ORCID Profile
0000-0001-6222-880X
Current Organisation
Federation University
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Publisher: Wiley
Date: 15-12-2009
Publisher: Elsevier BV
Date: 12-2020
Publisher: MDPI AG
Date: 12-11-2018
Abstract: This study investigated the effects of two plyometric training protocols on sprint and change of direction (COD) performance in elite hockey players. A parallel-group randomized controlled trial design was used and seventeen elite male and female field hockey players were randomly allocated into either low-to-high (L-H, n = 8) or high-to-low (H-L, n = 9) training groups. Each group performed separate variations of the drop jump exercise twice weekly for six weeks, with an emphasis on either jump height (L-H) or drop height (H-L). Performance variables assessed included sprint times over 10 m and 20 m, as well as 505 time. A two-way repeated measures analysis of variance was performed and Cohen’s d effect sizes (ESs) were calculated. The H-L group displayed a significant small ES improvement from baseline to post-training in the 10 m sprint (1.893 ± 0.08 s pre vs. 1.851 ± 0.06 s post) (ES = −0.44) (p 0.05). Differences between groups for 10 m and 20 m sprint performance failed to reach statistical significance, and no significant differences were observed within or between groups for 505 time. These findings highlight the difficulty in substantially enhancing speed and COD ability in highly trained athletic populations through the addition of a low volume, short duration plyometric training protocol.
Publisher: Springer Science and Business Media LLC
Date: 16-12-2019
DOI: 10.1007/S00221-019-05708-7
Abstract: Injury as a result of tripping is relatively common among older people. The risk of falling increases with fatigue and of importance is the ability to dorsiflex the foot through timely activation of the tibialis anterior (TA) muscle to ensure the foot clears the ground, or an obstacle, during the swing phase of walking. We, therefore, questioned whether the muscle spindle input to the motoneurons alters with ongoing fatigue in older people. We electrically stimulated the common peroneal nerve to assess the TA primary afferent efficacy using H-reflex before, immediately following and after a fatiguing maximal isometric contraction. M-response was kept unchanged throughout the experiment to ensure a similar stimulus intensity was delivered across time points. H-reflex increased significantly while the TA muscle was in a state of fatigue for the younger participants but tended to decrease with increasing age. The main contributor to the tonicity of TA muscle, i.e., excitatory synapses of spindle primary endings of motoneurons that innervate TA muscle, tend to lose their efficacy during fatigue in the older in iduals but increased efficiency in the majority of the younger people. Since TA muscle is the main dorsiflexor of the foot and it needs to be active during the swing phase of stepping to prevent tripping, older in iduals become more susceptible to falling when their muscles are fatigued. This finding may help improve devices/treatments to overcome the problem of tripping among older in iduals.
Publisher: MDPI AG
Date: 21-03-2022
DOI: 10.3390/BS12030086
Abstract: Social connections are crucial for an in idual’s health, wellbeing, and overall effective functioning. During the COVID-19 pandemic, one major preventative effort for reducing the spread of COVID-19 involved restricting people’s typical social interactions through physical distancing and isolation. The current cross-sectional study, conducted during the COVID-19 pandemic, explored the relationship among fear of COVID-19, social connectedness, resilience, depressive symptomologies, and self-perceived stress. Participants (N = 174) completed an anonymous, online questionnaire, and results indicated that social connectedness mediated the relationship between fear of COVID-19 and psychological wellbeing. In contrast, the relationship between fear of COVID-19 and psychological wellbeing was not mediated by resilience. These findings highlight the important role that social connections and resilience play in buffering against negative psychological wellbeing outcomes, especially during a pandemic.
Publisher: MDPI AG
Date: 19-12-2021
DOI: 10.3390/APP112412096
Abstract: (1) Background: Stimulating oropharyngeal transient receptor potential (TRP) channels inhibits muscle cr ing by triggering a supraspinal reflex to reduce α-motor neuron hyperexcitability. This study investigated whether the longer stimulation of the TRP channels via mouth rinsing with PJ is more effective than drinking PJ at inhibiting an electrically induced muscle cr (EIMC). Both conditions were compared to the control (water). (2) Methods: The tibial nerves in 11 cr -prone adults were percutaneously stimulated to elicit an EIMC of the flexor hallucis brevis in three trials that took place one week apart from each other. At cr onset, the participants received mouth rinsing and expelling PJ (25 mL), ingesting PJ (1 mL∙kg−1 body-mass (BM)), or ingesting water (1 mL∙kg−1 BM). Cr onset and offset were induced by electromyography, and the severity of discomfort was recorded using a visual analogue scale (VAS). (3) Results: The median time to cr cessation as a percentage of water was 82.8 ± 14.63% and 68.6 ± 47.78% for PJ ingestion and PJ mouth rinsing, respectively. These results had large variability, and no statistically significant differences were observed. There were also no differences in perceived cr discomfort between conditions, despite the hazard ratios for the time taken to reach VAS = 0, which was higher than water (control) for PJ ingestion (22%) and mouth rinsing (35%) (p = 0.66 and 0.51, respectively). (4) Conclusions: The data suggest no difference in cr duration and perceived discomfort between PJ and water.
Publisher: Informa UK Limited
Date: 31-12-2019
Publisher: MDPI AG
Date: 18-11-2022
Abstract: Fear is a factor contributing to poor return to sport after an anterior cruciate (ACL) injury, however the identification and assessment of fear is challenging. To improve understanding of fear, this study qualitatively and quantitatively assessed responses to videos depicting threat to knee stability in people who had experienced an ACL injury. ACL-injured participants who had above average fear on the T a Scale of Kinesiophobia and were at least 1-year post-injury/surgery were eligible. Participants were shown four videos depicting sequentially increasing threat to their knee stability (running, cut-and-pivot, feigned knee injury during cut-and-pivot, series of traumatic knee injuries). Qualitative interviews explored participants feeling related to viewing the videos. Participants quantitatively self-rated fear and distress in response to each video. Seventeen participants were included in this study (71% female, with an average time since last ACL injury of 5 ½ years). Five themes were identified: (1) Evoked physiological responses, (2) Deeper contextualisation of the meaning of an ACL injury influencing bodily confidence, (3) Recall of psychological difficulties, (4) Negative implications of a re-injury, and (5) Change to athletic identity. Quantitatively, direct proportionality was noticed between threat level and reported fear and distress. Specifically, participants reported increasing levels of fear and distress as the videos progressed in threat level, with the largest increase seen between a cut-and-pivot movement to a feigned injury during a cut and pivot. The results support the notion that in addition to being a physical injury, an ACL injury has more complex neurophysiological, psychological, and social characteristics which should be considered in management. Using video exposure in the clinic may assist identification of underlying psychological barriers to recovery following an ACL injury, facilitating person-centred care.
Publisher: MDPI AG
Date: 07-02-2023
Abstract: Fear is a significant factor affecting successful return to sport following an anterior cruciate ligament (ACL) injury. However, there is a lack of understanding of the emotional drivers of fear and how fear beliefs are formed. This study qualitatively explored the contextual and emotional underpinnings of fear and how these beliefs were formed, with reference to the Common-Sense Model of Self-Regulation. Face-to-face online interviews were conducted with ACL-injured participants (n = 18, 72% female) with a mean age of 28 years (range 18–50 years). Participants were either 1 year post ACL reconstruction surgery (n = 16) or at least 1 year post injury without surgery (n = 2) and scored above average on a modified T a Scale of Kinesiophobia. Four participants were playing state-level sport or higher. Five themes emerged describing factors contributing to fear: ‘External messages’, ‘Difficulty of the ACL rehabilitation journey’, ‘Threat to identity and independence’, ‘Socioeconomic factors’, and ‘Ongoing psychological barriers’. A sixth theme, ‘Positive coping strategies’, provided insight into influences that could reduce fear and resolve negative behaviors. This study identified a broad range of contextual biopsychosocial factors which contribute to fear, supporting the notion that ACL injuries should not be treated through a purely physical lens. Furthermore, aligning the themes to the common-sense model provided a conceptual framework conveying the inter-related, emergent nature of the identified themes. The framework provides clinicians with a means to understanding fear after an ACL injury. This could guide assessment and patient education.
Publisher: MDPI AG
Date: 10-12-2020
Abstract: Concussion is known to detrimentally affect brain health. Rugby tackles commonly occur with high collision force between tackler and ball carrier, and low impact head contact is not uncommon. Cognitive deficits following a bout of soccer ball heading has been attributed to the impact and termed sub-concussion. Although soccer ball heading studies provide evidence for acute effects of sub-concussion, it is unknown whether this phenomenon occurs following rugby tackles. This study investigates the acute effects of rugby tackles on brain function and balance in rugby players. Twenty-six volunteers were assigned to either the ball carrier (9), tackler (9) or control (8) group. Controls performed running without the tackle. Outcome measures included corticomotor function using transcranial magnetic brain stimulation (TMS) and balance was assessed by a series of tasks performed on a NeuroCom Balance Master before and immediately after a tackle training drill. Following the tackling bout, the cortical silent period (cSP) increased for the tacklers with no change for ball carrier and control groups, and no differences between groups for balance measures were observed. Lengthening of cSP observed in the tacklers following the bout has been reported in studies of concussion and may indicate long term detrimental effects.
Publisher: Frontiers Media SA
Date: 29-05-2020
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.CLINPH.2015.04.062
Abstract: All previous studies using TMS to assess short-interval intracortical inhibition (SICI) in older adults have used a conventional coil orientation, which produces posterior-to-anterior (PA) current flow in the motor cortex. However, no studies have examined SICI in older adults by reversing the coil to induce anterior-to-posterior (AP) current flow, which is considered more sensitive at detecting SICI. Therefore, we investigated age-related changes in SICI using both PA and AP TMS across different conditioning stimulus intensities and muscle activation states. In 22 young and 20 older adults, SICI was assessed using PA and AP coil orientations, across a range of conditioning stimulus intensities (70-90% active motor threshold), and whilst participants kept their first dorsal interosseous (FDI) muscle either relaxed or active (2N force). There were no age-related differences in SICI using conventional PA TMS in resting or active FDI muscle. However, SICI was increased in elderly participants when assessed with reverse coil AP TMS in resting FDI. Coil orientation is a key factor to consider when assessing age-related differences in SICI. Reverse coil AP TMS can reveal age-related changes in SICI, which were previously not evident with conventional PA TMS. This may have implications for the assessment of SICI in some clinical populations that may show subtle differences in SICI circuitry.
Publisher: MDPI AG
Date: 12-11-2021
Abstract: Rugby Union is a popular sport played by males and females worldwide, from junior to elite levels. The highly physical skill of tackling occurs every few seconds throughout a match and various injuries associated with tackling are relatively common. Of particular interest are head injuries that result in a concussion. Recently, repeated non-injurious head impacts in sport have attracted the attention of researchers interested in brain health. Therefore, this study assessed head movement during repeated rugby tackle drills among experienced Rugby Union players. Experienced male and female participants performed 15 1-on-1 tackles in a motion analysis laboratory to measure the head movements of the ball carrier and tackler during each tackle, using three-dimensional motion capture. The average peak acceleration of the head for ball carriers was 28.9 ± 24.08 g and 36.67 ± 28.91 g for the tacklers. This study found that the type of head impacts common while performing a tackle in Rugby Union are similar to those experienced by soccer players during heading, which has been found to alter brain function that lasts hours after the event. This has important implications for player health and suggests that mitigation strategies should be considered for Rugby Union.
Publisher: MDPI AG
Date: 22-08-2023
DOI: 10.3390/BS13090698
Abstract: The 2019 novel coronavirus disease (COVID-19) is a global threat that can have an adverse effect on an in iduals’ physical and mental health. Here, we investigate if disordered social media use predicts user stress and depression symptoms indirectly via fear of COVID-19. A total of 359 (timepoint 1 = 171, timepoint 2 = 188) participants were recruited via social media and snowball s ling. They completed an online survey that measured disordered social media use, fear of COVID-19, perceived stress, and depression symptomatology at two cross-sectional timepoints. We found that disordered social media use predicts depression indirectly through fear of COVID-19 at both timepoints. We also found that disordered social media use predicts perceived stress indirectly through fear of COVID-19, but only at timepoint 1. Taken together with previous research, our findings indicate that disordered social media use may lead to increased fear of COVID-19, which in turn may lead to poorer psychological wellbeing outcomes. Overall, there is evidence that the impact of the COVID-19 pandemic is affecting the physical, psychological, and emotional health of in iduals worldwide. Moreover, this impact may be exacerbated by disordered use of social media.
Publisher: MDPI AG
Date: 05-05-2021
DOI: 10.20944/PREPRINTS202105.0045.V1
Abstract: (1) Background: Stimulating oropharyngeal transient receptor potential (TRP) channels inhibits muscle cr ing by triggering a supraspinal reflex to reduce & alpha -motor neuron hyperexcitability. This study investigated whether longer stimulation of TRP channels via mouth rinsing with PJ is more effective than drinking PJ at inhibiting an electrically induced muscle cr (EIMC) (2) Methods: Tibial nerve in 11 cr -prone adults were percutaneously stimulated to elicit an EIMC of flexor hallucis brevis in three trials 1-week apart. At cr onset participants received mouth rinsing and expelling PJ (25 mL), ingesting PJ (1 mL∙kg-1 body-mass [BM]), or ingesting water (1 mL∙kg-1 BM). Cr onset and offset by electromyography and severity of discomfort was recorded using a visual analogue scale (VAS) (3) Results: Median time to cr cessation as a percentage of water was 82.8% & lusmn 14.634 and 68.6% & lusmn 47.782 for PJ ingestion and mouth rinse respectively. These results had large variability and no statistically significant difference was observed. There were also no differences in perceived cr discomfort between conditions, despite hazard ratios for time to VAS = 0 higher than water for PJ ingestion (22%) and mouth rinse (35%) (p = 0.66 and 0.51 respectively) (4) Conclusions: Data suggest no difference in cr duration and perceived discomfort between PJ and water.
Publisher: Informa UK Limited
Date: 20-06-2019
Publisher: MDPI AG
Date: 11-10-2018
DOI: 10.20944/PREPRINTS201810.0233.V1
Abstract: This study investigated the effects of two plyometric training protocols on sprint and change of direction (COD) performance in elite hockey players. A parallel-group randomized controlled trial design was used and seventeen elite male and female field hockey players were randomly allocated into either low-to-high (L-H, n = 8) or high-to-low (H-L, n = 9) training groups. Each group performed separate variations of the drop jump exercise twice weekly for six weeks, with an emphasis on either jump height (L-H) or drop height (H-L). Performance variables assessed included sprint times over 10 m and 20 m, as well as 505 time. A two-way repeated measures analysis of variance was performed and Cohen& rsquo s d effect sizes were calculated. The H-L group displayed significant small ES improvement from baseline to post-training in the 10 m sprint (1.893 & lusmn 0.08 s pre vs 1.851 & lusmn 0.06 s post) (ES = & minus .44) (P = & .05). Small but not statistically significant differences between groups were observed for 10 m and 20 m sprint performance, and no significant differences were observed within or between groups for 505 time. These findings highlight the difficulty in substantially enhancing speed and COD ability in highly trained athletic populations through the addition of a low volume, short duration plyometric training protocol.
Publisher: MDPI AG
Date: 15-03-2019
Abstract: Chronic smoking has been shown to have deleterious effects on brain function and is an important risk factor for ischemic stroke. Reduced cortical excitability has been shown among chronic smokers compared with non-smokers to have a long-term effect and so far no study has assessed the effect of smoking on short-term motor learning. Paired associative stimulation (PAS) is a commonly used method for inducing changes in excitability of the motor cortex (M1) in a way that simulates short-term motor learning. This study employed PAS to investigate the effect of chronic cigarette smoking on plasticity of M1. Stimulator output required to elicit a motor-evoked potential (MEP) of approximately 1 mV was similar between the groups prior to PAS. MEP response to single pulse stimuli increased in the control group and remained above baseline level for at least 30 min after the intervention, but not in the smokers who showed no significant increase in MEP size. The silent period was similar between groups at all time points of the experiment. This study suggests that chronic smoking may have a negative effect on the response to PAS and infers that chronic smoking may have a deleterious effect on the adaptability of M1.
Publisher: Hindawi Limited
Date: 18-03-2019
DOI: 10.1111/HSC.12747
Abstract: The number of falls and fall-associated injury rates among older people continues to rise worldwide. Increased efforts to influence older people's falls prevention behaviour are needed. A two-phase exploratory community-based participatory study was conducted in Western Australia. First, three prototype audio-visual (AV) falls prevention messages were designed collaboratively with six older people. Second, the messages' effect on community-dwelling older people's knowledge, awareness and motivation to take action regarding falls prevention was explored using focus groups. Data were analysed using thematic analysis to explore participants' responses to the messages. The participants' (n = 54) perspectives on the AV messages varied widely and stereotypes of ageing appeared to influence these. The presented falls facts (including falls epidemiology statistics) increased some participants' falls risk awareness and falls prevention knowledge. Other participants felt ready-to-use falls prevention information was lacking. Some expressed positive emotions or a personal connection to the messages and suggested the messages helped reduce ageing-related stigma. Strongly opposing viewpoints suggested that other participants identified implicit negative messages about ageing, which reduced their motivation with the messages. Suggestions to improve the message persuasiveness included adding more drama and tailoring messages to appeal to multiple age groups. Overall, the AV falls prevention messages designed in collaboration with older people elicited a ergent range of positive and negative perspectives from their peers, which was conceptualised by the overarching theme 'we all look at things different ways'. Opinions differed regarding whether the messages would appeal to older people. Public c aigns targeting falls prevention should be designed and tailored towards older peoples' differing perspectives about ageing.
Publisher: Elsevier BV
Date: 06-2008
DOI: 10.1016/J.JSAMS.2007.03.005
Abstract: This study investigated the hypothesis that a light eccentric exercise (ECC) that does not induce a loss of muscle function and delayed onset muscle soreness would confer a protective effect against a more strenuous ECC. Eighteen young men were randomly placed into two groups: 10-40% (n=9) and 40% (n=9). Subjects in the 10-40% group performed ECC of the elbow flexors (six sets of five reps) using a dumbbell set at 10% of maximal isometric strength (MVC) at an elbow joint angle of 90 degrees , followed 2 days later by ECC using a dumbbell weight of 40% MVC. Subjects in the 40% group performed the 40% ECC only. Changes in MVC, range of motion (ROM), upper arm circumference (CIR), plasma creatine kinase (CK) activity and muscle soreness before, immediately after, 1-5 and 7 days following the 40% ECC were compared between groups by a two-way repeated measures ANOVA. No significant changes in any of the criterion measures were found immediately and 1-2 days after the 10% ECC. Following the 40% ECC, the 10-40% group showed significantly (P<0.05) smaller decreases in MVC and ROM, and smaller increases in muscle soreness compared with the 40% group, but no significant differences between groups were evident for CIR and plasma CK activity. These results suggest that the 10% ECC induced some protection against a subsequent bout of 40% ECC performed 2 days later. It appears that the light eccentric exercise preconditioned the muscles for exposure to the subsequent damaging eccentric exercise bout.
Start Date: 2009
End Date: 2010
Funder: Japan Society for the Promotion of Science
View Funded Activity