The purpose of the present study was to determine the concurrent validity of learning potential and psychomotor ability measures for the prediction of haul truck operator (N=128) performance in an open-pit mine. Specific aims were to determine the nature of the relationship between learning potential and psychomotor ability; whether there are higher order cognitive or psychomotor factors present in the combined use of the TRAM 1 and Vienna Test System measures; and the relative contribution of learning potential and psychomotor ability in the prediction of haul truck operator performance. The validity of learning potential and psychomotor ability measures was partially supported. A positive correlation between general (cognitive) ability (g) and psychomotor ability was reported. Factor analysis provided relatively consistent evidence for a general (cognitive) ability factor (g) underlying performance on all measures. The relative contribution of learning potential and psychomotor ability in the prediction of performance could not be established. / Industrial and Organisational Psychology / M. Com. (Industrial and Organisational Psychology)

The changing nature of work and its competitive characteristics are global phenomena and are mainly fuelled by ongoing technological advancement. This creates unique challenges for talent attraction and the retention of high performing individuals. In addition, the global workforce is becoming more diverse due to demographic, societal and cultural changes and companies are placing greater demands on employee competency and performance. Managing the human factor as a strategic asset in organisations remains a primary challenge in securing a competitive advantage. The road construction industry in South Africa is no different. There is growing competition between civil engineering contractors to secure tenders and to maximise profitability. This is only possible with a sufficient and sustainable labour force. Valid selection processes are therefore required to ensure that the most productive individuals are selected for the most suitable jobs. Reliable and valid performance predictors will assist employers in making appropriate selection decisions. Selecting high performing individuals will support and enhance overall organisational performance. ix In this study the investigation focused on whether psychomotor ability and learning potential are statistically significant predictors of work performance - with specific reference to drivers and machine operators in a road construction company. A quantitative approach was followed to investigate the relationships between variables, or then the prediction of one dependent variable (driver and machine operator performance) by means of two independent variables (psychomotor ability and learning potential). Results from the study did not indicate any statistically significant relationships between the variables. Only scientifically validated assessment instruments were used in the study - which means the findings led to a renewed focus on the importance of performance measurement and the psychometric quality (reliability and validity) of performance data. / Industrial and Organisational Psychology / M.A. (Industrial and Organisational Psychology)

Female athletes exhibit three- to six-fold greater incidence of noncontact anterior cruciate ligament (ACL) injury relative to their male counterparts. The increased risk appears to stem from interactions between several risk factors, that can roughly be categorized as anatomic, biomechanical, hormonal, and neuromuscular. Neuromuscular risk factors have recently gained a greater focus, and include differences in the timing and magnitude of activation of lower extremity and trunk musculature. In addition to neuromuscular risk factors, the incidence of ACL injury is not evenly distributed across the menstrual cycle, suggesting that hormonal fluctuations may influence neuromuscular control. Finally, it is known that even well-trained athletes experience decrements in performance and postural control when forced to attend to multiple sensory stimuli, which is common in many sports. PURPOSE: To explore neuromuscular differences in the ways healthy and ACL-injured women respond to a secondary task requiring fine motor control and sustained mental focus (typing task). Our investigation encompassed three broad aims. First, we sought to determine whether ACL-injured individuals demonstrated similar reflex profiles to healthy individuals, as well as to determine whether the ACL-involved limb was similar to its uninvolved counterpart. Our second aim was to determine whether the typing task resulted in attenuated Hoffmann (H) reflex amplitudes, and to investigate whether any observed changes were similar in healthy and ACL-injured groups. Finally, our third broad aim was to utilize more complex H reflex analysis techniques to determine whether differences in spinal excitability existed at different points in the menstrual cycle. METHODS: Thirty nine recreationally active women (20 with prior unilateral noncontact ACL injury: 24.0 ± 4.5 years; 23.8 ± 4.5 kg•m⁻²; 4.1 ± 2.6 years post-injury; 19 with no history of knee injury: 23.8 ± 4.5 years; 23.1 ± 2.3 kg•m⁻²) agreed to participate, and were tested during days 2-5 (follicular phase) of the menstrual cycle. A sub-set of this original group (n=8; 24.0 ± 4.8 years; 22.0 ± 2.1 kg•m⁻²) also agreed to return for a second testing session 24-96 hours after ovulation (early luteal phase), in order to assess H reflex differences across the menstrual cycle. During each testing session, H reflex testing was used to explore spinal-level control mechanisms of the lower extremity musculature under both Rest and Task conditions. In the control group, the dominant limb was tested (CON-D) while in the ACL group, both the uninvolved (ACL-UN) and involved (ACL-INV) limbs were assessed. Differences between groups (Control vs. ACL) and within-groups (ACL-UN vs. ACL-INV) were explored. RESULTS: At rest, H reflex parameters in ACL-INV were generally similar to ACL-UN and to CON-D. However, differences in presynaptic inhibition were apparent in ACL-INV that imply reduced reflex plasticity. During the typing task, both the Control and ACL groups experienced attenuated H reflex parameters. In the sub-set of participants who were tested twice during the menstrual cycle, a significant increase in presynaptic inhibition was observed during the early luteal phase compared to the follicular phase. CONCLUSION: While individuals with prior ACL injury display similar H reflex profiles to healthy individuals, the ACL-involved limb may demonstrate less reflex plasticity in response to environmental changes. This lack of plasticity may potentially increase the risk of re-injury. In addition, an upper extremity task requiring fine motor control and sustained mental focus attenuates the H reflex in both groups. This attenuation has implications for lower-extremity neuromuscular control in dual-task environments. Finally, the increase in presynaptic inhibition observed during the early luteal phase may provide insight into why ACL injuries are not evenly distributed across the menstrual cycle. / Graduation date: 2012

The purpose of the present study was to determine the concurrent validity of learning potential and psychomotor ability measures for the prediction of haul truck operator (N=128) performance in an open-pit mine. Specific aims were to determine the nature of the relationship between learning potential and psychomotor ability; whether there are higher order cognitive or psychomotor factors present in the combined use of the TRAM 1 and Vienna Test System measures; and the relative contribution of learning potential and psychomotor ability in the prediction of haul truck operator performance. The validity of learning potential and psychomotor ability measures was partially supported. A positive correlation between general (cognitive) ability (g) and psychomotor ability was reported. Factor analysis provided relatively consistent evidence for a general (cognitive) ability factor (g) underlying performance on all measures. The relative contribution of learning potential and psychomotor ability in the prediction of performance could not be established. / Industrial and Organisational Psychology / M. Com. (Industrial and Organisational Psychology)

The changing nature of work and its competitive characteristics are global phenomena and are mainly fuelled by ongoing technological advancement. This creates unique challenges for talent attraction and the retention of high performing individuals. In addition, the global workforce is becoming more diverse due to demographic, societal and cultural changes and companies are placing greater demands on employee competency and performance. Managing the human factor as a strategic asset in organisations remains a primary challenge in securing a competitive advantage. The road construction industry in South Africa is no different. There is growing competition between civil engineering contractors to secure tenders and to maximise profitability. This is only possible with a sufficient and sustainable labour force. Valid selection processes are therefore required to ensure that the most productive individuals are selected for the most suitable jobs. Reliable and valid performance predictors will assist employers in making appropriate selection decisions. Selecting high performing individuals will support and enhance overall organisational performance. ix In this study the investigation focused on whether psychomotor ability and learning potential are statistically significant predictors of work performance - with specific reference to drivers and machine operators in a road construction company. A quantitative approach was followed to investigate the relationships between variables, or then the prediction of one dependent variable (driver and machine operator performance) by means of two independent variables (psychomotor ability and learning potential). Results from the study did not indicate any statistically significant relationships between the variables. Only scientifically validated assessment instruments were used in the study - which means the findings led to a renewed focus on the importance of performance measurement and the psychometric quality (reliability and validity) of performance data. / Industrial and Organisational Psychology / M.A. (Industrial and Organisational Psychology)

Indiana University-Purdue University Indianapolis (IUPUI) / Stroke is the main cause of disability in the United States. Individuals with stroke commonly report sensory impairment affects their recovery. Motor recovery and sensory impairment are related and impact individuals’ ability to perform valued occupations. Despite the prevalence of sensation impairment after stroke, many occupational therapists fail to include sensation assessment and intervention in treatment planning. The exclusion of sensation in occupational therapy interventions during stroke rehabilitation may be due to the lack of literature supporting the association between sensation and occupational performance. The current study aimed to determine the relationship between touch sensation of the affected hand and occupational performance and satisfaction in individuals with chronic stroke. Using a cross-sectional study design, this study associated factors related to hand sensation and function in individuals with chronic stroke. Fifty individuals with chronic stroke participated in a one-time testing session in which assessments related to sensation, movement of the hand and engagement in daily activities were administered. Correlation analyses were utilized to determine relationships between touch sensation of the affected hand with individuals’ abilities to engage in valued daily activities, arm and hand disability, and manual abilities. The main finding of the study was that individuals with intact sensation reported greater ability to perform valued occupations and satisfaction with their performance, as compared with individuals with touch sensation impairment. For individuals with impaired touch sensation of the affected hand, impairment of touch sensation of the hand did not correlate with individuals’ performance or satisfaction with valued occupations, arm or hand movement, or manual abilities. Collectively, the results of this study reflect the complex interaction between touch sensation, occupational performance, motor functioning, and manual abilities of the affected hand for individuals’ who have experienced a stroke. This study informs therapists, rehabilitation scientists, and other healthcare professionals that client-centered, individualized approaches, including a wide array of clinical assessments and intervention, including assessment of occupational performance and sensation, remain important components in stroke rehabilitation.