucose were attenuated in both men and women in the CLA (P=0.001) compared to control group. However, serum total cholesterol and LDL-cholesterol concentrations decreased in both groups and HDL-cholesterol concentrations decreased in women over 12 weeks (P=0.001, P=0.02, P=0.02, respectively). In conclusion, mixed-isomer CLA supplementation had a favourable effect on serum insulin and NEFA response to oral glucose in non-obese, regularly exercising women, but there were no CLA-specific effects on body composition, energy expenditure or appetite.
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    Innovative spinal cord injury rehabilitation in the context of a middle-income country: a pilot randomised control study investigating physiological and psychological effects
    (2021) Evans, Robert William; Albertus, Yumna; West, Sacha; Derman, Wayne
    A spinal cord injury (SCI) is life-altering, resulting in neurological deficits and a multitude of secondary complications. South Africa holds one of the highest traumatic SCI incidence rates in the world, where the social need for SCI prevention and rehabilitation is immense. Robotic locomotor training (RLT) is a novel rehabilitation technique that may improve health and wellbeing after SCI. A systematic review was conducted across 27 studies and 308 participants to explore the systemic effects of RLT. This review demonstrated that RLT shows promise as a tool for improving neurological rehabilitation outcomes; providing individuals with a SCI the ability to walk safely while improving their walking performance, as well as potentially improving cardiovascular outcomes and psychosocial factors. However, the studies reviewed were non-controlled with small, heterogenous sample sizes. Further high-powered, randomised controlled trials, with homogenous samples, are required to investigate these effects. If widespread adoption of these new technologies is to occur, sound evidence demonstrating efficacy and long-term cost saving is required. This dissertation aimed to explore some of these under-researched areas in a sample of sixteen persons with incomplete tetraplegia. Areas of focus included, 1) rehabilitation feasibility, adherence, and research challenges in an under-resourced environment 2) cardiovascular functioning and adaptation to a rehabilitation programme, and 3) psychological well-being. We implemented two interventions, robotic locomotor training (RLT) and activity-based training (ABT), over a 24-week pilot randomised control trial. Adherence to the interventions was high (93.9 ± 6.2%). Challenges to the study's feasibility included: ethical approval, medical clearance, transport and limited human/financial resources. Cardiovascular parameters demonstrated that efficiency of exoskeleton walking improved during the intervention. RLT may be more effective than ABT in improving cardiac responses to orthostatic stress, with standing heart rate at 24-weeks being significantly lower in the RLT group (75.1 ± 15.0 beats/min) compared to the ABT group (95.6 ± 12.6 beats/min). Standing and RLT had similar effects on the parasympathetic nervous system, whilst both interventions were limited in their effect on brachial and ankle blood pressure. Despite experiencing past trauma, participants possessed psychological resources including resilience, self-efficacy and post-traumatic growth which contributed to high perceptions of quality of life. The use of an exoskeleton may have had a greater positive impact on subjective psychological well-being. Expectations of participants entering the study centred around regaining the ability to walk again, despite past experiences and medical advice suggesting otherwise. Hope aids in buffering against negative emotions, however, a thin line exists between supporting high expectations and confronting unrealistic hope. Initial high expectations of recovery decreased and became more realistic during the intervention. This dissertation demonstrates potential physiological and psychological benefits that RLT provides. Despite this potential, barriers exist in the use of RLT in low- and middle-income countries such as South Africa, primarily due to a lack of financial and human resources. The development of lower-cost exoskeletons would lessen the burden of conducting large-scale trials and increase the likelihood of adopting these innovative rehabilitation tools into current standard of care practices.
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    The Effect of Robotic Walking and Activity-based Rehabilitation on Functional Capacity, Secondary Complications & Psychological Well-being in Individuals with Spinal Cord Injury (SCI)
    (2021) Shackleton, Claire Lauren; Albertus, Yumna; West, Sacha; Derman, Wayne
    Activity-based training (ABT) represents the current standard of care in neurological rehabilitation centers around the world. However, innovative rehabilitation techniques have been developed including robotic locomotor training (RLT). The conceptual basis for RLT initially appeared promising; a rehabilitation modality that removes the need for intensive assistance from therapists, whilst facilitating safe and effective over-ground ambulation. However, small sample sizes and a lack of homogeneity across studies have resulted in an underpowered evidence base supporting the efficacy of RLT for SCI rehabilitation. Thus, this randomized control pilot study aimed to investigate the effects of RLT compared to ABT on functional capacity, secondary complications, and psychological well-being in people with SCI after 24-weeks of rehabilitation. Participants with chronic, traumatic motor incomplete SCI were randomized into two intervention groups: RLT (n = 8) and ABT (n = 8) groups. RLT involved solely walking in the Ekso bionic suit. ABT involved a variety of resistance, cardiovascular and flexibility training combined with regular weight-bearing in the standing position. Outcome measures, including functional strength, ambulatory function, pain, spasticity, bladder/bowel, bone density, body composition, quality of life (QoL) and depression were tested at baseline, 6, 12 and 24-weeks of the intervention. There were no significant differences between the intervention groups for lower or upper extremity motor scores (UEMS effect size (ES) = 0.30; LEMS ES = 0.07), back strength (ES = 0.14) and abdominal strength (ES = 0.13) after training. However, both groups showed a significant increase of 2.00 points in UEMS and a significant increase in abdominal strength from pre- to post intervention. Only the RLT group showed a significant change in LEMS, with a mean increase of 3.00 [0.00; 16.5] points over time. Distance walked in the Functional Ambulatory Inventory (SCI-FAI) increased significantly (p = 0.02) over time only for the RLT group. Therefore, the RLT showed promising evidence for potentially inducing functional strength changes and improvements in ambulatory function after 24 weeks of training. There was some evidence to support RLT to induce bowel improvements in individuals with SCI and both interventions appeared to reduce urinary incontinence and improve bladder function (p = 0.04). Total spasticity and pain intensity were similar between groups (p = 0.25; p = 0.96). However, pain interference ratings significantly increased from pre-post intervention for both groups (p = 0.05). RLT prevented the progressive decline of bone mineral density usually occurring in the SCI population, as hip BMD was maintained during RLT; however, it was significantly reduced (p = 0.04) during ABT, with a mean reduction of 0.06 [-0.34, 0.22] g/cm2 (5%) from pre to post intervention. No change in leg fat-free soft tissue mass (FFSTM) occurred between groups or over time (p = 0.32), however, there was a significant 7% increase in arm FFSTM over time for both groups (p < 0.01). The ABT group was more effective (ES = 1.02) in reducing central and peripheral adiposity, with a significant decrease in visceral adipose tissue (VAT) (p = 0.04) and gynoid FM (p = 0.01) over time. Both groups reported increased QoL and decreased depression ratings over time, with the RLT group having a significant change in the general life and physical health domains, p = 0.03, respectively. This pilot trial offers promising evidence for the effectiveness of RLT for improving functional and ambulatory capacity, reducing secondary complications, and potentially improving QoL in people with incomplete SCI. Thus, this dissertation adds substantial weight to the lacking evidence base on the effects of RLT, by incorporating a large homogenous sample, comprehensive testing procedures and an extended intervention period within South Africa.